Paediatric in-patient prescribing errors in Malaysia: a cross-sectional multicentre study.

PubMed

Khoo, Teik Beng; Tan, Jing Wen; Ng, Hoong Phak; Choo, Chong Ming; Bt Abdul Shukor, Intan Nor Chahaya; Teh, Siao Hean

2017-06-01

Background There is a lack of large comprehensive studies in developing countries on paediatric in-patient prescribing errors in different settings. Objectives To determine the characteristics of in-patient prescribing errors among paediatric patients. Setting General paediatric wards, neonatal intensive care units and paediatric intensive care units in government hospitals in Malaysia. Methods This is a cross-sectional multicentre study involving 17 participating hospitals. Drug charts were reviewed in each ward to identify the prescribing errors. All prescribing errors identified were further assessed for their potential clinical consequences, likely causes and contributing factors. Main outcome measures Incidence, types, potential clinical consequences, causes and contributing factors of the prescribing errors. Results The overall prescribing error rate was 9.2% out of 17,889 prescribed medications. There was no significant difference in the prescribing error rates between different types of hospitals or wards. The use of electronic prescribing had a higher prescribing error rate than manual prescribing (16.9 vs 8.2%, p < 0.05). Twenty eight (1.7%) prescribing errors were deemed to have serious potential clinical consequences and 2 (0.1%) were judged to be potentially fatal. Most of the errors were attributed to human factors, i.e. performance or knowledge deficit. The most common contributing factors were due to lack of supervision or of knowledge. Conclusions Although electronic prescribing may potentially improve safety, it may conversely cause prescribing errors due to suboptimal interfaces and cumbersome work processes. Junior doctors need specific training in paediatric prescribing and close supervision to reduce prescribing errors in paediatric in-patients.

An Analysis of 34,218 Pediatric Outpatient Controlled Substance Prescriptions.

PubMed

George, Jessica A; Park, Paul S; Hunsberger, Joanne; Shay, Joanne E; Lehmann, Christoph U; White, Elizabeth D; Lee, Benjamin H; Yaster, Myron

2016-03-01

Prescription errors are among the most common types of iatrogenic errors. Because of a previously reported 82% error rate in handwritten discharge narcotic prescriptions, we developed a computerized, web-based, controlled substance prescription writer that includes weight-based dosing logic and alerts to reduce the error rate to (virtually) zero. Over the past 7 years, >34,000 prescriptions have been created by hospital providers using this platform. We sought to determine the ongoing efficacy of the program in prescription error reduction and the patterns with which providers prescribe controlled substances for children and young adults (ages 0-21 years) at hospital discharge. We examined a database of 34,218 controlled substance discharge prescriptions written by our institutional providers from January 1, 2007 to February 14, 2014, for demographic information, including age and weight, type of medication prescribed based on patient age, formulation of dispensed medication, and amount of drug to be dispensed at hospital discharge. In addition, we randomly regenerated 2% (700) of prescriptions based on stored data and analyzed them for errors using previously established error criteria. Weights that were manually entered into the prescription writer by the prescriber were compared with the patient's weight in the hospital's electronic medical record. Patients in the database averaged 9 ± 6.1 (range, 0-21) years of age and 36.7 ± 24.9 (1-195) kg. Regardless of age, the most commonly prescribed opioid was oxycodone (73%), which was prescribed as a single agent uncombined with acetaminophen. Codeine was prescribed to 7% of patients and always in a formulation containing acetaminophen. Liquid formulations were prescribed to 98% of children <6 years of age and to 16% of children >12 years of age (the remaining 84% received tablet formulations). Regardless of opioid prescribed, the amount of liquid dispensed averaged 106 ± 125 (range, 2-3240) mL, and the number of tablets dispensed averaged 51 ± 51 (range, 1-1080). Of the subset of 700 regenerated prescriptions, all were legible (drug, amount dispensed, dose, patient demographics, and provider name) and used best prescribing practice (e.g., no trailing zero after a decimal point, leading zero for doses <1). Twenty-five of the 700 (3.6%) had incorrectly entered weights compared with the most recent weight in the chart. Of these, 14 varied by 10% or less and only 2 varied by >15%. Of these, 1 resulted in underdosing (true weight 80 kg prescribed for a weight of 50 kg) and the other in overdosing (true weight 10 kg prescribed for a weight of 30 kg). A computerized prescription writer eliminated most but not all the errors common to handwritten prescriptions. Oxycodone has supplanted codeine as the most commonly prescribed oral opioid in current pediatric pain practice and, independent of formulation, is dispensed in large quantities. This study underscores the need for liquid opioid formulations in the pediatric population and, because of their abuse potential, the urgent need to determine how much of the prescribed medication is actually used by patients.

A survey of the criteria for prescribing in cases of borderline refractive errors

PubMed Central

Shneor, Einat; Evans, Bruce John William; Fine, Yael; Shapira, Yehudit; Gantz, Liat; Gordon-Shaag, Ariela

2015-01-01

Purpose This research investigated the reported optometric prescribing criteria of Israeli optometrists. Methods An online questionnaire based on previous studies was distributed via email and social networking sites to optometrists in Israel. The questionnaire surveyed the level of refractive error at which respondents would prescribe for different types of refractive error at various ages with and without symptoms. Results 124 responses were obtained, yielding a response rate of approximately 12–22%, 92% of whom had trained in Israel. For all refractive errors, the presence of symptoms strongly influenced prescribing criteria. For example, for 10–20 year old patients the degree of hyperopia for which 50% of practitioners would prescribe is +0.75 D in the presence of symptoms but twice this value (+1.50 D) in the absence of symptoms. As might be expected, optometrists prescribed at lower degrees of hyperopia for older compared with younger patients. There was a trend for more experienced practitioners to be less likely to prescribe for lower degrees of myopia and presbyopia. Practitioner gender, country of training, the type of practice environment, and financial incentives were not strongly related to prescribing criteria. Conclusions The prescribing criteria found in this study are broadly comparable with those in previous studies and with published prescribing guidelines. Subtle indications suggest that optometrists may become more conservative in their prescribing criteria with experience. PMID:26520884

A Novel Switching-Based Control Framework for Improved Task Performance in Teleoperation System With Asymmetric Time-Varying Delays.

PubMed

Zhai, Di-Hua; Xia, Yuanqing

2018-02-01

This paper addresses the adaptive control for task-space teleoperation systems with constrained predefined synchronization error, where a novel switched control framework is investigated. Based on multiple Lyapunov-Krasovskii functionals method, the stability of the resulting closed-loop system is established in the sense of state-independent input-to-output stability. Compared with previous work, the developed method can simultaneously handle the unknown kinematics/dynamics, asymmetric varying time delays, and prescribed performance control in a unified framework. It is shown that the developed controller can guarantee the prescribed transient-state and steady-state synchronization performances between the master and slave robots, which is demonstrated by the simulation study.

Improved prescribed performance control for air-breathing hypersonic vehicles with unknown deadzone input nonlinearity.

PubMed

Wang, Yingyang; Hu, Jianbo

2018-05-19

An improved prescribed performance controller is proposed for the longitudinal model of an air-breathing hypersonic vehicle (AHV) subject to uncertain dynamics and input nonlinearity. Different from the traditional non-affine model requiring non-affine functions to be differentiable, this paper utilizes a semi-decomposed non-affine model with non-affine functions being locally semi-bounded and possibly in-differentiable. A new error transformation combined with novel prescribed performance functions is proposed to bypass complex deductions caused by conventional error constraint approaches and circumvent high frequency chattering in control inputs. On the basis of backstepping technique, the improved prescribed performance controller with low structural and computational complexity is designed. The methodology guarantees the altitude and velocity tracking error within transient and steady state performance envelopes and presents excellent robustness against uncertain dynamics and deadzone input nonlinearity. Simulation results demonstrate the efficacy of the proposed method. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Zero tolerance prescribing: a strategy to reduce prescribing errors on the paediatric intensive care unit.

PubMed

Booth, Rachelle; Sturgess, Emma; Taberner-Stokes, Alison; Peters, Mark

2012-11-01

To establish the baseline prescribing error rate in a tertiary paediatric intensive care unit (PICU) and to determine the impact of a zero tolerance prescribing (ZTP) policy incorporating a dedicated prescribing area and daily feedback of prescribing errors. A prospective, non-blinded, observational study was undertaken in a 12-bed tertiary PICU over a period of 134 weeks. Baseline prescribing error data were collected on weekdays for all patients for a period of 32 weeks, following which the ZTP policy was introduced. Daily error feedback was introduced after a further 12 months. Errors were sub-classified as 'clinical', 'non-clinical' and 'infusion prescription' errors and the effects of interventions considered separately. The baseline combined prescribing error rate was 892 (95 % confidence interval (CI) 765-1,019) errors per 1,000 PICU occupied bed days (OBDs), comprising 25.6 % clinical, 44 % non-clinical and 30.4 % infusion prescription errors. The combined interventions of ZTP plus daily error feedback were associated with a reduction in the combined prescribing error rate to 447 (95 % CI 389-504) errors per 1,000 OBDs (p < 0.0001), an absolute risk reduction of 44.5 % (95 % CI 40.8-48.0 %). Introduction of the ZTP policy was associated with a significant decrease in clinical and infusion prescription errors, while the introduction of daily error feedback was associated with a significant reduction in non-clinical prescribing errors. The combined interventions of ZTP and daily error feedback were associated with a significant reduction in prescribing errors in the PICU, in line with Department of Health requirements of a 40 % reduction within 5 years.

? filtering for stochastic systems driven by Poisson processes

NASA Astrophysics Data System (ADS)

Song, Bo; Wu, Zheng-Guang; Park, Ju H.; Shi, Guodong; Zhang, Ya

2015-01-01

This paper investigates the ? filtering problem for stochastic systems driven by Poisson processes. By utilising the martingale theory such as the predictable projection operator and the dual predictable projection operator, this paper transforms the expectation of stochastic integral with respect to the Poisson process into the expectation of Lebesgue integral. Then, based on this, this paper designs an ? filter such that the filtering error system is mean-square asymptotically stable and satisfies a prescribed ? performance level. Finally, a simulation example is given to illustrate the effectiveness of the proposed filtering scheme.

A survey of the criteria for prescribing in cases of borderline refractive errors.

PubMed

Shneor, Einat; Evans, Bruce John William; Fine, Yael; Shapira, Yehudit; Gantz, Liat; Gordon-Shaag, Ariela

2016-01-01

This research investigated the reported optometric prescribing criteria of Israeli optometrists. An online questionnaire based on previous studies was distributed via email and social networking sites to optometrists in Israel. The questionnaire surveyed the level of refractive error at which respondents would prescribe for different types of refractive error at various ages with and without symptoms. 124 responses were obtained, yielding a response rate of approximately 12-22%, 92% of whom had trained in Israel. For all refractive errors, the presence of symptoms strongly influenced prescribing criteria. For example, for 10-20 year old patients the degree of hyperopia for which 50% of practitioners would prescribe is +0.75 D in the presence of symptoms but twice this value (+1.50 D) in the absence of symptoms. As might be expected, optometrists prescribed at lower degrees of hyperopia for older compared with younger patients. There was a trend for more experienced practitioners to be less likely to prescribe for lower degrees of myopia and presbyopia. Practitioner gender, country of training, the type of practice environment, and financial incentives were not strongly related to prescribing criteria. The prescribing criteria found in this study are broadly comparable with those in previous studies and with published prescribing guidelines. Subtle indications suggest that optometrists may become more conservative in their prescribing criteria with experience. Copyright © 2015 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

Concomitant prescribing and dispensing errors at a Brazilian hospital: a descriptive study

PubMed Central

Silva, Maria das Dores Graciano; Rosa, Mário Borges; Franklin, Bryony Dean; Reis, Adriano Max Moreira; Anchieta, Lêni Márcia; Mota, Joaquim Antônio César

2011-01-01

OBJECTIVE: To analyze the prevalence and types of prescribing and dispensing errors occurring with high-alert medications and to propose preventive measures to avoid errors with these medications. INTRODUCTION: The prevalence of adverse events in health care has increased, and medication errors are probably the most common cause of these events. Pediatric patients are known to be a high-risk group and are an important target in medication error prevention. METHODS: Observers collected data on prescribing and dispensing errors occurring with high-alert medications for pediatric inpatients in a university hospital. In addition to classifying the types of error that occurred, we identified cases of concomitant prescribing and dispensing errors. RESULTS: One or more prescribing errors, totaling 1,632 errors, were found in 632 (89.6%) of the 705 high-alert medications that were prescribed and dispensed. We also identified at least one dispensing error in each high-alert medication dispensed, totaling 1,707 errors. Among these dispensing errors, 723 (42.4%) content errors occurred concomitantly with the prescribing errors. A subset of dispensing errors may have occurred because of poor prescription quality. The observed concomitancy should be examined carefully because improvements in the prescribing process could potentially prevent these problems. CONCLUSION: The system of drug prescribing and dispensing at the hospital investigated in this study should be improved by incorporating the best practices of medication safety and preventing medication errors. High-alert medications may be used as triggers for improving the safety of the drug-utilization system. PMID:22012039

Medication errors: problems and recommendations from a consensus meeting

PubMed Central

Agrawal, Abha; Aronson, Jeffrey K; Britten, Nicky; Ferner, Robin E; de Smet, Peter A; Fialová, Daniela; Fitzgerald, Richard J; Likić, Robert; Maxwell, Simon R; Meyboom, Ronald H; Minuz, Pietro; Onder, Graziano; Schachter, Michael; Velo, Giampaolo

2009-01-01

Here we discuss 15 recommendations for reducing the risks of medication errors: Provision of sufficient undergraduate learning opportunities to make medical students safe prescribers. Provision of opportunities for students to practise skills that help to reduce errors. Education of students about common types of medication errors and how to avoid them. Education of prescribers in taking accurate drug histories. Assessment in medical schools of prescribing knowledge and skills and demonstration that newly qualified doctors are safe prescribers. European harmonization of prescribing and safety recommendations and regulatory measures, with regular feedback about rational drug use. Comprehensive assessment of elderly patients for declining function. Exploration of low-dose regimens for elderly patients and preparation of special formulations as required. Training for all health-care professionals in drug use, adverse effects, and medication errors in elderly people. More involvement of pharmacists in clinical practice. Introduction of integrated prescription forms and national implementation in individual countries. Development of better monitoring systems for detecting medication errors, based on classification and analysis of spontaneous reports of previous reactions, and for investigating the possible role of medication errors when patients die. Use of IT systems, when available, to provide methods of avoiding medication errors; standardization, proper evaluation, and certification of clinical information systems. Nonjudgmental communication with patients about their concerns and elicitation of symptoms that they perceive to be adverse drug reactions. Avoidance of defensive reactions if patients mention symptoms resulting from medication errors. PMID:19594525

Underlying risk factors for prescribing errors in long-term aged care: a qualitative study.

PubMed

Tariq, Amina; Georgiou, Andrew; Raban, Magdalena; Baysari, Melissa Therese; Westbrook, Johanna

2016-09-01

To identify system-related risk factors perceived to contribute to prescribing errors in Australian long-term care settings, that is, residential aged care facilities (RACFs). The study used qualitative methods to explore factors that contribute to unsafe prescribing in RACFs. Data were collected at three RACFs in metropolitan Sydney, Australia between May and November 2011. Participants included RACF managers, doctors, pharmacists and RACF staff actively involved in prescribing-related processes. Methods included non-participant observations (74 h), in-depth semistructured interviews (n=25) and artefact analysis. Detailed process activity models were developed for observed prescribing episodes supplemented by triangulated analysis using content analysis methods. System-related factors perceived to increase the risk of prescribing errors in RACFs were classified into three overarching themes: communication systems, team coordination and staff management. Factors associated with communication systems included limited point-of-care access to information, inadequate handovers, information storage across different media (paper, electronic and memory), poor legibility of charts, information double handling, multiple faxing of medication charts and reliance on manual chart reviews. Team factors included lack of established lines of responsibility, inadequate team communication and limited participation of doctors in multidisciplinary initiatives like medication advisory committee meetings. Factors related to staff management and workload included doctors' time constraints and their accessibility, lack of trained RACF staff and high RACF staff turnover. The study highlights several system-related factors including laborious methods for exchanging medication information, which often act together to contribute to prescribing errors. Multiple interventions (eg, technology systems, team communication protocols) are required to support the collaborative nature of RACF prescribing. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Frequency of dosage prescribing medication errors associated with manual prescriptions for very preterm infants.

PubMed

Horri, J; Cransac, A; Quantin, C; Abrahamowicz, M; Ferdynus, C; Sgro, C; Robillard, P-Y; Iacobelli, S; Gouyon, J-B

2014-12-01

The risk of dosage Prescription Medication Error (PME) among manually written prescriptions within 'mixed' prescribing system (computerized physician order entry (CPOE) + manual prescriptions) has not been previously assessed in neonatology. This study aimed to evaluate the rate of dosage PME related to manual prescriptions in the high-risk population of very preterm infants (GA < 33 weeks) in a mixed prescription system. The study was based on a retrospective review of a random sample of manual daily prescriptions in two neonatal intensive care units (NICU) A and B, located in different French University hospitals (Dijon and La Reunion island). Daily prescription was defined as the set of all drugs manually prescribed on a single day for one patient. Dosage error was defined as a deviation of at least ±10% from the weight-appropriate recommended dose. The analyses were based on the assessment of 676 manually prescribed drugs from NICU A (58 different drugs from 93 newborns and 240 daily prescriptions) and 354 manually prescribed drugs from NICU B (73 different drugs from 131 newborns and 241 daily prescriptions). The dosage error rate per 100 manually prescribed drugs was similar in both NICU: 3·8% (95% CI: 2·5-5·6%) in NICU A and 3·1% (95% CI: 1·6-5·5%) in NICU B (P = 0·54). Among all the 37 identified dosage errors, the over-dosing was almost as frequent as the under-dosing (17 and 20 errors, respectively). Potentially severe dosage errors occurred in a total of seven drug prescriptions. None of the dosage PME was recorded in the corresponding medical files and information on clinical outcome was not sufficient to identify clinical conditions related to dosage PME. Overall, 46·8% of manually prescribed drugs were off label or unlicensed, with no significant differences between prescriptions with or without dosage error. The risk of a dosage PME increased significantly if the drug was included in the CPOE system but was manually prescribed (OR = 3·3; 95% CI: 1·6-7·0, P < 0·001). The presence of dosage PME in the manual prescriptions written within mixed prescription systems suggests that manual prescriptions should be totally avoided in neonatal units. © 2014 John Wiley & Sons Ltd.

Command generator tracker based direct model reference adaptive tracking guidance for Mars atmospheric entry

NASA Astrophysics Data System (ADS)

Li, Shuang; Peng, Yuming

2012-01-01

In order to accurately deliver an entry vehicle through the Martian atmosphere to the prescribed parachute deployment point, active Mars entry guidance is essential. This paper addresses the issue of Mars atmospheric entry guidance using the command generator tracker (CGT) based direct model reference adaptive control to reduce the adverse effect of the bounded uncertainties on atmospheric density and aerodynamic coefficients. Firstly, the nominal drag acceleration profile meeting a variety of constraints is planned off-line in the longitudinal plane as the reference model to track. Then, the CGT based direct model reference adaptive controller and the feed-forward compensator are designed to robustly track the aforementioned reference drag acceleration profile and to effectively reduce the downrange error. Afterwards, the heading alignment logic is adopted in the lateral plane to reduce the crossrange error. Finally, the validity of the guidance algorithm proposed in this paper is confirmed by Monte Carlo simulation analysis.

Outpatient Prescribing Errors and the Impact of Computerized Prescribing

PubMed Central

Gandhi, Tejal K; Weingart, Saul N; Seger, Andrew C; Borus, Joshua; Burdick, Elisabeth; Poon, Eric G; Leape, Lucian L; Bates, David W

2005-01-01

Background Medication errors are common among inpatients and many are preventable with computerized prescribing. Relatively little is known about outpatient prescribing errors or the impact of computerized prescribing in this setting. Objective To assess the rates, types, and severity of outpatient prescribing errors and understand the potential impact of computerized prescribing. Design Prospective cohort study in 4 adult primary care practices in Boston using prescription review, patient survey, and chart review to identify medication errors, potential adverse drug events (ADEs) and preventable ADEs. Participants Outpatients over age 18 who received a prescription from 24 participating physicians. Results We screened 1879 prescriptions from 1202 patients, and completed 661 surveys (response rate 55%). Of the prescriptions, 143 (7.6%; 95% confidence interval (CI) 6.4% to 8.8%) contained a prescribing error. Three errors led to preventable ADEs and 62 (43%; 3% of all prescriptions) had potential for patient injury (potential ADEs); 1 was potentially life-threatening (2%) and 15 were serious (24%). Errors in frequency (n=77, 54%) and dose (n=26, 18%) were common. The rates of medication errors and potential ADEs were not significantly different at basic computerized prescribing sites (4.3% vs 11.0%, P=.31; 2.6% vs 4.0%, P=.16) compared to handwritten sites. Advanced checks (including dose and frequency checking) could have prevented 95% of potential ADEs. Conclusions Prescribing errors occurred in 7.6% of outpatient prescriptions and many could have harmed patients. Basic computerized prescribing systems may not be adequate to reduce errors. More advanced systems with dose and frequency checking are likely needed to prevent potentially harmful errors. PMID:16117752

E-prescribing errors in community pharmacies: exploring consequences and contributing factors.

PubMed

Odukoya, Olufunmilola K; Stone, Jamie A; Chui, Michelle A

2014-06-01

To explore types of e-prescribing errors in community pharmacies and their potential consequences, as well as the factors that contribute to e-prescribing errors. Data collection involved performing 45 total hours of direct observations in five pharmacies. Follow-up interviews were conducted with 20 study participants. Transcripts from observations and interviews were subjected to content analysis using NVivo 10. Pharmacy staff detected 75 e-prescription errors during the 45 h observation in pharmacies. The most common e-prescribing errors were wrong drug quantity, wrong dosing directions, wrong duration of therapy, and wrong dosage formulation. Participants estimated that 5 in 100 e-prescriptions have errors. Drug classes that were implicated in e-prescribing errors were antiinfectives, inhalers, ophthalmic, and topical agents. The potential consequences of e-prescribing errors included increased likelihood of the patient receiving incorrect drug therapy, poor disease management for patients, additional work for pharmacy personnel, increased cost for pharmacies and patients, and frustrations for patients and pharmacy staff. Factors that contribute to errors included: technology incompatibility between pharmacy and clinic systems, technology design issues such as use of auto-populate features and dropdown menus, and inadvertently entering incorrect information. Study findings suggest that a wide range of e-prescribing errors is encountered in community pharmacies. Pharmacists and technicians perceive that causes of e-prescribing errors are multidisciplinary and multifactorial, that is to say e-prescribing errors can originate from technology used in prescriber offices and pharmacies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

E-Prescribing Errors in Community Pharmacies: Exploring Consequences and Contributing Factors

PubMed Central

Stone, Jamie A.; Chui, Michelle A.

2014-01-01

Objective To explore types of e-prescribing errors in community pharmacies and their potential consequences, as well as the factors that contribute to e-prescribing errors. Methods Data collection involved performing 45 total hours of direct observations in five pharmacies. Follow-up interviews were conducted with 20 study participants. Transcripts from observations and interviews were subjected to content analysis using NVivo 10. Results Pharmacy staff detected 75 e-prescription errors during the 45 hour observation in pharmacies. The most common e-prescribing errors were wrong drug quantity, wrong dosing directions, wrong duration of therapy, and wrong dosage formulation. Participants estimated that 5 in 100 e-prescriptions have errors. Drug classes that were implicated in e-prescribing errors were antiinfectives, inhalers, ophthalmic, and topical agents. The potential consequences of e-prescribing errors included increased likelihood of the patient receiving incorrect drug therapy, poor disease management for patients, additional work for pharmacy personnel, increased cost for pharmacies and patients, and frustrations for patients and pharmacy staff. Factors that contribute to errors included: technology incompatibility between pharmacy and clinic systems, technology design issues such as use of auto-populate features and dropdown menus, and inadvertently entering incorrect information. Conclusion Study findings suggest that a wide range of e-prescribing errors are encountered in community pharmacies. Pharmacists and technicians perceive that causes of e-prescribing errors are multidisciplinary and multifactorial, that is to say e-prescribing errors can originate from technology used in prescriber offices and pharmacies. PMID:24657055

Assessment of the knowledge and attitudes of intern doctors to medication prescribing errors in a Nigeria tertiary hospital

PubMed Central

Ajemigbitse, Adetutu A.; Omole, Moses Kayode; Ezike, Nnamdi Chika; Erhun, Wilson O.

2013-01-01

Context: Junior doctors are reported to make most of the prescribing errors in the hospital setting. Aims: The aim of the following study is to determine the knowledge intern doctors have about prescribing errors and circumstances contributing to making them. Settings and Design: A structured questionnaire was distributed to intern doctors in National Hospital Abuja Nigeria. Subjects and Methods: Respondents gave information about their experience with prescribing medicines, the extent to which they agreed with the definition of a clinically meaningful prescribing error and events that constituted such. Their experience with prescribing certain categories of medicines was also sought. Statistical Analysis Used: Data was analyzed with Statistical Package for the Social Sciences (SPSS) software version 17 (SPSS Inc Chicago, Ill, USA). Chi-squared analysis contrasted differences in proportions; P < 0.05 was considered to be statistically significant. Results: The response rate was 90.9% and 27 (90%) had <1 year of prescribing experience. 17 (56.7%) respondents totally agreed with the definition of a clinically meaningful prescribing error. Most common reasons for prescribing mistakes were a failure to check prescriptions with a reference source (14, 25.5%) and failure to check for adverse drug interactions (14, 25.5%). Omitting some essential information such as duration of therapy (13, 20%), patient age (14, 21.5%) and dosage errors (14, 21.5%) were the most common types of prescribing errors made. Respondents considered workload (23, 76.7%), multitasking (19, 63.3%), rushing (18, 60.0%) and tiredness/stress (16, 53.3%) as important factors contributing to prescribing errors. Interns were least confident prescribing antibiotics (12, 25.5%), opioid analgesics (12, 25.5%) cytotoxics (10, 21.3%) and antipsychotics (9, 19.1%) unsupervised. Conclusions: Respondents seemed to have a low awareness of making prescribing errors. Principles of rational prescribing and events that constitute prescribing errors should be taught in the practice setting. PMID:24808682

Assessment of the knowledge and attitudes of intern doctors to medication prescribing errors in a Nigeria tertiary hospital.

PubMed

Ajemigbitse, Adetutu A; Omole, Moses Kayode; Ezike, Nnamdi Chika; Erhun, Wilson O

2013-12-01

Junior doctors are reported to make most of the prescribing errors in the hospital setting. The aim of the following study is to determine the knowledge intern doctors have about prescribing errors and circumstances contributing to making them. A structured questionnaire was distributed to intern doctors in National Hospital Abuja Nigeria. Respondents gave information about their experience with prescribing medicines, the extent to which they agreed with the definition of a clinically meaningful prescribing error and events that constituted such. Their experience with prescribing certain categories of medicines was also sought. Data was analyzed with Statistical Package for the Social Sciences (SPSS) software version 17 (SPSS Inc Chicago, Ill, USA). Chi-squared analysis contrasted differences in proportions; P < 0.05 was considered to be statistically significant. The response rate was 90.9% and 27 (90%) had <1 year of prescribing experience. 17 (56.7%) respondents totally agreed with the definition of a clinically meaningful prescribing error. Most common reasons for prescribing mistakes were a failure to check prescriptions with a reference source (14, 25.5%) and failure to check for adverse drug interactions (14, 25.5%). Omitting some essential information such as duration of therapy (13, 20%), patient age (14, 21.5%) and dosage errors (14, 21.5%) were the most common types of prescribing errors made. Respondents considered workload (23, 76.7%), multitasking (19, 63.3%), rushing (18, 60.0%) and tiredness/stress (16, 53.3%) as important factors contributing to prescribing errors. Interns were least confident prescribing antibiotics (12, 25.5%), opioid analgesics (12, 25.5%) cytotoxics (10, 21.3%) and antipsychotics (9, 19.1%) unsupervised. Respondents seemed to have a low awareness of making prescribing errors. Principles of rational prescribing and events that constitute prescribing errors should be taught in the practice setting.

Prescribing Errors Involving Medication Dosage Forms

PubMed Central

Lesar, Timothy S

2002-01-01

CONTEXT Prescribing errors involving medication dose formulations have been reported to occur frequently in hospitals. No systematic evaluations of the characteristics of errors related to medication dosage formulation have been performed. OBJECTIVE To quantify the characteristics, frequency, and potential adverse patient effects of prescribing errors involving medication dosage forms . DESIGN Evaluation of all detected medication prescribing errors involving or related to medication dosage forms in a 631-bed tertiary care teaching hospital. MAIN OUTCOME MEASURES Type, frequency, and potential for adverse effects of prescribing errors involving or related to medication dosage forms. RESULTS A total of 1,115 clinically significant prescribing errors involving medication dosage forms were detected during the 60-month study period. The annual number of detected errors increased throughout the study period. Detailed analysis of the 402 errors detected during the last 16 months of the study demonstrated the most common errors to be: failure to specify controlled release formulation (total of 280 cases; 69.7%) both when prescribing using the brand name (148 cases; 36.8%) and when prescribing using the generic name (132 cases; 32.8%); and prescribing controlled delivery formulations to be administered per tube (48 cases; 11.9%). The potential for adverse patient outcome was rated as potentially “fatal or severe” in 3 cases (0.7%), and “serious” in 49 cases (12.2%). Errors most commonly involved cardiovascular agents (208 cases; 51.7%). CONCLUSIONS Hospitalized patients are at risk for adverse outcomes due to prescribing errors related to inappropriate use of medication dosage forms. This information should be considered in the development of strategies to prevent adverse patient outcomes resulting from such errors. PMID:12213138

Using EHR Data to Detect Prescribing Errors in Rapidly Discontinued Medication Orders.

PubMed

Burlison, Jonathan D; McDaniel, Robert B; Baker, Donald K; Hasan, Murad; Robertson, Jennifer J; Howard, Scott C; Hoffman, James M

2018-01-01

Previous research developed a new method for locating prescribing errors in rapidly discontinued electronic medication orders. Although effective, the prospective design of that research hinders its feasibility for regular use. Our objectives were to assess a method to retrospectively detect prescribing errors, to characterize the identified errors, and to identify potential improvement opportunities. Electronically submitted medication orders from 28 randomly selected days that were discontinued within 120 minutes of submission were reviewed and categorized as most likely errors, nonerrors, or not enough information to determine status. Identified errors were evaluated by amount of time elapsed from original submission to discontinuation, error type, staff position, and potential clinical significance. Pearson's chi-square test was used to compare rates of errors across prescriber types. In all, 147 errors were identified in 305 medication orders. The method was most effective for orders that were discontinued within 90 minutes. Duplicate orders were most common; physicians in training had the highest error rate ( p  < 0.001), and 24 errors were potentially clinically significant. None of the errors were voluntarily reported. It is possible to identify prescribing errors in rapidly discontinued medication orders by using retrospective methods that do not require interrupting prescribers to discuss order details. Future research could validate our methods in different clinical settings. Regular use of this measure could help determine the causes of prescribing errors, track performance, and identify and evaluate interventions to improve prescribing systems and processes. Schattauer GmbH Stuttgart.

The Role of Hospital Inpatients in Supporting Medication Safety: A Qualitative Study.

PubMed

Garfield, Sara; Jheeta, Seetal; Husson, Fran; Lloyd, Jill; Taylor, Alex; Boucher, Charles; Jacklin, Ann; Bischler, Anna; Norton, Christine; Hayles, Rob; Franklin, Bryony Dean

2016-01-01

Inpatient medication errors are a significant concern. An approach not yet widely studied is to facilitate greater involvement of inpatients with their medication. At the same time, electronic prescribing is becoming increasingly prevalent in the hospital setting. In this study we aimed to explore hospital inpatients' involvement with medication safety-related behaviours, facilitators and barriers to this involvement, and the impact of electronic prescribing. We conducted ethnographic observations and interviews in two UK hospital organisations, one with established electronic prescribing and one that changed from paper to electronic prescribing during our study. Researchers and lay volunteers observed nurses' medication administration rounds, pharmacists' ward rounds, doctor-led ward rounds and drug history taking. We also conducted interviews with healthcare professionals, patients and carers. Interviews were audio-recorded and transcribed. Observation notes and transcripts were coded thematically. Paper or electronic medication records were shown to patients in only 4 (2%) of 247 cases. However, where they were available during patient-healthcare professional interactions, healthcare professionals often viewed them in order to inform patients about their medicines and answer any questions. Interprofessional discussions about medicines seemed more likely to happen in front of the patient where paper or electronic drug charts were available near the bedside. Patients and carers had more access to paper-based drug charts than electronic equivalents. However, interviews and observations suggest there are potentially more significant factors that affect patient involvement with their inpatient medication. These include patient and healthcare professional beliefs concerning patient involvement, the way in which healthcare professionals operate as a team, and the underlying culture. Patients appear to have more access to paper-based records than electronic equivalents. However, to develop interventions to increase patient involvement with medication safety behaviours, a wider range of factors needs to be considered.

Improving specialist drug prescribing in primary care using task and error analysis: an observational study.

PubMed

Chana, Narinder; Porat, Talya; Whittlesea, Cate; Delaney, Brendan

2017-03-01

Electronic prescribing has benefited from computerised clinical decision support systems (CDSSs); however, no published studies have evaluated the potential for a CDSS to support GPs in prescribing specialist drugs. To identify potential weaknesses and errors in the existing process of prescribing specialist drugs that could be addressed in the development of a CDSS. Semi-structured interviews with key informants followed by an observational study involving GPs in the UK. Twelve key informants were interviewed to investigate the use of CDSSs in the UK. Nine GPs were observed while performing case scenarios depicting requests from hospitals or patients to prescribe a specialist drug. Activity diagrams, hierarchical task analysis, and systematic human error reduction and prediction approach analyses were performed. The current process of prescribing specialist drugs by GPs is prone to error. Errors of omission due to lack of information were the most common errors, which could potentially result in a GP prescribing a specialist drug that should only be prescribed in hospitals, or prescribing a specialist drug without reference to a shared care protocol. Half of all possible errors in the prescribing process had a high probability of occurrence. A CDSS supporting GPs during the process of prescribing specialist drugs is needed. This could, first, support the decision making of whether or not to undertake prescribing, and, second, provide drug-specific parameters linked to shared care protocols, which could reduce the errors identified and increase patient safety. © British Journal of General Practice 2017.

Impact of electronic chemotherapy order forms on prescribing errors at an urban medical center: results from an interrupted time-series analysis.

PubMed

Elsaid, K; Truong, T; Monckeberg, M; McCarthy, H; Butera, J; Collins, C

2013-12-01

To evaluate the impact of electronic standardized chemotherapy templates on incidence and types of prescribing errors. A quasi-experimental interrupted time series with segmented regression. A 700-bed multidisciplinary tertiary care hospital with an ambulatory cancer center. A multidisciplinary team including oncology physicians, nurses, pharmacists and information technologists. Standardized, regimen-specific, chemotherapy prescribing forms were developed and implemented over a 32-month period. Trend of monthly prevented prescribing errors per 1000 chemotherapy doses during the pre-implementation phase (30 months), immediate change in the error rate from pre-implementation to implementation and trend of errors during the implementation phase. Errors were analyzed according to their types: errors in communication or transcription, errors in dosing calculation and errors in regimen frequency or treatment duration. Relative risk (RR) of errors in the post-implementation phase (28 months) compared with the pre-implementation phase was computed with 95% confidence interval (CI). Baseline monthly error rate was stable with 16.7 prevented errors per 1000 chemotherapy doses. A 30% reduction in prescribing errors was observed with initiating the intervention. With implementation, a negative change in the slope of prescribing errors was observed (coefficient = -0.338; 95% CI: -0.612 to -0.064). The estimated RR of transcription errors was 0.74; 95% CI (0.59-0.92). The estimated RR of dosing calculation errors was 0.06; 95% CI (0.03-0.10). The estimated RR of chemotherapy frequency/duration errors was 0.51; 95% CI (0.42-0.62). Implementing standardized chemotherapy-prescribing templates significantly reduced all types of prescribing errors and improved chemotherapy safety.

The pattern of the discovery of medication errors in a tertiary hospital in Hong Kong.

PubMed

Samaranayake, N R; Cheung, S T D; Chui, W C M; Cheung, B M Y

2013-06-01

The primary goal of reducing medication errors is to eliminate those that reach the patient. We aimed to study the pattern of interceptions to tackle medication errors along the medication use processes. Tertiary care hospital in Hong Kong. The 'Swiss Cheese Model' was used to explain the interceptions targeting medication error reporting over 5 years (2006-2010). Proportions of prescribing, dispensing and drug administration errors intercepted by pharmacists and nurses; proportions of prescribing, dispensing and drug administration errors that reached the patient. Our analysis included 1,268 in-patient medication errors, of which 53.4% were related to prescribing, 29.0% to administration and 17.6% to dispensing. 34.1% of all medication errors (4.9% prescribing, 26.8% drug administration and 2.4% dispensing) were not intercepted. Pharmacy staff intercepted 85.4% of the prescribing errors. Nurses detected 83.0% of dispensing and 5.0% of prescribing errors. However, 92.4% of all drug administration errors reached the patient. Having a preventive measure at each stage of the medication use process helps to prevent most errors. Most drug administration errors reach the patient as there is no defense against these. Therefore, more interventions to prevent drug administration errors are warranted.

Learning-based adaptive prescribed performance control of postcapture space robot-target combination without inertia identifications

NASA Astrophysics Data System (ADS)

Wei, Caisheng; Luo, Jianjun; Dai, Honghua; Bian, Zilin; Yuan, Jianping

2018-05-01

In this paper, a novel learning-based adaptive attitude takeover control method is investigated for the postcapture space robot-target combination with guaranteed prescribed performance in the presence of unknown inertial properties and external disturbance. First, a new static prescribed performance controller is developed to guarantee that all the involved attitude tracking errors are uniformly ultimately bounded by quantitatively characterizing the transient and steady-state performance of the combination. Then, a learning-based supplementary adaptive strategy based on adaptive dynamic programming is introduced to improve the tracking performance of static controller in terms of robustness and adaptiveness only utilizing the input/output data of the combination. Compared with the existing works, the prominent advantage is that the unknown inertial properties are not required to identify in the development of learning-based adaptive control law, which dramatically decreases the complexity and difficulty of the relevant controller design. Moreover, the transient and steady-state performance is guaranteed a priori by designer-specialized performance functions without resorting to repeated regulations of the controller parameters. Finally, the three groups of illustrative examples are employed to verify the effectiveness of the proposed control method.

Medication errors in paediatric care: a systematic review of epidemiology and an evaluation of evidence supporting reduction strategy recommendations

PubMed Central

Miller, Marlene R; Robinson, Karen A; Lubomski, Lisa H; Rinke, Michael L; Pronovost, Peter J

2007-01-01

Background Although children are at the greatest risk for medication errors, little is known about the overall epidemiology of these errors, where the gaps are in our knowledge, and to what extent national medication error reduction strategies focus on children. Objective To synthesise peer reviewed knowledge on children's medication errors and on recommendations to improve paediatric medication safety by a systematic literature review. Data sources PubMed, Embase and Cinahl from 1 January 2000 to 30 April 2005, and 11 national entities that have disseminated recommendations to improve medication safety. Study selection Inclusion criteria were peer reviewed original data in English language. Studies that did not separately report paediatric data were excluded. Data extraction Two reviewers screened articles for eligibility and for data extraction, and screened all national medication error reduction strategies for relevance to children. Data synthesis From 358 articles identified, 31 were included for data extraction. The definition of medication error was non‐uniform across the studies. Dispensing and administering errors were the most poorly and non‐uniformly evaluated. Overall, the distributional epidemiological estimates of the relative percentages of paediatric error types were: prescribing 3–37%, dispensing 5–58%, administering 72–75%, and documentation 17–21%. 26 unique recommendations for strategies to reduce medication errors were identified; none were based on paediatric evidence. Conclusions Medication errors occur across the entire spectrum of prescribing, dispensing, and administering, are common, and have a myriad of non‐evidence based potential reduction strategies. Further research in this area needs a firmer standardisation for items such as dose ranges and definitions of medication errors, broader scope beyond inpatient prescribing errors, and prioritisation of implementation of medication error reduction strategies. PMID:17403758

Feedback on prescribing errors to junior doctors: exploring views, problems and preferred methods.

PubMed

Bertels, Jeroen; Almoudaris, Alex M; Cortoos, Pieter-Jan; Jacklin, Ann; Franklin, Bryony Dean

2013-06-01

Prescribing errors are common in hospital inpatients. However, the literature suggests that doctors are often unaware of their errors as they are not always informed of them. It has been suggested that providing more feedback to prescribers may reduce subsequent error rates. Only few studies have investigated the views of prescribers towards receiving such feedback, or the views of hospital pharmacists as potential feedback providers. Our aim was to explore the views of junior doctors and hospital pharmacists regarding feedback on individual doctors' prescribing errors. Objectives were to determine how feedback was currently provided and any associated problems, to explore views on other approaches to feedback, and to make recommendations for designing suitable feedback systems. A large London NHS hospital trust. To explore views on current and possible feedback mechanisms, self-administered questionnaires were given to all junior doctors and pharmacists, combining both 5-point Likert scale statements and open-ended questions. Agreement scores for statements regarding perceived prescribing error rates, opinions on feedback, barriers to feedback, and preferences for future practice. Response rates were 49% (37/75) for junior doctors and 57% (57/100) for pharmacists. In general, doctors did not feel threatened by feedback on their prescribing errors. They felt that feedback currently provided was constructive but often irregular and insufficient. Most pharmacists provided feedback in various ways; however some did not or were inconsistent. They were willing to provide more feedback, but did not feel it was always effective or feasible due to barriers such as communication problems and time constraints. Both professional groups preferred individual feedback with additional regular generic feedback on common or serious errors. Feedback on prescribing errors was valued and acceptable to both professional groups. From the results, several suggested methods of providing feedback on prescribing errors emerged. Addressing barriers such as the identification of individual prescribers would facilitate feedback in practice. Research investigating whether or not feedback reduces the subsequent error rate is now needed.

Boundary control for a constrained two-link rigid-flexible manipulator with prescribed performance

NASA Astrophysics Data System (ADS)

Cao, Fangfei; Liu, Jinkun

2018-05-01

In this paper, we consider a boundary control problem for a constrained two-link rigid-flexible manipulator. The nonlinear system is described by hybrid ordinary differential equation-partial differential equation (ODE-PDE) dynamic model. Based on the coupled ODE-PDE model, boundary control is proposed to regulate the joint positions and eliminate the elastic vibration simultaneously. With the help of prescribed performance functions, the tracking error can converge to an arbitrarily small residual set and the convergence rate is no less than a certain pre-specified value. Asymptotic stability of the closed-loop system is rigorously proved by the LaSalle's Invariance Principle extended to infinite-dimensional system. Numerical simulations are provided to demonstrate the effectiveness of the proposed controller.

Medication errors in the obstetrics emergency ward in a low resource setting.

PubMed

Kandil, Mohamed; Sayyed, Tarek; Emarh, Mohamed; Ellakwa, Hamed; Masood, Alaa

2012-08-01

To investigate the patterns of medication errors in the obstetric emergency ward in a low resource setting. This prospective observational study included 10,000 women who presented at the obstetric emergency ward, department of Obstetrics and Gynecology, Menofyia University Hospital, Egypt between March and December 2010. All medications prescribed in the emergency ward were monitored for different types of errors. The head nurse in each shift was asked to monitor each pharmacologic order from the moment of prescribing till its administration. Retrospective review of the patients' charts and nurses' notes was carried out by the authors of this paper. Results were tabulated and statistically analyzed. A total of 1976 medication errors were detected. Administration errors were the commonest error reported. Omitted errors ranked second followed by unauthorized and prescription errors. Three administration errors resulted in three Cesareans were performed for fetal distress because of wrong doses of oxytocin infusion. The rest of errors did not cause patients harm but may have lead to an increase in monitoring. Most errors occurred during night shifts. The availability of automated infusion pumps will probably decrease administration errors significantly. There is a need for more obstetricians and nurses during the nightshifts to minimize errors resulting from working under stressful conditions.

Medication safety at the interface: evaluating risks associated with discharge prescriptions from mental health hospitals.

PubMed

Keers, R N; Williams, S D; Vattakatuchery, J J; Brown, P; Miller, J; Prescott, L; Ashcroft, D M

2015-12-01

When compared to general hospitals, relatively little is known about the quality and safety of discharge prescriptions from specialist mental health settings. We aimed to investigate the quality and safety of discharge prescriptions written at mental health hospitals. This study was undertaken on acute adult and later life inpatient units at three National Health Service (NHS) mental health trusts. Trained pharmacy teams prospectively reviewed all newly written discharge prescriptions over a 6-week period, recording the number of prescribing errors, clerical errors and errors involving lack of communication about medicines stopped during hospital admission. All prescribing errors were reviewed and validated by a multidisciplinary panel. Main outcome measures were the prevalence (95% CI) of prescribing errors, clerical errors and errors involving a lack of details about medicines stopped. Risk factors for prescribing and clerical errors were examined via logistic regression and results presented as odds ratios (OR) with corresponding 95% CI. Of 274 discharge prescriptions, 259 contained a total of 1456 individually prescribed items. One in five [20·8% (95%CI 15·9-25·8%)] eligible discharge prescriptions and one in twenty [5·1% (95%CI 4·0-6·2%)] prescribed or omitted items were affected by at least one prescribing error. One or more clerical errors were found in 71·9% (95%CI 66·5-77·3%) of discharge prescriptions, and more than two-thirds [68·8% (95%CI 56·6-78·8%)] of eligible discharge prescriptions erroneously lacked information on medicines discontinued during hospital admission. Logistic regression analyses revealed that middle-grade [whole discharge prescription level OR 3·28 (3·03-3·56)] and senior [whole discharge OR 1·43 (1·04-1·96)] prescribers as well as electronic discharge prescription pro formas [whole discharge OR 2·43 (2·08-2·83)] were all associated with significantly higher risks of prescribing errors than junior prescribers and handwritten discharges, respectively. Similar findings were reported at the individually prescribed item level. Middle-grade prescribers were also more likely to make both non-psychotropic and psychotropic prescribing errors than their junior colleagues [individual item OR 4·24 (2·14-8·40) and OR 1·70 (1·16-2·48), respectively]. Discharge prescriptions issued by mental health NHS hospitals are affected by high levels of prescribing, clerical and communication errors. Important targets for intervention have been identified to improve medication safety problems at care transfer. © 2015 John Wiley & Sons Ltd.

Prevalence of medication errors in primary health care at Bahrain Defence Force Hospital – prescription-based study

PubMed Central

Aljasmi, Fatema; Almalood, Fatema

2018-01-01

Background One of the important activities that physicians – particularly general practitioners – perform is prescribing. It occurs in most health care facilities and especially in primary health care (PHC) settings. Objectives This study aims to determine what types of prescribing errors are made in PHC at Bahrain Defence Force (BDF) Hospital, and how common they are. Methods This was a retrospective study of data from PHC at BDF Hospital. The data consisted of 379 prescriptions randomly selected from the pharmacy between March and May 2013, and errors in the prescriptions were classified into five types: major omission, minor omission, commission, integration, and skill-related errors. Results Of the total prescriptions, 54.4% (N=206) were given to male patients and 45.6% (N=173) to female patients; 24.8% were given to patients under the age of 10 years. On average, there were 2.6 drugs per prescription. In the prescriptions, 8.7% of drugs were prescribed by their generic names, and 28% (N=106) of prescriptions included an antibiotic. Out of the 379 prescriptions, 228 had an error, and 44.3% (N=439) of the 992 prescribed drugs contained errors. The proportions of errors were as follows: 9.9% (N=38) were minor omission errors; 73.6% (N=323) were major omission errors; 9.3% (N=41) were commission errors; and 17.1% (N=75) were skill-related errors. Conclusion This study provides awareness of the presence of prescription errors and frequency of the different types of errors that exist in this hospital. Understanding the different types of errors could help future studies explore the causes of specific errors and develop interventions to reduce them. Further research should be conducted to understand the causes of these errors and demonstrate whether the introduction of electronic prescriptions has an effect on patient outcomes. PMID:29445304

The use of a contextual, modal and psychological classification of medication errors in the emergency department: a retrospective descriptive study.

PubMed

Cabilan, C J; Hughes, James A; Shannon, Carl

2017-12-01

To describe the contextual, modal and psychological classification of medication errors in the emergency department to know the factors associated with the reported medication errors. The causes of medication errors are unique in every clinical setting; hence, error minimisation strategies are not always effective. For this reason, it is fundamental to understand the causes specific to the emergency department so that targeted strategies can be implemented. Retrospective analysis of reported medication errors in the emergency department. All voluntarily staff-reported medication-related incidents from 2010-2015 from the hospital's electronic incident management system were retrieved for analysis. Contextual classification involved the time, place and the type of medications involved. Modal classification pertained to the stage and issue (e.g. wrong medication, wrong patient). Psychological classification categorised the errors in planning (knowledge-based and rule-based errors) and skill (slips and lapses). There were 405 errors reported. Most errors occurred in the acute care area, short-stay unit and resuscitation area, during the busiest shifts (0800-1559, 1600-2259). Half of the errors involved high-alert medications. Many of the errors occurred during administration (62·7%), prescribing (28·6%) and commonly during both stages (18·5%). Wrong dose, wrong medication and omission were the issues that dominated. Knowledge-based errors characterised the errors that occurred in prescribing and administration. The highest proportion of slips (79·5%) and lapses (76·1%) occurred during medication administration. It is likely that some of the errors occurred due to the lack of adherence to safety protocols. Technology such as computerised prescribing, barcode medication administration and reminder systems could potentially decrease the medication errors in the emergency department. There was a possibility that some of the errors could be prevented if safety protocols were adhered to, which highlights the need to also address clinicians' attitudes towards safety. Technology can be implemented to help minimise errors in the ED, but this must be coupled with efforts to enhance the culture of safety. © 2017 John Wiley & Sons Ltd.

Hospital prescribing errors: epidemiological assessment of predictors

PubMed Central

Fijn, R; Van den Bemt, P M L A; Chow, M; De Blaey, C J; De Jong-Van den Berg, L T W; Brouwers, J R B J

2002-01-01

Aims To demonstrate an epidemiological method to assess predictors of prescribing errors. Methods A retrospective case-control study, comparing prescriptions with and without errors. Results Only prescriber and drug characteristics were associated with errors. Prescriber characteristics were medical specialty (e.g. orthopaedics: OR: 3.4, 95% CI 2.1, 5.4) and prescriber status (e.g. verbal orders transcribed by nursing staff: OR: 2.5, 95% CI 1.8, 3.6). Drug characteristics were dosage form (e.g. inhalation devices: OR: 4.1, 95% CI 2.6, 6.6), therapeutic area (e.g. gastrointestinal tract: OR: 1.7, 95% CI 1.2, 2.4) and continuation of preadmission treatment (Yes: OR: 1.7, 95% CI 1.3, 2.3). Conclusions Other hospitals could use our epidemiological framework to identify their own error predictors. Our findings suggest a focus on specific prescribers, dosage forms and therapeutic areas. We also found that prescriptions originating from general practitioners involved errors and therefore, these should be checked when patients are hospitalized. PMID:11874397

Prescribing errors in adult congenital heart disease patients admitted to a pediatric cardiovascular intensive care unit.

PubMed

Echeta, Genevieve; Moffett, Brady S; Checchia, Paul; Benton, Mary Kay; Klouda, Leda; Rodriguez, Fred H; Franklin, Wayne

2014-01-01

Adults with congenital heart disease (CHD) are often cared for at pediatric hospitals. There are no data describing the incidence or type of medication prescribing errors in adult patients admitted to a pediatric cardiovascular intensive care unit (CVICU). A review of patients >18 years of age admitted to the pediatric CVICU at our institution from 2009 to 2011 occurred. A comparator group <18 years of age but >70 kg (a typical adult weight) was identified. Medication prescribing errors were determined according to a commonly used adult drug reference. An independent panel consisting of a physician specializing in the care of adult CHD patients, a nurse, and a pharmacist evaluated all errors. Medication prescribing orders were classified as appropriate, underdose, overdose, or nonstandard (dosing per weight instead of standard adult dosing), and severity of error was classified. Eighty-five adult (74 patients) and 33 pediatric admissions (32 patients) met study criteria (mean age 27.5 ± 9.4 years, 53% male vs. 14.9 ± 1.8 years, 63% male). A cardiothoracic surgical procedure occurred in 81.4% of admissions. Adult admissions weighed less than pediatric admissions (72.8 ± 22.4 kg vs. 85.6 ± 14.9 kg, P < .01) but hospital length of stay was similar. (Adult 6 days [range 1-216 days]; pediatric 5 days [Range 2-123 days], P = .52.) A total of 112 prescribing errors were identified and they occurred less often in adults (42.4% of admissions vs. 66.7% of admissions, P = .02). Adults had a lower mean number of errors (0.7 errors per adult admission vs. 1.7 errors per pediatric admission, P < .01). Prescribing errors occurred most commonly with antimicrobials (n = 27). Underdosing was the most common category of prescribing error. Most prescribing errors were determined to have not caused harm to the patient. Prescribing errors occur frequently in adult patients admitted to a pediatric CVICU but occur more often in pediatric patients of adult weight. © 2013 Wiley Periodicals, Inc.

The Role of Hospital Inpatients in Supporting Medication Safety: A Qualitative Study

PubMed Central

Garfield, Sara; Jheeta, Seetal; Husson, Fran; Lloyd, Jill; Taylor, Alex; Boucher, Charles; Jacklin, Ann; Bischler, Anna; Norton, Christine; Hayles, Rob; Dean Franklin, Bryony

2016-01-01

Background Inpatient medication errors are a significant concern. An approach not yet widely studied is to facilitate greater involvement of inpatients with their medication. At the same time, electronic prescribing is becoming increasingly prevalent in the hospital setting. In this study we aimed to explore hospital inpatients’ involvement with medication safety-related behaviours, facilitators and barriers to this involvement, and the impact of electronic prescribing. Methods We conducted ethnographic observations and interviews in two UK hospital organisations, one with established electronic prescribing and one that changed from paper to electronic prescribing during our study. Researchers and lay volunteers observed nurses’ medication administration rounds, pharmacists’ ward rounds, doctor-led ward rounds and drug history taking. We also conducted interviews with healthcare professionals, patients and carers. Interviews were audio-recorded and transcribed. Observation notes and transcripts were coded thematically. Results Paper or electronic medication records were shown to patients in only 4 (2%) of 247 cases. However, where they were available during patient-healthcare professional interactions, healthcare professionals often viewed them in order to inform patients about their medicines and answer any questions. Interprofessional discussions about medicines seemed more likely to happen in front of the patient where paper or electronic drug charts were available near the bedside. Patients and carers had more access to paper-based drug charts than electronic equivalents. However, interviews and observations suggest there are potentially more significant factors that affect patient involvement with their inpatient medication. These include patient and healthcare professional beliefs concerning patient involvement, the way in which healthcare professionals operate as a team, and the underlying culture. Conclusion Patients appear to have more access to paper-based records than electronic equivalents. However, to develop interventions to increase patient involvement with medication safety behaviours, a wider range of factors needs to be considered. PMID:27093438

Automation bias in electronic prescribing.

PubMed

Lyell, David; Magrabi, Farah; Raban, Magdalena Z; Pont, L G; Baysari, Melissa T; Day, Richard O; Coiera, Enrico

2017-03-16

Clinical decision support (CDS) in e-prescribing can improve safety by alerting potential errors, but introduces new sources of risk. Automation bias (AB) occurs when users over-rely on CDS, reducing vigilance in information seeking and processing. Evidence of AB has been found in other clinical tasks, but has not yet been tested with e-prescribing. This study tests for the presence of AB in e-prescribing and the impact of task complexity and interruptions on AB. One hundred and twenty students in the final two years of a medical degree prescribed medicines for nine clinical scenarios using a simulated e-prescribing system. Quality of CDS (correct, incorrect and no CDS) and task complexity (low, low + interruption and high) were varied between conditions. Omission errors (failure to detect prescribing errors) and commission errors (acceptance of false positive alerts) were measured. Compared to scenarios with no CDS, correct CDS reduced omission errors by 38.3% (p < .0001, n = 120), 46.6% (p < .0001, n = 70), and 39.2% (p < .0001, n = 120) for low, low + interrupt and high complexity scenarios respectively. Incorrect CDS increased omission errors by 33.3% (p < .0001, n = 120), 24.5% (p < .009, n = 82), and 26.7% (p < .0001, n = 120). Participants made commission errors, 65.8% (p < .0001, n = 120), 53.5% (p < .0001, n = 82), and 51.7% (p < .0001, n = 120). Task complexity and interruptions had no impact on AB. This study found evidence of AB omission and commission errors in e-prescribing. Verification of CDS alerts is key to avoiding AB errors. However, interventions focused on this have had limited success to date. Clinicians should remain vigilant to the risks of CDS failures and verify CDS.

Simple prescribing errors and allergy documentation in medical hospital admissions in Australia and New Zealand.

PubMed

Barton, Lorna; Futtermenger, Judith; Gaddi, Yash; Kang, Angela; Rivers, Jon; Spriggs, David; Jenkins, Paul F; Thompson, Campbell H; Thomas, Josephine S

2012-04-01

This study aimed to quantify and compare the prevalence of simple prescribing errors made by clinicians in the first 24 hours of a general medical patient's hospital admission. Four public or private acute care hospitals across Australia and New Zealand each audited 200 patients' drug charts. Patient demographics, pharmacist review and pre-defined prescribing errors were recorded. At least one simple error was present on the medication charts of 672/715 patients, with a linear relationship between the number of medications prescribed and the number of errors (r = 0.571, p < 0.001). The four sites differed significantly in the prevalence of different types of simple prescribing errors. Pharmacists were more likely to review patients aged > or = 75 years (39.9% vs 26.0%; p < 0.001) and those with more than 10 drug prescriptions (39.4% vs 25.7%; p < 0.001). Patients reviewed by a pharmacist were less likely to have inadequate documentation of allergies (13.5% vs 29.4%, p < 0.001). Simple prescribing errors are common, although their nature differs from site to site. Clinical pharmacists target patients with the most complex health situations, and their involvement leads to improved documentation.

Adaptive Neural Networks Prescribed Performance Control Design for Switched Interconnected Uncertain Nonlinear Systems.

PubMed

Li, Yongming; Tong, Shaocheng

2017-06-28

In this paper, an adaptive neural networks (NNs)-based decentralized control scheme with the prescribed performance is proposed for uncertain switched nonstrict-feedback interconnected nonlinear systems. It is assumed that nonlinear interconnected terms and nonlinear functions of the concerned systems are unknown, and also the switching signals are unknown and arbitrary. A linear state estimator is constructed to solve the problem of unmeasured states. The NNs are employed to approximate unknown interconnected terms and nonlinear functions. A new output feedback decentralized control scheme is developed by using the adaptive backstepping design technique. The control design problem of nonlinear interconnected switched systems with unknown switching signals can be solved by the proposed scheme, and only a tuning parameter is needed for each subsystem. The proposed scheme can ensure that all variables of the control systems are semi-globally uniformly ultimately bounded and the tracking errors converge to a small residual set with the prescribed performance bound. The effectiveness of the proposed control approach is verified by some simulation results.

The effect of the electronic transmission of prescriptions on dispensing errors and prescription enhancements made in English community pharmacies: a naturalistic stepped wedge study

PubMed Central

Franklin, Bryony Dean; Reynolds, Matthew; Sadler, Stacey; Hibberd, Ralph; Avery, Anthony J; Armstrong, Sarah J; Mehta, Rajnikant; Boyd, Matthew J; Barber, Nick

2014-01-01

Objectives To compare prevalence and types of dispensing errors and pharmacists’ labelling enhancements, for prescriptions transmitted electronically versus paper prescriptions. Design Naturalistic stepped wedge study. Setting 15 English community pharmacies. Intervention Electronic transmission of prescriptions between prescriber and pharmacy. Main outcome measures Prevalence of labelling errors, content errors and labelling enhancements (beneficial additions to the instructions), as identified by researchers visiting each pharmacy. Results Overall, we identified labelling errors in 5.4% of 16 357 dispensed items, and content errors in 1.4%; enhancements were made for 13.6%. Pharmacists also edited the label for a further 21.9% of electronically transmitted items. Electronically transmitted prescriptions had a higher prevalence of labelling errors (7.4% of 3733 items) than other prescriptions (4.8% of 12 624); OR 1.46 (95% CI 1.21 to 1.76). There was no difference for content errors or enhancements. The increase in labelling errors was mainly accounted for by errors (mainly at one pharmacy) involving omission of the indication, where specified by the prescriber, from the label. A sensitivity analysis in which these cases (n=158) were not considered errors revealed no remaining difference between prescription types. Conclusions We identified a higher prevalence of labelling errors for items transmitted electronically, but this was predominantly accounted for by local practice in a single pharmacy, independent of prescription type. Community pharmacists made labelling enhancements to about one in seven dispensed items, whether electronically transmitted or not. Community pharmacists, prescribers, professional bodies and software providers should work together to agree how items should be dispensed and labelled to best reap the benefits of electronically transmitted prescriptions. Community pharmacists need to ensure their computer systems are promptly updated to help reduce errors. PMID:24742778

The effect of the electronic transmission of prescriptions on dispensing errors and prescription enhancements made in English community pharmacies: a naturalistic stepped wedge study.

PubMed

Franklin, Bryony Dean; Reynolds, Matthew; Sadler, Stacey; Hibberd, Ralph; Avery, Anthony J; Armstrong, Sarah J; Mehta, Rajnikant; Boyd, Matthew J; Barber, Nick

2014-08-01

To compare prevalence and types of dispensing errors and pharmacists' labelling enhancements, for prescriptions transmitted electronically versus paper prescriptions. Naturalistic stepped wedge study. 15 English community pharmacies. Electronic transmission of prescriptions between prescriber and pharmacy. Prevalence of labelling errors, content errors and labelling enhancements (beneficial additions to the instructions), as identified by researchers visiting each pharmacy. Overall, we identified labelling errors in 5.4% of 16,357 dispensed items, and content errors in 1.4%; enhancements were made for 13.6%. Pharmacists also edited the label for a further 21.9% of electronically transmitted items. Electronically transmitted prescriptions had a higher prevalence of labelling errors (7.4% of 3733 items) than other prescriptions (4.8% of 12,624); OR 1.46 (95% CI 1.21 to 1.76). There was no difference for content errors or enhancements. The increase in labelling errors was mainly accounted for by errors (mainly at one pharmacy) involving omission of the indication, where specified by the prescriber, from the label. A sensitivity analysis in which these cases (n=158) were not considered errors revealed no remaining difference between prescription types. We identified a higher prevalence of labelling errors for items transmitted electronically, but this was predominantly accounted for by local practice in a single pharmacy, independent of prescription type. Community pharmacists made labelling enhancements to about one in seven dispensed items, whether electronically transmitted or not. Community pharmacists, prescribers, professional bodies and software providers should work together to agree how items should be dispensed and labelled to best reap the benefits of electronically transmitted prescriptions. Community pharmacists need to ensure their computer systems are promptly updated to help reduce errors. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Task errors by emergency physicians are associated with interruptions, multitasking, fatigue and working memory capacity: a prospective, direct observation study.

PubMed

Westbrook, Johanna I; Raban, Magdalena Z; Walter, Scott R; Douglas, Heather

2018-01-09

Interruptions and multitasking have been demonstrated in experimental studies to reduce individuals' task performance. These behaviours are frequently used by clinicians in high-workload, dynamic clinical environments, yet their effects have rarely been studied. To assess the relative contributions of interruptions and multitasking by emergency physicians to prescribing errors. 36 emergency physicians were shadowed over 120 hours. All tasks, interruptions and instances of multitasking were recorded. Physicians' working memory capacity (WMC) and preference for multitasking were assessed using the Operation Span Task (OSPAN) and Inventory of Polychronic Values. Following observation, physicians were asked about their sleep in the previous 24 hours. Prescribing errors were used as a measure of task performance. We performed multivariate analysis of prescribing error rates to determine associations with interruptions and multitasking, also considering physician seniority, age, psychometric measures, workload and sleep. Physicians experienced 7.9 interruptions/hour. 28 clinicians were observed prescribing 239 medication orders which contained 208 prescribing errors. While prescribing, clinicians were interrupted 9.4 times/hour. Error rates increased significantly if physicians were interrupted (rate ratio (RR) 2.82; 95% CI 1.23 to 6.49) or multitasked (RR 1.86; 95% CI 1.35 to 2.56) while prescribing. Having below-average sleep showed a >15-fold increase in clinical error rate (RR 16.44; 95% CI 4.84 to 55.81). WMC was protective against errors; for every 10-point increase on the 75-point OSPAN, a 19% decrease in prescribing errors was observed. There was no effect of polychronicity, workload, physician gender or above-average sleep on error rates. Interruptions, multitasking and poor sleep were associated with significantly increased rates of prescribing errors among emergency physicians. WMC mitigated the negative influence of these factors to an extent. These results confirm experimental findings in other fields and raise questions about the acceptability of the high rates of multitasking and interruption in clinical environments. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Measuring the relationship between interruptions, multitasking and prescribing errors in an emergency department: a study protocol

PubMed Central

Raban, Magdalena Z; Walter, Scott R; Douglas, Heather E; Strumpman, Dana; Mackenzie, John; Westbrook, Johanna I

2015-01-01

Introduction Interruptions and multitasking are frequent in clinical settings, and have been shown in the cognitive psychology literature to affect performance, increasing the risk of error. However, comparatively less is known about their impact on errors in clinical work. This study will assess the relationship between prescribing errors, interruptions and multitasking in an emergency department (ED) using direct observations and chart review. Methods and analysis The study will be conducted in an ED of a 440-bed teaching hospital in Sydney, Australia. Doctors will be shadowed at proximity by observers for 2 h time intervals while they are working on day shift (between 0800 and 1800). Time stamped data on tasks, interruptions and multitasking will be recorded on a handheld computer using the validated Work Observation Method by Activity Timing (WOMBAT) tool. The prompts leading to interruptions and multitasking will also be recorded. When doctors prescribe medication, type of chart and chart sections written on, along with the patient's medical record number (MRN) will be recorded. A clinical pharmacist will access patient records and assess the medication orders for prescribing errors. The prescribing error rate will be calculated per prescribing task and is defined as the number of errors divided by the number of medication orders written during the prescribing task. The association between prescribing error rates, and rates of prompts, interruptions and multitasking will be assessed using statistical modelling. Ethics and dissemination Ethics approval has been obtained from the hospital research ethics committee. Eligible doctors will be provided with written information sheets and written consent will be obtained if they agree to participate. Doctor details and MRNs will be kept separate from the data on prescribing errors, and will not appear in the final data set for analysis. Study results will be disseminated in publications and feedback to the ED. PMID:26463224

Measuring the relationship between interruptions, multitasking and prescribing errors in an emergency department: a study protocol.

PubMed

Raban, Magdalena Z; Walter, Scott R; Douglas, Heather E; Strumpman, Dana; Mackenzie, John; Westbrook, Johanna I

2015-10-13

Interruptions and multitasking are frequent in clinical settings, and have been shown in the cognitive psychology literature to affect performance, increasing the risk of error. However, comparatively less is known about their impact on errors in clinical work. This study will assess the relationship between prescribing errors, interruptions and multitasking in an emergency department (ED) using direct observations and chart review. The study will be conducted in an ED of a 440-bed teaching hospital in Sydney, Australia. Doctors will be shadowed at proximity by observers for 2 h time intervals while they are working on day shift (between 0800 and 1800). Time stamped data on tasks, interruptions and multitasking will be recorded on a handheld computer using the validated Work Observation Method by Activity Timing (WOMBAT) tool. The prompts leading to interruptions and multitasking will also be recorded. When doctors prescribe medication, type of chart and chart sections written on, along with the patient's medical record number (MRN) will be recorded. A clinical pharmacist will access patient records and assess the medication orders for prescribing errors. The prescribing error rate will be calculated per prescribing task and is defined as the number of errors divided by the number of medication orders written during the prescribing task. The association between prescribing error rates, and rates of prompts, interruptions and multitasking will be assessed using statistical modelling. Ethics approval has been obtained from the hospital research ethics committee. Eligible doctors will be provided with written information sheets and written consent will be obtained if they agree to participate. Doctor details and MRNs will be kept separate from the data on prescribing errors, and will not appear in the final data set for analysis. Study results will be disseminated in publications and feedback to the ED. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

A description of medication errors reported by pharmacists in a neonatal intensive care unit.

PubMed

Pawluk, Shane; Jaam, Myriam; Hazi, Fatima; Al Hail, Moza Sulaiman; El Kassem, Wessam; Khalifa, Hanan; Thomas, Binny; Abdul Rouf, Pallivalappila

2017-02-01

Background Patients in the Neonatal Intensive Care Unit (NICU) are at an increased risk for medication errors. Objective The objective of this study is to describe the nature and setting of medication errors occurring in patients admitted to an NICU in Qatar based on a standard electronic system reported by pharmacists. Setting Neonatal intensive care unit, Doha, Qatar. Method This was a retrospective cross-sectional study on medication errors reported electronically by pharmacists in the NICU between January 1, 2014 and April 30, 2015. Main outcome measure Data collected included patient information, and incident details including error category, medications involved, and follow-up completed. Results A total of 201 NICU pharmacists-reported medication errors were submitted during the study period. All reported errors did not reach the patient and did not cause harm. Of the errors reported, 98.5% occurred in the prescribing phase of the medication process with 58.7% being due to calculation errors. Overall, 53 different medications were documented in error reports with the anti-infective agents being the most frequently cited. The majority of incidents indicated that the primary prescriber was contacted and the error was resolved before reaching the next phase of the medication process. Conclusion Medication errors reported by pharmacists occur most frequently in the prescribing phase of the medication process. Our data suggest that error reporting systems need to be specific to the population involved. Special attention should be paid to frequently used medications in the NICU as these were responsible for the greatest numbers of medication errors.

Computer calculated dose in paediatric prescribing.

PubMed

Kirk, Richard C; Li-Meng Goh, Denise; Packia, Jeya; Min Kam, Huey; Ong, Benjamin K C

2005-01-01

Medication errors are an important cause of hospital-based morbidity and mortality. However, only a few medication error studies have been conducted in children. These have mainly quantified errors in the inpatient setting; there is very little data available on paediatric outpatient and emergency department medication errors and none on discharge medication. This deficiency is of concern because medication errors are more common in children and it has been suggested that the risk of an adverse drug event as a consequence of a medication error is higher in children than in adults. The aims of this study were to assess the rate of medication errors in predominantly ambulatory paediatric patients and the effect of computer calculated doses on medication error rates of two commonly prescribed drugs. This was a prospective cohort study performed in a paediatric unit in a university teaching hospital between March 2003 and August 2003. The hospital's existing computer clinical decision support system was modified so that doctors could choose the traditional prescription method or the enhanced method of computer calculated dose when prescribing paracetamol (acetaminophen) or promethazine. All prescriptions issued to children (<16 years of age) at the outpatient clinic, emergency department and at discharge from the inpatient service were analysed. A medication error was defined as to have occurred if there was an underdose (below the agreed value), an overdose (above the agreed value), no frequency of administration specified, no dose given or excessive total daily dose. The medication error rates and the factors influencing medication error rates were determined using SPSS version 12. From March to August 2003, 4281 prescriptions were issued. Seven prescriptions (0.16%) were excluded, hence 4274 prescriptions were analysed. Most prescriptions were issued by paediatricians (including neonatologists and paediatric surgeons) and/or junior doctors. The error rate in the children's emergency department was 15.7%, for outpatients was 21.5% and for discharge medication was 23.6%. Most errors were the result of an underdose (64%; 536/833). The computer calculated dose error rate was 12.6% compared with the traditional prescription error rate of 28.2%. Logistical regression analysis showed that computer calculated dose was an important and independent variable influencing the error rate (adjusted relative risk = 0.436, 95% CI 0.336, 0.520, p < 0.001). Other important independent variables were seniority and paediatric training of the person prescribing and the type of drug prescribed. Medication error, especially underdose, is common in outpatient, emergency department and discharge prescriptions. Computer calculated doses can significantly reduce errors, but other risk factors have to be concurrently addressed to achieve maximum benefit.

The impact of a closed-loop electronic prescribing and administration system on prescribing errors, administration errors and staff time: a before-and-after study.

PubMed

Franklin, Bryony Dean; O'Grady, Kara; Donyai, Parastou; Jacklin, Ann; Barber, Nick

2007-08-01

To assess the impact of a closed-loop electronic prescribing, automated dispensing, barcode patient identification and electronic medication administration record (EMAR) system on prescribing and administration errors, confirmation of patient identity before administration, and staff time. Before-and-after study in a surgical ward of a teaching hospital, involving patients and staff of that ward. Closed-loop electronic prescribing, automated dispensing, barcode patient identification and EMAR system. Percentage of new medication orders with a prescribing error, percentage of doses with medication administration errors (MAEs) and percentage given without checking patient identity. Time spent prescribing and providing a ward pharmacy service. Nursing time on medication tasks. Prescribing errors were identified in 3.8% of 2450 medication orders pre-intervention and 2.0% of 2353 orders afterwards (p<0.001; chi(2) test). MAEs occurred in 7.0% of 1473 non-intravenous doses pre-intervention and 4.3% of 1139 afterwards (p = 0.005; chi(2) test). Patient identity was not checked for 82.6% of 1344 doses pre-intervention and 18.9% of 1291 afterwards (p<0.001; chi(2) test). Medical staff required 15 s to prescribe a regular inpatient drug pre-intervention and 39 s afterwards (p = 0.03; t test). Time spent providing a ward pharmacy service increased from 68 min to 98 min each weekday (p = 0.001; t test); 22% of drug charts were unavailable pre-intervention. Time per drug administration round decreased from 50 min to 40 min (p = 0.006; t test); nursing time on medication tasks outside of drug rounds increased from 21.1% to 28.7% (p = 0.006; chi(2) test). A closed-loop electronic prescribing, dispensing and barcode patient identification system reduced prescribing errors and MAEs, and increased confirmation of patient identity before administration. Time spent on medication-related tasks increased.

Nonlinear robust control of hypersonic aircrafts with interactions between flight dynamics and propulsion systems.

PubMed

Li, Zhaoying; Zhou, Wenjie; Liu, Hao

2016-09-01

This paper addresses the nonlinear robust tracking controller design problem for hypersonic vehicles. This problem is challenging due to strong coupling between the aerodynamics and the propulsion system, and the uncertainties involved in the vehicle dynamics including parametric uncertainties, unmodeled model uncertainties, and external disturbances. By utilizing the feedback linearization technique, a linear tracking error system is established with prescribed references. For the linear model, a robust controller is proposed based on the signal compensation theory to guarantee that the tracking error dynamics is robustly stable. Numerical simulation results are given to show the advantages of the proposed nonlinear robust control method, compared to the robust loop-shaping control approach. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

A framework for considering business models.

PubMed

Anderson, James G

2003-01-01

Information technology (IT) such as computerized physician order entry, computer-based decision support and alerting systems, and electronic prescribing can reduce medical errors and improve the quality of health care. However, the business value of these systems is frequently questioned. At present a number of barriers exist to realizing the potential of IT to improve quality of care. Some of these barriers are: the ineffectiveness of existing error reporting systems, low investment in IT infrastructure, legal impediments to reforms, and the difficulty in demonstrating a sufficient return on investment to justify expenditures for quality improvement. This paper provides an overview of these issues, a framework for considering business models, and examples of successful implementations of IT to improve quality of patient care.

Electronic prescribing in pediatrics: toward safer and more effective medication management.

PubMed

Johnson, Kevin B; Lehmann, Christoph U

2013-04-01

This technical report discusses recent advances in electronic prescribing (e-prescribing) systems, including the evidence base supporting their limitations and potential benefits. Specifically, this report acknowledges that there are limited but positive pediatric data supporting the role of e-prescribing in mitigating medication errors, improving communication with dispensing pharmacists, and improving medication adherence. On the basis of these data and on the basis of federal statutes that provide incentives for the use of e-prescribing systems, the American Academy of Pediatrics recommends the adoption of e-prescribing systems with pediatric functionality. This report supports the accompanying policy statement from the American Academy of Pediatrics recommending the adoption of e-prescribing by pediatric health care providers.

What are incident reports telling us? A comparative study at two Australian hospitals of medication errors identified at audit, detected by staff and reported to an incident system

PubMed Central

Westbrook, Johanna I.; Li, Ling; Lehnbom, Elin C.; Baysari, Melissa T.; Braithwaite, Jeffrey; Burke, Rosemary; Conn, Chris; Day, Richard O.

2015-01-01

Objectives To (i) compare medication errors identified at audit and observation with medication incident reports; (ii) identify differences between two hospitals in incident report frequency and medication error rates; (iii) identify prescribing error detection rates by staff. Design Audit of 3291patient records at two hospitals to identify prescribing errors and evidence of their detection by staff. Medication administration errors were identified from a direct observational study of 180 nurses administering 7451 medications. Severity of errors was classified. Those likely to lead to patient harm were categorized as ‘clinically important’. Setting Two major academic teaching hospitals in Sydney, Australia. Main Outcome Measures Rates of medication errors identified from audit and from direct observation were compared with reported medication incident reports. Results A total of 12 567 prescribing errors were identified at audit. Of these 1.2/1000 errors (95% CI: 0.6–1.8) had incident reports. Clinically important prescribing errors (n = 539) were detected by staff at a rate of 218.9/1000 (95% CI: 184.0–253.8), but only 13.0/1000 (95% CI: 3.4–22.5) were reported. 78.1% (n = 421) of clinically important prescribing errors were not detected. A total of 2043 drug administrations (27.4%; 95% CI: 26.4–28.4%) contained ≥1 errors; none had an incident report. Hospital A had a higher frequency of incident reports than Hospital B, but a lower rate of errors at audit. Conclusions Prescribing errors with the potential to cause harm frequently go undetected. Reported incidents do not reflect the profile of medication errors which occur in hospitals or the underlying rates. This demonstrates the inaccuracy of using incident frequency to compare patient risk or quality performance within or across hospitals. New approaches including data mining of electronic clinical information systems are required to support more effective medication error detection and mitigation. PMID:25583702

Prescribers' expectations and barriers to electronic prescribing of controlled substances

PubMed Central

Kim, Meelee; McDonald, Ann; Kreiner, Peter; Kelleher, Stephen J; Blackman, Michael B; Kaufman, Peter N; Carrow, Grant M

2011-01-01

Objective To better understand barriers associated with the adoption and use of electronic prescribing of controlled substances (EPCS), a practice recently established by US Drug Enforcement Administration regulation. Materials and methods Prescribers of controlled substances affiliated with a regional health system were surveyed regarding current electronic prescribing (e-prescribing) activities, current prescribing of controlled substances, and expectations and barriers to the adoption of EPCS. Results 246 prescribers (response rate of 64%) represented a range of medical specialties, with 43.1% of these prescribers current users of e-prescribing for non-controlled substances. Reported issues with controlled substances included errors, pharmacy call-backs, and diversion; most prescribers expected EPCS to address many of these problems, specifically reduce medical errors, improve work flow and efficiency of practice, help identify prescription diversion or misuse, and improve patient treatment management. Prescribers expected, however, that it would be disruptive to practice, and over one-third of respondents reported that carrying a security authentication token at all times would be so burdensome as to discourage adoption. Discussion Although adoption of e-prescribing has been shown to dramatically reduce medication errors, challenges to efficient processes and errors still persist from the perspective of the prescriber, that may interfere with the adoption of EPCS. Most prescribers regarded EPCS security measures as a small or moderate inconvenience (other than carrying a security token), with advantages outweighing the burden. Conclusion Prescribers are optimistic about the potential for EPCS to improve practice, but view certain security measures as a burden and potential barrier. PMID:21946239

Using nurses and office staff to report prescribing errors in primary care.

PubMed

Kennedy, Amanda G; Littenberg, Benjamin; Senders, John W

2008-08-01

To implement a prescribing-error reporting system in primary care offices and analyze the reports. Descriptive analysis of a voluntary prescribing-error-reporting system Seven primary care offices in Vermont, USA. One hundred and three prescribers, managers, nurses and office staff. Nurses and office staff were asked to report all communications with community pharmacists regarding prescription problems. All reports were classified by severity category, setting, error mode, prescription domain and error-producing conditions. All practices submitted reports, although reporting decreased by 3.6 reports per month (95% CI, -2.7 to -4.4, P<0.001, by linear regression analysis). Two hundred and sixteen reports were submitted. Nearly 90% (142/165) of errors were severity Category B (errors that did not reach the patient) according to the National Coordinating Council for Medication Error Reporting and Prevention Index for Categorizing Medication Errors. Nineteen errors reached the patient without causing harm (Category C); and 4 errors caused temporary harm requiring intervention (Category E). Errors involving strength were found in 30% of reports, including 23 prescriptions written for strengths not commercially available. Antidepressants, narcotics and antihypertensives were the most frequent drug classes reported. Participants completed an exit survey with a response rate of 84.5% (87/103). Nearly 90% (77/87) of respondents were willing to continue reporting after the study ended, however none of the participants currently submit reports. Nurses and office staff are a valuable resource for reporting prescribing errors. However, without ongoing reminders, the reporting system is not sustainable.

How do Community Pharmacies Recover from E-prescription Errors?

PubMed Central

Odukoya, Olufunmilola K.; Stone, Jamie A.; Chui, Michelle A.

2014-01-01

Background The use of e-prescribing is increasing annually, with over 788 million e-prescriptions received in US pharmacies in 2012. Approximately 9% of e-prescriptions have medication errors. Objective To describe the process used by community pharmacy staff to detect, explain, and correct e-prescription errors. Methods The error recovery conceptual framework was employed for data collection and analysis. 13 pharmacists and 14 technicians from five community pharmacies in Wisconsin participated in the study. A combination of data collection methods were utilized, including direct observations, interviews, and focus groups. The transcription and content analysis of recordings were guided by the three-step error recovery model. Results Most of the e-prescription errors were detected during the entering of information into the pharmacy system. These errors were detected by both pharmacists and technicians using a variety of strategies which included: (1) performing double checks of e-prescription information; (2) printing the e-prescription to paper and confirming the information on the computer screen with information from the paper printout; and (3) using colored pens to highlight important information. Strategies used for explaining errors included: (1) careful review of patient’ medication history; (2) pharmacist consultation with patients; (3) consultation with another pharmacy team member; and (4) use of online resources. In order to correct e-prescription errors, participants made educated guesses of the prescriber’s intent or contacted the prescriber via telephone or fax. When e-prescription errors were encountered in the community pharmacies, the primary goal of participants was to get the order right for patients by verifying the prescriber’s intent. Conclusion Pharmacists and technicians play an important role in preventing e-prescription errors through the detection of errors and the verification of prescribers’ intent. Future studies are needed to examine factors that facilitate or hinder recovery from e-prescription errors. PMID:24373898

Medication prescribing errors in the medical intensive care unit of Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia.

PubMed

Sada, Oumer; Melkie, Addisu; Shibeshi, Workineh

2015-09-16

Medication errors (MEs) are important problems in all hospitalized populations, especially in intensive care unit (ICU). Little is known about the prevalence of medication prescribing errors in the ICU of hospitals in Ethiopia. The aim of this study was to assess medication prescribing errors in the ICU of Tikur Anbessa Specialized Hospital using retrospective cross-sectional analysis of patient cards and medication charts. About 220 patient charts were reviewed with a total of 1311 patient-days, and 882 prescription episodes. 359 MEs were detected; with prevalence of 40 per 100 orders. Common prescribing errors were omission errors 154 (42.89%), 101 (28.13%) wrong combination, 48 (13.37%) wrong abbreviation, 30 (8.36%) wrong dose, wrong frequency 18 (5.01%) and wrong indications 8 (2.23%). The present study shows that medication errors are common in medical ICU of Tikur Anbessa Specialized Hospital. These results suggest future targets of prevention strategies to reduce the rate of medication error.

Review of medication errors that are new or likely to occur more frequently with electronic medication management systems.

PubMed

Van de Vreede, Melita; McGrath, Anne; de Clifford, Jan

2018-05-14

Objective. The aim of the present study was to identify and quantify medication errors reportedly related to electronic medication management systems (eMMS) and those considered likely to occur more frequently with eMMS. This included developing a new classification system relevant to eMMS errors. Methods. Eight Victorian hospitals with eMMS participated in a retrospective audit of reported medication incidents from their incident reporting databases between May and July 2014. Site-appointed project officers submitted deidentified incidents they deemed new or likely to occur more frequently due to eMMS, together with the Incident Severity Rating (ISR). The authors reviewed and classified incidents. Results. There were 5826 medication-related incidents reported. In total, 93 (47 prescribing errors, 46 administration errors) were identified as new or potentially related to eMMS. Only one ISR2 (moderate) and no ISR1 (severe or death) errors were reported, so harm to patients in this 3-month period was minimal. The most commonly reported error types were 'human factors' and 'unfamiliarity or training' (70%) and 'cross-encounter or hybrid system errors' (22%). Conclusions. Although the results suggest that the errors reported were of low severity, organisations must remain vigilant to the risk of new errors and avoid the assumption that eMMS is the panacea to all medication error issues. What is known about the topic? eMMS have been shown to reduce some types of medication errors, but it has been reported that some new medication errors have been identified and some are likely to occur more frequently with eMMS. There are few published Australian studies that have reported on medication error types that are likely to occur more frequently with eMMS in more than one organisation and that include administration and prescribing errors. What does this paper add? This paper includes a new simple classification system for eMMS that is useful and outlines the most commonly reported incident types and can inform organisations and vendors on possible eMMS improvements. The paper suggests a new classification system for eMMS medication errors. What are the implications for practitioners? The results of the present study will highlight to organisations the need for ongoing review of system design, refinement of workflow issues, staff education and training and reporting and monitoring of errors.

The impact of a closed‐loop electronic prescribing and administration system on prescribing errors, administration errors and staff time: a before‐and‐after study

PubMed Central

Franklin, Bryony Dean; O'Grady, Kara; Donyai, Parastou; Jacklin, Ann; Barber, Nick

2007-01-01

Objectives To assess the impact of a closed‐loop electronic prescribing, automated dispensing, barcode patient identification and electronic medication administration record (EMAR) system on prescribing and administration errors, confirmation of patient identity before administration, and staff time. Design, setting and participants Before‐and‐after study in a surgical ward of a teaching hospital, involving patients and staff of that ward. Intervention Closed‐loop electronic prescribing, automated dispensing, barcode patient identification and EMAR system. Main outcome measures Percentage of new medication orders with a prescribing error, percentage of doses with medication administration errors (MAEs) and percentage given without checking patient identity. Time spent prescribing and providing a ward pharmacy service. Nursing time on medication tasks. Results Prescribing errors were identified in 3.8% of 2450 medication orders pre‐intervention and 2.0% of 2353 orders afterwards (p<0.001; χ2 test). MAEs occurred in 7.0% of 1473 non‐intravenous doses pre‐intervention and 4.3% of 1139 afterwards (p = 0.005; χ2 test). Patient identity was not checked for 82.6% of 1344 doses pre‐intervention and 18.9% of 1291 afterwards (p<0.001; χ2 test). Medical staff required 15 s to prescribe a regular inpatient drug pre‐intervention and 39 s afterwards (p = 0.03; t test). Time spent providing a ward pharmacy service increased from 68 min to 98 min each weekday (p = 0.001; t test); 22% of drug charts were unavailable pre‐intervention. Time per drug administration round decreased from 50 min to 40 min (p = 0.006; t test); nursing time on medication tasks outside of drug rounds increased from 21.1% to 28.7% (p = 0.006; χ2 test). Conclusions A closed‐loop electronic prescribing, dispensing and barcode patient identification system reduced prescribing errors and MAEs, and increased confirmation of patient identity before administration. Time spent on medication‐related tasks increased. PMID:17693676

Safe prescribing: a titanic challenge

PubMed Central

Routledge, Philip A

2012-01-01

The challenge to achieve safe prescribing merits the adjective ‘titanic’. The organisational and human errors leading to poor prescribing (e.g. underprescribing, overprescribing, misprescribing or medication errors) have parallels in the organisational and human errors that led to the loss of the Titanic 100 years ago this year. Prescribing can be adversely affected by communication failures, critical conditions, complacency, corner cutting, callowness and a lack of courage of conviction, all of which were also factors leading to the Titanic tragedy. These issues need to be addressed by a commitment to excellence, the final component of the ‘Seven C's’. Optimal prescribing is dependent upon close communication and collaborative working between highly trained health professionals, whose role is to ensure maximum clinical effectiveness, whilst also protecting their patients from avoidable harm. Since humans are prone to error, and the environments in which they work are imperfect, it is not surprising that medication errors are common, occurring more often during the prescribing stage than during dispensing or administration. A commitment to excellence in prescribing includes a continued focus on lifelong learning (including interprofessional learning) in pharmacology and therapeutics. This should be accompanied by improvements in the clinical working environment of prescribers, and the encouragement of a strong safety culture (including reporting of adverse incidents as well as suspected adverse drug reactions whenever appropriate). Finally, members of the clinical team must be prepared to challenge each other, when necessary, to ensure that prescribing combines the highest likelihood of benefit with the lowest potential for harm. PMID:22738396

What are incident reports telling us? A comparative study at two Australian hospitals of medication errors identified at audit, detected by staff and reported to an incident system.

PubMed

Westbrook, Johanna I; Li, Ling; Lehnbom, Elin C; Baysari, Melissa T; Braithwaite, Jeffrey; Burke, Rosemary; Conn, Chris; Day, Richard O

2015-02-01

To (i) compare medication errors identified at audit and observation with medication incident reports; (ii) identify differences between two hospitals in incident report frequency and medication error rates; (iii) identify prescribing error detection rates by staff. Audit of 3291 patient records at two hospitals to identify prescribing errors and evidence of their detection by staff. Medication administration errors were identified from a direct observational study of 180 nurses administering 7451 medications. Severity of errors was classified. Those likely to lead to patient harm were categorized as 'clinically important'. Two major academic teaching hospitals in Sydney, Australia. Rates of medication errors identified from audit and from direct observation were compared with reported medication incident reports. A total of 12 567 prescribing errors were identified at audit. Of these 1.2/1000 errors (95% CI: 0.6-1.8) had incident reports. Clinically important prescribing errors (n = 539) were detected by staff at a rate of 218.9/1000 (95% CI: 184.0-253.8), but only 13.0/1000 (95% CI: 3.4-22.5) were reported. 78.1% (n = 421) of clinically important prescribing errors were not detected. A total of 2043 drug administrations (27.4%; 95% CI: 26.4-28.4%) contained ≥ 1 errors; none had an incident report. Hospital A had a higher frequency of incident reports than Hospital B, but a lower rate of errors at audit. Prescribing errors with the potential to cause harm frequently go undetected. Reported incidents do not reflect the profile of medication errors which occur in hospitals or the underlying rates. This demonstrates the inaccuracy of using incident frequency to compare patient risk or quality performance within or across hospitals. New approaches including data mining of electronic clinical information systems are required to support more effective medication error detection and mitigation. © The Author 2015. Published by Oxford University Press in association with the International Society for Quality in Health Care.

A Novel Design for Drug-Drug Interaction Alerts Improves Prescribing Efficiency.

PubMed

Russ, Alissa L; Chen, Siying; Melton, Brittany L; Johnson, Elizabette G; Spina, Jeffrey R; Weiner, Michael; Zillich, Alan J

2015-09-01

Drug-drug interactions (DDIs) are common in clinical care and pose serious risks for patients. Electronic health records display DDI alerts that can influence prescribers, but the interface design of DDI alerts has largely been unstudied. In this study, the objective was to apply human factors engineering principles to alert design. It was hypothesized that redesigned DDI alerts would significantly improve prescribers' efficiency and reduce prescribing errors. In a counterbalanced, crossover study with prescribers, two DDI alert designs were evaluated. Department of Veterans Affairs (VA) prescribers were video recorded as they completed fictitious patient scenarios, which included DDI alerts of varying severity. Efficiency was measured from time-stamped recordings. Prescribing errors were evaluated against predefined criteria. Efficiency and prescribing errors were analyzed with the Wilcoxon signed-rank test. Other usability data were collected on the adequacy of alert content, prescribers' use of the DDI monograph, and alert navigation. Twenty prescribers completed patient scenarios for both designs. Prescribers resolved redesigned alerts in about half the time (redesign: 52 seconds versus original design: 97 seconds; p<.001). Prescribing errors were not significantly different between the two designs. Usability results indicate that DDI alerts might be enhanced by facilitating easier access to laboratory data and dosing information and by allowing prescribers to cancel either interacting medication directly from the alert. Results also suggest that neither design provided adequate information for decision making via the primary interface. Applying human factors principles to DDI alerts improved overall efficiency. Aspects of DDI alert design that could be further enhanced prior to implementation were also identified.

Clinical Errors and Medical Negligence

PubMed Central

Oyebode, Femi

2013-01-01

This paper discusses the definition, nature and origins of clinical errors including their prevention. The relationship between clinical errors and medical negligence is examined as are the characteristics of litigants and events that are the source of litigation. The pattern of malpractice claims in different specialties and settings is examined. Among hospitalized patients worldwide, 3–16s% suffer injury as a result of medical intervention, the most common being the adverse effects of drugs. The frequency of adverse drug effects appears superficially to be higher in intensive care units and emergency departments but once rates have been corrected for volume of patients, comorbidity of conditions and number of drugs prescribed, the difference is not significant. It is concluded that probably no more than 1 in 7 adverse events in medicine result in a malpractice claim and the factors that predict that a patient will resort to litigation include a prior poor relationship with the clinician and the feeling that the patient is not being kept informed. Methods for preventing clinical errors are still in their infancy. The most promising include new technologies such as electronic prescribing systems, diagnostic and clinical decision-making aids and error-resistant systems. PMID:23343656

Clinical errors and medical negligence.

PubMed

Oyebode, Femi

2013-01-01

This paper discusses the definition, nature and origins of clinical errors including their prevention. The relationship between clinical errors and medical negligence is examined as are the characteristics of litigants and events that are the source of litigation. The pattern of malpractice claims in different specialties and settings is examined. Among hospitalized patients worldwide, 3-16% suffer injury as a result of medical intervention, the most common being the adverse effects of drugs. The frequency of adverse drug effects appears superficially to be higher in intensive care units and emergency departments but once rates have been corrected for volume of patients, comorbidity of conditions and number of drugs prescribed, the difference is not significant. It is concluded that probably no more than 1 in 7 adverse events in medicine result in a malpractice claim and the factors that predict that a patient will resort to litigation include a prior poor relationship with the clinician and the feeling that the patient is not being kept informed. Methods for preventing clinical errors are still in their infancy. The most promising include new technologies such as electronic prescribing systems, diagnostic and clinical decision-making aids and error-resistant systems. Copyright © 2013 S. Karger AG, Basel.

H∞ state estimation of stochastic memristor-based neural networks with time-varying delays.

PubMed

Bao, Haibo; Cao, Jinde; Kurths, Jürgen; Alsaedi, Ahmed; Ahmad, Bashir

2018-03-01

This paper addresses the problem of H ∞ state estimation for a class of stochastic memristor-based neural networks with time-varying delays. Under the framework of Filippov solution, the stochastic memristor-based neural networks are transformed into systems with interval parameters. The present paper is the first to investigate the H ∞ state estimation problem for continuous-time Itô-type stochastic memristor-based neural networks. By means of Lyapunov functionals and some stochastic technique, sufficient conditions are derived to ensure that the estimation error system is asymptotically stable in the mean square with a prescribed H ∞ performance. An explicit expression of the state estimator gain is given in terms of linear matrix inequalities (LMIs). Compared with other results, our results reduce control gain and control cost effectively. Finally, numerical simulations are provided to demonstrate the efficiency of the theoretical results. Copyright © 2018 Elsevier Ltd. All rights reserved.

Which non-technical skills do junior doctors require to prescribe safely? A systematic review.

PubMed

Dearden, Effie; Mellanby, Edward; Cameron, Helen; Harden, Jeni

2015-12-01

Prescribing errors are a major source of avoidable morbidity and mortality. Junior doctors write most in-hospital prescriptions and are the least experienced members of the healthcare team. This puts them at high risk of error and makes them attractive targets for interventions to improve prescription safety. Error analysis has shown a background of complex environments with multiple contributory conditions. Similar conditions in other high risk industries, such as aviation, have led to an increased understanding of so-called human factors and the use of non-technical skills (NTS) training to try to reduce error. To date no research has examined the NTS required for safe prescribing. The aim of this review was to develop a prototype NTS taxonomy for safe prescribing, by junior doctors, in hospital settings. A systematic search identified 14 studies analyzing prescribing behaviours and errors by junior doctors. Framework analysis was used to extract data from the studies and identify behaviours related to categories of NTS that might be relevant to safe and effective prescribing performance by junior doctors. Categories were derived from existing literature and inductively from the data. A prototype taxonomy of relevant categories (situational awareness, decision making, communication and team working, and task management) and elements was constructed. This prototype will form the basis of future work to create a tool that can be used for training and assessment of medical students and junior doctors to reduce prescribing error in the future. © 2015 The British Pharmacological Society.

Outpatient CPOE orders discontinued due to 'erroneous entry': prospective survey of prescribers' explanations for errors.

PubMed

Hickman, Thu-Trang T; Quist, Arbor Jessica Lauren; Salazar, Alejandra; Amato, Mary G; Wright, Adam; Volk, Lynn A; Bates, David W; Schiff, Gordon

2018-04-01

Computerised prescriber order entry (CPOE) systems users often discontinue medications because the initial order was erroneous. To elucidate error types by querying prescribers about their reasons for discontinuing outpatient medication orders that they had self-identified as erroneous. During a nearly 3 year retrospective data collection period, we identified 57 972 drugs discontinued with the reason 'Error (erroneous entry)." Because chart reviews revealed limited information about these errors, we prospectively studied consecutive, discontinued erroneous orders by querying prescribers in near-real-time to learn more about the erroneous orders. From January 2014 to April 2014, we prospectively emailed prescribers about outpatient drug orders that they had discontinued due to erroneous initial order entry. Of 2 50 806 medication orders in these 4 months, 1133 (0.45%) of these were discontinued due to error. From these 1133, we emailed 542 unique prescribers to ask about their reason(s) for discontinuing these mediation orders in error. We received 312 responses (58% response rate). We categorised these responses using a previously published taxonomy. The top reasons for these discontinued erroneous orders included: medication ordered for wrong patient (27.8%, n=60); wrong drug ordered (18.5%, n=40); and duplicate order placed (14.4%, n=31). Other common discontinued erroneous orders related to drug dosage and formulation (eg, extended release versus not). Oxycodone (3%) was the most frequent drug discontinued error. Drugs are not infrequently discontinued 'in error.' Wrong patient and wrong drug errors constitute the leading types of erroneous prescriptions recognised and discontinued by prescribers. Data regarding erroneous medication entries represent an important source of intelligence about how CPOE systems are functioning and malfunctioning, providing important insights regarding areas for designing CPOE more safely in the future. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Safe prescribing: a titanic challenge.

PubMed

Routledge, Philip A

2012-10-01

The challenge to achieve safe prescribing merits the adjective 'titanic'. The organisational and human errors leading to poor prescribing (e.g. underprescribing, overprescribing, misprescribing or medication errors) have parallels in the organisational and human errors that led to the loss of the Titanic 100 years ago this year. Prescribing can be adversely affected by communication failures, critical conditions, complacency, corner cutting, callowness and a lack of courage of conviction, all of which were also factors leading to the Titanic tragedy. These issues need to be addressed by a commitment to excellence, the final component of the 'Seven C's'. Optimal prescribing is dependent upon close communication and collaborative working between highly trained health professionals, whose role is to ensure maximum clinical effectiveness, whilst also protecting their patients from avoidable harm. Since humans are prone to error, and the environments in which they work are imperfect, it is not surprising that medication errors are common, occurring more often during the prescribing stage than during dispensing or administration. A commitment to excellence in prescribing includes a continued focus on lifelong learning (including interprofessional learning) in pharmacology and therapeutics. This should be accompanied by improvements in the clinical working environment of prescribers, and the encouragement of a strong safety culture (including reporting of adverse incidents as well as suspected adverse drug reactions whenever appropriate). Finally, members of the clinical team must be prepared to challenge each other, when necessary, to ensure that prescribing combines the highest likelihood of benefit with the lowest potential for harm. © 2012 The Author. British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society.

Unit of Measurement Used and Parent Medication Dosing Errors

PubMed Central

Dreyer, Benard P.; Ugboaja, Donna C.; Sanchez, Dayana C.; Paul, Ian M.; Moreira, Hannah A.; Rodriguez, Luis; Mendelsohn, Alan L.

2014-01-01

BACKGROUND AND OBJECTIVES: Adopting the milliliter as the preferred unit of measurement has been suggested as a strategy to improve the clarity of medication instructions; teaspoon and tablespoon units may inadvertently endorse nonstandard kitchen spoon use. We examined the association between unit used and parent medication errors and whether nonstandard instruments mediate this relationship. METHODS: Cross-sectional analysis of baseline data from a larger study of provider communication and medication errors. English- or Spanish-speaking parents (n = 287) whose children were prescribed liquid medications in 2 emergency departments were enrolled. Medication error defined as: error in knowledge of prescribed dose, error in observed dose measurement (compared to intended or prescribed dose); >20% deviation threshold for error. Multiple logistic regression performed adjusting for parent age, language, country, race/ethnicity, socioeconomic status, education, health literacy (Short Test of Functional Health Literacy in Adults); child age, chronic disease; site. RESULTS: Medication errors were common: 39.4% of parents made an error in measurement of the intended dose, 41.1% made an error in the prescribed dose. Furthermore, 16.7% used a nonstandard instrument. Compared with parents who used milliliter-only, parents who used teaspoon or tablespoon units had twice the odds of making an error with the intended (42.5% vs 27.6%, P = .02; adjusted odds ratio=2.3; 95% confidence interval, 1.2–4.4) and prescribed (45.1% vs 31.4%, P = .04; adjusted odds ratio=1.9; 95% confidence interval, 1.03–3.5) dose; associations greater for parents with low health literacy and non–English speakers. Nonstandard instrument use partially mediated teaspoon and tablespoon–associated measurement errors. CONCLUSIONS: Findings support a milliliter-only standard to reduce medication errors. PMID:25022742

Unit of measurement used and parent medication dosing errors.

PubMed

Yin, H Shonna; Dreyer, Benard P; Ugboaja, Donna C; Sanchez, Dayana C; Paul, Ian M; Moreira, Hannah A; Rodriguez, Luis; Mendelsohn, Alan L

2014-08-01

Adopting the milliliter as the preferred unit of measurement has been suggested as a strategy to improve the clarity of medication instructions; teaspoon and tablespoon units may inadvertently endorse nonstandard kitchen spoon use. We examined the association between unit used and parent medication errors and whether nonstandard instruments mediate this relationship. Cross-sectional analysis of baseline data from a larger study of provider communication and medication errors. English- or Spanish-speaking parents (n = 287) whose children were prescribed liquid medications in 2 emergency departments were enrolled. Medication error defined as: error in knowledge of prescribed dose, error in observed dose measurement (compared to intended or prescribed dose); >20% deviation threshold for error. Multiple logistic regression performed adjusting for parent age, language, country, race/ethnicity, socioeconomic status, education, health literacy (Short Test of Functional Health Literacy in Adults); child age, chronic disease; site. Medication errors were common: 39.4% of parents made an error in measurement of the intended dose, 41.1% made an error in the prescribed dose. Furthermore, 16.7% used a nonstandard instrument. Compared with parents who used milliliter-only, parents who used teaspoon or tablespoon units had twice the odds of making an error with the intended (42.5% vs 27.6%, P = .02; adjusted odds ratio=2.3; 95% confidence interval, 1.2-4.4) and prescribed (45.1% vs 31.4%, P = .04; adjusted odds ratio=1.9; 95% confidence interval, 1.03-3.5) dose; associations greater for parents with low health literacy and non-English speakers. Nonstandard instrument use partially mediated teaspoon and tablespoon-associated measurement errors. Findings support a milliliter-only standard to reduce medication errors. Copyright © 2014 by the American Academy of Pediatrics.

Improved characterisation of measurement errors in electrical resistivity tomography (ERT) surveys

NASA Astrophysics Data System (ADS)

Tso, C. H. M.; Binley, A. M.; Kuras, O.; Graham, J.

2016-12-01

Measurement errors can play a pivotal role in geophysical inversion. Most inverse models require users to prescribe a statistical model of data errors before inversion. Wrongly prescribed error levels can lead to over- or under-fitting of data, yet commonly used models of measurement error are relatively simplistic. With the heightening interests in uncertainty estimation across hydrogeophysics, better characterisation and treatment of measurement errors is needed to provide more reliable estimates of uncertainty. We have analysed two time-lapse electrical resistivity tomography (ERT) datasets; one contains 96 sets of direct and reciprocal data collected from a surface ERT line within a 24h timeframe, while the other is a year-long cross-borehole survey at a UK nuclear site with over 50,000 daily measurements. Our study included the characterisation of the spatial and temporal behaviour of measurement errors using autocorrelation and covariance analysis. We find that, in addition to well-known proportionality effects, ERT measurements can also be sensitive to the combination of electrodes used. This agrees with reported speculation in previous literature that ERT errors could be somewhat correlated. Based on these findings, we develop a new error model that allows grouping based on electrode number in additional to fitting a linear model to transfer resistance. The new model fits the observed measurement errors better and shows superior inversion and uncertainty estimates in synthetic examples. It is robust, because it groups errors together based on the number of the four electrodes used to make each measurement. The new model can be readily applied to the diagonal data weighting matrix commonly used in classical inversion methods, as well as to the data covariance matrix in the Bayesian inversion framework. We demonstrate its application using extensive ERT monitoring datasets from the two aforementioned sites.

Pharmacists' interventions in prescribing errors at hospital discharge: an observational study in the context of an electronic prescribing system in a UK teaching hospital.

PubMed

Abdel-Qader, Derar H; Harper, Lindsay; Cantrill, Judith A; Tully, Mary P

2010-11-01

Pharmacists have an essential role in improving drug usage and preventing prescribing errors (PEs). PEs at the interface of care are common, sometimes leading to adverse drug events (ADEs). This was the first study to investigate, using a computerized search method, the number, types, severity, pharmacists' impact on PEs and predictors of PEs in the context of electronic prescribing (e-prescribing) at hospital discharge. This was a retrospective, observational, 4-week study, carried out in 2008 in the Medical and Elderly Care wards of a 904-bed teaching hospital in the northwest of England, operating an e-prescribing system at discharge. Details were obtained, using a systematic computerized search of the system, of medication orders either entered by doctors and discontinued by pharmacists or entered by pharmacists. Meetings were conducted within 5 days of data extraction with pharmacists doing their routine clinical work, who categorized the occurrence, type and severity of their interventions using a scale. An independent senior pharmacist retrospectively rated the severity and potential impact, and subjectively judged, based on experience, whether any error was a computer-related error (CRE). Discrepancies were resolved by multidisciplinary discussion. The Statistical Package for Social Sciences was used for descriptive data analysis. For the PE predictors, a multivariate logistic regression was performed using STATA 7. Nine predictors were selected a priori from available prescribers', patients' and drug data. There were 7920 medication orders entered for 1038 patients (doctors entered 7712 orders; pharmacists entered 208 omitted orders). There were 675 (8.5% of 7920) interventions by pharmacists; 11 were not associated with PEs. Incidences of erroneous orders and patients with error were 8.0% (95% CI 7.4, 8.5 [n = 630/7920]) and 20.4% (95% CI 18.1, 22.9 [n = 212/1038]), respectively. The PE incidence was 8.4% (95% CI 7.8, 9.0 [n = 664/7920]). The top three medications associated with PEs were paracetamol (acetaminophen; 30 [4.8%]), salbutamol (albuterol; 28 [4.4%]) and omeprazole (25 [4.0%]). Pharmacists intercepted 524 (83.2%) erroneous orders without referring to doctors, and 70% of erroneous orders within 24 hours. Omission (31.0%), drug selection (29.4%) and dosage regimen (18.1%) error types accounted for >75% of PEs. There were 18 (2.9%) serious, 481 (76.3%) significant and 131 (20.8%) minor erroneous orders. Most erroneous orders (469 [74.4%]) were rated as of significant severity and significant impact of pharmacists on PEs. CREs (n = 279) accounted for 44.3% of erroneous orders. There was a significant difference in severity between CREs and non-CREs (χ2 = 38.88; df = 4; p < 0.001), with CREs being less severe than non-CREs. Drugs with multiple oral formulations (odds ratio [OR] 2.1; 95% CI 1.25, 3.37; p = 0.004) and prescribing by junior doctors (OR 2.54; 95% CI 1.08, 5.99; p = 0.03) were significant predictors of PEs. PEs commonly occur at hospital discharge, even with the use of an e-prescribing system. User and computer factors both appeared to contribute to the high error rate. The e-prescribing system facilitated the systematic extraction of data to investigate PEs in hospital practice. Pharmacists play an important role in rapidly documenting and preventing PEs before they reach and possibly harm patients. Pharmacists should understand CREs, so they complement, rather than duplicate, the e-prescribing system's strengths.

Barriers and facilitators to recovering from e-prescribing errors in community pharmacies.

PubMed

Odukoya, Olufunmilola K; Stone, Jamie A; Chui, Michelle A

2015-01-01

To explore barriers and facilitators to recovery from e-prescribing errors in community pharmacies and to explore practical solutions for work system redesign to ensure successful recovery from errors. Cross-sectional qualitative design using direct observations, interviews, and focus groups. Five community pharmacies in Wisconsin. 13 pharmacists and 14 pharmacy technicians. Observational field notes and transcribed interviews and focus groups were subjected to thematic analysis guided by the Systems Engineering Initiative for Patient Safety (SEIPS) work system and patient safety model. Barriers and facilitators to recovering from e-prescription errors in community pharmacies. Organizational factors, such as communication, training, teamwork, and staffing levels, play an important role in recovering from e-prescription errors. Other factors that could positively or negatively affect recovery of e-prescription errors include level of experience, knowledge of the pharmacy personnel, availability or usability of tools and technology, interruptions and time pressure when performing tasks, and noise in the physical environment. The SEIPS model sheds light on key factors that may influence recovery from e-prescribing errors in pharmacies, including the environment, teamwork, communication, technology, tasks, and other organizational variables. To be successful in recovering from e-prescribing errors, pharmacies must provide the appropriate working conditions that support recovery from errors.

Unrealized potential and residual consequences of electronic prescribing on pharmacy workflow in the outpatient pharmacy.

PubMed

Nanji, Karen C; Rothschild, Jeffrey M; Boehne, Jennifer J; Keohane, Carol A; Ash, Joan S; Poon, Eric G

2014-01-01

Electronic prescribing systems have often been promoted as a tool for reducing medication errors and adverse drug events. Recent evidence has revealed that adoption of electronic prescribing systems can lead to unintended consequences such as the introduction of new errors. The purpose of this study is to identify and characterize the unrealized potential and residual consequences of electronic prescribing on pharmacy workflow in an outpatient pharmacy. A multidisciplinary team conducted direct observations of workflow in an independent pharmacy and semi-structured interviews with pharmacy staff members about their perceptions of the unrealized potential and residual consequences of electronic prescribing systems. We used qualitative methods to iteratively analyze text data using a grounded theory approach, and derive a list of major themes and subthemes related to the unrealized potential and residual consequences of electronic prescribing. We identified the following five themes: Communication, workflow disruption, cost, technology, and opportunity for new errors. These contained 26 unique subthemes representing different facets of our observations and the pharmacy staff's perceptions of the unrealized potential and residual consequences of electronic prescribing. We offer targeted solutions to improve electronic prescribing systems by addressing the unrealized potential and residual consequences that we identified. These recommendations may be applied not only to improve staff perceptions of electronic prescribing systems but also to improve the design and/or selection of these systems in order to optimize communication and workflow within pharmacies while minimizing both cost and the potential for the introduction of new errors.

Design of materials with prescribed nonlinear properties

NASA Astrophysics Data System (ADS)

Wang, F.; Sigmund, O.; Jensen, J. S.

2014-09-01

We systematically design materials using topology optimization to achieve prescribed nonlinear properties under finite deformation. Instead of a formal homogenization procedure, a numerical experiment is proposed to evaluate the material performance in longitudinal and transverse tensile tests under finite deformation, i.e. stress-strain relations and Poissons ratio. By minimizing errors between actual and prescribed properties, materials are tailored to achieve the target. Both two dimensional (2D) truss-based and continuum materials are designed with various prescribed nonlinear properties. The numerical examples illustrate optimized materials with rubber-like behavior and also optimized materials with extreme strain-independent Poissons ratio for axial strain intervals of εi∈[0.00, 0.30].

Using E-Learning to Improve Prescribing Practice in Emerging Prescribers

ERIC Educational Resources Information Center

Baskett, Karen

2011-01-01

This paper reports on "The National Prescribing Curriculum" (NPC), a series of online, case-based modules designed to improve prescribing performance and confidence in emerging Australian prescribers. The modules mirror the decision-making process outlined in the "WHO Guide to Good Prescribing" (de Vries "et al.",…

Computations of Aerodynamic Performance Databases Using Output-Based Refinement

NASA Technical Reports Server (NTRS)

Nemec, Marian; Aftosmis, Michael J.

2009-01-01

Objectives: Handle complex geometry problems; Control discretization errors via solution-adaptive mesh refinement; Focus on aerodynamic databases of parametric and optimization studies: 1. Accuracy: satisfy prescribed error bounds 2. Robustness and speed: may require over 105 mesh generations 3. Automation: avoid user supervision Obtain "expert meshes" independent of user skill; and Run every case adaptively in production settings.

Prescribed-performance fault-tolerant control for feedback linearisable systems with an aircraft application

NASA Astrophysics Data System (ADS)

Gao, Gang; Wang, Jinzhi; Wang, Xianghua

2017-05-01

This paper investigates fault-tolerant control (FTC) for feedback linearisable systems (FLSs) and its application to an aircraft. To ensure desired transient and steady-state behaviours of the tracking error under actuator faults, the dynamic effect caused by the actuator failures on the error dynamics of a transformed model is analysed, and three control strategies are designed. The first FTC strategy is proposed as a robust controller, which relies on the explicit information about several parameters of the actuator faults. To eliminate the need for these parameters and the input chattering phenomenon, the robust control law is later combined with the adaptive technique to generate the adaptive FTC law. Next, the adaptive control law is further improved to achieve the prescribed performance under more severe input disturbance. Finally, the proposed control laws are applied to an air-breathing hypersonic vehicle (AHV) subject to actuator failures, which confirms the effectiveness of the proposed strategies.

A long-term follow-up evaluation of electronic health record prescribing safety

PubMed Central

Abramson, Erika L; Malhotra, Sameer; Osorio, S Nena; Edwards, Alison; Cheriff, Adam; Cole, Curtis; Kaushal, Rainu

2013-01-01

Objective To be eligible for incentives through the Electronic Health Record (EHR) Incentive Program, many providers using older or locally developed EHRs will be transitioning to new, commercial EHRs. We previously evaluated prescribing errors made by providers in the first year following transition from a locally developed EHR with minimal prescribing clinical decision support (CDS) to a commercial EHR with robust CDS. Following system refinements, we conducted this study to assess the rates and types of errors 2 years after transition and determine the evolution of errors. Materials and methods We conducted a mixed methods cross-sectional case study of 16 physicians at an academic-affiliated ambulatory clinic from April to June 2010. We utilized standardized prescription and chart review to identify errors. Fourteen providers also participated in interviews. Results We analyzed 1905 prescriptions. The overall prescribing error rate was 3.8 per 100 prescriptions (95% CI 2.8 to 5.1). Error rates were significantly lower 2 years after transition (p<0.001 compared to pre-implementation, 12 weeks and 1 year after transition). Rates of near misses remained unchanged. Providers positively appreciated most system refinements, particularly reduced alert firing. Discussion Our study suggests that over time and with system refinements, use of a commercial EHR with advanced CDS can lead to low prescribing error rates, although more serious errors may require targeted interventions to eliminate them. Reducing alert firing frequency appears particularly important. Our results provide support for federal efforts promoting meaningful use of EHRs. Conclusions Ongoing error monitoring can allow CDS to be optimally tailored and help achieve maximal safety benefits. Clinical Trials Registration ClinicalTrials.gov, Identifier: NCT00603070. PMID:23578816

Adaptive control of nonlinear uncertain active suspension systems with prescribed performance.

PubMed

Huang, Yingbo; Na, Jing; Wu, Xing; Liu, Xiaoqin; Guo, Yu

2015-01-01

This paper proposes adaptive control designs for vehicle active suspension systems with unknown nonlinear dynamics (e.g., nonlinear spring and piece-wise linear damper dynamics). An adaptive control is first proposed to stabilize the vertical vehicle displacement and thus to improve the ride comfort and to guarantee other suspension requirements (e.g., road holding and suspension space limitation) concerning the vehicle safety and mechanical constraints. An augmented neural network is developed to online compensate for the unknown nonlinearities, and a novel adaptive law is developed to estimate both NN weights and uncertain model parameters (e.g., sprung mass), where the parameter estimation error is used as a leakage term superimposed on the classical adaptations. To further improve the control performance and simplify the parameter tuning, a prescribed performance function (PPF) characterizing the error convergence rate, maximum overshoot and steady-state error is used to propose another adaptive control. The stability for the closed-loop system is proved and particular performance requirements are analyzed. Simulations are included to illustrate the effectiveness of the proposed control schemes. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Prescribing and formulating neonatal intravenous feeding solutions by microcomputer.

PubMed Central

MacMahon, P

1984-01-01

This paper describes a computer programme for a low cost microcomputer designed to assist in the task of administering total parenteral nutrition to neonates: no knowledge of computers is necessary to operate the system. The programme displays recommended values for each of the total parenteral nutrition constituents that must be prescribed, based on detailed analysis of all the pertinent variables. The recommended values may be rejected but they do provide a useful prompt, especially for the more junior doctors. The programme includes a number of safeguards that protect against entering potentially dangerous values. As soon as the operator has completed the procedure of entering total parenteral nutrition requirements the calculations necessary to formulate a solution containing these are automatically performed. The print out contains this data plus instructions on the infusion rate and an analysis of the formulation's calorific content. This system makes it easier to vary the quantity of individual total parenteral nutrition constituents and time has been saved which was previously wasted performing laborious calculations. One of the most important contributions has been the virtual elimination of errors in the complex task of prescribing and formulating total parenteral nutrition for sick neonates. PMID:6430246

Fuzzy Adaptive Output Feedback Control of Uncertain Nonlinear Systems With Prescribed Performance.

PubMed

Zhang, Jin-Xi; Yang, Guang-Hong

2018-05-01

This paper investigates the tracking control problem for a family of strict-feedback systems in the presence of unknown nonlinearities and immeasurable system states. A low-complexity adaptive fuzzy output feedback control scheme is proposed, based on a backstepping method. In the control design, a fuzzy adaptive state observer is first employed to estimate the unmeasured states. Then, a novel error transformation approach together with a new modification mechanism is introduced to guarantee the finite-time convergence of the output error to a predefined region and ensure the closed-loop stability. Compared with the existing methods, the main advantages of our approach are that: 1) without using extra command filters or auxiliary dynamic surface control techniques, the problem of explosion of complexity can still be addressed and 2) the design procedures are independent of the initial conditions. Finally, two practical examples are performed to further illustrate the above theoretic findings.

Improved characterisation and modelling of measurement errors in electrical resistivity tomography (ERT) surveys

NASA Astrophysics Data System (ADS)

Tso, Chak-Hau Michael; Kuras, Oliver; Wilkinson, Paul B.; Uhlemann, Sebastian; Chambers, Jonathan E.; Meldrum, Philip I.; Graham, James; Sherlock, Emma F.; Binley, Andrew

2017-11-01

Measurement errors can play a pivotal role in geophysical inversion. Most inverse models require users to prescribe or assume a statistical model of data errors before inversion. Wrongly prescribed errors can lead to over- or under-fitting of data; however, the derivation of models of data errors is often neglected. With the heightening interest in uncertainty estimation within hydrogeophysics, better characterisation and treatment of measurement errors is needed to provide improved image appraisal. Here we focus on the role of measurement errors in electrical resistivity tomography (ERT). We have analysed two time-lapse ERT datasets: one contains 96 sets of direct and reciprocal data collected from a surface ERT line within a 24 h timeframe; the other is a two-year-long cross-borehole survey at a UK nuclear site with 246 sets of over 50,000 measurements. Our study includes the characterisation of the spatial and temporal behaviour of measurement errors using autocorrelation and correlation coefficient analysis. We find that, in addition to well-known proportionality effects, ERT measurements can also be sensitive to the combination of electrodes used, i.e. errors may not be uncorrelated as often assumed. Based on these findings, we develop a new error model that allows grouping based on electrode number in addition to fitting a linear model to transfer resistance. The new model explains the observed measurement errors better and shows superior inversion results and uncertainty estimates in synthetic examples. It is robust, because it groups errors together based on the electrodes used to make the measurements. The new model can be readily applied to the diagonal data weighting matrix widely used in common inversion methods, as well as to the data covariance matrix in a Bayesian inversion framework. We demonstrate its application using extensive ERT monitoring datasets from the two aforementioned sites.

CPOE in Iran--a viable prospect? Physicians' opinions on using CPOE in an Iranian teaching hospital.

PubMed

Kazemi, Alireza; Ellenius, Johan; Tofighi, Shahram; Salehi, Aref; Eghbalian, Fatemeh; Fors, Uno G

2009-03-01

In recent years, the theory that on-line clinical decision support systems can improve patients' safety among hospitalised individuals has gained greater acceptance. However, the feasibility of implementing such a system in a middle or low-income country has rarely been studied. Understanding the current prescription process and a proper needs assessment of prescribers can act as the key to successful implementation. The aim of this study was to explore physicians' opinions on the current prescription process, and the expected benefits and perceived obstacles to employ Computerised Physician Order Entry in an Iranian teaching hospital. Initially, the interview guideline was developed through focus group discussions with eight experts. Then semi-structured interviews were held with 19 prescribers. After verbatim transcription, inductive thematic analysis was performed on empirical data. Forty hours of on-looker observations were performed in different wards to explore the current prescription process. The current prescription process was identified as a physician-centred, top-down, model, where prescribers were found to mostly rely on their memories as well as being overconfident. Some errors may occur during different paper-based registrations, transcriptions and transfers. Physician opinions on Computerised Physician Order Entry were categorised into expected benefits and perceived obstacles. Confidentiality issues, reduction of medication errors and educational benefits were identified as three themes in the expected benefits category. High cost, social and cultural barriers, data entry time and problems with technical support emerged as four themes in the perceived obstacles category. The current prescription process has a high possibility of medication errors. Although there are different barriers confronting the implementation and continuation of Computerised Physician Order Entry in Iranian hospitals, physicians have a willingness to use them if these systems provide significant benefits. A pilot study in a limited setting and a comprehensive analysis of health outcomes and economic indicators should be performed, to assess the merits of introducing Computerised Physician Order Entry with decision support capabilities in Iran.

Standardized Competencies for Parenteral Nutrition Prescribing: The American Society for Parenteral and Enteral Nutrition Model.

PubMed

Guenter, Peggi; Boullata, Joseph I; Ayers, Phil; Gervasio, Jane; Malone, Ainsley; Raymond, Erica; Holcombe, Beverly; Kraft, Michael; Sacks, Gordon; Seres, David

2015-08-01

Parenteral nutrition (PN) provision is complex, as it is a high-alert medication and prone to a variety of potential errors. With changes in clinical practice models and recent federal rulings, the number of PN prescribers may be increasing. Safe prescribing of this therapy requires that competency for prescribers from all disciplines be demonstrated using a standardized process. A standardized model for PN prescribing competency is proposed based on a competency framework, the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.)-published interdisciplinary core competencies, safe practice recommendations, and clinical guidelines. This framework will guide institutions and agencies in developing and maintaining competency for safe PN prescription by their staff. © 2015 American Society for Parenteral and Enteral Nutrition.

Homogenous polynomially parameter-dependent H∞ filter designs of discrete-time fuzzy systems.

PubMed

Zhang, Huaguang; Xie, Xiangpeng; Tong, Shaocheng

2011-10-01

This paper proposes a novel H(∞) filtering technique for a class of discrete-time fuzzy systems. First, a novel kind of fuzzy H(∞) filter, which is homogenous polynomially parameter dependent on membership functions with an arbitrary degree, is developed to guarantee the asymptotic stability and a prescribed H(∞) performance of the filtering error system. Second, relaxed conditions for H(∞) performance analysis are proposed by using a new fuzzy Lyapunov function and the Finsler lemma with homogenous polynomial matrix Lagrange multipliers. Then, based on a new kind of slack variable technique, relaxed linear matrix inequality-based H(∞) filtering conditions are proposed. Finally, two numerical examples are provided to illustrate the effectiveness of the proposed approach.

Prescribing error at hospital discharge: a retrospective review of medication information in an Irish hospital.

PubMed

Michaelson, M; Walsh, E; Bradley, C P; McCague, P; Owens, R; Sahm, L J

2017-08-01

Prescribing error may result in adverse clinical outcomes leading to increased patient morbidity, mortality and increased economic burden. Many errors occur during transitional care as patients move between different stages and settings of care. To conduct a review of medication information and identify prescribing error among an adult population in an urban hospital. Retrospective review of medication information was conducted. Part 1: an audit of discharge prescriptions which assessed: legibility, compliance with legal requirements, therapeutic errors (strength, dose and frequency) and drug interactions. Part 2: A review of all sources of medication information (namely pre-admission medication list, drug Kardex, discharge prescription, discharge letter) for 15 inpatients to identify unintentional prescription discrepancies, defined as: "undocumented and/or unjustified medication alteration" throughout the hospital stay. Part 1: of the 5910 prescribed items; 53 (0.9%) were deemed illegible. Of the controlled drug prescriptions 11.1% (n = 167) met all the legal requirements. Therapeutic errors occurred in 41% of prescriptions (n = 479) More than 1 in 5 patients (21.9%) received a prescription containing a drug interaction. Part 2: 175 discrepancies were identified across all sources of medication information; of which 78 were deemed unintentional. Of these: 10.2% (n = 8) occurred at the point of admission, whereby 76.9% (n = 60) occurred at the point of discharge. The study identified the time of discharge as a point at which prescribing errors are likely to occur. This has implications for patient safety and provider work load in both primary and secondary care.

Medication errors in the Middle East countries: a systematic review of the literature.

PubMed

Alsulami, Zayed; Conroy, Sharon; Choonara, Imti

2013-04-01

Medication errors are a significant global concern and can cause serious medical consequences for patients. Little is known about medication errors in Middle Eastern countries. The objectives of this systematic review were to review studies of the incidence and types of medication errors in Middle Eastern countries and to identify the main contributory factors involved. A systematic review of the literature related to medication errors in Middle Eastern countries was conducted in October 2011 using the following databases: Embase, Medline, Pubmed, the British Nursing Index and the Cumulative Index to Nursing & Allied Health Literature. The search strategy included all ages and languages. Inclusion criteria were that the studies assessed or discussed the incidence of medication errors and contributory factors to medication errors during the medication treatment process in adults or in children. Forty-five studies from 10 of the 15 Middle Eastern countries met the inclusion criteria. Nine (20 %) studies focused on medication errors in paediatric patients. Twenty-one focused on prescribing errors, 11 measured administration errors, 12 were interventional studies and one assessed transcribing errors. Dispensing and documentation errors were inadequately evaluated. Error rates varied from 7.1 % to 90.5 % for prescribing and from 9.4 % to 80 % for administration. The most common types of prescribing errors reported were incorrect dose (with an incidence rate from 0.15 % to 34.8 % of prescriptions), wrong frequency and wrong strength. Computerised physician rder entry and clinical pharmacist input were the main interventions evaluated. Poor knowledge of medicines was identified as a contributory factor for errors by both doctors (prescribers) and nurses (when administering drugs). Most studies did not assess the clinical severity of the medication errors. Studies related to medication errors in the Middle Eastern countries were relatively few in number and of poor quality. Educational programmes on drug therapy for doctors and nurses are urgently needed.

HL7 Structured Product Labeling - electronic prescribing information for provider order entry decision support.

PubMed

Schadow, Gunther

2005-01-01

Prescribing errors are an important cause of adverse events, and lack of knowledge of the drug is a root cause for prescribing errors. The FDA is issuing new regulations that will make the drug labels much more useful not only to physicians, but also to computerized order entry systems that support physicians to practice safe prescribing. For this purpose, FDA works with HL7 to create the Structured Product Label (SPL) standard that includes a document format as well as a drug knowledge representation, this poster introduces the basic concepts of SPL.

Estimation of reliable range of electron temperature measurements with sets of given optical bandpass filters for KSTAR Thomson scattering system based on synthetic Thomson data

NASA Astrophysics Data System (ADS)

Kim, K.-h.; Oh, T.-s.; Park, K.-r.; Lee, J. H.; Ghim, Y.-c.

2017-11-01

One factor determining the reliability of measurements of electron temperature using a Thomson scattering (TS) system is transmittance of the optical bandpass filters in polychromators. We investigate the system performance as a function of electron temperature to determine reliable range of measurements for a given set of the optical bandpass filters. We show that such a reliability, i.e., both bias and random errors, can be obtained by building a forward model of the KSTAR TS system to generate synthetic TS data with the prescribed electron temperature and density profiles. The prescribed profiles are compared with the estimated ones to quantify both bias and random errors.

Using total quality management approach to improve patient safety by preventing medication error incidences*.

PubMed

Yousef, Nadin; Yousef, Farah

2017-09-04

Whereas one of the predominant causes of medication errors is a drug administration error, a previous study related to our investigations and reviews estimated that the incidences of medication errors constituted 6.7 out of 100 administrated medication doses. Therefore, we aimed by using six sigma approach to propose a way that reduces these errors to become less than 1 out of 100 administrated medication doses by improving healthcare professional education and clearer handwritten prescriptions. The study was held in a General Government Hospital. First, we systematically studied the current medication use process. Second, we used six sigma approach by utilizing the five-step DMAIC process (Define, Measure, Analyze, Implement, Control) to find out the real reasons behind such errors. This was to figure out a useful solution to avoid medication error incidences in daily healthcare professional practice. Data sheet was used in Data tool and Pareto diagrams were used in Analyzing tool. In our investigation, we reached out the real cause behind administrated medication errors. As Pareto diagrams used in our study showed that the fault percentage in administrated phase was 24.8%, while the percentage of errors related to prescribing phase was 42.8%, 1.7 folds. This means that the mistakes in prescribing phase, especially because of the poor handwritten prescriptions whose percentage in this phase was 17.6%, are responsible for the consequent) mistakes in this treatment process later on. Therefore, we proposed in this study an effective low cost strategy based on the behavior of healthcare workers as Guideline Recommendations to be followed by the physicians. This method can be a prior caution to decrease errors in prescribing phase which may lead to decrease the administrated medication error incidences to less than 1%. This improvement way of behavior can be efficient to improve hand written prescriptions and decrease the consequent errors related to administrated medication doses to less than the global standard; as a result, it enhances patient safety. However, we hope other studies will be made later in hospitals to practically evaluate how much effective our proposed systematic strategy really is in comparison with other suggested remedies in this field.

Corner smoothing of 2D milling toolpath using b-spline curve by optimizing the contour error and the feedrate

NASA Astrophysics Data System (ADS)

Özcan, Abdullah; Rivière-Lorphèvre, Edouard; Ducobu, François

2018-05-01

In part manufacturing, efficient process should minimize the cycle time needed to reach the prescribed quality on the part. In order to optimize it, the machining time needs to be as low as possible and the quality needs to meet some requirements. For a 2D milling toolpath defined by sharp corners, the programmed feedrate is different from the reachable feedrate due to kinematic limits of the motor drives. This phenomena leads to a loss of productivity. Smoothing the toolpath allows to reduce significantly the machining time but the dimensional accuracy should not be neglected. Therefore, a way to address the problem of optimizing a toolpath in part manufacturing is to take into account the manufacturing time and the part quality. On one hand, maximizing the feedrate will minimize the manufacturing time and, on the other hand, the maximum of the contour error needs to be set under a threshold to meet the quality requirements. This paper presents a method to optimize sharp corner smoothing using b-spline curves by adjusting the control points defining the curve. The objective function used in the optimization process is based on the contour error and the difference between the programmed feedrate and an estimation of the reachable feedrate. The estimation of the reachable feedrate is based on geometrical information. Some simulation results are presented in the paper and the machining times are compared in each cases.

Event-triggered distributed filtering over sensor networks with deception attacks and partial measurements

NASA Astrophysics Data System (ADS)

Bu, Xianye; Dong, Hongli; Han, Fei; Li, Gongfa

2018-07-01

This paper is concerned with the distributed filtering problem for a class of time-varying systems subject to deception attacks and event-triggering protocols. Due to the bandwidth limitation, an event-triggered communication strategy is adopted to alleviate the data transmission pressure in the algorithm implementation process. The partial nodes-based filtering problem is considered, where only a partial of nodes can measure the information of the plant. Meanwhile, the measurement information possibly suffers the deception attacks in the transmission process. Sufficient conditions can be established such that the error dynamics satisfies the prescribed average ? performance constraints. The parameters of designed filters can be calculated by solving a series of recursive linear matrix inequalities. A simulation example is presented to demonstrate the effectiveness of the proposed filtering method in this paper.

Barriers to accepting e-prescribing in the U.S.A.

PubMed

Smith, Alan D

2006-01-01

With the number of prescriptions rising nationally each year, it is surprising that Web-based technology is not fully embraced in the pharmacy industry as an aid to quality-assuring prescribing processes. Traditional prescription handling is done in a manual fashion with physicians hand-writing prescriptions for the patients during an office visit, giving the patient the responsibility of taking the prescription to a pharmacy or mailing the prescription to a mail order company for fulfillment. Electronic prescribing (e-prescribing) has the ability not only to streamline the prescription writing process, but also to reduce the number of errors that may be incurred with hand-written prescriptions. The purpose of this paper is to investigate these phenomena in the U.S.A. A number of hypotheses were tested using principal-components analysis (PCA) and factor analyses. As a result, a total of 55 fully employed, professional and semi-professional service management and internet users, representing a college-educated and knowledge-based sample derived from the metropolitan section of Pittsburgh, was selected. The six major constructs generated from the factor loadings in descending order of importance were: profit and risk factors, shipping and handling, saving, customer relationship management (CRM) and ethics, age, and awareness. The dependent variable chosen to be regressed against these major independent factor-based constructs was willingness to purchase prescriptions online. The overall relationship was found to be statistically significant (F = 2.971, p = 0.015) in predicting willingness to use e-prescribing options based on the various independent constructs. However, when testing the various standardized beta coefficients in the linear model, only the factor score-based construct CRM and ethics was found to significantly contribute to predicting the willingness to purchase prescriptions online (t = -3.074, p = 0.003). Although this study appears to represent the e-prescribing process in the U.S.A., the sample size and region studied are only one slice of the general population. Practical implications - Unfortunately, the adoption of e-prescribing has been difficult to attain owing to numerous barriers throughout the industry. Such acceptance barriers include lack of technology trust, associated system costs, and risk of un-securing patient health and medical information. This article documents that increasing numbers of pharmacies today are building their IT-infrastructures to accept electronic prescriptions and it may soon be the preferred method for physicians to write prescriptions. It is with great anticipation that this technology will also enhance the prescription-writing abilities of prescribing physicians globally, giving them electronic access to patient medical records and resources that will assist them in prescribing the correct drug for the patient.

Medication errors reported to the National Medication Error Reporting System in Malaysia: a 4-year retrospective review (2009 to 2012).

PubMed

Samsiah, A; Othman, Noordin; Jamshed, Shazia; Hassali, Mohamed Azmi; Wan-Mohaina, W M

2016-12-01

Reporting and analysing the data on medication errors (MEs) is important and contributes to a better understanding of the error-prone environment. This study aims to examine the characteristics of errors submitted to the National Medication Error Reporting System (MERS) in Malaysia. A retrospective review of reports received from 1 January 2009 to 31 December 2012 was undertaken. Descriptive statistics method was applied. A total of 17,357 MEs reported were reviewed. The majority of errors were from public-funded hospitals. Near misses were classified in 86.3 % of the errors. The majority of errors (98.1 %) had no harmful effects on the patients. Prescribing contributed to more than three-quarters of the overall errors (76.1 %). Pharmacists detected and reported the majority of errors (92.1 %). Cases of erroneous dosage or strength of medicine (30.75 %) were the leading type of error, whilst cardiovascular (25.4 %) was the most common category of drug found. MERS provides rich information on the characteristics of reported MEs. Low contribution to reporting from healthcare facilities other than government hospitals and non-pharmacists requires further investigation. Thus, a feasible approach to promote MERS among healthcare providers in both public and private sectors needs to be formulated and strengthened. Preventive measures to minimise MEs should be directed to improve prescribing competency among the fallible prescribers identified.

Residents' numeric inputting error in computerized physician order entry prescription.

PubMed

Wu, Xue; Wu, Changxu; Zhang, Kan; Wei, Dong

2016-04-01

Computerized physician order entry (CPOE) system with embedded clinical decision support (CDS) can significantly reduce certain types of prescription error. However, prescription errors still occur. Various factors such as the numeric inputting methods in human computer interaction (HCI) produce different error rates and types, but has received relatively little attention. This study aimed to examine the effects of numeric inputting methods and urgency levels on numeric inputting errors of prescription, as well as categorize the types of errors. Thirty residents participated in four prescribing tasks in which two factors were manipulated: numeric inputting methods (numeric row in the main keyboard vs. numeric keypad) and urgency levels (urgent situation vs. non-urgent situation). Multiple aspects of participants' prescribing behavior were measured in sober prescribing situations. The results revealed that in urgent situations, participants were prone to make mistakes when using the numeric row in the main keyboard. With control of performance in the sober prescribing situation, the effects of the input methods disappeared, and urgency was found to play a significant role in the generalized linear model. Most errors were either omission or substitution types, but the proportion of transposition and intrusion error types were significantly higher than that of the previous research. Among numbers 3, 8, and 9, which were the less common digits used in prescription, the error rate was higher, which was a great risk to patient safety. Urgency played a more important role in CPOE numeric typing error-making than typing skills and typing habits. It was recommended that inputting with the numeric keypad had lower error rates in urgent situation. An alternative design could consider increasing the sensitivity of the keys with lower frequency of occurrence and decimals. To improve the usability of CPOE, numeric keyboard design and error detection could benefit from spatial incidence of errors found in this study. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

An Auto-Calibrating Knee Flexion-Extension Axis Estimator Using Principal Component Analysis with Inertial Sensors.

PubMed

McGrath, Timothy; Fineman, Richard; Stirling, Leia

2018-06-08

Inertial measurement units (IMUs) have been demonstrated to reliably measure human joint angles—an essential quantity in the study of biomechanics. However, most previous literature proposed IMU-based joint angle measurement systems that required manual alignment or prescribed calibration motions. This paper presents a simple, physically-intuitive method for IMU-based measurement of the knee flexion/extension angle in gait without requiring alignment or discrete calibration, based on computationally-efficient and easy-to-implement Principle Component Analysis (PCA). The method is compared against an optical motion capture knee flexion/extension angle modeled through OpenSim. The method is evaluated using both measured and simulated IMU data in an observational study ( n = 15) with an absolute root-mean-square-error (RMSE) of 9.24∘ and a zero-mean RMSE of 3.49∘. Variation in error across subjects was found, made emergent by the larger subject population than previous literature considers. Finally, the paper presents an explanatory model of RMSE on IMU mounting location. The observational data suggest that RMSE of the method is a function of thigh IMU perturbation and axis estimation quality. However, the effect size for these parameters is small in comparison to potential gains from improved IMU orientation estimations. Results also highlight the need to set relevant datums from which to interpret joint angles for both truth references and estimated data.

Three independent one-dimensional margins for single-fraction frameless stereotactic radiosurgery brain cases using CBCT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Qinghui; Chan, Maria F.; Burman, Chandra

2013-12-15

Purpose: Setting a proper margin is crucial for not only delivering the required radiation dose to a target volume, but also reducing the unnecessary radiation to the adjacent organs at risk. This study investigated the independent one-dimensional symmetric and asymmetric margins between the clinical target volume (CTV) and the planning target volume (PTV) for linac-based single-fraction frameless stereotactic radiosurgery (SRS).Methods: The authors assumed a Dirac delta function for the systematic error of a specific machine and a Gaussian function for the residual setup errors. Margin formulas were then derived in details to arrive at a suitable CTV-to-PTV margin for single-fractionmore » frameless SRS. Such a margin ensured that the CTV would receive the prescribed dose in 95% of the patients. To validate our margin formalism, the authors retrospectively analyzed nine patients who were previously treated with noncoplanar conformal beams. Cone-beam computed tomography (CBCT) was used in the patient setup. The isocenter shifts between the CBCT and linac were measured for a Varian Trilogy linear accelerator for three months. For each plan, the authors shifted the isocenter of the plan in each direction by ±3 mm simultaneously to simulate the worst setup scenario. Subsequently, the asymptotic behavior of the CTV V{sub 80%} for each patient was studied as the setup error approached the CTV-PTV margin.Results: The authors found that the proper margin for single-fraction frameless SRS cases with brain cancer was about 3 mm for the machine investigated in this study. The isocenter shifts between the CBCT and the linac remained almost constant over a period of three months for this specific machine. This confirmed our assumption that the machine systematic error distribution could be approximated as a delta function. This definition is especially relevant to a single-fraction treatment. The prescribed dose coverage for all the patients investigated was 96.1%± 5.5% with an extreme 3-mm setup error in all three directions simultaneously. It was found that the effect of the setup error on dose coverage was tumor location dependent. It mostly affected the tumors located in the posterior part of the brain, resulting in a minimum coverage of approximately 72%. This was entirely due to the unique geometry of the posterior head.Conclusions: Margin expansion formulas were derived for single-fraction frameless SRS such that the CTV would receive the prescribed dose in 95% of the patients treated for brain cancer. The margins defined in this study are machine-specific and account for nonzero mean systematic error. The margin for single-fraction SRS for a group of machines was also derived in this paper.« less

Medication errors with electronic prescribing (eP): Two views of the same picture

PubMed Central

2010-01-01

Background Quantitative prospective methods are widely used to evaluate the impact of new technologies such as electronic prescribing (eP) on medication errors. However, they are labour-intensive and it is not always feasible to obtain pre-intervention data. Our objective was to compare the eP medication error picture obtained with retrospective quantitative and qualitative methods. Methods The study was carried out at one English district general hospital approximately two years after implementation of an integrated electronic prescribing, administration and records system. Quantitative: A structured retrospective analysis was carried out of clinical records and medication orders for 75 randomly selected patients admitted to three wards (medicine, surgery and paediatrics) six months after eP implementation. Qualitative: Eight doctors, 6 nurses, 8 pharmacy staff and 4 other staff at senior, middle and junior grades, and 19 adult patients on acute surgical and medical wards were interviewed. Staff interviews explored experiences of developing and working with the system; patient interviews focused on experiences of medicine prescribing and administration on the ward. Interview transcripts were searched systematically for accounts of medication incidents. A classification scheme was developed and applied to the errors identified in the records review. Results The two approaches produced similar pictures of the drug use process. Interviews identified types of error identified in the retrospective notes review plus two eP-specific errors which were not detected by record review. Interview data took less time to collect than record review, and provided rich data on the prescribing process, and reasons for delays or non-administration of medicines, including "once only" orders and "as required" medicines. Conclusions The qualitative approach provided more understanding of processes, and some insights into why medication errors can happen. The method is cost-effective and could be used to supplement information from anonymous error reporting schemes. PMID:20497532

Who Do Hospital Physicians and Nurses Go to for Advice About Medications? A Social Network Analysis and Examination of Prescribing Error Rates.

PubMed

Creswick, Nerida; Westbrook, Johanna Irene

2015-09-01

To measure the weekly medication advice-seeking networks of hospital staff, to compare patterns across professional groups, and to examine these in the context of prescribing error rates. A social network analysis was conducted. All 101 staff in 2 wards in a large, academic teaching hospital in Sydney, Australia, were surveyed (response rate, 90%) using a detailed social network questionnaire. The extent of weekly medication advice seeking was measured by density of connections, proportion of reciprocal relationships by reciprocity, number of colleagues to whom each person provided advice by in-degree, and perceptions of amount and impact of advice seeking between physicians and nurses. Data on prescribing error rates from the 2 wards were compared. Weekly medication advice-seeking networks were sparse (density: 7% ward A and 12% ward B). Information sharing across professional groups was modest, and rates of reciprocation of advice were low (9% ward A, 14% ward B). Pharmacists provided advice to most people, and junior physicians also played central roles. Senior physicians provided medication advice to few people. Many staff perceived that physicians rarely sought advice from nurses when prescribing, but almost all believed that an increase in communication between physicians and nurses about medications would improve patient safety. The medication networks in ward B had higher measures for density, reciprocation, and fewer senior physicians who were isolates. Ward B had a significantly lower rate of both procedural and clinical prescribing errors than ward A (0.63 clinical prescribing errors per admission [95%CI, 0.47-0.79] versus 1.81/ admission [95%CI, 1.49-2.13]). Medication advice-seeking networks among staff on hospital wards are limited. Hubs of advice provision include pharmacists, junior physicians, and senior nurses. Senior physicians are poorly integrated into medication advice networks. Strategies to improve the advice-giving networks between senior and junior physicians may be a fruitful area for intervention to improve medication safety. We found that one ward with stronger networks also had a significantly lower prescribing error rate, suggesting a promising area for further investigation.

Technology and medication errors: impact in nursing homes.

PubMed

Baril, Chantal; Gascon, Viviane; St-Pierre, Liette; Lagacé, Denis

2014-01-01

The purpose of this paper is to study a medication distribution technology's (MDT) impact on medication errors reported in public nursing homes in Québec Province. The work was carried out in six nursing homes (800 patients). Medication error data were collected from nursing staff through a voluntary reporting process before and after MDT was implemented. The errors were analysed using: totals errors; medication error type; severity and patient consequences. A statistical analysis verified whether there was a significant difference between the variables before and after introducing MDT. The results show that the MDT detected medication errors. The authors' analysis also indicates that errors are detected more rapidly resulting in less severe consequences for patients. MDT is a step towards safer and more efficient medication processes. Our findings should convince healthcare administrators to implement technology such as electronic prescriber or bar code medication administration systems to improve medication processes and to provide better healthcare to patients. Few studies have been carried out in long-term healthcare facilities such as nursing homes. The authors' study extends what is known about MDT's impact on medication errors in nursing homes.

Improving Patient Safety With Error Identification in Chemotherapy Orders by Verification Nurses.

PubMed

Baldwin, Abigail; Rodriguez, Elizabeth S

2016-02-01

The prevalence of medication errors associated with chemotherapy administration is not precisely known. Little evidence exists concerning the extent or nature of errors; however, some evidence demonstrates that errors are related to prescribing. This article demonstrates how the review of chemotherapy orders by a designated nurse known as a verification nurse (VN) at a National Cancer Institute-designated comprehensive cancer center helps to identify prescribing errors that may prevent chemotherapy administration mistakes and improve patient safety in outpatient infusion units. This article will describe the role of the VN and details of the verification process. To identify benefits of the VN role, a retrospective review and analysis of chemotherapy near-miss events from 2009-2014 was performed. A total of 4,282 events related to chemotherapy were entered into the Reporting to Improve Safety and Quality system. A majority of the events were categorized as near-miss events, or those that, because of chance, did not result in patient injury, and were identified at the point of prescribing.

Quantifying Carbon Flux Estimation Errors

NASA Astrophysics Data System (ADS)

Wesloh, D.

2017-12-01

Atmospheric Bayesian inversions have been used to estimate surface carbon dioxide (CO2) fluxes from global to sub-continental scales using atmospheric mixing ratio measurements. These inversions use an atmospheric transport model, coupled to a set of fluxes, in order to simulate mixing ratios that can then be compared to the observations. The comparison is then used to update the fluxes to better match the observations in a manner consistent with the uncertainties prescribed for each. However, inversion studies disagree with each other at continental scales, prompting further investigations to examine the causes of these differences. Inter-comparison studies have shown that the errors resulting from atmospheric transport inaccuracies are comparable to those from the errors in the prior fluxes. However, not as much effort has gone into studying the origins of the errors induced by errors in the transport as by errors in the prior distribution. This study uses a mesoscale transport model to evaluate the effects of representation errors in the observations and of incorrect descriptions of the transport. To obtain realizations of these errors, we performed an Observing System Simulation Experiments (OSSEs), with the transport model used for the inversion operating at two resolutions, one typical of a global inversion and the other of a mesoscale, and with various prior flux distributions to. Transport error covariances are inferred from an ensemble of perturbed mesoscale simulations while flux error covariances are computed using prescribed distributions and magnitudes. We examine how these errors can be diagnosed in the inversion process using aircraft, ground-based, and satellite observations of meteorological variables and CO2.

Incorporating medication indications into the prescribing process.

PubMed

Kron, Kevin; Myers, Sara; Volk, Lynn; Nathan, Aaron; Neri, Pamela; Salazar, Alejandra; Amato, Mary G; Wright, Adam; Karmiy, Sam; McCord, Sarah; Seoane-Vazquez, Enrique; Eguale, Tewodros; Rodriguez-Monguio, Rosa; Bates, David W; Schiff, Gordon

2018-04-19

The incorporation of medication indications into the prescribing process to improve patient safety is discussed. Currently, most prescriptions lack a key piece of information needed for safe medication use: the patient-specific drug indication. Integrating indications could pave the way for safer prescribing in multiple ways, including avoiding look-alike/sound-alike errors, facilitating selection of drugs of choice, aiding in communication among the healthcare team, bolstering patient understanding and adherence, and organizing medication lists to facilitate medication reconciliation. Although strongly supported by pharmacists, multiple prior attempts to encourage prescribers to include the indication on prescriptions have not been successful. We convened 6 expert panels to consult high-level stakeholders on system design considerations and requirements necessary for building and implementing an indications-based computerized prescriber order-entry (CPOE) system. We summarize our findings from the 6 expert stakeholder panels, including rationale, literature findings, potential benefits, and challenges of incorporating indications into the prescribing process. Based on this stakeholder input, design requirements for a new CPOE interface and workflow have been identified. The emergence of universal electronic prescribing and content knowledge vendors has laid the groundwork for incorporating indications into the CPOE prescribing process. As medication prescribing moves in the direction of inclusion of the indication, it is imperative to design CPOE systems to efficiently and effectively incorporate indications into prescriber workflows and optimize ways this can best be accomplished. Copyright © 2018 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

The use of discrete-event simulation modeling to compare handwritten and electronic prescribing systems.

PubMed

Ghany, Ahmad; Vassanji, Karim; Kuziemsky, Craig; Keshavjee, Karim

2013-01-01

Electronic prescribing (e-prescribing) is expected to bring many benefits to Canadian healthcare, such as a reduction in errors and adverse drug reactions. As there currently is no functioning e-prescribing system in Canada that is completely electronic, we are unable to evaluate the performance of a live system. An alternative approach is to use simulation modeling for evaluation. We developed two discrete-event simulation models, one of the current handwritten prescribing system and one of a proposed e-prescribing system, to compare the performance of these two systems. We were able to compare the number of processes in each model, workflow efficiency, and the distribution of patients or prescriptions. Although we were able to compare these models to each other, using discrete-event simulation software was challenging. We were limited in the number of variables we could measure. We discovered non-linear processes and feedback loops in both models that could not be adequately represented using discrete-event simulation software. Finally, interactions between entities in both models could not be modeled using this type of software. We have come to the conclusion that a more appropriate approach to modeling both the handwritten and electronic prescribing systems would be to use a complex adaptive systems approach using agent-based modeling or systems-based modeling.

Prevalence of Refractive Error among Preschool Children in an Urban Population: The Baltimore Pediatric Eye Disease Study

PubMed Central

Giordano, Lydia; Friedman, David S.; Repka, Michael X.; Katz, Joanne; Ibironke, Josephine; Hawes, Patricia; Tielsch, James M.

2009-01-01

Purpose To determine the age-specific prevalence of refractive errors in White and African-American preschool children. Design The Baltimore Pediatric Eye Disease Study is a population-based evaluation of the prevalence of ocular disorders in children aged six through 71 months in Baltimore, Maryland, United States. Participants Among 4,132 children identified, 3,990 eligible children (97%) were enrolled and 2,546 children (62%) were examined. Methods Cycloplegic autorefraction was attempted on all children using a Nikon Retinomax K-Plus 2. If a reliable autorefraction could not be obtained after three attempts, cycloplegic streak retinoscopy was performed. Main Outcome Measures Mean spherical equivalent (SE) refractive error, astigmatism, and prevalence of higher refractive errors among African American and White children. Results The mean spherical equivalent (SE) of right eyes was +1.49 diopter (D) (standard deviation (SD) =1.23) in White and +0.71D (SD=1.35) in African-American children (mean difference of 0.78D, 95% CI: 0.67, 0.89). Mean SE refractive error did not decline with age in either group. The prevalence of myopia of 1.00 D or more in the eye with the lesser refractive error was 0.7% in White and 5.5% in African-American children (RR: 8.01 95% confidence interval (CI): 3.70, 17.35). The prevalence of hyperopia of +3D or more in the eye with the lesser refractive error was 8.9% in White and 4.4% in African-American children (relative risk (RR): 0.49, 95% CI: 0.35, 0.68). The prevalence of emmetropia (less than −1.00 D to less than +1.00 D) was 35.6% in Whites and 58.0 % in African-Americans (RR: 1.64, 95% CI: 1.49, 1.80). Based on published prescribing guidelines 5.1% of the children would have benefited from spectacle correction. However, only 1.3% had been previously prescribed correction. Conclusions Significant refractive errors are uncommon in this population of urban preschool children. There was no evidence for a myopic shift over this age range in this cross-sectional study. A small proportion of preschool children would likely benefit from refractive correction, but few have had this prescribed. PMID:19243832

Medication errors in chemotherapy preparation and administration: a survey conducted among oncology nurses in Turkey.

PubMed

Ulas, Arife; Silay, Kamile; Akinci, Sema; Dede, Didem Sener; Akinci, Muhammed Bulent; Sendur, Mehmet Ali Nahit; Cubukcu, Erdem; Coskun, Hasan Senol; Degirmenci, Mustafa; Utkan, Gungor; Ozdemir, Nuriye; Isikdogan, Abdurrahman; Buyukcelik, Abdullah; Inanc, Mevlude; Bilici, Ahmet; Odabasi, Hatice; Cihan, Sener; Avci, Nilufer; Yalcin, Bulent

2015-01-01

Medication errors in oncology may cause severe clinical problems due to low therapeutic indices and high toxicity of chemotherapeutic agents. We aimed to investigate unintentional medication errors and underlying factors during chemotherapy preparation and administration based on a systematic survey conducted to reflect oncology nurses experience. This study was conducted in 18 adult chemotherapy units with volunteer participation of 206 nurses. A survey developed by primary investigators and medication errors (MAEs) defined preventable errors during prescription of medication, ordering, preparation or administration. The survey consisted of 4 parts: demographic features of nurses; workload of chemotherapy units; errors and their estimated monthly number during chemotherapy preparation and administration; and evaluation of the possible factors responsible from ME. The survey was conducted by face to face interview and data analyses were performed with descriptive statistics. Chi-square or Fisher exact tests were used for a comparative analysis of categorical data. Some 83.4% of the 210 nurses reported one or more than one error during chemotherapy preparation and administration. Prescribing or ordering wrong doses by physicians (65.7%) and noncompliance with administration sequences during chemotherapy administration (50.5%) were the most common errors. The most common estimated average monthly error was not following the administration sequence of the chemotherapeutic agents (4.1 times/month, range 1-20). The most important underlying reasons for medication errors were heavy workload (49.7%) and insufficient number of staff (36.5%). Our findings suggest that the probability of medication error is very high during chemotherapy preparation and administration, the most common involving prescribing and ordering errors. Further studies must address the strategies to minimize medication error in chemotherapy receiving patients, determine sufficient protective measures and establishing multistep control mechanisms.

Influencing physician prescribing.

PubMed

Segal, R; Wang, F

1999-10-01

The drug use process suffers from problems related to quality and cost that have not responded well to administrative or educational interventions. In many cases, attempts to improve the quality of physician prescribing have been clumsy, often based on intuition. This article begins by describing the drug use process and the role of prescribing in that process. In the following section, we describe what is known about how physicians make drug choice decisions. The paper concludes with suggestions, based on evidence, about the design of strategies for influencing prescribing.

A pharmacist-led information technology intervention for medication errors (PINCER): a multicentre, cluster randomised, controlled trial and cost-effectiveness analysis

PubMed Central

Avery, Anthony J; Rodgers, Sarah; Cantrill, Judith A; Armstrong, Sarah; Cresswell, Kathrin; Eden, Martin; Elliott, Rachel A; Howard, Rachel; Kendrick, Denise; Morris, Caroline J; Prescott, Robin J; Swanwick, Glen; Franklin, Matthew; Putman, Koen; Boyd, Matthew; Sheikh, Aziz

2012-01-01

Summary Background Medication errors are common in primary care and are associated with considerable risk of patient harm. We tested whether a pharmacist-led, information technology-based intervention was more effective than simple feedback in reducing the number of patients at risk of measures related to hazardous prescribing and inadequate blood-test monitoring of medicines 6 months after the intervention. Methods In this pragmatic, cluster randomised trial general practices in the UK were stratified by research site and list size, and randomly assigned by a web-based randomisation service in block sizes of two or four to one of two groups. The practices were allocated to either computer-generated simple feedback for at-risk patients (control) or a pharmacist-led information technology intervention (PINCER), composed of feedback, educational outreach, and dedicated support. The allocation was masked to general practices, patients, pharmacists, researchers, and statisticians. Primary outcomes were the proportions of patients at 6 months after the intervention who had had any of three clinically important errors: non-selective non-steroidal anti-inflammatory drugs (NSAIDs) prescribed to those with a history of peptic ulcer without co-prescription of a proton-pump inhibitor; β blockers prescribed to those with a history of asthma; long-term prescription of angiotensin converting enzyme (ACE) inhibitor or loop diuretics to those 75 years or older without assessment of urea and electrolytes in the preceding 15 months. The cost per error avoided was estimated by incremental cost-effectiveness analysis. This study is registered with Controlled-Trials.com, number ISRCTN21785299. Findings 72 general practices with a combined list size of 480 942 patients were randomised. At 6 months' follow-up, patients in the PINCER group were significantly less likely to have been prescribed a non-selective NSAID if they had a history of peptic ulcer without gastroprotection (OR 0·58, 95% CI 0·38–0·89); a β blocker if they had asthma (0·73, 0·58–0·91); or an ACE inhibitor or loop diuretic without appropriate monitoring (0·51, 0·34–0·78). PINCER has a 95% probability of being cost effective if the decision-maker's ceiling willingness to pay reaches £75 per error avoided at 6 months. Interpretation The PINCER intervention is an effective method for reducing a range of medication errors in general practices with computerised clinical records. Funding Patient Safety Research Portfolio, Department of Health, England. PMID:22357106

Prescribing errors during hospital inpatient care: factors influencing identification by pharmacists.

PubMed

Tully, Mary P; Buchan, Iain E

2009-12-01

To investigate the prevalence of prescribing errors identified by pharmacists in hospital inpatients and the factors influencing error identification rates by pharmacists throughout hospital admission. 880-bed university teaching hospital in North-west England. Data about prescribing errors identified by pharmacists (median: 9 (range 4-17) collecting data per day) when conducting routine work were prospectively recorded on 38 randomly selected days over 18 months. Proportion of new medication orders in which an error was identified; predictors of error identification rate, adjusted for workload and seniority of pharmacist, day of week, type of ward or stage of patient admission. 33,012 new medication orders were reviewed for 5,199 patients; 3,455 errors (in 10.5% of orders) were identified for 2,040 patients (39.2%; median 1, range 1-12). Most were problem orders (1,456, 42.1%) or potentially significant errors (1,748, 50.6%); 197 (5.7%) were potentially serious; 1.6% (n = 54) were potentially severe or fatal. Errors were 41% (CI: 28-56%) more likely to be identified at patient's admission than at other times, independent of confounders. Workload was the strongest predictor of error identification rates, with 40% (33-46%) less errors identified on the busiest days than at other times. Errors identified fell by 1.9% (1.5-2.3%) for every additional chart checked, independent of confounders. Pharmacists routinely identify errors but increasing workload may reduce identification rates. Where resources are limited, they may be better spent on identifying and addressing errors immediately after admission to hospital.

Antiretroviral medication prescribing errors are common with hospitalization of HIV-infected patients.

PubMed

Commers, Tessa; Swindells, Susan; Sayles, Harlan; Gross, Alan E; Devetten, Marcel; Sandkovsky, Uriel

2014-01-01

Errors in prescribing antiretroviral therapy (ART) often occur with the hospitalization of HIV-infected patients. The rapid identification and prevention of errors may reduce patient harm and healthcare-associated costs. A retrospective review of hospitalized HIV-infected patients was carried out between 1 January 2009 and 31 December 2011. Errors were documented as omission, underdose, overdose, duplicate therapy, incorrect scheduling and/or incorrect therapy. The time to error correction was recorded. Relative risks (RRs) were computed to evaluate patient characteristics and error rates. A total of 289 medication errors were identified in 146/416 admissions (35%). The most common was drug omission (69%). At an error rate of 31%, nucleoside reverse transcriptase inhibitors were associated with an increased risk of error when compared with protease inhibitors (RR 1.32; 95% CI 1.04-1.69) and co-formulated drugs (RR 1.59; 95% CI 1.19-2.09). Of the errors, 31% were corrected within the first 24 h, but over half (55%) were never remedied. Admissions with an omission error were 7.4 times more likely to have all errors corrected within 24 h than were admissions without an omission. Drug interactions with ART were detected on 51 occasions. For the study population (n = 177), an increased risk of admission error was observed for black (43%) compared with white (28%) individuals (RR 1.53; 95% CI 1.16-2.03) but no significant differences were observed between white patients and other minorities or between men and women. Errors in inpatient ART were common, and the majority were never detected. The most common errors involved omission of medication, and nucleoside reverse transcriptase inhibitors had the highest rate of prescribing error. Interventions to prevent and correct errors are urgently needed.

Robust inertia-free attitude takeover control of postcapture combined spacecraft with guaranteed prescribed performance.

PubMed

Luo, Jianjun; Wei, Caisheng; Dai, Honghua; Yin, Zeyang; Wei, Xing; Yuan, Jianping

2018-03-01

In this paper, a robust inertia-free attitude takeover control scheme with guaranteed prescribed performance is investigated for postcapture combined spacecraft with consideration of unmeasurable states, unknown inertial property and external disturbance torque. Firstly, to estimate the unavailable angular velocity of combination accurately, a novel finite-time-convergent tracking differentiator is developed with a quite computationally achievable structure free from the unknown nonlinear dynamics of combined spacecraft. Then, a robust inertia-free prescribed performance control scheme is proposed, wherein, the transient and steady-state performance of combined spacecraft is first quantitatively studied by stabilizing the filtered attitude tracking errors. Compared with the existing works, the prominent advantage is that no parameter identifications and no neural or fuzzy nonlinear approximations are needed, which decreases the complexity of robust controller design dramatically. Moreover, the prescribed performance of combined spacecraft is guaranteed a priori without resorting to repeated regulations of the controller parameters. Finally, four illustrative examples are employed to validate the effectiveness of the proposed control scheme and tracking differentiator. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

The charging security study of electric vehicle charging spot based on automatic testing platform

NASA Astrophysics Data System (ADS)

Li, Yulan; Yang, Zhangli; Zhu, Bin; Ran, Shengyi

2018-03-01

With the increasing of charging spots, the testing of charging security and interoperability becomes more and more urgent and important. In this paper, an interface simulator for ac charging test is designed, the automatic testing platform for electric vehicle charging spots is set up and used to test and analyze the abnormal state during the charging process. On the platform, the charging security and interoperability of ac charging spots and IC-CPD can be checked efficiently, the test report can be generated automatically with No artificial reading error. From the test results, the main reason why the charging spot is not qualified is that the power supply cannot be cut off in the prescribed time when the charging anomaly occurs.

The impact of pharmacy services on opioid prescribing in dental practice.

PubMed

Stewart, Autumn; Zborovancik, Kelsey J; Stiely, Kara L

To compare rates of dental opioid prescribing between periods of full and partial integration of pharmacy services and periods of no integration. This observational study used a retrospective chart review of opioid prescriptions written by dental providers practicing in a free dental clinic for the medically underserved over a period of 74 months. Pharmacy services were fully integrated into the practice model for 48 of the 74 months under study. During this time frame, all dental opioid orders required review by the pharmacy department before prescribing. Outcomes related to prescribing rates and errors were compared between groups, which were defined by the level of integrated pharmacy services. Demographic and prescription-specific data (drug name, dose, quantity, directions, professional designation of individual entering order) and clinic appointment data were collected and analyzed with the use of descriptive and inferential statistics. A total of 102 opioids were prescribed to 89 patients; hydrocodone-acetaminophen combination products were the most frequently used. Opioid prescribing rates were 5 times greater when pharmacy services were not integrated (P <0.001); and dentists were 81% less likely to prescribe opioids when pharmacy was fully integrated (odds ratio 0.19, 95% confidence interval 0.124-0.293; P <0.001). Frequency of hydrocodone use compared with other opioids did not decrease after the rescheduling of hydrocodone to a Schedule II controlled substance. The frequency of prescribing errors was not statistically different between groups, although there were numerically fewer errors with integrated pharmacy services. The literature reports that dentists are the third most frequent prescribers of opioids. The findings from this study suggest that collaboration between pharmacists and dentists has the potential to decrease opioid utilization in primary dental practice. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Barriers to electronic prescribing: Nebraska pharmacists' perspective.

PubMed

Lander, Lina; Klepser, Donald G; Cochran, Gary L; Lomelin, Daniel E; Morien, Marsha

2013-01-01

Electronic prescribing (e-prescribing) and its accompanying clinical decision support capabilities have been promoted as means for reducing medication errors and improving efficiency. The objectives of this study were to identify the barriers to adoption of e-prescribing among nonparticipating Nebraska pharmacies and to describe how the lack of pharmacy participation impacts the ability of physicians to meet meaningful use criteria. We interviewed pharmacists and/or managers from nonparticipating pharmacies to determine barriers to the adoption of e-prescribing. We used open-ended questions and a structured questionnaire to capture participants' responses. Of the 23 participants, 10 (43%) reported plans to implement e-prescribing sometime in the future but delayed participation due to transaction fees and maintenance costs, as well as lack of demand from customers and prescribers to implement e-prescribing. Nine participants (39%) reported no intention to e-prescribe in the future, citing start-up costs for implementing e-prescribing, transaction fees and maintenance costs, happiness with the current system, and lack of understanding about e-prescribing's benefits and how to implement e-prescribing. The barriers to e-prescribing identified by both late adopters and those not willing to accept e-prescriptions were similar and were mainly initial costs and transaction fees associated with each new prescription. For some rural pharmacies, not participating in e-prescribing may be a rational business decision. To increase participation, waiving or reimbursing transaction fees, based on demographic or financial characteristics of the pharmacy, may be warranted. © 2012 National Rural Health Association.

Current Controller for Multi-level Front-end Converter and Its Digital Implementation Considerations on Three-level Flying Capacitor Topology

NASA Astrophysics Data System (ADS)

Tekwani, P. N.; Shah, M. T.

2017-10-01

This paper presents behaviour analysis and digital implementation of current error space phasor based hysteresis controller applied to three-phase three-level flying capacitor converter as front-end topology. The controller is self-adaptive in nature, and takes the converter from three-level to two-level mode of operation and vice versa, following various trajectories of sector change with the change in reference dc-link voltage demanded by the load. It keeps current error space phasor within the prescribed hexagonal boundary. During the contingencies, the proposed controller takes the converter in over modulation mode to meet the load demand, and once the need is satisfied, controller brings back the converter in normal operating range. Simulation results are presented to validate behaviour of controller to meet the said contingencies. Unity power factor is assured by proposed controller with low current harmonic distortion satisfying limits prescribed in IEEE 519-2014. Proposed controller is implemented using TMS320LF2407 16-bit fixed-point digital signal processor. Detailed analysis of numerical format to avoid overflow of sensed variables in processor, and per-unit model implementation in software are discussed and hardware results are presented at various stages of signal conditioning to validate the experimental setup. Control logic for the generation of reference currents is implemented in TMS320LF2407A using assembly language and experimental results are also presented for the same.

hp-Adaptive time integration based on the BDF for viscous flows

NASA Astrophysics Data System (ADS)

Hay, A.; Etienne, S.; Pelletier, D.; Garon, A.

2015-06-01

This paper presents a procedure based on the Backward Differentiation Formulas of order 1 to 5 to obtain efficient time integration of the incompressible Navier-Stokes equations. The adaptive algorithm performs both stepsize and order selections to control respectively the solution accuracy and the computational efficiency of the time integration process. The stepsize selection (h-adaptivity) is based on a local error estimate and an error controller to guarantee that the numerical solution accuracy is within a user prescribed tolerance. The order selection (p-adaptivity) relies on the idea that low-accuracy solutions can be computed efficiently by low order time integrators while accurate solutions require high order time integrators to keep computational time low. The selection is based on a stability test that detects growing numerical noise and deems a method of order p stable if there is no method of lower order that delivers the same solution accuracy for a larger stepsize. Hence, it guarantees both that (1) the used method of integration operates inside of its stability region and (2) the time integration procedure is computationally efficient. The proposed time integration procedure also features a time-step rejection and quarantine mechanisms, a modified Newton method with a predictor and dense output techniques to compute solution at off-step points.

A Criterion to Control Nonlinear Error in the Mixed-Mode Bending Test

NASA Technical Reports Server (NTRS)

Reeder, James R.

2002-01-01

The mixed-mode bending test ha: been widely used to measure delamination toughness and was recently standardized by ASTM as Standard Test Method D6671-01. This simple test is a combination of the standard Mode I (opening) test and a Mode II (sliding) test. This test uses a unidirectional composite test specimen with an artificial delamination subjected to bending loads to characterize when a delamination will extend. When the displacements become large, the linear theory used to analyze the results of the test yields errors in the calcu1ated toughness values. The current standard places no limit on the specimen loading and therefore test data can be created using the standard that are significantly in error. A method of limiting the error that can be incurred in the calculated toughness values is needed. In this paper, nonlinear models of the MMB test are refined. One of the nonlinear models is then used to develop a simple criterion for prescribing conditions where thc nonlinear error will remain below 5%.

Prevalence of refractive error among preschool children in an urban population: the Baltimore Pediatric Eye Disease Study.

PubMed

Giordano, Lydia; Friedman, David S; Repka, Michael X; Katz, Joanne; Ibironke, Josephine; Hawes, Patricia; Tielsch, James M

2009-04-01

To determine the age-specific prevalence of refractive errors in white and African-American preschool children. The Baltimore Pediatric Eye Disease Study is a population-based evaluation of the prevalence of ocular disorders in children aged 6 to 71 months in Baltimore, Maryland. Among 4132 children identified, 3990 eligible children (97%) were enrolled and 2546 children (62%) were examined. Cycloplegic autorefraction was attempted in all children with the use of a Nikon Retinomax K-Plus 2 (Nikon Corporation, Tokyo, Japan). If a reliable autorefraction could not be obtained after 3 attempts, cycloplegic streak retinoscopy was performed. Mean spherical equivalent (SE) refractive error, astigmatism, and prevalence of higher refractive errors among African-American and white children. The mean SE of right eyes was +1.49 diopters (D) (standard deviation [SD] = 1.23) in white children and +0.71 D (SD = 1.35) in African-American children (mean difference of 0.78 D; 95% confidence interval [CI], 0.67-0.89). Mean SE refractive error did not decline with age in either group. The prevalence of myopia of 1.00 D or more in the eye with the lesser refractive error was 0.7% in white children and 5.5% in African-American children (relative risk [RR], 8.01; 95% CI, 3.70-17.35). The prevalence of hyperopia of +3 D or more in the eye with the lesser refractive error was 8.9% in white children and 4.4% in African-American children (RR, 0.49; 95% CI, 0.35-0.68). The prevalence of emmetropia (<-1.00 D to <+1.00 D) was 35.6% in white children and 58.0% in African-American children (RR, 1.64; 95% CI, 1.49-1.80). On the basis of published prescribing guidelines, 5.1% of the children would have benefited from spectacle correction. However, only 1.3% had been prescribed correction. Significant refractive errors are uncommon in this population of urban preschool children. There was no evidence for a myopic shift over this age range in this cross-sectional study. A small proportion of preschool children would likely benefit from refractive correction, but few have had this prescribed.

Modeling of outpatient prescribing process in iran: a gateway toward electronic prescribing system.

PubMed

Ahmadi, Maryam; Samadbeik, Mahnaz; Sadoughi, Farahnaz

2014-01-01

Implementation of electronic prescribing system can overcome many problems of the paper prescribing system, and provide numerous opportunities of more effective and advantageous prescribing. Successful implementation of such a system requires complete and deep understanding of work content, human force, and workflow of paper prescribing. The current study was designed in order to model the current business process of outpatient prescribing in Iran and clarify different actions during this process. In order to describe the prescribing process and the system features in Iran, the methodology of business process modeling and analysis was used in the present study. The results of the process documentation were analyzed using a conceptual model of workflow elements and the technique of modeling "As-Is" business processes. Analysis of the current (as-is) prescribing process demonstrated that Iran stood at the first levels of sophistication in graduated levels of electronic prescribing, namely electronic prescription reference, and that there were problematic areas including bottlenecks, redundant and duplicated work, concentration of decision nodes, and communicative weaknesses among stakeholders of the process. Using information technology in some activities of medication prescription in Iran has not eliminated the dependence of the stakeholders on paper-based documents and prescriptions. Therefore, it is necessary to implement proper system programming in order to support change management and solve the problems in the existing prescribing process. To this end, a suitable basis should be provided for reorganization and improvement of the prescribing process for the future electronic systems.

An analysis of errors, discrepancies, and variation in opioid prescriptions for adult outpatients at a teaching hospital

PubMed Central

Bicket, Mark C.; Kattail, Deepa; Yaster, Myron; Wu, Christopher L.; Pronovost, Peter

2017-01-01

Objective To determine opioid prescribing patterns and rate of three types of errors, discrepancies, and variation from ideal practice. Design Retrospective review of opioid prescriptions processed at an outpatient pharmacy Setting Tertiary institutional medical center Patients We examined 510 consecutive opioid medication prescriptions for adult patients processed at an institutional outpatient pharmacy in June 2016 for patient, provider, and prescription characteristics. Main Outcome Measure(s) We analyzed prescriptions for deviation from best practice guidelines, lack of two patient identifiers, and noncompliance with Drug Enforcement Agency (DEA) rules. Results Mean patient age (SD) was 47.5 years (17.4). The most commonly prescribed opioid was oxycodone (71%), usually not combined with acetaminophen. Practitioners prescribed tablet formulation to 92% of the sample, averaging 57 (47) pills. We identified at least one error on 42% of prescriptions. Among all prescriptions, 9% deviated from best practice guidelines, 21% failed to include two patient identifiers, and 41% were noncompliant with DEA rules. Errors occurred in 89% of handwritten prescriptions, 0% of electronic health record (EHR) computer-generated prescriptions, and 12% of non-EHR computer-generated prescriptions. Inter-rater reliability by kappa was 0.993. Conclusions Inconsistencies in opioid prescribing remain common. Handwritten prescriptions continue to demonstrate higher associations of errors, discrepancies, and variation from ideal practice and government regulations. All computer-generated prescriptions adhered to best practice guidelines and contained two patient identifiers, and all EHR prescriptions were fully compliant with DEA rules. PMID:28345746

A pharmacist-led information technology intervention for medication errors (PINCER): a multicentre, cluster randomised, controlled trial and cost-effectiveness analysis.

PubMed

Avery, Anthony J; Rodgers, Sarah; Cantrill, Judith A; Armstrong, Sarah; Cresswell, Kathrin; Eden, Martin; Elliott, Rachel A; Howard, Rachel; Kendrick, Denise; Morris, Caroline J; Prescott, Robin J; Swanwick, Glen; Franklin, Matthew; Putman, Koen; Boyd, Matthew; Sheikh, Aziz

2012-04-07

Medication errors are common in primary care and are associated with considerable risk of patient harm. We tested whether a pharmacist-led, information technology-based intervention was more effective than simple feedback in reducing the number of patients at risk of measures related to hazardous prescribing and inadequate blood-test monitoring of medicines 6 months after the intervention. In this pragmatic, cluster randomised trial general practices in the UK were stratified by research site and list size, and randomly assigned by a web-based randomisation service in block sizes of two or four to one of two groups. The practices were allocated to either computer-generated simple feedback for at-risk patients (control) or a pharmacist-led information technology intervention (PINCER), composed of feedback, educational outreach, and dedicated support. The allocation was masked to researchers and statisticians involved in processing and analysing the data. The allocation was not masked to general practices, pharmacists, patients, or researchers who visited practices to extract data. [corrected]. Primary outcomes were the proportions of patients at 6 months after the intervention who had had any of three clinically important errors: non-selective non-steroidal anti-inflammatory drugs (NSAIDs) prescribed to those with a history of peptic ulcer without co-prescription of a proton-pump inhibitor; β blockers prescribed to those with a history of asthma; long-term prescription of angiotensin converting enzyme (ACE) inhibitor or loop diuretics to those 75 years or older without assessment of urea and electrolytes in the preceding 15 months. The cost per error avoided was estimated by incremental cost-effectiveness analysis. This study is registered with Controlled-Trials.com, number ISRCTN21785299. 72 general practices with a combined list size of 480,942 patients were randomised. At 6 months' follow-up, patients in the PINCER group were significantly less likely to have been prescribed a non-selective NSAID if they had a history of peptic ulcer without gastroprotection (OR 0·58, 95% CI 0·38-0·89); a β blocker if they had asthma (0·73, 0·58-0·91); or an ACE inhibitor or loop diuretic without appropriate monitoring (0·51, 0·34-0·78). PINCER has a 95% probability of being cost effective if the decision-maker's ceiling willingness to pay reaches £75 per error avoided at 6 months. The PINCER intervention is an effective method for reducing a range of medication errors in general practices with computerised clinical records. Patient Safety Research Portfolio, Department of Health, England. Copyright © 2012 Elsevier Ltd. All rights reserved.

Fatal overdoses involving hydromorphone and morphine among inpatients: a case series

PubMed Central

Lowe, Amanda; Hamilton, Michael; Greenall BScPhm MHSc, Julie; Ma, Jessica; Dhalla, Irfan; Persaud, Nav

2017-01-01

Background: Opioids have narrow therapeutic windows, and errors in ordering or administration can be fatal. The purpose of this study was to describe deaths involving hydromorphone and morphine, which have similar-sounding names, but different potencies. Methods: In this case series, we describe deaths of patients admitted to hospital or residents of long-term care facilities that involved hydromorphone and morphine. We searched for deaths referred to the Patient Safety Review Committee of the Office of the Chief Coroner for Ontario between 2007 and 2012, and subsequently reviewed by 2014. We reviewed each case to identify intervention points where errors could have been prevented. Results: We identified 8 cases involving decedents aged 19 to 91 years. The cases involved errors in prescribing, order processing and transcription, dispensing, administration and monitoring. For 7 of the 8 cases, there were multiple (2 or more) possible intervention points. Six cases may have been prevented by additional patient monitoring, and 5 cases involved dispensing errors. Interpretation: Opioid toxicity deaths in patients living in institutions can be prevented at multiple points in the prescribing and dispensing processes. Interventions aimed at preventing errors in hydromorphone and morphine prescribing, administration and patient monitoring should be implemented and rigorously evaluated. PMID:28401133

Fatal overdoses involving hydromorphone and morphine among inpatients: a case series.

PubMed

Lowe, Amanda; Hamilton, Michael; Greenall BScPhm MHSc, Julie; Ma, Jessica; Dhalla, Irfan; Persaud, Nav

2017-01-01

Opioids have narrow therapeutic windows, and errors in ordering or administration can be fatal. The purpose of this study was to describe deaths involving hydromorphone and morphine, which have similar-sounding names, but different potencies. In this case series, we describe deaths of patients admitted to hospital or residents of long-term care facilities that involved hydromorphone and morphine. We searched for deaths referred to the Patient Safety Review Committee of the Office of the Chief Coroner for Ontario between 2007 and 2012, and subsequently reviewed by 2014. We reviewed each case to identify intervention points where errors could have been prevented. We identified 8 cases involving decedents aged 19 to 91 years. The cases involved errors in prescribing, order processing and transcription, dispensing, administration and monitoring. For 7 of the 8 cases, there were multiple (2 or more) possible intervention points. Six cases may have been prevented by additional patient monitoring, and 5 cases involved dispensing errors. Opioid toxicity deaths in patients living in institutions can be prevented at multiple points in the prescribing and dispensing processes. Interventions aimed at preventing errors in hydromorphone and morphine prescribing, administration and patient monitoring should be implemented and rigorously evaluated.

Protocol for the PINCER trial: a cluster randomised trial comparing the effectiveness of a pharmacist-led IT-based intervention with simple feedback in reducing rates of clinically important errors in medicines management in general practices

PubMed Central

Avery, Anthony J; Rodgers, Sarah; Cantrill, Judith A; Armstrong, Sarah; Elliott, Rachel; Howard, Rachel; Kendrick, Denise; Morris, Caroline J; Murray, Scott A; Prescott, Robin J; Cresswell, Kathrin; Sheikh, Aziz

2009-01-01

Background Medication errors are an important cause of morbidity and mortality in primary care. The aims of this study are to determine the effectiveness, cost effectiveness and acceptability of a pharmacist-led information-technology-based complex intervention compared with simple feedback in reducing proportions of patients at risk from potentially hazardous prescribing and medicines management in general (family) practice. Methods Research subject group: "At-risk" patients registered with computerised general practices in two geographical regions in England. Design: Parallel group pragmatic cluster randomised trial. Interventions: Practices will be randomised to either: (i) Computer-generated feedback; or (ii) Pharmacist-led intervention comprising of computer-generated feedback, educational outreach and dedicated support. Primary outcome measures: The proportion of patients in each practice at six and 12 months post intervention: - with a computer-recorded history of peptic ulcer being prescribed non-selective non-steroidal anti-inflammatory drugs - with a computer-recorded diagnosis of asthma being prescribed beta-blockers - aged 75 years and older receiving long-term prescriptions for angiotensin converting enzyme inhibitors or loop diuretics without a recorded assessment of renal function and electrolytes in the preceding 15 months. Secondary outcome measures; These relate to a number of other examples of potentially hazardous prescribing and medicines management. Economic analysis: An economic evaluation will be done of the cost per error avoided, from the perspective of the UK National Health Service (NHS), comparing the pharmacist-led intervention with simple feedback. Qualitative analysis: A qualitative study will be conducted to explore the views and experiences of health care professionals and NHS managers concerning the interventions, and investigate possible reasons why the interventions prove effective, or conversely prove ineffective. Sample size: 34 practices in each of the two treatment arms would provide at least 80% power (two-tailed alpha of 0.05) to demonstrate a 50% reduction in error rates for each of the three primary outcome measures in the pharmacist-led intervention arm compared with a 11% reduction in the simple feedback arm. Discussion At the time of submission of this article, 72 general practices have been recruited (36 in each arm of the trial) and the interventions have been delivered. Analysis has not yet been undertaken. Trial registration Current controlled trials ISRCTN21785299 PMID:19409095

Protocol for the PINCER trial: a cluster randomised trial comparing the effectiveness of a pharmacist-led IT-based intervention with simple feedback in reducing rates of clinically important errors in medicines management in general practices.

PubMed

Avery, Anthony J; Rodgers, Sarah; Cantrill, Judith A; Armstrong, Sarah; Elliott, Rachel; Howard, Rachel; Kendrick, Denise; Morris, Caroline J; Murray, Scott A; Prescott, Robin J; Cresswell, Kathrin; Sheikh, Aziz

2009-05-01

Medication errors are an important cause of morbidity and mortality in primary care. The aims of this study are to determine the effectiveness, cost effectiveness and acceptability of a pharmacist-led information-technology-based complex intervention compared with simple feedback in reducing proportions of patients at risk from potentially hazardous prescribing and medicines management in general (family) practice. RESEARCH SUBJECT GROUP: "At-risk" patients registered with computerised general practices in two geographical regions in England. Parallel group pragmatic cluster randomised trial. Practices will be randomised to either: (i) Computer-generated feedback; or (ii) Pharmacist-led intervention comprising of computer-generated feedback, educational outreach and dedicated support. The proportion of patients in each practice at six and 12 months post intervention: - with a computer-recorded history of peptic ulcer being prescribed non-selective non-steroidal anti-inflammatory drugs; - with a computer-recorded diagnosis of asthma being prescribed beta-blockers; - aged 75 years and older receiving long-term prescriptions for angiotensin converting enzyme inhibitors or loop diuretics without a recorded assessment of renal function and electrolytes in the preceding 15 months. SECONDARY OUTCOME MEASURES; These relate to a number of other examples of potentially hazardous prescribing and medicines management. An economic evaluation will be done of the cost per error avoided, from the perspective of the UK National Health Service (NHS), comparing the pharmacist-led intervention with simple feedback. QUALITATIVE ANALYSIS: A qualitative study will be conducted to explore the views and experiences of health care professionals and NHS managers concerning the interventions, and investigate possible reasons why the interventions prove effective, or conversely prove ineffective. 34 practices in each of the two treatment arms would provide at least 80% power (two-tailed alpha of 0.05) to demonstrate a 50% reduction in error rates for each of the three primary outcome measures in the pharmacist-led intervention arm compared with a 11% reduction in the simple feedback arm. At the time of submission of this article, 72 general practices have been recruited (36 in each arm of the trial) and the interventions have been delivered. Analysis has not yet been undertaken.

Frequency and Severity of Parenteral Nutrition Medication Errors at a Large Children's Hospital After Implementation of Electronic Ordering and Compounding.

PubMed

MacKay, Mark; Anderson, Collin; Boehme, Sabrina; Cash, Jared; Zobell, Jeffery

2016-04-01

The Institute for Safe Medication Practices has stated that parenteral nutrition (PN) is considered a high-risk medication and has the potential of causing harm. Three organizations--American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.), American Society of Health-System Pharmacists, and National Advisory Group--have published guidelines for ordering, transcribing, compounding and administering PN. These national organizations have published data on compliance to the guidelines and the risk of errors. The purpose of this article is to compare total compliance with ordering, transcription, compounding, administration, and error rate with a large pediatric institution. A computerized prescriber order entry (CPOE) program was developed that incorporates dosing with soft and hard stop recommendations and simultaneously eliminating the need for paper transcription. A CPOE team prioritized and identified issues, then developed solutions and integrated innovative CPOE and automated compounding device (ACD) technologies and practice changes to minimize opportunities for medication errors in PN prescription, transcription, preparation, and administration. Thirty developmental processes were identified and integrated in the CPOE program, resulting in practices that were compliant with A.S.P.E.N. safety consensus recommendations. Data from 7 years of development and implementation were analyzed and compared with published literature comparing error, harm rates, and cost reductions to determine if our process showed lower error rates compared with national outcomes. The CPOE program developed was in total compliance with the A.S.P.E.N. guidelines for PN. The frequency of PN medication errors at our hospital over the 7 years was 230 errors/84,503 PN prescriptions, or 0.27% compared with national data that determined that 74 of 4730 (1.6%) of prescriptions over 1.5 years were associated with a medication error. Errors were categorized by steps in the PN process: prescribing, transcription, preparation, and administration. There were no transcription errors, and most (95%) errors occurred during administration. We conclude that PN practices that conferred a meaningful cost reduction and a lower error rate (2.7/1000 PN) than reported in the literature (15.6/1000 PN) were ascribed to the development and implementation of practices that conform to national PN guidelines and recommendations. Electronic ordering and compounding programs eliminated all transcription and related opportunities for errors. © 2015 American Society for Parenteral and Enteral Nutrition.

Cost-effectiveness analysis of a hospital electronic medication management system

PubMed Central

Gospodarevskaya, Elena; Li, Ling; Richardson, Katrina L; Roffe, David; Heywood, Maureen; Day, Richard O; Graves, Nicholas

2015-01-01

Objective To conduct a cost–effectiveness analysis of a hospital electronic medication management system (eMMS). Methods We compared costs and benefits of paper-based prescribing with a commercial eMMS (CSC MedChart) on one cardiology ward in a major 326-bed teaching hospital, assuming a 15-year time horizon and a health system perspective. The eMMS implementation and operating costs were obtained from the study site. We used data on eMMS effectiveness in reducing potential adverse drug events (ADEs), and potential ADEs intercepted, based on review of 1 202 patient charts before (n = 801) and after (n = 401) eMMS. These were combined with published estimates of actual ADEs and their costs. Results The rate of potential ADEs following eMMS fell from 0.17 per admission to 0.05; a reduction of 71%. The annualized eMMS implementation, maintenance, and operating costs for the cardiology ward were A$61 741 (US$55 296). The estimated reduction in ADEs post eMMS was approximately 80 actual ADEs per year. The reduced costs associated with these ADEs were more than sufficient to offset the costs of the eMMS. Estimated savings resulting from eMMS implementation were A$63–66 (US$56–59) per admission (A$97 740–$102 000 per annum for this ward). Sensitivity analyses demonstrated results were robust when both eMMS effectiveness and costs of actual ADEs were varied substantially. Conclusion The eMMS within this setting was more effective and less expensive than paper-based prescribing. Comparison with the few previous full economic evaluations available suggests a marked improvement in the cost–effectiveness of eMMS, largely driven by increased effectiveness of contemporary eMMs in reducing medication errors. PMID:25670756

Cost-effectiveness analysis of a hospital electronic medication management system.

PubMed

Westbrook, Johanna I; Gospodarevskaya, Elena; Li, Ling; Richardson, Katrina L; Roffe, David; Heywood, Maureen; Day, Richard O; Graves, Nicholas

2015-07-01

To conduct a cost-effectiveness analysis of a hospital electronic medication management system (eMMS). We compared costs and benefits of paper-based prescribing with a commercial eMMS (CSC MedChart) on one cardiology ward in a major 326-bed teaching hospital, assuming a 15-year time horizon and a health system perspective. The eMMS implementation and operating costs were obtained from the study site. We used data on eMMS effectiveness in reducing potential adverse drug events (ADEs), and potential ADEs intercepted, based on review of 1 202 patient charts before (n = 801) and after (n = 401) eMMS. These were combined with published estimates of actual ADEs and their costs. The rate of potential ADEs following eMMS fell from 0.17 per admission to 0.05; a reduction of 71%. The annualized eMMS implementation, maintenance, and operating costs for the cardiology ward were A$61 741 (US$55 296). The estimated reduction in ADEs post eMMS was approximately 80 actual ADEs per year. The reduced costs associated with these ADEs were more than sufficient to offset the costs of the eMMS. Estimated savings resulting from eMMS implementation were A$63-66 (US$56-59) per admission (A$97 740-$102 000 per annum for this ward). Sensitivity analyses demonstrated results were robust when both eMMS effectiveness and costs of actual ADEs were varied substantially. The eMMS within this setting was more effective and less expensive than paper-based prescribing. Comparison with the few previous full economic evaluations available suggests a marked improvement in the cost-effectiveness of eMMS, largely driven by increased effectiveness of contemporary eMMs in reducing medication errors. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association.

A medical informatics perspective on clinical decision support systems. Findings from the yearbook 2013 section on decision support.

PubMed

Bouaud, J; Lamy, J-B

2013-01-01

To summarize excellent research and to select best papers published in 2012 in the field of computer-based decision support in healthcare. A bibliographic search focused on clinical decision support systems (CDSSs) and computer provider order entry was performed, followed by a double-blind literature review. The review process yielded six papers, illustrating various aspects of clinical decision support. The first paper is a systematic review of CDSS intervention trials in real settings, and considers different types of possible outcomes. It emphasizes the heterogeneity of studies and confirms that CDSSs can improve process measures but that evidence lacks for other types of outcomes, especially clinical or economic. Four other papers tackle the safety of drug prescribing and show that CDSSs can be efficient in reducing prescription errors. The sixth paper exemplifies the growing role of ontological resources which can be used for several applications including decision support. CDSS research has to be continuously developed and assessed. The wide variety of systems and of interventions limits the understanding of factors of success of CDSS implementations. A standardization in the characterization of CDSSs and of intervention trial reporting will help to overcome this obstacle.

Can utilizing a computerized provider order entry (CPOE) system prevent hospital medical errors and adverse drug events?

PubMed

Charles, Krista; Cannon, Margaret; Hall, Robert; Coustasse, Alberto

2014-01-01

Computerized provider order entry (CPOE) systems allow physicians to prescribe patient services electronically. In hospitals, CPOE essentially eliminates the need for handwritten paper orders and achieves cost savings through increased efficiency. The purpose of this research study was to examine the benefits of and barriers to CPOE adoption in hospitals to determine the effects on medical errors and adverse drug events (ADEs) and examine cost and savings associated with the implementation of this newly mandated technology. This study followed a methodology using the basic principles of a systematic review and referenced 50 sources. CPOE systems in hospitals were found to be capable of reducing medical errors and ADEs, especially when CPOE systems are bundled with clinical decision support systems designed to alert physicians and other healthcare providers of pending lab or medical errors. However, CPOE systems face major barriers associated with adoption in a hospital system, mainly high implementation costs and physicians' resistance to change.

Interobserver error involved in independent attempts to measure cusp base areas of Pan M1s

PubMed Central

Bailey, Shara E; Pilbrow, Varsha C; Wood, Bernard A

2004-01-01

Cusp base areas measured from digitized images increase the amount of detailed quantitative information one can collect from post-canine crown morphology. Although this method is gaining wide usage for taxonomic analyses of extant and extinct hominoids, the techniques for digitizing images and taking measurements differ between researchers. The aim of this study was to investigate interobserver error in order to help assess the reliability of cusp base area measurement within extant and extinct hominoid taxa. Two of the authors measured individual cusp base areas and total cusp base area of 23 maxillary first molars (M1) of Pan. From these, relative cusp base areas were calculated. No statistically significant interobserver differences were found for either absolute or relative cusp base areas. On average the hypocone and paracone showed the least interobserver error (< 1%) whereas the protocone and metacone showed the most (2.6–4.5%). We suggest that the larger measurement error in the metacone/protocone is due primarily to either weakly defined fissure patterns and/or the presence of accessory occlusal features. Overall, levels of interobserver error are similar to those found for intraobserver error. The results of our study suggest that if certain prescribed standards are employed then cusp and crown base areas measured by different individuals can be pooled into a single database. PMID:15447691

Systematic Review of Medical Informatics-Supported Medication Decision Making.

PubMed

Melton, Brittany L

2017-01-01

This systematic review sought to assess the applications and implications of current medical informatics-based decision support systems related to medication prescribing and use. Studies published between January 2006 and July 2016 which were indexed in PubMed and written in English were reviewed, and 39 studies were ultimately included. Most of the studies looked at computerized provider order entry or clinical decision support systems. Most studies examined decision support systems as a means of reducing errors or risk, particularly associated with medication prescribing, whereas a few studies evaluated the impact medical informatics-based decision support systems have on workflow or operations efficiency. Most studies identified benefits associated with decision support systems, but some indicate there is room for improvement.

Translating Radiometric Requirements for Satellite Sensors to Match International Standards.

PubMed

Pearlman, Aaron; Datla, Raju; Kacker, Raghu; Cao, Changyong

2014-01-01

International scientific standards organizations created standards on evaluating uncertainty in the early 1990s. Although scientists from many fields use these standards, they are not consistently implemented in the remote sensing community, where traditional error analysis framework persists. For a satellite instrument under development, this can create confusion in showing whether requirements are met. We aim to create a methodology for translating requirements from the error analysis framework to the modern uncertainty approach using the product level requirements of the Advanced Baseline Imager (ABI) that will fly on the Geostationary Operational Environmental Satellite R-Series (GOES-R). In this paper we prescribe a method to combine several measurement performance requirements, written using a traditional error analysis framework, into a single specification using the propagation of uncertainties formula. By using this approach, scientists can communicate requirements in a consistent uncertainty framework leading to uniform interpretation throughout the development and operation of any satellite instrument.

Translating Radiometric Requirements for Satellite Sensors to Match International Standards

PubMed Central

Pearlman, Aaron; Datla, Raju; Kacker, Raghu; Cao, Changyong

2014-01-01

International scientific standards organizations created standards on evaluating uncertainty in the early 1990s. Although scientists from many fields use these standards, they are not consistently implemented in the remote sensing community, where traditional error analysis framework persists. For a satellite instrument under development, this can create confusion in showing whether requirements are met. We aim to create a methodology for translating requirements from the error analysis framework to the modern uncertainty approach using the product level requirements of the Advanced Baseline Imager (ABI) that will fly on the Geostationary Operational Environmental Satellite R-Series (GOES-R). In this paper we prescribe a method to combine several measurement performance requirements, written using a traditional error analysis framework, into a single specification using the propagation of uncertainties formula. By using this approach, scientists can communicate requirements in a consistent uncertainty framework leading to uniform interpretation throughout the development and operation of any satellite instrument. PMID:26601032

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dall'Anese, Emiliano; Baker, Kyri; Summers, Tyler

The paper focuses on distribution systems featuring renewable energy sources and energy storage devices, and develops an optimal power flow (OPF) approach to optimize the system operation in spite of forecasting errors. The proposed method builds on a chance-constrained multi-period AC OPF formulation, where probabilistic constraints are utilized to enforce voltage regulation with a prescribed probability. To enable a computationally affordable solution approach, a convex reformulation of the OPF task is obtained by resorting to i) pertinent linear approximations of the power flow equations, and ii) convex approximations of the chance constraints. Particularly, the approximate chance constraints provide conservative boundsmore » that hold for arbitrary distributions of the forecasting errors. An adaptive optimization strategy is then obtained by embedding the proposed OPF task into a model predictive control framework.« less

Water quality management using statistical analysis and time-series prediction model

NASA Astrophysics Data System (ADS)

Parmar, Kulwinder Singh; Bhardwaj, Rashmi

2014-12-01

This paper deals with water quality management using statistical analysis and time-series prediction model. The monthly variation of water quality standards has been used to compare statistical mean, median, mode, standard deviation, kurtosis, skewness, coefficient of variation at Yamuna River. Model validated using R-squared, root mean square error, mean absolute percentage error, maximum absolute percentage error, mean absolute error, maximum absolute error, normalized Bayesian information criterion, Ljung-Box analysis, predicted value and confidence limits. Using auto regressive integrated moving average model, future water quality parameters values have been estimated. It is observed that predictive model is useful at 95 % confidence limits and curve is platykurtic for potential of hydrogen (pH), free ammonia, total Kjeldahl nitrogen, dissolved oxygen, water temperature (WT); leptokurtic for chemical oxygen demand, biochemical oxygen demand. Also, it is observed that predicted series is close to the original series which provides a perfect fit. All parameters except pH and WT cross the prescribed limits of the World Health Organization /United States Environmental Protection Agency, and thus water is not fit for drinking, agriculture and industrial use.

Adjoint-Based, Three-Dimensional Error Prediction and Grid Adaptation

NASA Technical Reports Server (NTRS)

Park, Michael A.

2002-01-01

Engineering computational fluid dynamics (CFD) analysis and design applications focus on output functions (e.g., lift, drag). Errors in these output functions are generally unknown and conservatively accurate solutions may be computed. Computable error estimates can offer the possibility to minimize computational work for a prescribed error tolerance. Such an estimate can be computed by solving the flow equations and the linear adjoint problem for the functional of interest. The computational mesh can be modified to minimize the uncertainty of a computed error estimate. This robust mesh-adaptation procedure automatically terminates when the simulation is within a user specified error tolerance. This procedure for estimating and adapting to error in a functional is demonstrated for three-dimensional Euler problems. An adaptive mesh procedure that links to a Computer Aided Design (CAD) surface representation is demonstrated for wing, wing-body, and extruded high lift airfoil configurations. The error estimation and adaptation procedure yielded corrected functions that are as accurate as functions calculated on uniformly refined grids with ten times as many grid points.

Delay decomposition approach to [Formula: see text] filtering analysis of genetic oscillator networks with time-varying delays.

PubMed

Revathi, V M; Balasubramaniam, P

2016-04-01

In this paper, the [Formula: see text] filtering problem is treated for N coupled genetic oscillator networks with time-varying delays and extrinsic molecular noises. Each individual genetic oscillator is a complex dynamical network that represents the genetic oscillations in terms of complicated biological functions with inner or outer couplings denote the biochemical interactions of mRNAs, proteins and other small molecules. Throughout the paper, first, by constructing appropriate delay decomposition dependent Lyapunov-Krasovskii functional combined with reciprocal convex approach, improved delay-dependent sufficient conditions are obtained to ensure the asymptotic stability of the filtering error system with a prescribed [Formula: see text] performance. Second, based on the above analysis, the existence of the designed [Formula: see text] filters are established in terms of linear matrix inequalities with Kronecker product. Finally, numerical examples including a coupled Goodwin oscillator model are inferred to illustrate the effectiveness and less conservatism of the proposed techniques.

Going digital: a narrative overview of the clinical and organisational impacts of eHealth technologies in hospital practice.

PubMed

Keasberry, Justin; Scott, Ian A; Sullivan, Clair; Staib, Andrew; Ashby, Richard

2017-12-01

Objective The aim of the present study was to determine the effects of hospital-based eHealth technologies on quality, safety and efficiency of care and clinical outcomes. Methods Systematic reviews and reviews of systematic reviews of eHealth technologies published in PubMed/Medline/Cochrane Library between January 2010 and October 2015 were evaluated. Reviews of implementation issues, non-hospital settings or remote care or patient-focused technologies were excluded from analysis. Methodological quality was assessed using a validated appraisal tool. Outcome measures were benefits and harms relating to electronic medical records (EMRs), computerised physician order entry (CPOE), electronic prescribing (ePrescribing) and computerised decision support systems (CDSS). Results are presented as a narrative overview given marked study heterogeneity. Results Nineteen systematic reviews and two reviews of systematic reviews were included from 1197 abstracts, nine rated as high quality. For EMR functions, there was moderate-quality evidence of reduced hospitalisations and length of stay and low-quality evidence of improved organisational efficiency, greater accuracy of information and reduced documentation and process turnaround times. For CPOE functions, there was moderate-quality evidence of reductions in turnaround times and resource utilisation. For ePrescribing, there was moderate-quality evidence of substantially fewer medications errors and adverse drug events, greater guideline adherence, improved disease control and decreased dispensing turnaround times. For CDSS, there was moderate-quality evidence of increased use of preventive care and drug interaction reminders and alerts, increased use of diagnostic aids, more appropriate test ordering with fewer tests per patient, greater guideline adherence, improved processes of care and less disease morbidity. There was conflicting evidence regarding effects on in-patient mortality and overall costs. Reported harms were alert fatigue, increased technology interaction time, creation of disruptive workarounds and new prescribing errors. Conclusion eHealth technologies in hospital settings appear to improve efficiency and appropriateness of care, prescribing safety and disease control. Effects on mortality, readmissions, total costs and patient and provider experience remain uncertain. What is known about the topic? Healthcare systems internationally are undertaking large-scale digitisation programs with hospitals being a major focus. Although predictive analyses suggest that eHealth technologies have the potential to markedly transform health care delivery, contemporary peer-reviewed research evidence detailing their benefits and harms is limited. What does this paper add? This narrative overview of 19 systematic reviews and two reviews of systematic reviews published over the past 5 years provides a summary of cumulative evidence of clinical and organisational effects of contemporary eHealth technologies in hospital practice. EMRs have the potential to increase accuracy and completeness of clinical information, reduce documentation time and enhance information transfer and organisational efficiency. CPOE appears to improve laboratory turnaround times and decrease resource utilisation. ePrescribing significantly reduces medication errors and adverse drug events. CDSS, especially those used at the point of care and integrated into workflows, attract the strongest evidence for substantially increasing clinician adherence to guidelines, appropriateness of disease and treatment monitoring and optimal medication use. Evidence of effects of eHealth technologies on discrete clinical outcomes, such as morbid events, mortality and readmissions, is currently limited and conflicting. What are the implications for practitioners? eHealth technologies confer benefits in improving quality and safety of care with little evidence of major hazards. Whether EMRs and CPOE can affect clinical outcomes or overall costs in the absence of auxiliary support systems, such as ePrescribing and CDSS, remains unclear. eHealth technologies are evolving rapidly and the evidence base used to inform clinician and managerial decisions to invest in these technologies must be updated continually. More rigorous field research using appropriate evaluation methods is needed to better define real-world benefits and harms. Customisation of eHealth applications to the context of patient-centred care and management of highly complex patients with multimorbidity will be an ongoing challenge.

How often are spectacle lenses not dispensed as prescribed?

PubMed

Mohan, Kanwar; Sharma, Ashok

2012-01-01

Spectacles are routinely prescribed by the ophthalmologist and dispensed by the opticians. We investigated how frequently the spectacles are not dispensed as prescribed and whether the frequency of inaccurate spectacles would decrease if the patients, at the time of collecting spectacles, ask the optician to verify that the spectacles have been dispensed accurately. We found inaccurate spectacles in about one-third of our patients and incorrect spherocylinders more frequently with an error in the spherical element and cylinder axis. These inaccuracies decreased significantly when patients while collecting spectacles, asked the optician to verify the accuracy of the spectacles dispensed. It is suggested that while prescribing spectacles, the patients should be made aware of the possibility of dispensing errors. To decrease the frequency of incorrect spectacles, the patients while collecting spectacles, should ask the optician to check whether the spectacles have been dispensed accurately.

Information technology and medication safety: what is the benefit?

PubMed Central

Kaushal, R; Bates, D

2002-01-01



 Medication errors occur frequently and have significant clinical and financial consequences. Several types of information technologies can be used to decrease rates of medication errors. Computerized physician order entry with decision support significantly reduces serious inpatient medication error rates in adults. Other available information technologies that may prove effective for inpatients include computerized medication administration records, robots, automated pharmacy systems, bar coding, "smart" intravenous devices, and computerized discharge prescriptions and instructions. In outpatients, computerization of prescribing and patient oriented approaches such as personalized web pages and delivery of web based information may be important. Public and private mandates for information technology interventions are growing, but further development, application, evaluation, and dissemination are required. PMID:12486992

Objectified quantification of uncertainties in Bayesian atmospheric inversions

NASA Astrophysics Data System (ADS)

Berchet, A.; Pison, I.; Chevallier, F.; Bousquet, P.; Bonne, J.-L.; Paris, J.-D.

2015-05-01

Classical Bayesian atmospheric inversions process atmospheric observations and prior emissions, the two being connected by an observation operator picturing mainly the atmospheric transport. These inversions rely on prescribed errors in the observations, the prior emissions and the observation operator. When data pieces are sparse, inversion results are very sensitive to the prescribed error distributions, which are not accurately known. The classical Bayesian framework experiences difficulties in quantifying the impact of mis-specified error distributions on the optimized fluxes. In order to cope with this issue, we rely on recent research results to enhance the classical Bayesian inversion framework through a marginalization on a large set of plausible errors that can be prescribed in the system. The marginalization consists in computing inversions for all possible error distributions weighted by the probability of occurrence of the error distributions. The posterior distribution of the fluxes calculated by the marginalization is not explicitly describable. As a consequence, we carry out a Monte Carlo sampling based on an approximation of the probability of occurrence of the error distributions. This approximation is deduced from the well-tested method of the maximum likelihood estimation. Thus, the marginalized inversion relies on an automatic objectified diagnosis of the error statistics, without any prior knowledge about the matrices. It robustly accounts for the uncertainties on the error distributions, contrary to what is classically done with frozen expert-knowledge error statistics. Some expert knowledge is still used in the method for the choice of an emission aggregation pattern and of a sampling protocol in order to reduce the computation cost. The relevance and the robustness of the method is tested on a case study: the inversion of methane surface fluxes at the mesoscale with virtual observations on a realistic network in Eurasia. Observing system simulation experiments are carried out with different transport patterns, flux distributions and total prior amounts of emitted methane. The method proves to consistently reproduce the known "truth" in most cases, with satisfactory tolerance intervals. Additionally, the method explicitly provides influence scores and posterior correlation matrices. An in-depth interpretation of the inversion results is then possible. The more objective quantification of the influence of the observations on the fluxes proposed here allows us to evaluate the impact of the observation network on the characterization of the surface fluxes. The explicit correlations between emission aggregates reveal the mis-separated regions, hence the typical temporal and spatial scales the inversion can analyse. These scales are consistent with the chosen aggregation patterns.

Design and Evaluation of an Electronic Override Mechanism for Medication Alerts to Facilitate Communication Between Prescribers and Pharmacists.

PubMed

Russ, Alissa L; Chen, Siying; Melton, Brittany L; Saleem, Jason J; Weiner, Michael; Spina, Jeffrey R; Daggy, Joanne K; Zillich, Alan J

2015-07-01

Computerized medication alerts can often be bypassed by entering an override rationale, but prescribers' override reasons are frequently ambiguous to pharmacists who review orders. To develop and evaluate a new override mechanism for adverse reaction and drug-drug interaction alerts. We hypothesized that the new mechanism would improve usability for prescribers and increase the clinical appropriateness of override reasons. A counterbalanced, crossover study was conducted with 20 prescribers in a simulated prescribing environment. We modified the override mechanism timing, navigation, and text entry. Instead of free-text entry, the new mechanism presented prescribers with a predefined set of override reasons. We assessed usability (learnability, perceived efficiency, and usability errors) and used a priori criteria to evaluate the clinical appropriateness of override reasons entered. Prescribers rated the new mechanism as more efficient (Wilcoxon signed-rank test, P = 0.032). When first using the new design, 5 prescribers had difficulty finding the new mechanism, and 3 interpreted the navigation to mean that the alert could not be overridden. The number of appropriate override reasons significantly increased with the new mechanism compared with the original mechanism (median change of 3.0; interquartile range = 3.0; P < 0.0001). When prescribers were given a menu-based choice for override reasons, clinical appropriateness of these reasons significantly improved. Further enhancements are necessary, but this study is an important first step toward a more standardized menu of override choices. Findings may be used to improve communication through e-prescribing systems between prescribers and pharmacists. © The Author(s) 2015.

Asynchronous State Estimation for Discrete-Time Switched Complex Networks With Communication Constraints.

PubMed

Zhang, Dan; Wang, Qing-Guo; Srinivasan, Dipti; Li, Hongyi; Yu, Li

2018-05-01

This paper is concerned with the asynchronous state estimation for a class of discrete-time switched complex networks with communication constraints. An asynchronous estimator is designed to overcome the difficulty that each node cannot access to the topology/coupling information. Also, the event-based communication, signal quantization, and the random packet dropout problems are studied due to the limited communication resource. With the help of switched system theory and by resorting to some stochastic system analysis method, a sufficient condition is proposed to guarantee the exponential stability of estimation error system in the mean-square sense and a prescribed performance level is also ensured. The characterization of the desired estimator gains is derived in terms of the solution to a convex optimization problem. Finally, the effectiveness of the proposed design approach is demonstrated by a simulation example.

H∞ state estimation for discrete-time memristive recurrent neural networks with stochastic time-delays

NASA Astrophysics Data System (ADS)

Liu, Hongjian; Wang, Zidong; Shen, Bo; Alsaadi, Fuad E.

2016-07-01

This paper deals with the robust H∞ state estimation problem for a class of memristive recurrent neural networks with stochastic time-delays. The stochastic time-delays under consideration are governed by a Bernoulli-distributed stochastic sequence. The purpose of the addressed problem is to design the robust state estimator such that the dynamics of the estimation error is exponentially stable in the mean square, and the prescribed ? performance constraint is met. By utilizing the difference inclusion theory and choosing a proper Lyapunov-Krasovskii functional, the existence condition of the desired estimator is derived. Based on it, the explicit expression of the estimator gain is given in terms of the solution to a linear matrix inequality. Finally, a numerical example is employed to demonstrate the effectiveness and applicability of the proposed estimation approach.

A model of methods for influencing prescribing: Part I. A review of prescribing models, persuasion theories, and administrative and educational methods.

PubMed

Raisch, D W

1990-04-01

The purpose of this literature review is to develop a model of methods to be used to influence prescribing. Four bodies of literature were identified as being important for developing the model: (1) Theoretical prescribing models furnish information concerning factors that affect prescribing and how prescribing decisions are made. (2) Theories of persuasion provide insight into important components of educational communications. (3) Research articles of programs to improve prescribing identify types of programs that have been found to be successful. (4) Theories of human inference describe how judgments are formulated and identify errors in judgment that can play a role in prescribing. This review is presented in two parts. This article reviews prescribing models, theories of persuasion, studies of administrative programs to control prescribing, and sub-optimally designed studies of educational efforts to influence drug prescribing.

The impact of e-prescribing on prescriber and staff time in ambulatory care clinics: a time motion study.

PubMed

Hollingworth, William; Devine, Emily Beth; Hansen, Ryan N; Lawless, Nathan M; Comstock, Bryan A; Wilson-Norton, Jennifer L; Tharp, Kathleen L; Sullivan, Sean D

2007-01-01

Electronic prescribing has improved the quality and safety of care. One barrier preventing widespread adoption is the potential detrimental impact on workflow. We used time-motion techniques to compare prescribing times at three ambulatory care sites that used paper-based prescribing, desktop, or laptop e-prescribing. An observer timed all prescriber (n = 27) and staff (n = 42) tasks performed during a 4-hour period. At the sites with optional e-prescribing >75% of prescription-related events were performed electronically. Prescribers at e-prescribing sites spent less time writing, but time-savings were offset by increased computer tasks. After adjusting for site, prescriber and prescription type, e-prescribing tasks took marginally longer than hand written prescriptions (12.0 seconds; -1.6, 25.6 CI). Nursing staff at the e-prescribing sites spent longer on computer tasks (5.4 minutes/hour; 0.0, 10.7 CI). E-prescribing was not associated with an increase in combined computer and writing time for prescribers. If carefully implemented, e-prescribing will not greatly disrupt workflow.

ANALYZING NUMERICAL ERRORS IN DOMAIN HEAT TRANSPORT MODELS USING THE CVBEM.

USGS Publications Warehouse

Hromadka, T.V.; ,

1985-01-01

Besides providing an exact solution for steady-state heat conduction processes (Laplace Poisson equations), the CVBEM (complex variable boundary element method) can be used for the numerical error analysis of domain model solutions. For problems where soil water phase change latent heat effects dominate the thermal regime, heat transport can be approximately modeled as a time-stepped steady-state condition in the thawed and frozen regions, respectively. The CVBEM provides an exact solution of the two-dimensional steady-state heat transport problem, and also provides the error in matching the prescribed boundary conditions by the development of a modeling error distribution or an approximative boundary generation. This error evaluation can be used to develop highly accurate CVBEM models of the heat transport process, and the resulting model can be used as a test case for evaluating the precision of domain models based on finite elements or finite differences.

Impact of Internally Developed Electronic Prescription on Prescribing Errors at Discharge from the Emergency Department

PubMed Central

Hitti, Eveline; Tamim, Hani; Bakhti, Rinad; Zebian, Dina; Mufarrij, Afif

2017-01-01

Introduction Medication errors are common, with studies reporting at least one error per patient encounter. At hospital discharge, medication errors vary from 15%–38%. However, studies assessing the effect of an internally developed electronic (E)-prescription system at discharge from an emergency department (ED) are comparatively minimal. Additionally, commercially available electronic solutions are cost-prohibitive in many resource-limited settings. We assessed the impact of introducing an internally developed, low-cost E-prescription system, with a list of commonly prescribed medications, on prescription error rates at discharge from the ED, compared to handwritten prescriptions. Methods We conducted a pre- and post-intervention study comparing error rates in a randomly selected sample of discharge prescriptions (handwritten versus electronic) five months pre and four months post the introduction of the E-prescription. The internally developed, E-prescription system included a list of 166 commonly prescribed medications with the generic name, strength, dose, frequency and duration. We included a total of 2,883 prescriptions in this study: 1,475 in the pre-intervention phase were handwritten (HW) and 1,408 in the post-intervention phase were electronic. We calculated rates of 14 different errors and compared them between the pre- and post-intervention period. Results Overall, E-prescriptions included fewer prescription errors as compared to HW-prescriptions. Specifically, E-prescriptions reduced missing dose (11.3% to 4.3%, p <0.0001), missing frequency (3.5% to 2.2%, p=0.04), missing strength errors (32.4% to 10.2%, p <0.0001) and legibility (0.7% to 0.2%, p=0.005). E-prescriptions, however, were associated with a significant increase in duplication errors, specifically with home medication (1.7% to 3%, p=0.02). Conclusion A basic, internally developed E-prescription system, featuring commonly used medications, effectively reduced medication errors in a low-resource setting where the costs of sophisticated commercial electronic solutions are prohibitive. PMID:28874948

Impact of Internally Developed Electronic Prescription on Prescribing Errors at Discharge from the Emergency Department.

PubMed

Hitti, Eveline; Tamim, Hani; Bakhti, Rinad; Zebian, Dina; Mufarrij, Afif

2017-08-01

Medication errors are common, with studies reporting at least one error per patient encounter. At hospital discharge, medication errors vary from 15%-38%. However, studies assessing the effect of an internally developed electronic (E)-prescription system at discharge from an emergency department (ED) are comparatively minimal. Additionally, commercially available electronic solutions are cost-prohibitive in many resource-limited settings. We assessed the impact of introducing an internally developed, low-cost E-prescription system, with a list of commonly prescribed medications, on prescription error rates at discharge from the ED, compared to handwritten prescriptions. We conducted a pre- and post-intervention study comparing error rates in a randomly selected sample of discharge prescriptions (handwritten versus electronic) five months pre and four months post the introduction of the E-prescription. The internally developed, E-prescription system included a list of 166 commonly prescribed medications with the generic name, strength, dose, frequency and duration. We included a total of 2,883 prescriptions in this study: 1,475 in the pre-intervention phase were handwritten (HW) and 1,408 in the post-intervention phase were electronic. We calculated rates of 14 different errors and compared them between the pre- and post-intervention period. Overall, E-prescriptions included fewer prescription errors as compared to HW-prescriptions. Specifically, E-prescriptions reduced missing dose (11.3% to 4.3%, p <0.0001), missing frequency (3.5% to 2.2%, p=0.04), missing strength errors (32.4% to 10.2%, p <0.0001) and legibility (0.7% to 0.2%, p=0.005). E-prescriptions, however, were associated with a significant increase in duplication errors, specifically with home medication (1.7% to 3%, p=0.02). A basic, internally developed E-prescription system, featuring commonly used medications, effectively reduced medication errors in a low-resource setting where the costs of sophisticated commercial electronic solutions are prohibitive.

Reliability of clinical impact grading by healthcare professionals of common prescribing error and optimisation cases in critical care patients.

PubMed

Bourne, Richard S; Shulman, Rob; Tomlin, Mark; Borthwick, Mark; Berry, Will; Mills, Gary H

2017-04-01

To identify between and within profession-rater reliability of clinical impact grading for common critical care prescribing error and optimisation cases. To identify representative clinical impact grades for each individual case. Electronic questionnaire. 5 UK NHS Trusts. 30 Critical care healthcare professionals (doctors, pharmacists and nurses). Participants graded severity of clinical impact (5-point categorical scale) of 50 error and 55 optimisation cases. Case between and within profession-rater reliability and modal clinical impact grading. Between and within profession rater reliability analysis used linear mixed model and intraclass correlation, respectively. The majority of error and optimisation cases (both 76%) had a modal clinical severity grade of moderate or higher. Error cases: doctors graded clinical impact significantly lower than pharmacists (-0.25; P < 0.001) and nurses (-0.53; P < 0.001), with nurses significantly higher than pharmacists (0.28; P < 0.001). Optimisation cases: doctors graded clinical impact significantly lower than nurses and pharmacists (-0.39 and -0.5; P < 0.001, respectively). Within profession reliability grading was excellent for pharmacists (0.88 and 0.89; P < 0.001) and doctors (0.79 and 0.83; P < 0.001) but only fair to good for nurses (0.43 and 0.74; P < 0.001), for optimisation and error cases, respectively. Representative clinical impact grades for over 100 common prescribing error and optimisation cases are reported for potential clinical practice and research application. The between professional variability highlights the importance of multidisciplinary perspectives in assessment of medication error and optimisation cases in clinical practice and research. © The Author 2017. Published by Oxford University Press in association with the International Society for Quality in Health Care. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Systemic fluoroquinolone prescriptions for hospitalized children in Belgium, results of a multicenter retrospective drug utilization study.

PubMed

Meesters, Kevin; Mauel, Reiner; Dhont, Evelyn; Walle, Johan Vande; De Bruyne, Pauline

2018-02-23

Fluoroquinolones (FQ) are increasingly prescribed for children, despite being labeled for only a limited number of labeled pediatric indications. In this multicenter retrospective drug utilization study, we analyzed indications for systemic FQ prescriptions in hospitalized children and the appropriateness of the prescribed dose. Using data obtained from electronic medical files, the study included all children who received a systemic FQ prescription in two Belgian university children's hospitals between 2010 and 2013. Two authors reviewed prescribed daily doses. Univariate and multivariate logistic regression models were used to analyze risk factors for inadequately dosing. Results262 FQ prescriptions for individual patients were included for analysis. 16.8% of these prescriptions were for labeled indications, and 35.1% were guided by bacteriological findings. Prescribed daily dose was considered to be inappropriate in 79 prescriptions (30.2%). Other FQ than ciprofloxacin accounted for 9 prescriptions (3.4%), of which 8 were correctly dosed. Underdosing represented 45 (56.9%) dosing errors. Infants and preschool children were at particular risk for dosing errors, with associated adjusted OR of 0.263 (0.097-0.701) and 0.254 (0.106-0.588) respectively. FQ were often prescribed off-label and not guided by bacteriological findings in our study population. Dosing errors were common, particularly in infants and preschool children. FQ prescriptions for children should be improved by specific pediatric antimicrobial stewardship teams. Furthermore, pharmacokinetic studies should optimise dosing recommendations for children.

A smart medication recommendation model for the electronic prescription.

PubMed

Syed-Abdul, Shabbir; Nguyen, Alex; Huang, Frank; Jian, Wen-Shan; Iqbal, Usman; Yang, Vivian; Hsu, Min-Huei; Li, Yu-Chuan

2014-11-01

The report from the Institute of Medicine, To Err Is Human: Building a Safer Health System in 1999 drew a special attention towards preventable medical errors and patient safety. The American Reinvestment and Recovery Act of 2009 and federal criteria of 'Meaningful use' stage 1 mandated e-prescribing to be used by eligible providers in order to access Medicaid and Medicare incentive payments. Inappropriate prescribing has been identified as a preventable cause of at least 20% of drug-related adverse events. A few studies reported system-related errors and have offered targeted recommendations on improving and enhancing e-prescribing system. This study aims to enhance efficiency of the e-prescribing system by shortening the medication list, reducing the risk of inappropriate selection of medication, as well as in reducing the prescribing time of physicians. 103.48 million prescriptions from Taiwan's national health insurance claim data were used to compute Diagnosis-Medication association. Furthermore, 100,000 prescriptions were randomly selected to develop a smart medication recommendation model by using association rules of data mining. The important contribution of this model is to introduce a new concept called Mean Prescription Rank (MPR) of prescriptions and Coverage Rate (CR) of prescriptions. A proactive medication list (PML) was computed using MPR and CR. With this model the medication drop-down menu is significantly shortened, thereby reducing medication selection errors and prescription times. The physicians will still select relevant medications even in the case of inappropriate (unintentional) selection. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Data Mining on Numeric Error in Computerized Physician Order Entry System Prescriptions.

PubMed

Wu, Xue; Wu, Changxu

2017-01-01

This study revealed the numeric error patterns related to dosage when doctors prescribed in computerized physician order entry system. Error categories showed that the '6','7', and '9' key produced a higher incidence of errors in Numpad typing, while the '2','3', and '0' key produced a higher incidence of errors in main keyboard digit line typing. Errors categorized as omission and substitution were higher in prevalence than transposition and intrusion.

Networking Hospital ePrescribing: A Systemic View of Digitalization of Medicines' Use in England.

PubMed

Lichtner, Valentina; Hibberd, Ralph; Cornford, Tony

2016-01-01

Medicine management is at the core of hospital care and digitalization of prescribing and administration of medicines is often the focus of attention of health IT programs. This may be conveyed to the public in terms of the elimination of paper-based drug charts and increased readability of doctors' prescriptions. Based on analysis of documents about hospital medicines supply and use (including systems' implementation) in the UK, in this conceptual paper electronic prescribing and administration are repositioned as only one aspect of an important wider transformation in medicine management in hospital settings, involving, for example, procurement, dispensing, auditing, waste management, research and safety vigilance. Approaching digitalization from a systemic perspective has the potential to uncover the wider implications of this transformation for patients, the organization and the wider health care system.

[Errors in prescriptions and their preparation at the outpatient pharmacy of a regional hospital].

PubMed

Alvarado A, Carolina; Ossa G, Ximena; Bustos M, Luis

2017-01-01

Adverse effects of medications are an important cause of morbidity and hospital admissions. Errors in prescription or preparation of medications by pharmacy personnel are a factor that may influence these occurrence of the adverse effects Aim: To assess the frequency and type of errors in prescriptions and in their preparation at the pharmacy unit of a regional public hospital. Prescriptions received by ambulatory patients and those being discharged from the hospital, were reviewed using a 12-item checklist. The preparation of such prescriptions at the pharmacy unit was also reviewed using a seven item checklist. Seventy two percent of prescriptions had at least one error. The most common mistake was the impossibility of determining the concentration of the prescribed drug. Prescriptions for patients being discharged from the hospital had the higher number of errors. When a prescription had more than two drugs, the risk of error increased 2.4 times. Twenty four percent of prescription preparations had at least one error. The most common mistake was the labeling of drugs with incomplete medical indications. When a preparation included more than three drugs, the risk of preparation error increased 1.8 times. Prescription and preparation of medication delivered to patients had frequent errors. The most important risk factor for errors was the number of drugs prescribed.

Technical Papers Presented at the Defense Nuclear Agency Global Effects Review Held in Santa Barbara, California on 7-9 April 1987. Volume 2

DTIC Science & Technology

1987-05-19

Prescribed 341 Burn - Einfield, Zak, Mokler and Morrison 23. Measurements of Cloud Active Aerosol in Large Scale Fires - Hudson 356 24. Optical Depth...Cover A LAI change with I Leaf drop temperaturelseason STEMSilraio I R u plo oilS u r fa c e Surfctie %ooil temeraureUpper leyer wetness layer( du...Michigan can be attributed to an unforecast mesoscale region of cloudiness. The positive error region in western Tennessee and Kentucky is associated

Clinical review: Medication errors in critical care

PubMed Central

Moyen, Eric; Camiré, Eric; Stelfox, Henry Thomas

2008-01-01

Medication errors in critical care are frequent, serious, and predictable. Critically ill patients are prescribed twice as many medications as patients outside of the intensive care unit (ICU) and nearly all will suffer a potentially life-threatening error at some point during their stay. The aim of this article is to provide a basic review of medication errors in the ICU, identify risk factors for medication errors, and suggest strategies to prevent errors and manage their consequences. PMID:18373883

The epidemiology and type of medication errors reported to the National Poisons Information Centre of Ireland.

PubMed

Cassidy, Nicola; Duggan, Edel; Williams, David J P; Tracey, Joseph A

2011-07-01

Medication errors are widely reported for hospitalised patients, but limited data are available for medication errors that occur in community-based and clinical settings. Epidemiological data from poisons information centres enable characterisation of trends in medication errors occurring across the healthcare spectrum. The objective of this study was to characterise the epidemiology and type of medication errors reported to the National Poisons Information Centre (NPIC) of Ireland. A 3-year prospective study on medication errors reported to the NPIC was conducted from 1 January 2007 to 31 December 2009 inclusive. Data on patient demographics, enquiry source, location, pharmaceutical agent(s), type of medication error, and treatment advice were collated from standardised call report forms. Medication errors were categorised as (i) prescribing error (i.e. physician error), (ii) dispensing error (i.e. pharmacy error), and (iii) administration error involving the wrong medication, the wrong dose, wrong route, or the wrong time. Medication errors were reported for 2348 individuals, representing 9.56% of total enquiries to the NPIC over 3 years. In total, 1220 children and adolescents under 18 years of age and 1128 adults (≥ 18 years old) experienced a medication error. The majority of enquiries were received from healthcare professionals, but members of the public accounted for 31.3% (n = 736) of enquiries. Most medication errors occurred in a domestic setting (n = 2135), but a small number occurred in healthcare facilities: nursing homes (n = 110, 4.68%), hospitals (n = 53, 2.26%), and general practitioner surgeries (n = 32, 1.36%). In children, medication errors with non-prescription pharmaceuticals predominated (n = 722) and anti-pyretics and non-opioid analgesics, anti-bacterials, and cough and cold preparations were the main pharmaceutical classes involved. Medication errors with prescription medication predominated for adults (n = 866) and the major medication classes included anti-pyretics and non-opioid analgesics, psychoanaleptics, and psychleptic agents. Approximately 97% (n = 2279) of medication errors were as a result of drug administration errors (comprising a double dose [n = 1040], wrong dose [n = 395], wrong medication [n = 597], wrong route [n = 133], and wrong time [n = 110]). Prescribing and dispensing errors accounted for 0.68% (n = 16) and 2.26% (n = 53) of errors, respectively. Empirical data from poisons information centres facilitate the characterisation of medication errors occurring in the community and across the healthcare spectrum. Poison centre data facilitate the detection of subtle trends in medication errors and can contribute to pharmacovigilance. Collaboration between pharmaceutical manufacturers, consumers, medical, and regulatory communities is needed to advance patient safety and reduce medication errors.

Event-Based $H_\\infty $ State Estimation for Time-Varying Stochastic Dynamical Networks With State- and Disturbance-Dependent Noises.

PubMed

Sheng, Li; Wang, Zidong; Zou, Lei; Alsaadi, Fuad E

2017-10-01

In this paper, the event-based finite-horizon H ∞ state estimation problem is investigated for a class of discrete time-varying stochastic dynamical networks with state- and disturbance-dependent noises [also called (x,v) -dependent noises]. An event-triggered scheme is proposed to decrease the frequency of the data transmission between the sensors and the estimator, where the signal is transmitted only when certain conditions are satisfied. The purpose of the problem addressed is to design a time-varying state estimator in order to estimate the network states through available output measurements. By employing the completing-the-square technique and the stochastic analysis approach, sufficient conditions are established to ensure that the error dynamics of the state estimation satisfies a prescribed H ∞ performance constraint over a finite horizon. The desired estimator parameters can be designed via solving coupled backward recursive Riccati difference equations. Finally, a numerical example is exploited to demonstrate the effectiveness of the developed state estimation scheme.

On making laboratory report work more meaningful through criterion-based evaluation.

PubMed

Naeraa, N

1987-05-01

The purpose of this work was to encourage students to base their laboratory report work on guidelines reflecting a quality criterion set, previously derived from the functional role of the various sections in scientific papers. The materials were developed by a trial-and-error approach and comprise learning objectives, a parallel structure of manual and reports, general and specific report guidelines and a new common starting experiment. The principal contents are presented, followed by an account of the author's experience with them. Most of the author's students now follow the guidelines. Their conclusions are affected by difficulties in adjusting expected results with due regard to the specific conditions of the experimental subject or to their own deviations from the experimental or analytical procedures prescribed in the manual. Also, problems in interpreting data unbiased by explicit expectations are evident, although a clear distinction between expected and actual results has been helpful for them in seeing the relationship between experiments and textbook contents more clearly, and thus in understanding the hypothetico-deductive approach.

Post-Newtonian equations of motion for LEO debris objects and space-based acquisition, pointing and tracking laser systems

NASA Astrophysics Data System (ADS)

Gambi, J. M.; García del Pino, M. L.; Gschwindl, J.; Weinmüller, E. B.

2017-12-01

This paper deals with the problem of throwing middle-sized low Earth orbit debris objects into the atmosphere via laser ablation. The post-Newtonian equations here provided allow (hypothetical) space-based acquisition, pointing and tracking systems endowed with very narrow laser beams to reach the pointing accuracy presently prescribed. In fact, whatever the orbital elements of these objects may be, these equations will allow the operators to account for the corrections needed to balance the deviations of the line of sight directions due to the curvature of the paths the laser beams are to travel along. To minimize the respective corrections, the systems will have to perform initial positioning manoeuvres, and the shooting point-ahead angles will have to be adapted in real time. The enclosed numerical experiments suggest that neglecting these measures will cause fatal errors, due to differences in the actual locations of the objects comparable to their size.

A Hierarchical Algorithm for Fast Debye Summation with Applications to Small Angle Scattering

PubMed Central

Gumerov, Nail A.; Berlin, Konstantin; Fushman, David; Duraiswami, Ramani

2012-01-01

Debye summation, which involves the summation of sinc functions of distances between all pair of atoms in three dimensional space, arises in computations performed in crystallography, small/wide angle X-ray scattering (SAXS/WAXS) and small angle neutron scattering (SANS). Direct evaluation of Debye summation has quadratic complexity, which results in computational bottleneck when determining crystal properties, or running structure refinement protocols that involve SAXS or SANS, even for moderately sized molecules. We present a fast approximation algorithm that efficiently computes the summation to any prescribed accuracy ε in linear time. The algorithm is similar to the fast multipole method (FMM), and is based on a hierarchical spatial decomposition of the molecule coupled with local harmonic expansions and translation of these expansions. An even more efficient implementation is possible when the scattering profile is all that is required, as in small angle scattering reconstruction (SAS) of macromolecules. We examine the relationship of the proposed algorithm to existing approximate methods for profile computations, and show that these methods may result in inaccurate profile computations, unless an error bound derived in this paper is used. Our theoretical and computational results show orders of magnitude improvement in computation complexity over existing methods, while maintaining prescribed accuracy. PMID:22707386

Drug utilization, prescription errors and potential drug-drug interactions: an experience in rural Sri Lanka.

PubMed

Rathish, Devarajan; Bahini, Sivaswamy; Sivakumar, Thanikai; Thiranagama, Thilani; Abarajithan, Tharmarajah; Wijerathne, Buddhika; Jayasumana, Channa; Siribaddana, Sisira

2016-06-25

Prescription writing is a process which transfers the therapeutic message from the prescriber to the patient through the pharmacist. Prescribing errors, drug duplication and potential drug-drug interactions (pDDI) in prescriptions lead to medication error. Assessment of the above was made in prescriptions dispensed at State Pharmaceutical Corporation (SPC), Anuradhapura, Sri Lanka. A cross sectional study was conducted. Drugs were classified according to the WHO anatomical, therapeutic chemical classification system. A three point Likert scale, a checklist and Medscape online drug interaction checker were used to assess legibility, completeness and pDDIs respectively. Thousand prescriptions were collected. Majority were hand written (99.8 %) and from the private sector (73 %). The most frequently prescribed substance and subgroup were atorvastatin (4 %, n = 3668) and proton pump inhibitors (7 %, n = 3668) respectively. Out of the substances prescribed from the government and private sectors, 59 and 50 % respectively were available in the national list of essential medicines, Sri Lanka. Patients address (5 %), Sri Lanka Medical Council (SLMC) registration number (35 %), route (7 %), generic name (16 %), treatment symbol (48 %), diagnosis (41 %) and refill information (6 %) were seen in less than half of the prescriptions. Most were legible with effort (65 %) and illegibility was seen in 9 %. There was significant difference in omission and/or errors of generic name (P = 0.000), dose (P = 0.000), SLMC registration number (P = 0.000), and in evidence of pDDI (P = 0.009) with regards to the sector of prescribing. The commonest subgroup involved in duplication was non-steroidal anti-inflammatory drugs (NSAIDs) (43 %; 56/130). There were 1376 potential drug interactions (466/887 prescriptions). Most common pair causing pDDI was aspirin with losartan (4 %, n = 1376). Atorvastatin was the most frequently prescribed substance. Fifteen percent of the prescriptions originate from government sector. SLMC registration number and trade names were seen more in prescriptions originating from the private sector. Most prescriptions were legible with effort. NSAIDs were the commonest implicated in drug class duplication. Fifty three percent of prescriptions have pDDI.

Effects of skilled nursing facility structure and process factors on medication errors during nursing home admission.

PubMed

Lane, Sandi J; Troyer, Jennifer L; Dienemann, Jacqueline A; Laditka, Sarah B; Blanchette, Christopher M

2014-01-01

Older adults are at greatest risk of medication errors during the transition period of the first 7 days after admission and readmission to a skilled nursing facility (SNF). The aim of this study was to evaluate structure- and process-related factors that contribute to medication errors and harm during transition periods at a SNF. Data for medication errors and potential medication errors during the 7-day transition period for residents entering North Carolina SNFs were from the Medication Error Quality Initiative-Individual Error database from October 2006 to September 2007. The impact of SNF structure and process measures on the number of reported medication errors and harm from errors were examined using bivariate and multivariate model methods. A total of 138 SNFs reported 581 transition period medication errors; 73 (12.6%) caused harm. Chain affiliation was associated with a reduction in the volume of errors during the transition period. One third of all reported transition errors occurred during the medication administration phase of the medication use process, where dose omissions were the most common type of error; however, dose omissions caused harm less often than wrong-dose errors did. Prescribing errors were much less common than administration errors but were much more likely to cause harm. Both structure and process measures of quality were related to the volume of medication errors.However, process quality measures may play a more important role in predicting harm from errors during the transition of a resident into an SNF. Medication errors during transition could be reduced by improving both prescribing processes and transcription and documentation of orders.

Eddy-covariance data with low signal-to-noise ratio: time-lag determination, uncertainties and limit of detection

NASA Astrophysics Data System (ADS)

Langford, B.; Acton, W.; Ammann, C.; Valach, A.; Nemitz, E.

2015-10-01

All eddy-covariance flux measurements are associated with random uncertainties which are a combination of sampling error due to natural variability in turbulence and sensor noise. The former is the principal error for systems where the signal-to-noise ratio of the analyser is high, as is usually the case when measuring fluxes of heat, CO2 or H2O. Where signal is limited, which is often the case for measurements of other trace gases and aerosols, instrument uncertainties dominate. Here, we are applying a consistent approach based on auto- and cross-covariance functions to quantify the total random flux error and the random error due to instrument noise separately. As with previous approaches, the random error quantification assumes that the time lag between wind and concentration measurement is known. However, if combined with commonly used automated methods that identify the individual time lag by looking for the maximum in the cross-covariance function of the two entities, analyser noise additionally leads to a systematic bias in the fluxes. Combining data sets from several analysers and using simulations, we show that the method of time-lag determination becomes increasingly important as the magnitude of the instrument error approaches that of the sampling error. The flux bias can be particularly significant for disjunct data, whereas using a prescribed time lag eliminates these effects (provided the time lag does not fluctuate unduly over time). We also demonstrate that when sampling at higher elevations, where low frequency turbulence dominates and covariance peaks are broader, both the probability and magnitude of bias are magnified. We show that the statistical significance of noisy flux data can be increased (limit of detection can be decreased) by appropriate averaging of individual fluxes, but only if systematic biases are avoided by using a prescribed time lag. Finally, we make recommendations for the analysis and reporting of data with low signal-to-noise and their associated errors.

Eddy-covariance data with low signal-to-noise ratio: time-lag determination, uncertainties and limit of detection

NASA Astrophysics Data System (ADS)

Langford, B.; Acton, W.; Ammann, C.; Valach, A.; Nemitz, E.

2015-03-01

All eddy-covariance flux measurements are associated with random uncertainties which are a combination of sampling error due to natural variability in turbulence and sensor noise. The former is the principal error for systems where the signal-to-noise ratio of the analyser is high, as is usually the case when measuring fluxes of heat, CO2 or H2O. Where signal is limited, which is often the case for measurements of other trace gases and aerosols, instrument uncertainties dominate. We are here applying a consistent approach based on auto- and cross-covariance functions to quantifying the total random flux error and the random error due to instrument noise separately. As with previous approaches, the random error quantification assumes that the time-lag between wind and concentration measurement is known. However, if combined with commonly used automated methods that identify the individual time-lag by looking for the maximum in the cross-covariance function of the two entities, analyser noise additionally leads to a systematic bias in the fluxes. Combining datasets from several analysers and using simulations we show that the method of time-lag determination becomes increasingly important as the magnitude of the instrument error approaches that of the sampling error. The flux bias can be particularly significant for disjunct data, whereas using a prescribed time-lag eliminates these effects (provided the time-lag does not fluctuate unduly over time). We also demonstrate that when sampling at higher elevations, where low frequency turbulence dominates and covariance peaks are broader, both the probability and magnitude of bias are magnified. We show that the statistical significance of noisy flux data can be increased (limit of detection can be decreased) by appropriate averaging of individual fluxes, but only if systematic biases are avoided by using a prescribed time-lag. Finally, we make recommendations for the analysis and reporting of data with low signal-to-noise and their associated errors.

Paper-based and web-based intervention modeling experiments identified the same predictors of general practitioners' antibiotic-prescribing behavior.

PubMed

Treweek, Shaun; Bonetti, Debbie; Maclennan, Graeme; Barnett, Karen; Eccles, Martin P; Jones, Claire; Pitts, Nigel B; Ricketts, Ian W; Sullivan, Frank; Weal, Mark; Francis, Jill J

2014-03-01

To evaluate the robustness of the intervention modeling experiment (IME) methodology as a way of developing and testing behavioral change interventions before a full-scale trial by replicating an earlier paper-based IME. Web-based questionnaire and clinical scenario study. General practitioners across Scotland were invited to complete the questionnaire and scenarios, which were then used to identify predictors of antibiotic-prescribing behavior. These predictors were compared with the predictors identified in an earlier paper-based IME and used to develop a new intervention. Two hundred seventy general practitioners completed the questionnaires and scenarios. The constructs that predicted simulated behavior and intention were attitude, perceived behavioral control, risk perception/anticipated consequences, and self-efficacy, which match the targets identified in the earlier paper-based IME. The choice of persuasive communication as an intervention in the earlier IME was also confirmed. Additionally, a new intervention, an action plan, was developed. A web-based IME replicated the findings of an earlier paper-based IME, which provides confidence in the IME methodology. The interventions will now be evaluated in the next stage of the IME, a web-based randomized controlled trial. Copyright © 2014 Elsevier Inc. All rights reserved.

Evaluation of Faculty and Non-faculty Physicians’ Medication Errors in Outpatients’ Prescriptions in Shiraz, Iran

PubMed Central

Misagh, Pegah; Vazin, Afsaneh; Namazi, Soha

2018-01-01

This study was aimed at finding the occurrence rate of prescription errors in the outpatients› prescriptions written by faculty and non-faculty physicians practicing in Shiraz, Iran. In this cross-sectional study 2000 outpatient prescriptions were randomly collected from pharmacies affiliated with Shiraz University of Medical Sciences (SUMS) and social security insurance in Shiraz, Iran. Patient information including age, weight, diagnosis and chief complain were recorded. Physicians ‘characteristics were extracted from prescriptions. Prescription errors including errors in spelling, instruction, strength, dosage form and quantity as well as drug-drug interactions and contraindications were identified. The mean ± SD age of patients was 37.91 ± 21.10 years. Most of the patients were male (77.15%) and 81.50% of patients were adults. The average total number of drugs per prescription was 3.19 ± 1.60. The mean ± SD of prescription errors was 7.38 ± 4.06. Spelling error (26.4%), instruction error (21.03%), and strength error (19.18%) were the most frequent prescription errors. The mean ± SD of prescription errors was 7.83 ± 4.2 and 6.93 ± 3.88 in non-faculty and faculty physicians, respectively (P < 0.05). Number of prescription errors increased significantly as the number of prescribed drugs increased. All prescriptions had at least one error. The rate of prescription errors was higher in non-faculty physicians. Number of prescription errors related with the prescribed drugs in the prescription.

[Prospective assessment of medication errors in critically ill patients in a university hospital].

PubMed

Salazar L, Nicole; Jirón A, Marcela; Escobar O, Leslie; Tobar, Eduardo; Romero, Carlos

2011-11-01

Critically ill patients are especially vulnerable to medication errors (ME) due to their severe clinical situation and the complexities of their management. To determine the frequency and characteristics of ME and identify shortcomings in the processes of medication management in an Intensive Care Unit. During a 3 months period, an observational prospective and randomized study was carried out in the ICU of a university hospital. Every step of patient's medication management (prescription, transcription, dispensation, preparation and administration) was evaluated by an external trained professional. Steps with higher frequency of ME and their therapeutic groups involved were identified. Medications errors were classified according to the National Coordinating Council for Medication Error Reporting and Prevention. In 52 of 124 patients evaluated, 66 ME were found in 194 drugs prescribed. In 34% of prescribed drugs, there was at least 1 ME during its use. Half of ME occurred during medication administration, mainly due to problems in infusion rates and schedule times. Antibacterial drugs had the highest rate of ME. We found a 34% rate of ME per drug prescribed, which is in concordance with international reports. The identification of those steps more prone to ME in the ICU, will allow the implementation of an intervention program to improve the quality and security of medication management.

Threat Assessment and Remediation Analysis (TARA)

DTIC Science & Technology

2014-10-01

of countermeasure selection strategies that prescribe the application of countermeasures based on level of risk tolerance. This paper outlines the...catalog data, which are discussed later in this paper . The methodology can be described as conjoined trade studies, where the first trade identifies and...ranks vulnerabilities based on assessed risk, and the second identifies and selects countermeasures based on assessed utility and cost. This paper

Maneuvering and control of flexible space robots

NASA Technical Reports Server (NTRS)

Meirovitch, Leonard; Lim, Seungchul

1994-01-01

This paper is concerned with a flexible space robot capable of maneuvering payloads. The robot is assumed to consist of two hinge-connected flexible arms and a rigid end-effector holding a payload; the robot is mounted on a rigid platform floating in space. The equations of motion are nonlinear and of high order. Based on the assumption that the maneuvering motions are one order of magnitude larger than the elastic vibrations, a perturbation approach permits design of controls for the two types of motion separately. The rigid-body maneuvering is carried out open loop, but the elastic motions are controlled closed loop, by means of discrete-time linear quadratic regulator theory with prescribed degree of stability. A numerical example demonstrates the approach. In the example, the controls derived by the perturbation approach are applied to the original nonlinear system and errors are found to be relatively small.

Event-triggered H∞ state estimation for semi-Markov jumping discrete-time neural networks with quantization.

PubMed

Rakkiyappan, R; Maheswari, K; Velmurugan, G; Park, Ju H

2018-05-17

This paper investigates H ∞ state estimation problem for a class of semi-Markovian jumping discrete-time neural networks model with event-triggered scheme and quantization. First, a new event-triggered communication scheme is introduced to determine whether or not the current sampled sensor data should be broad-casted and transmitted to the quantizer, which can save the limited communication resource. Second, a novel communication framework is employed by the logarithmic quantizer that quantifies and reduces the data transmission rate in the network, which apparently improves the communication efficiency of networks. Third, a stabilization criterion is derived based on the sufficient condition which guarantees a prescribed H ∞ performance level in the estimation error system in terms of the linear matrix inequalities. Finally, numerical simulations are given to illustrate the correctness of the proposed scheme. Copyright © 2018 Elsevier Ltd. All rights reserved.

A review of the factors influencing antimicrobial prescribing.

PubMed

Calbo, Esther; Alvarez-Rocha, Luis; Gudiol, Francisco; Pasquau, Juan

2013-09-01

There are multiple benefits of appropriate antimicrobial prescribing: it has a direct impact on clinical outcomes, avoids adverse effects, is cost effective and, perhaps most importantly, it helps to prevent the emergence of resistance. However, any physician can prescribe antibiotics, which is not the case with other clinically relevant drugs. There is great variability in the prescribing physician's (PP) training, motivation, workload and setting, including accessibility to infectious diseases consultants and/or diagnostic techniques, and therefore there is a high risk of inappropriate prescription. Many antibiotic prescribing errors occur around the selection and duration of treatment. This includes a low threshold for the indication of antibiotics, delayed initiation of treatment when indicated, limited knowledge of local antimicrobial resistance patterns by the PPs, errors in the final choice of dose, route or drug and a lack of de-escalation. Similarly, the prescription of prophylactic antibiotics to prevent surgical site infections, despite being commonly accepted, is suboptimal. Factors that may explain suboptimal use are related to the absence of well-defined protocols, poor knowledge of prophylactic protocols, miscommunication or disagreement between physicians, logistical problems, and a lack of audits. A proper understanding of the prescribing process can guide interventions to improve the PP's practices. Some of the potential interventions included in a stewardship program are education in antimicrobial prescribing, information on the local resistance patterns and accessibility to a qualified infectious diseases consultant. Copyright © 2013 Elsevier España, S.L. All rights reserved.

Laboratory testing in primary care: A systematic review of health IT impacts.

PubMed

Maillet, Éric; Paré, Guy; Currie, Leanne M; Raymond, Louis; Ortiz de Guinea, Ana; Trudel, Marie-Claude; Marsan, Josianne

2018-08-01

Laboratory testing in primary care is a fundamental process that supports patient management and care. Any breakdown in the process may alter clinical information gathering and decision-making activities and can lead to medical errors and potential adverse outcomes for patients. Various information technologies are being used in primary care with the goal to support the process, maximize patient benefits and reduce medical errors. However, the overall impact of health information technologies on laboratory testing processes has not been evaluated. To synthesize the positive and negative impacts resulting from the use of health information technology in each phase of the laboratory 'total testing process' in primary care. We conducted a systematic review. Databases including Medline, PubMed, CINAHL, Web of Science and Google Scholar were searched. Studies eligible for inclusion reported empirical data on: 1) the use of a specific IT system, 2) the impacts of the systems to support the laboratory testing process, and were conducted in 3) primary care settings (including ambulatory care and primary care offices). Our final sample consisted of 22 empirical studies which were mapped to a framework that outlines the phases of the laboratory total testing process, focusing on phases where medical errors may occur. Health information technology systems support several phases of the laboratory testing process, from ordering the test to following-up with patients. This is a growing field of research with most studies focusing on the use of information technology during the final phases of the laboratory total testing process. The findings were largely positive. Positive impacts included easier access to test results by primary care providers, reduced turnaround times, and increased prescribed tests based on best practice guidelines. Negative impacts were reported in several studies: paper-based processes employed in parallel to the electronic process increased the potential for medical errors due to clinicians' cognitive overload; systems deemed not reliable or user-friendly hampered clinicians' performance; and organizational issues arose when results tracking relied on the prescribers' memory. The potential of health information technology lies not only in the exchange of health information, but also in knowledge sharing among clinicians. This review has underscored the important role played by cognitive factors, which are critical in the clinician's decision-making, the selection of the most appropriate tests, correct interpretation of the results and efficient interventions. By providing the right information, at the right time to the right clinician, many IT solutions adequately support the laboratory testing process and help primary care clinicians make better decisions. However, several technological and organizational barriers require more attention to fully support the highly fragmented and error-prone process of laboratory testing. Copyright © 2018 Elsevier B.V. All rights reserved.

An observational study of drug administration errors in a Malaysian hospital (study of drug administration errors).

PubMed

Chua, S S; Tea, M H; Rahman, M H A

2009-04-01

Drug administration errors were the second most frequent type of medication errors, after prescribing errors but the latter were often intercepted hence, administration errors were more probably to reach the patients. Therefore, this study was conducted to determine the frequency and types of drug administration errors in a Malaysian hospital ward. This is a prospective study that involved direct, undisguised observations of drug administrations in a hospital ward. A researcher was stationed in the ward under study for 15 days to observe all drug administrations which were recorded in a data collection form and then compared with the drugs prescribed for the patient. A total of 1118 opportunities for errors were observed and 127 administrations had errors. This gave an error rate of 11.4 % [95% confidence interval (CI) 9.5-13.3]. If incorrect time errors were excluded, the error rate reduced to 8.7% (95% CI 7.1-10.4). The most common types of drug administration errors were incorrect time (25.2%), followed by incorrect technique of administration (16.3%) and unauthorized drug errors (14.1%). In terms of clinical significance, 10.4% of the administration errors were considered as potentially life-threatening. Intravenous routes were more likely to be associated with an administration error than oral routes (21.3% vs. 7.9%, P < 0.001). The study indicates that the frequency of drug administration errors in developing countries such as Malaysia is similar to that in the developed countries. Incorrect time errors were also the most common type of drug administration errors. A non-punitive system of reporting medication errors should be established to encourage more information to be documented so that risk management protocol could be developed and implemented.

Introduction to the Application of Web-Based Surveys.

ERIC Educational Resources Information Center

Timmerman, Annemarie

This paper discusses some basic assumptions and issues concerning web-based surveys. Discussion includes: assumptions regarding cost and ease of use; disadvantages of web-based surveys, concerning the inability to compensate for four common errors of survey research: coverage error, sampling error, measurement error and nonresponse error; and…

On selecting satellite conjunction filter parameters

NASA Astrophysics Data System (ADS)

Alfano, Salvatore; Finkleman, David

2014-06-01

This paper extends concepts of signal detection theory to predict the performance of conjunction screening techniques and guiding the selection of keepout and screening thresholds. The most efficient way to identify satellites likely to collide is to employ filters to identify orbiting pairs that should not come close enough over a prescribed time period to be considered hazardous. Such pairings can then be eliminated from further computation to accelerate overall processing time. Approximations inherent in filtering techniques include screening using only unperturbed Newtonian two body astrodynamics and uncertainties in orbit elements. Therefore, every filtering process is vulnerable to including objects that are not threats and excluding some that are threats, Type I and Type II errors. The approach in this paper guides selection of the best operating point for the filters suited to a user's tolerance for false alarms and unwarned threats. We demonstrate the approach using three archetypal filters with an initial three-day span, select filter parameters based on performance, and then test those parameters using eight historical snapshots of the space catalog. This work provides a mechanism for selecting filter parameters but the choices depend on the circumstances.

Master-slave control with trajectory planning and Bouc-Wen model for tracking control of piezo-driven stage

NASA Astrophysics Data System (ADS)

Lu, Xiaojun; Liu, Changli; Chen, Lei

2018-04-01

In this paper, a redundant Piezo-driven stage having 3RRR compliant mechanism is introduced, we propose the master-slave control with trajectory planning (MSCTP) strategy and Bouc-Wen model to improve its micro-motion tracking performance. The advantage of the proposed controller lies in that its implementation only requires a simple control strategy without the complexity of modeling to avoid the master PEA's tracking error. The dynamic model of slave PEA system with Bouc-Wen hysteresis is established and identified via particle swarm optimization (PSO) approach. The Piezo-driven stage with operating period T=1s and 2s is implemented to track a prescribed circle. The simulation results show that MSCTP with Bouc-Wen model reduces the trajectory tracking errors to the range of the accuracy of our available measurement.

Optimal Power Flow for Distribution Systems under Uncertain Forecasts: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dall'Anese, Emiliano; Baker, Kyri; Summers, Tyler

2016-12-01

The paper focuses on distribution systems featuring renewable energy sources and energy storage devices, and develops an optimal power flow (OPF) approach to optimize the system operation in spite of forecasting errors. The proposed method builds on a chance-constrained multi-period AC OPF formulation, where probabilistic constraints are utilized to enforce voltage regulation with a prescribed probability. To enable a computationally affordable solution approach, a convex reformulation of the OPF task is obtained by resorting to i) pertinent linear approximations of the power flow equations, and ii) convex approximations of the chance constraints. Particularly, the approximate chance constraints provide conservative boundsmore » that hold for arbitrary distributions of the forecasting errors. An adaptive optimization strategy is then obtained by embedding the proposed OPF task into a model predictive control framework.« less

DRUGS System Improving the Effects of Clinical Pathways: A Systematic Study.

PubMed

Wang, Shan; Zhu, Xiaohe; Zhao, Xian; Lu, Yang; Yang, Zhifu; Qian, Xiaoliang; Li, Weiwei; Ma, Lixiazi; Guo, Huning; Wang, Jingwen; Wen, Aidong

2016-03-01

The aim of the study is to assess the feasibility of Drugs Rational Usage Guideline System (DRUGS)-supported clinical pathway (CP) for breast carcinoma, cataract, inguinal hernia and 2-diabetes mellitus whether the application of such a system could improve work efficiency, medical safety, and decrease hospital cost. Four kinds of diseases which included 1773 cases (where 901 cases using paper-based clinical pathways and 872 cases using DRUGS-supported clinical pathways) were selected and their demographic and clinical data were collected. The evaluation criteria were length of stay, preoperative length of stay, hospital cost, antibiotics prescribed during hospitalization, unscheduled surgery, complications and prognosis. The median total LOS was 1 to 3 days shorter in the DRUGS-supported CP group as compared to the Paper-based CP group for all types (p < 0.05). Totel hospital cost decreased significantly in the DRUGS-supported CP group than that in Paper-based CP group. About antibiotics prescribed during hospitalization, there were no statistically differences in the time of initial dose of antibiotic and the duration of administration except the choice of antibiotic categories. The proportion of DRUGS-supported clinical pathway conditions where a broad-spectrum antibiotic was prescribed decreased from 63.6 to 34.5 % (p < 0.01) in the Paper-based group. While after the intervention, the differences were statistically not significant in unscheduled surgery, complications and prognosis. In this study, DRUGS-supported clinical pathway for breast carcinoma, cataract, inguinal hernia, 2-diabetes mellitus was smoothly shifted from a paper-based to an electronic system, and confer benefits at the hospital level.

Global error estimation based on the tolerance proportionality for some adaptive Runge-Kutta codes

NASA Astrophysics Data System (ADS)

Calvo, M.; González-Pinto, S.; Montijano, J. I.

2008-09-01

Modern codes for the numerical solution of Initial Value Problems (IVPs) in ODEs are based in adaptive methods that, for a user supplied tolerance [delta], attempt to advance the integration selecting the size of each step so that some measure of the local error is [similar, equals][delta]. Although this policy does not ensure that the global errors are under the prescribed tolerance, after the early studies of Stetter [Considerations concerning a theory for ODE-solvers, in: R. Burlisch, R.D. Grigorieff, J. Schröder (Eds.), Numerical Treatment of Differential Equations, Proceedings of Oberwolfach, 1976, Lecture Notes in Mathematics, vol. 631, Springer, Berlin, 1978, pp. 188-200; Tolerance proportionality in ODE codes, in: R. März (Ed.), Proceedings of the Second Conference on Numerical Treatment of Ordinary Differential Equations, Humbold University, Berlin, 1980, pp. 109-123] and the extensions of Higham [Global error versus tolerance for explicit Runge-Kutta methods, IMA J. Numer. Anal. 11 (1991) 457-480; The tolerance proportionality of adaptive ODE solvers, J. Comput. Appl. Math. 45 (1993) 227-236; The reliability of standard local error control algorithms for initial value ordinary differential equations, in: Proceedings: The Quality of Numerical Software: Assessment and Enhancement, IFIP Series, Springer, Berlin, 1997], it has been proved that in many existing explicit Runge-Kutta codes the global errors behave asymptotically as some rational power of [delta]. This step-size policy, for a given IVP, determines at each grid point tn a new step-size hn+1=h(tn;[delta]) so that h(t;[delta]) is a continuous function of t. In this paper a study of the tolerance proportionality property under a discontinuous step-size policy that does not allow to change the size of the step if the step-size ratio between two consecutive steps is close to unity is carried out. This theory is applied to obtain global error estimations in a few problems that have been solved with the code Gauss2 [S. Gonzalez-Pinto, R. Rojas-Bello, Gauss2, a Fortran 90 code for second order initial value problems, ], based on an adaptive two stage Runge-Kutta-Gauss method with this discontinuous step-size policy.

Learning from Errors in Dual Vocational Education: Video-Enhanced Instructional Strategies

ERIC Educational Resources Information Center

Cattaneo, Alberto A. P.; Boldrini, Elena

2017-01-01

Purpose: Starting from the identification of some theoretically driven instructional principles, this paper presents a set of empirical cases based on strategies to learn from errors. The purpose of this paper is to provide first evidence about the feasibility and the effectiveness for learning of video-enhanced error-based strategies in…

Pharmaceutical company influences on medication prescribing and their potential impact on quality use of medicines.

PubMed

Kyle, G J; Nissen, L M; Tett, S E

2008-10-01

Pharmaceuticals are big business, reporting strong market growth year after year. The 'gatekeepers' of this market are prescribers of medicines, who are the major target of pharmaceutical companies, utilizing direct and indirect influences. This paper draws on previous research investigating pharmaceutical company prescribing influences to develop a qualitative model demonstrating the synergism between commercial influences on prescribing. The generic model was used to explore a realistic but hypothetical scenario to ascertain the applicability of the model. A generic influence model was developed. The model was readily able to be adapted to reflect a realistic practice scenario. Prescriber awareness of the linkages between various seemingly separate marketing techniques could potentially improve medicines usage in an evidence-based practice paradigm.

Analysis of knowledge and attitude surveys to identify barriers and enablers of appropriate antimicrobial prescribing in three Australian tertiary hospitals.

PubMed

Chaves, N J; Cheng, A C; Runnegar, N; Kirschner, J; Lee, T; Buising, K

2014-06-01

Antimicrobial stewardship programmes aim to optimise use of antibiotics and are now mandatory in all Australian hospitals. We aimed to identify barriers to and enablers of appropriate antimicrobial prescribing among hospital doctors. Two paper-based and one web-based surveys were administered at three Australian university teaching hospitals from March 2010 to May 2011. The 18-item questionnaire recorded doctors’ level of experience, their knowledge regarding the use of common antimicrobials and their attitudes regarding antimicrobial prescribing. Local survey modifications allowed inclusion of specific questions on: infections in intensive care unit patients, clinical microbiology and use of local guidelines. The respondents (n = 272) were comprised of 96 (35%) registrars, 67 (25%)residents, 57 (21%) interns and 47 (17%) consultant hospital doctors. Forty-one per cent were working in a medical specialty. Identified barriers included: gaps in antimicrobial prescribing knowledge (especially among interns), a lack of awareness about which antimicrobials were restricted and a reliance on senior colleagues to make antimicrobial prescribing decisions. Enablers of optimal prescribing included: an acknowledgement of the need for assistance in prescribing and reported readiness to consult national prescribing guidelines. These results were used to help guide and prioritise interventions to improve prescribing practices. A transferable knowledge and attitudes survey tool can be used to highlight barriers and facilitators to optimal hospital antimicrobial prescribing in order to inform tailored antimicrobial stewardship interventions.

A comparison of smartphone and paper data-collection tools in the Burden of Obstructive Lung Disease (BOLD) study in Gezira state, Sudan

PubMed Central

Ahmed, Rana; Robinson, Ryan; Elsony, Asma; Thomson, Rachael; Squire, S. Bertel; Malmborg, Rasmus; Burney, Peter

2018-01-01

Introduction Data collection using paper-based questionnaires can be time consuming and return errors affect data accuracy, completeness, and information quality in health surveys. We compared smartphone and paper-based data collection systems in the Burden of Obstructive Lung Disease (BOLD) study in rural Sudan. Methods This exploratory pilot study was designed to run in parallel with the cross-sectional household survey. The Open Data Kit was used to programme questionnaires in Arabic into smartphones. We included 100 study participants (83% women; median age = 41.5 ± 16.4 years) from the BOLD study from 3 rural villages in East-Gezira and Kamleen localities of Gezira state, Sudan. Questionnaire data were collected using smartphone and paper-based technologies simultaneously. We used Kappa statistics and inter-rater class coefficient to test agreement between the two methods. Results Symptoms reported included cough (24%), phlegm (15%), wheezing (17%), and shortness of breath (18%). One in five were or had been cigarette smokers. The two data collection methods varied between perfect to slight agreement across the 204 variables evaluated (Kappa varied between 1.00 and 0.02 and inter-rater coefficient between 1.00 and -0.12). Errors were most commonly seen with paper questionnaires (83% of errors seen) vs smartphones (17% of errors seen) administered questionnaires with questions with complex skip-patterns being a major source of errors in paper questionnaires. Automated checks and validations in smartphone-administered questionnaires avoided skip-pattern related errors. Incomplete and inconsistent records were more likely seen on paper questionnaires. Conclusion Compared to paper-based data collection, smartphone technology worked well for data collection in the study, which was conducted in a challenging rural environment in Sudan. This approach provided timely, quality data with fewer errors and inconsistencies compared to paper-based data collection. We recommend this method for future BOLD studies and other population-based studies in similar settings. PMID:29518132

Exploring Discretization Error in Simulation-Based Aerodynamic Databases

NASA Technical Reports Server (NTRS)

Aftosmis, Michael J.; Nemec, Marian

2010-01-01

This work examines the level of discretization error in simulation-based aerodynamic databases and introduces strategies for error control. Simulations are performed using a parallel, multi-level Euler solver on embedded-boundary Cartesian meshes. Discretization errors in user-selected outputs are estimated using the method of adjoint-weighted residuals and we use adaptive mesh refinement to reduce these errors to specified tolerances. Using this framework, we examine the behavior of discretization error throughout a token database computed for a NACA 0012 airfoil consisting of 120 cases. We compare the cost and accuracy of two approaches for aerodynamic database generation. In the first approach, mesh adaptation is used to compute all cases in the database to a prescribed level of accuracy. The second approach conducts all simulations using the same computational mesh without adaptation. We quantitatively assess the error landscape and computational costs in both databases. This investigation highlights sensitivities of the database under a variety of conditions. The presence of transonic shocks or the stiffness in the governing equations near the incompressible limit are shown to dramatically increase discretization error requiring additional mesh resolution to control. Results show that such pathologies lead to error levels that vary by over factor of 40 when using a fixed mesh throughout the database. Alternatively, controlling this sensitivity through mesh adaptation leads to mesh sizes which span two orders of magnitude. We propose strategies to minimize simulation cost in sensitive regions and discuss the role of error-estimation in database quality.

Medication dosing errors and associated factors in hospitalized pediatric patients from the South Area of the West Bank - Palestine.

PubMed

Al-Ramahi, Rowa'; Hmedat, Bayan; Alnjajrah, Eman; Manasrah, Israa; Radwan, Iqbal; Alkhatib, Maram

2017-09-01

Medication dosing errors are a significant global concern and can cause serious medical consequences for patients. Pediatric patients are at increased risk of dosing errors due to differences in medication pharmacodynamics and pharmacokinetics. The aims of this study were to find the rate of medication dosing errors in hospitalized pediatric patients and possible associated factors. The study was an observational cohort study including pediatric inpatients less than 16 years from three governmental hospitals from the West Bank/Palestine during one month in 2014, and sample size was 400 pediatric inpatients from these three hospitals. Pediatric patients' medical records were reviewed. Patients' weight, age, medical conditions, all prescribed medications, their doses and frequency were documented. Then the doses of medications were evaluated. Among 400 patients, the medications prescribed were 949 medications, 213 of them (22.4%) were out of the recommended range, and 160 patients (40.0%) were prescribed one or more potentially inappropriate doses. The most common cause of hospital admission was sepsis which presented 14.3% of cases, followed by fever (13.5%) and meningitis (10.0%). The most commonly used medications were ampicillin in 194 cases (20.4%), ceftriaxone in 182 cases (19.2%), and cefotaxime in 144 cases (12.0%). No significant association was found between potentially inappropriate doses and gender or hospital (chi-square test p -value > 0.05).The results showed that patients with lower body weight, who had a higher number of medications and stayed in hospital for a longer time, were more likely to have inappropriate doses. Potential medication dosing errors were high among pediatric hospitalized patients in Palestine. Younger patients, patients with lower body weight, who were prescribed higher number of medications and stayed in hospital for a longer time were more likely to have inappropriate doses, so these populations require special care. Many children were hospitalized for infectious causes and antibiotics were widely used. Strategies to reduce pediatric medication dosing errors are recommended.

A new composite adaptive controller featuring the neural network and prescribed sliding surface with application to vibration control

NASA Astrophysics Data System (ADS)

Phu, Do Xuan; Huy, Ta Duc; Mien, Van; Choi, Seung-Bok

2018-07-01

This work proposes a novel composite adaptive controller based on the prescribed performance of the sliding surface and applies it to vibration control of a semi-active vehicle seat suspension system subjected to severe external disturbances. As a first step, the online fast interval type 2 fuzzy neural network system is adopted to establish a model and two sliding surfaces are used; conventional surface and prescribed surface. Then, an equivalent control is determined by assuming the derivative of the prescribed surface is zero, followed by the design of a controller which can guarantee both stability and robustness. Then, two controllers are combined and integrated with adaptation laws using the projection algorithm. The effectiveness of the proposed composite controller is validated through both simulation and experiment by undertaking vibration control of a semi-active seat suspension system equipped with a magneto-rheological (MR) damper. It is shown from both simulation and experimental realization that excellent vibration control performances are achieved with a small tracking error between the proposed and prescribed objectives. In addition, the control superiority of the proposed controller to conventional sliding mode controller featuring one sliding surface and proportional-integral-derivative (PID) controllers are demonstrated through a comparative work.

An examination of the operational error database for air route traffic control centers.

DOT National Transportation Integrated Search

1993-12-01

Monitoring the frequency and determining the causes of operational errors - defined as the loss of prescribed separation between aircraft - is one approach to assessing the operational safety of the air traffic control system. The Federal Aviation Ad...

Models and theories of prescribing decisions: A review and suggested a new model.

PubMed

Murshid, Mohsen Ali; Mohaidin, Zurina

2017-01-01

To date, research on the prescribing decisions of physician lacks sound theoretical foundations. In fact, drug prescribing by doctors is a complex phenomenon influenced by various factors. Most of the existing studies in the area of drug prescription explain the process of decision-making by physicians via the exploratory approach rather than theoretical. Therefore, this review is an attempt to suggest a value conceptual model that explains the theoretical linkages existing between marketing efforts, patient and pharmacist and physician decision to prescribe the drugs. The paper follows an inclusive review approach and applies the previous theoretical models of prescribing behaviour to identify the relational factors. More specifically, the report identifies and uses several valuable perspectives such as the 'persuasion theory - elaboration likelihood model', the stimuli-response marketing model', the 'agency theory', the theory of planned behaviour,' and 'social power theory,' in developing an innovative conceptual paradigm. Based on the combination of existing methods and previous models, this paper suggests a new conceptual model of the physician decision-making process. This unique model has the potential for use in further research.

The effect of a computerized prescribing and calculating system on hypo- and hyperglycemias and on prescribing time efficiency in neonatal intensive care patients.

PubMed

Maat, Barbara; Rademaker, Carin M A; Oostveen, Marloes I; Krediet, Tannette G; Egberts, Toine C G; Bollen, Casper W

2013-01-01

Prescribing glucose requires complex calculations because glucose is present in parenteral and enteral nutrition and drug vehicles, making it error prone and contributing to the burden of prescribing errors. Evaluation of the impact of a computerized physician order entry (CPOE) system with clinical decision support (CDS) for glucose control in neonatal intensive care patients (NICU) focusing on hypo- and hyperglycemic episodes and prescribing time efficiency. An interrupted time-series design to examine the effect of CPOE on hypo- and hyperglycemias and a crossover simulation study to examine the influence of CPOE on prescribing time efficiency. NICU patients at risk for glucose imbalance hospitalized at the University Medical Center Utrecht during 2001-2007 were selected. The risks of hypo- and hyperglycemias were expressed as incidences per 100 patient days in consecutive 3-month intervals during 3 years before and after CPOE implementation. To assess prescribing time efficiency, time needed to calculate glucose intake with and without CPOE was measured. No significant difference was found between pre- and post-CPOE mean incidences of hypo- and hyperglycemias per 100 hospital days of neonates at risk in every 3-month period (hypoglycemias, 4.0 [95% confidence interval, 3.2-4.8] pre-CPOE and 3.1 [2.7-3.5] post-CPOE, P = .88; hyperglycemias, 6.0 [4.3-7.7] pre-CPOE and 5.0 [3.7-6.3] post-CPOE, P = .75). CPOE led to a significant time reduction of 16% (1.3 [0.3-2.3] minutes) for simple and 60% (8.6 [5.1-12.1] minutes) for complex calculations. CPOE including a special CDS tool preserved accuracy for calculation and control of glucose intake and increased prescribing time efficiency.

Evaluation of Hand Written and Computerized Out-Patient Prescriptions in Urban Part of Central Gujarat.

PubMed

Joshi, Anuradha; Buch, Jatin; Kothari, Nitin; Shah, Nishal

2016-06-01

Prescription order is an important therapeutic transaction between physician and patient. A good quality prescription is an extremely important factor for minimizing errors in dispensing medication and it should be adherent to guidelines for prescription writing for benefit of the patient. To evaluate frequency and type of prescription errors in outpatient prescriptions and find whether prescription writing abides with WHO standards of prescription writing. A cross-sectional observational study was conducted at Anand city. Allopathic private practitioners practising at Anand city of different specialities were included in study. Collection of prescriptions was started a month after the consent to minimize bias in prescription writing. The prescriptions were collected from local pharmacy stores of Anand city over a period of six months. Prescriptions were analysed for errors in standard information, according to WHO guide to good prescribing. Descriptive analysis was performed to estimate frequency of errors, data were expressed as numbers and percentage. Total 749 (549 handwritten and 200 computerised) prescriptions were collected. Abundant omission errors were identified in handwritten prescriptions e.g., OPD number was mentioned in 6.19%, patient's age was mentioned in 25.50%, gender in 17.30%, address in 9.29% and weight of patient mentioned in 11.29%, while in drug items only 2.97% drugs were prescribed by generic name. Route and Dosage form was mentioned in 77.35%-78.15%, dose mentioned in 47.25%, unit in 13.91%, regimens were mentioned in 72.93% while signa (direction for drug use) in 62.35%. Total 4384 errors out of 549 handwritten prescriptions and 501 errors out of 200 computerized prescriptions were found in clinicians and patient details. While in drug item details, total number of errors identified were 5015 and 621 in handwritten and computerized prescriptions respectively. As compared to handwritten prescriptions, computerized prescriptions appeared to be associated with relatively lower rates of error. Since out-patient prescription errors are abundant and often occur in handwritten prescriptions, prescribers need to adapt themselves to computerized prescription order entry in their daily practice.

Evaluation of Hand Written and Computerized Out-Patient Prescriptions in Urban Part of Central Gujarat

PubMed Central

Buch, Jatin; Kothari, Nitin; Shah, Nishal

2016-01-01

Introduction Prescription order is an important therapeutic transaction between physician and patient. A good quality prescription is an extremely important factor for minimizing errors in dispensing medication and it should be adherent to guidelines for prescription writing for benefit of the patient. Aim To evaluate frequency and type of prescription errors in outpatient prescriptions and find whether prescription writing abides with WHO standards of prescription writing. Materials and Methods A cross-sectional observational study was conducted at Anand city. Allopathic private practitioners practising at Anand city of different specialities were included in study. Collection of prescriptions was started a month after the consent to minimize bias in prescription writing. The prescriptions were collected from local pharmacy stores of Anand city over a period of six months. Prescriptions were analysed for errors in standard information, according to WHO guide to good prescribing. Statistical Analysis Descriptive analysis was performed to estimate frequency of errors, data were expressed as numbers and percentage. Results Total 749 (549 handwritten and 200 computerised) prescriptions were collected. Abundant omission errors were identified in handwritten prescriptions e.g., OPD number was mentioned in 6.19%, patient’s age was mentioned in 25.50%, gender in 17.30%, address in 9.29% and weight of patient mentioned in 11.29%, while in drug items only 2.97% drugs were prescribed by generic name. Route and Dosage form was mentioned in 77.35%-78.15%, dose mentioned in 47.25%, unit in 13.91%, regimens were mentioned in 72.93% while signa (direction for drug use) in 62.35%. Total 4384 errors out of 549 handwritten prescriptions and 501 errors out of 200 computerized prescriptions were found in clinicians and patient details. While in drug item details, total number of errors identified were 5015 and 621 in handwritten and computerized prescriptions respectively. Conclusion As compared to handwritten prescriptions, computerized prescriptions appeared to be associated with relatively lower rates of error. Since out-patient prescription errors are abundant and often occur in handwritten prescriptions, prescribers need to adapt themselves to computerized prescription order entry in their daily practice. PMID:27504305

Preventing medication errors in cancer chemotherapy.

PubMed

Cohen, M R; Anderson, R W; Attilio, R M; Green, L; Muller, R J; Pruemer, J M

1996-04-01

Recommendations for preventing medication errors in cancer chemotherapy are made. Before a health care provider is granted privileges to prescribe, dispense, or administer antineoplastic agents, he or she should undergo a tailored educational program and possibly testing or certification. Appropriate reference materials should be developed. Each institution should develop a dose-verification process with as many independent checks as possible. A detailed checklist covering prescribing, transcribing, dispensing, and administration should be used. Oral orders are not acceptable. All doses should be calculated independently by the physician, the pharmacist, and the nurse. Dosage limits should be established and a review process set up for doses that exceed the limits. These limits should be entered into pharmacy computer systems, listed on preprinted order forms, stated on the product packaging, placed in strategic locations in the institution, and communicated to employees. The prescribing vocabulary must be standardized. Acronyms, abbreviations, and brand names must be avoided and steps taken to avoid other sources of confusion in the written orders, such as trailing zeros. Preprinted antineoplastic drug order forms containing checklists can help avoid errors. Manufacturers should be encouraged to avoid or eliminate ambiguities in drug names and dosing information. Patients must be educated about all aspects of their cancer chemotherapy, as patients represent a last line of defense against errors. An interdisciplinary team at each practice site should review every medication error reported. Pharmacists should be involved at all sites where antineoplastic agents are dispensed. Although it may not be possible to eliminate all medication errors in cancer chemotherapy, the risk can be minimized through specific steps. Because of their training and experience, pharmacists should take the lead in this effort.

Enhancing adaptive sparse grid approximations and improving refinement strategies using adjoint-based a posteriori error estimates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jakeman, J.D., E-mail: jdjakem@sandia.gov; Wildey, T.

2015-01-01

In this paper we present an algorithm for adaptive sparse grid approximations of quantities of interest computed from discretized partial differential equations. We use adjoint-based a posteriori error estimates of the physical discretization error and the interpolation error in the sparse grid to enhance the sparse grid approximation and to drive adaptivity of the sparse grid. Utilizing these error estimates provides significantly more accurate functional values for random samples of the sparse grid approximation. We also demonstrate that alternative refinement strategies based upon a posteriori error estimates can lead to further increases in accuracy in the approximation over traditional hierarchicalmore » surplus based strategies. Throughout this paper we also provide and test a framework for balancing the physical discretization error with the stochastic interpolation error of the enhanced sparse grid approximation.« less

Searching for Real-World Effectiveness of Health Care Innovations: Scoping Study of Social Prescribing for Diabetes

PubMed Central

Loef, Martin; Polley, Marie

2017-01-01

Background Social prescribing is a process whereby primary care patients are linked or referred to nonmedical sources of support in the community and voluntary sector. It is a concept that has arisen in practice and implemented widely in the United Kingdom and has been evaluated by various organizations. Objective The aim of our study was to characterize, collate, and analyze the evidence from evaluation of social prescribing for type 2 diabetes in the United Kingdom and Ireland, comparing information available on publicly available websites with the published literature. Methods We used a broad, pragmatic definition of social prescribing and conducted Web-based searches for websites of organizations providing potentially relevant services. We also explored linked information. In parallel, we searched Medline, PubMed, Cochrane Library, Google Scholar, and reference lists for relevant studies published in peer-reviewed journals. We extracted the data systematically on the characteristics, any reported evaluation, outcomes measured and results, and terminology used to describe each service. Results We identified 40 UK- or Ireland-based projects that referred people with type 2 diabetes and prediabetes to nonmedical interventions or services provided in the community. We located evaluations of 24 projects; 11 as published papers, 12 as Web-based reports, and 1 as both a paper and a Web-based report. The interventions and services identified included structured group educational programs, exercise referral schemes, and individualized advice and support with signposting of health-related activities in the community. Although specific interventions such as community-based group educational programs and exercise referral have been evaluated in randomized controlled trials, evaluation of individualized social prescribing services involving people with type 2 diabetes has, in most cases, used pre-post and mixed methods approaches. These evaluations report generic improvement in a broad range of outcomes and provide an insight into the criteria for the success of social prescribing services. Conclusions Our study revealed the varied models of social prescribing and nonmedical, community-based services available to people with type 2 diabetes and the extent of evaluation of these, which would not have been achieved by searching databases alone. The findings of this scoping study do not prove that social prescribing is an effective measure for people with type 2 diabetes in the United Kingdom, but can be used to inform future evaluation and contribute to the development of the evidence base for social prescribing. Accessing Web-based information provides a potential method for investigating how specific innovative health concepts, such as social prescribing, have been translated, implemented, and evaluated in practice. Several challenges were encountered including defining the concept, focusing on process plus intervention, and searching diverse, evolving Web-based sources. Further exploration of this approach will inform future research on the application of innovative health care concepts into practice. PMID:28153817

PID-based error signal modeling

NASA Astrophysics Data System (ADS)

Yohannes, Tesfay

1997-10-01

This paper introduces a PID based signal error modeling. The error modeling is based on the betterment process. The resulting iterative learning algorithm is introduced and a detailed proof is provided for both linear and nonlinear systems.

Prevalence and pattern of prescription errors in a Nigerian kidney hospital.

PubMed

Babatunde, Kehinde M; Akinbodewa, Akinwumi A; Akinboye, Ayodele O; Adejumo, Ademola O

2016-12-01

To determine (i) the prevalence and pattern of prescription errors in our Centre and, (ii) appraise pharmacists' intervention and correction of identified prescription errors. A descriptive, single blinded cross-sectional study. Kidney Care Centre is a public Specialist hospital. The monthly patient load averages 60 General Out-patient cases and 17.4 in-patients. A total of 31 medical doctors (comprising of 2 Consultant Nephrologists, 15 Medical Officers, 14 House Officers), 40 nurses and 24 ward assistants participated in the study. One pharmacist runs the daily call schedule. Prescribers were blinded to the study. Prescriptions containing only galenicals were excluded. An error detection mechanism was set up to identify and correct prescription errors. Life-threatening prescriptions were discussed with the Quality Assurance Team of the Centre who conveyed such errors to the prescriber without revealing the on-going study. Prevalence of prescription errors, pattern of prescription errors, pharmacist's intervention. A total of 2,660 (75.0%) combined prescription errors were found to have one form of error or the other; illegitimacy 1,388 (52.18%), omission 1,221(45.90%), wrong dose 51(1.92%) and no error of style was detected. Life-threatening errors were low (1.1-2.2%). Errors were found more commonly among junior doctors and non-medical doctors. Only 56 (1.6%) of the errors were detected and corrected during the process of dispensing. Prescription errors related to illegitimacy and omissions were highly prevalent. There is a need to improve on patient-to-healthcare giver ratio. A medication quality assurance unit is needed in our hospitals. No financial support was received by any of the authors for this study.

Predictive models of safety based on audit findings: Part 1: Model development and reliability.

PubMed

Hsiao, Yu-Lin; Drury, Colin; Wu, Changxu; Paquet, Victor

2013-03-01

This consecutive study was aimed at the quantitative validation of safety audit tools as predictors of safety performance, as we were unable to find prior studies that tested audit validity against safety outcomes. An aviation maintenance domain was chosen for this work as both audits and safety outcomes are currently prescribed and regulated. In Part 1, we developed a Human Factors/Ergonomics classification framework based on HFACS model (Shappell and Wiegmann, 2001a,b), for the human errors detected by audits, because merely counting audit findings did not predict future safety. The framework was tested for measurement reliability using four participants, two of whom classified errors on 1238 audit reports. Kappa values leveled out after about 200 audits at between 0.5 and 0.8 for different tiers of errors categories. This showed sufficient reliability to proceed with prediction validity testing in Part 2. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Refractive Errors and Academic Achievements of Primary School Children.

PubMed

Joseph, Lucyamma

2014-01-01

The current study was conducted among school children of selected schools of Thiruvananthapuram district of Kerala. It was designed to investigate the effect of refractive errors on academic achievement of primary school children. Experimental method was used in the study and the study used a sample of 185 children. An equated sample without myopia were selected as control group. Academic achievement tests based on the study syllabus were prepared and administered to both groups. The children with myopia were given corrective devices such as glasses prescribed by the ophthalmologist. After five months academic achievement tests were again given to both groups and the results of the scores between two groups as well as the scores before and after correction of errors were compared, which showed a significant influence of myopia on academic achievement and examination anxiety of children.

Prescription Errors in Older Individuals with an Intellectual Disability: Prevalence and Risk Factors in the Healthy Ageing and Intellectual Disability Study

ERIC Educational Resources Information Center

Zaal, Rianne J.; van der Kaaij, Annemieke D. M.; Evenhuis, Heleen M.; van den Bemt, Patricia M. L. A.

2013-01-01

Prescribing pharmacotherapy for older individuals with an intellectual disability (ID) is a complex process, possibly leading to an increased risk of prescription errors. The objectives of this study were (1) to determine the prevalence of older individuals with an intellectual disability with at least one prescription error and (2) to identify…

Simulation of co-phase error correction of optical multi-aperture imaging system based on stochastic parallel gradient decent algorithm

NASA Astrophysics Data System (ADS)

He, Xiaojun; Ma, Haotong; Luo, Chuanxin

2016-10-01

The optical multi-aperture imaging system is an effective way to magnify the aperture and increase the resolution of telescope optical system, the difficulty of which lies in detecting and correcting of co-phase error. This paper presents a method based on stochastic parallel gradient decent algorithm (SPGD) to correct the co-phase error. Compared with the current method, SPGD method can avoid detecting the co-phase error. This paper analyzed the influence of piston error and tilt error on image quality based on double-aperture imaging system, introduced the basic principle of SPGD algorithm, and discuss the influence of SPGD algorithm's key parameters (the gain coefficient and the disturbance amplitude) on error control performance. The results show that SPGD can efficiently correct the co-phase error. The convergence speed of the SPGD algorithm is improved with the increase of gain coefficient and disturbance amplitude, but the stability of the algorithm reduced. The adaptive gain coefficient can solve this problem appropriately. This paper's results can provide the theoretical reference for the co-phase error correction of the multi-aperture imaging system.

A characteristic based volume penalization method for general evolution problems applied to compressible viscous flows

NASA Astrophysics Data System (ADS)

Brown-Dymkoski, Eric; Kasimov, Nurlybek; Vasilyev, Oleg V.

2014-04-01

In order to introduce solid obstacles into flows, several different methods are used, including volume penalization methods which prescribe appropriate boundary conditions by applying local forcing to the constitutive equations. One well known method is Brinkman penalization, which models solid obstacles as porous media. While it has been adapted for compressible, incompressible, viscous and inviscid flows, it is limited in the types of boundary conditions that it imposes, as are most volume penalization methods. Typically, approaches are limited to Dirichlet boundary conditions. In this paper, Brinkman penalization is extended for generalized Neumann and Robin boundary conditions by introducing hyperbolic penalization terms with characteristics pointing inward on solid obstacles. This Characteristic-Based Volume Penalization (CBVP) method is a comprehensive approach to conditions on immersed boundaries, providing for homogeneous and inhomogeneous Dirichlet, Neumann, and Robin boundary conditions on hyperbolic and parabolic equations. This CBVP method can be used to impose boundary conditions for both integrated and non-integrated variables in a systematic manner that parallels the prescription of exact boundary conditions. Furthermore, the method does not depend upon a physical model, as with porous media approach for Brinkman penalization, and is therefore flexible for various physical regimes and general evolutionary equations. Here, the method is applied to scalar diffusion and to direct numerical simulation of compressible, viscous flows. With the Navier-Stokes equations, both homogeneous and inhomogeneous Neumann boundary conditions are demonstrated through external flow around an adiabatic and heated cylinder. Theoretical and numerical examination shows that the error from penalized Neumann and Robin boundary conditions can be rigorously controlled through an a priori penalization parameter η. The error on a transient boundary is found to converge as O(η), which is more favorable than the error convergence of the already established Dirichlet boundary condition.

27 CFR 46.252 - Claim based on error on return.

Code of Federal Regulations, 2011 CFR

2011-04-01

... PRODUCTS AND CIGARETTE PAPERS AND TUBES Floor Stocks Tax on Certain Tobacco Products, Cigarette Papers, and Cigarette Tubes Held for Sale on April 1, 2009 Claims § 46.252 Claim based on error on return. If the dealer...

27 CFR 46.252 - Claim based on error on return.

Code of Federal Regulations, 2012 CFR

2012-04-01

... PRODUCTS AND CIGARETTE PAPERS AND TUBES Floor Stocks Tax on Certain Tobacco Products, Cigarette Papers, and Cigarette Tubes Held for Sale on April 1, 2009 Claims § 46.252 Claim based on error on return. If the dealer...

27 CFR 46.252 - Claim based on error on return.

Code of Federal Regulations, 2014 CFR

2014-04-01

... PRODUCTS AND CIGARETTE PAPERS AND TUBES Floor Stocks Tax on Certain Tobacco Products, Cigarette Papers, and Cigarette Tubes Held for Sale on April 1, 2009 Claims § 46.252 Claim based on error on return. If the dealer...

27 CFR 46.252 - Claim based on error on return.

Code of Federal Regulations, 2013 CFR

2013-04-01

... PRODUCTS AND CIGARETTE PAPERS AND TUBES Floor Stocks Tax on Certain Tobacco Products, Cigarette Papers, and Cigarette Tubes Held for Sale on April 1, 2009 Claims § 46.252 Claim based on error on return. If the dealer...

27 CFR 46.252 - Claim based on error on return.

Code of Federal Regulations, 2010 CFR

2010-04-01

... PRODUCTS AND CIGARETTE PAPERS AND TUBES Floor Stocks Tax on Certain Tobacco Products, Cigarette Papers, and Cigarette Tubes Held for Sale on April 1, 2009 Claims § 46.252 Claim based on error on return. If the dealer...

Coil motion effects in watt balances: a theoretical check

NASA Astrophysics Data System (ADS)

Li, Shisong; Schlamminger, Stephan; Haddad, Darine; Seifert, Frank; Chao, Leon; Pratt, Jon R.

2016-04-01

A watt balance is a precision apparatus for the measurement of the Planck constant that has been proposed as a primary method for realizing the unit of mass in a revised International System of Units. In contrast to an ampere balance, which was historically used to realize the unit of current in terms of the kilogram, the watt balance relates electrical and mechanical units through a virtual power measurement and has far greater precision. However, because the virtual power measurement requires the execution of a prescribed motion of a coil in a fixed magnetic field, systematic errors introduced by horizontal and rotational deviations of the coil from its prescribed path will compromise the accuracy. We model these potential errors using an analysis that accounts for the fringing field in the magnet, creating a framework for assessing the impact of this class of errors on the uncertainty of watt balance results.

Adaptive robust motion trajectory tracking control of pneumatic cylinders with LuGre model-based friction compensation

NASA Astrophysics Data System (ADS)

Meng, Deyuan; Tao, Guoliang; Liu, Hao; Zhu, Xiaocong

2014-07-01

Friction compensation is particularly important for motion trajectory tracking control of pneumatic cylinders at low speed movement. However, most of the existing model-based friction compensation schemes use simple classical models, which are not enough to address applications with high-accuracy position requirements. Furthermore, the friction force in the cylinder is time-varying, and there exist rather severe unmodelled dynamics and unknown disturbances in the pneumatic system. To deal with these problems effectively, an adaptive robust controller with LuGre model-based dynamic friction compensation is constructed. The proposed controller employs on-line recursive least squares estimation (RLSE) to reduce the extent of parametric uncertainties, and utilizes the sliding mode control method to attenuate the effects of parameter estimation errors, unmodelled dynamics and disturbances. In addition, in order to realize LuGre model-based friction compensation, the modified dual-observer structure for estimating immeasurable friction internal state is developed. Therefore, a prescribed motion tracking transient performance and final tracking accuracy can be guaranteed. Since the system model uncertainties are unmatched, the recursive backstepping design technology is applied. In order to solve the conflicts between the sliding mode control design and the adaptive control design, the projection mapping is used to condition the RLSE algorithm so that the parameter estimates are kept within a known bounded convex set. Finally, the proposed controller is tested for tracking sinusoidal trajectories and smooth square trajectory under different loads and sudden disturbance. The testing results demonstrate that the achievable performance of the proposed controller is excellent and is much better than most other studies in literature. Especially when a 0.5 Hz sinusoidal trajectory is tracked, the maximum tracking error is 0.96 mm and the average tracking error is 0.45 mm. This paper constructs an adaptive robust controller which can compensate the friction force in the cylinder.

Predesigned labels to prevent medication errors in hospitalized patients: a quasi-experimental design study.

PubMed

Morales-González, María Fernanda; Galiano Gálvez, María Alejandra

2017-09-08

Our institution implemented the use of pre-designed labeling of intravenous drugs and fluids, administration routes and infusion pumps of to prevent medication errors. To evaluate the effectiveness of predesigned labeling in reducing medication errors in the preparation and administration stages of prescribed medication in patients hospitalized with invasive lines, and to characterize medication errors. This is a pre/post intervention study. Pre-intervention group: invasively administered dose from July 1st to December 31st, 2014, using traditional labeling (adhesive paper handwritten note). Post-intervention group: dose administered from January 1st to June 30th, 2015, using predesigned labeling (labeling with preset data-adhesive labels, color- grouped by drugs, labels with colors for invasive lines). Outcome: medication errors in hospitalized patients, as measured with notification form and record electronics. Tabulation/analysis Stata-10, with descriptive statistics, hypotheses testing, estimating risk with 95% confidence. In the pre-intervention group, 5,819 doses of drugs were administered invasively in 634 patients. Error rate of 1.4 x 1,000 administrations. The post-intervention group of 1088 doses comprised 8,585 patients with similar routes of administration. The error rate was 0.3 x 1,000 (p = 0.034). Patients receiving medication through an invasive route who did not use predesigned labeling had 4.6 times more risk of medication error than those who had used predesigned labels (95% CI: 1.25 to 25.4). The adult critically ill patient unit had the highest proportion of medication errors. The most frequent error was wrong dose administration. 41.2% produced harm to the patient. The use of predesigned labeling in invasive lines reduces errors in medication in the last two phases: preparation and administration.

Analysis of measured data of human body based on error correcting frequency

NASA Astrophysics Data System (ADS)

Jin, Aiyan; Peipei, Gao; Shang, Xiaomei

2014-04-01

Anthropometry is to measure all parts of human body surface, and the measured data is the basis of analysis and study of the human body, establishment and modification of garment size and formulation and implementation of online clothing store. In this paper, several groups of the measured data are gained, and analysis of data error is gotten by analyzing the error frequency and using analysis of variance method in mathematical statistics method. Determination of the measured data accuracy and the difficulty of measured parts of human body, further studies of the causes of data errors, and summarization of the key points to minimize errors possibly are also mentioned in the paper. This paper analyses the measured data based on error frequency, and in a way , it provides certain reference elements to promote the garment industry development.

Assessing pediatrics residents' mathematical skills for prescribing medication: a need for improved training.

PubMed

Glover, Mark L; Sussmane, Jeffrey B

2002-10-01

To evaluate residents' skills in performing basic mathematical calculations used for prescribing medications to pediatric patients. In 2001, a test of ten questions on basic calculations was given to first-, second-, and third-year residents at Miami Children's Hospital in Florida. Four additional questions were included to obtain the residents' levels of training, specific pediatrics intensive care unit (PICU) experience, and whether or not they routinely double-checked doses and adjusted them for each patient's weight. The test was anonymous and calculators were permitted. The overall score and the score for each resident class were calculated. Twenty-one residents participated. The overall average test score and the mean test score of each resident class was less than 70%. Second-year residents had the highest mean test scores, although there was no significant difference between the classes of residents (p =.745) or relationship between the residents' PICU experiences and their exam scores (p =.766). There was no significant difference between residents' levels of training and whether they double-checked their calculations (p =.633) or considered each patient's weight relative to the dose prescribed (p =.869). Seven residents committed tenfold dosing errors, and one resident committed a 1,000-fold dosing error. Pediatrics residents need to receive additional education in performing the calculations needed to prescribe medications. In addition, residents should be required to demonstrate these necessary mathematical skills before they are allowed to prescribe medications.

The prescriber as moralist: values in the antidepressant debate.

PubMed

Scheurich, Neil

2006-01-01

The past decade has seen a growing debate about the expanding use of psychotropic medications. Of particular concern are current antidepressants, as well as hypothetical "mood brighteners" that could modify affect and behavior in people heretofore classified as being within the normal range. This paper argues that objections to such pharmacologic applications are based on appeals to cultural values--authenticity, diversity, inwardness, and stoicism among others--that are viewed as being under increasing threat in contemporary American culture. Critiques of mood brighteners, like critiques of technological, consumer-driven culture, repudiate the ideals of shallow satisfaction and of the self as commodity. The decision to prescribe or not to prescribe a psychotropic medication in any given case is based on cultural values as well as clinical judgment.

Response to "Improving Patient Safety With Error Identification in Chemotherapy Orders by Verification Nurses"
.

PubMed

Zhu, Ling-Ling; Lv, Na; Zhou, Quan

2016-12-01

We read, with great interest, the study by Baldwin and Rodriguez (2016), which described the role of the verification nurse and details the verification process in identifying errors related to chemotherapy orders. We strongly agree with their findings that a verification nurse, collaborating closely with the prescribing physician, pharmacist, and treating nurse, can better identify errors and maintain safety during chemotherapy administration.

Models and theories of prescribing decisions: A review and suggested a new model

PubMed Central

Mohaidin, Zurina

2017-01-01

To date, research on the prescribing decisions of physician lacks sound theoretical foundations. In fact, drug prescribing by doctors is a complex phenomenon influenced by various factors. Most of the existing studies in the area of drug prescription explain the process of decision-making by physicians via the exploratory approach rather than theoretical. Therefore, this review is an attempt to suggest a value conceptual model that explains the theoretical linkages existing between marketing efforts, patient and pharmacist and physician decision to prescribe the drugs. The paper follows an inclusive review approach and applies the previous theoretical models of prescribing behaviour to identify the relational factors. More specifically, the report identifies and uses several valuable perspectives such as the ‘persuasion theory - elaboration likelihood model’, the stimuli–response marketing model’, the ‘agency theory’, the theory of planned behaviour,’ and ‘social power theory,’ in developing an innovative conceptual paradigm. Based on the combination of existing methods and previous models, this paper suggests a new conceptual model of the physician decision-making process. This unique model has the potential for use in further research. PMID:28690701

Preventability of Voluntarily Reported or Trigger Tool-Identified Medication Errors in a Pediatric Institution by Information Technology: A Retrospective Cohort Study.

PubMed

Stultz, Jeremy S; Nahata, Milap C

2015-07-01

Information technology (IT) has the potential to prevent medication errors. While many studies have analyzed specific IT technologies and preventable adverse drug events, no studies have identified risk factors for errors still occurring that are not preventable by IT. The objective of this study was to categorize reported or trigger tool-identified errors and adverse events (AEs) at a pediatric tertiary care institution. Also, we sought to identify medication errors preventable by IT, determine why IT-preventable errors occurred, and to identify risk factors for errors that were not preventable by IT. This was a retrospective analysis of voluntarily reported or trigger tool-identified errors and AEs occurring from 1 July 2011 to 30 June 2012. Medication errors reaching the patients were categorized based on the origin, severity, and location of the error, the month in which they occurred, and the age of the patient involved. Error characteristics were included in a multivariable logistic regression model to determine independent risk factors for errors occurring that were not preventable by IT. A medication error was defined as a medication-related failure of a planned action to be completed as intended or the use of a wrong plan to achieve an aim. An IT-preventable error was defined as having an IT system in place to aid in prevention of the error at the phase and location of its origin. There were 936 medication errors (identified by voluntarily reporting or a trigger tool system) included and analyzed. Drug administration errors were identified most frequently (53.4% ), but prescribing errors most frequently caused harm (47.2 % of harmful errors). There were 470 (50.2 %) errors that were IT preventable at their origin, including 155 due to IT system bypasses, 103 due to insensitivity of IT alerting systems, and 47 with IT alert overrides. Dispensing, administration, and documentation errors had higher odds than prescribing errors for being not preventable by IT [odds ratio (OR) 8.0, 95 % CI 4.4-14.6; OR 2.4, 95 % CI 1.7-3.7; and OR 6.7, 95 % CI 3.3-14.5, respectively; all p < 0.001). Errors occurring in the operating room and in the outpatient setting had higher odds than intensive care units for being not preventable by IT (OR 10.4, 95 % CI 4.0-27.2, and OR 2.6, 95 % CI 1.3-5.0, respectively; all p ≤ 0.004). Despite extensive IT implementation at the studied institution, approximately one-half of the medication errors identified by voluntarily reporting or a trigger tool system were not preventable by the utilized IT systems. Inappropriate use of IT systems was a common cause of errors. The identified risk factors represent areas where IT safety features were lacking.

Pattern and Predictors of Medication Dosing Errors in Chronic Kidney Disease Patients in Pakistan: A Single Center Retrospective Analysis

PubMed Central

Saleem, Ahsan; Masood, Imran

2016-01-01

Background Chronic kidney disease (CKD) alters the pharmacokinetic and pharmacodynamic response of various drugs and increases the risk of toxicity. The data regarding the pattern and predictors of medication dosing errors is scare from the developing countries. Therefore, the present study was conducted to assess the pattern and predictors of medication dosing errors in CKD patients in a tertiary care setting in Pakistan. Methods A retrospective study design was employed and medical charts of all those CKD patients who had an eGFR ≤60ml/min/1.73m2, hospitalization ≥24 hours, and admitted in the nephrology unit during January 2013 to December 2014 were assessed. Descriptive statistics and the logistic regression analysis were done using IBM SPSS version 20. Results In total, 205 medical charts were assessed. The mean age of patients was 38.64 (±16.82) years. Overall, 1534 drugs were prescribed to CKD patients, of which, nearly 34.0% drugs required dose adjustment. Among those drugs, only 41.8% were properly adjusted, and the remaining 58.2% were unadjusted. The logistic regression analysis revealed that the medication dosing errors were significantly associated with the CKD stages, i.e. stage 4 (OR 0.054; 95% CI [0.017–0.177]; p <0.001) and stage 5 (OR 0.098; 95% CI [0.040–0.241]; p <0.001), the number of prescribed medicines ≥ 5 (OR 0.306; 95% CI [0.133–0.704]; p 0.005), and the presence of a comorbidity (OR 0.455; 95% CI [0.226–0.916]; p 0.027) such as the hypertension (OR 0.453; 95% CI [0.231–0.887]; p 0.021). Conclusions It is concluded that more than half drugs prescribed to CKD patients requiring dose adjustment were unadjusted. The predictors of medication dosing errors were the severe-to-end stages of chronic kidney disease, the presence of a comorbidity such as hypertension, and a higher number of prescribed medicines. Therefore, attention should be paid to these risk factors. PMID:27367594

Impact of Stewardship Interventions on Antiretroviral Medication Errors in an Urban Medical Center: A 3-Year, Multiphase Study.

PubMed

Zucker, Jason; Mittal, Jaimie; Jen, Shin-Pung; Cheng, Lucy; Cennimo, David

2016-03-01

There is a high prevalence of HIV infection in Newark, New Jersey, with University Hospital admitting approximately 600 HIV-infected patients per year. Medication errors involving antiretroviral therapy (ART) could significantly affect treatment outcomes. The goal of this study was to evaluate the effectiveness of various stewardship interventions in reducing the prevalence of prescribing errors involving ART. This was a retrospective review of all inpatients receiving ART for HIV treatment during three distinct 6-month intervals over a 3-year period. During the first year, the baseline prevalence of medication errors was determined. During the second year, physician and pharmacist education was provided, and a computerized order entry system with drug information resources and prescribing recommendations was implemented. Prospective audit of ART orders with feedback was conducted in the third year. Analyses and comparisons were made across the three phases of this study. Of the 334 patients with HIV admitted in the first year, 45% had at least one antiretroviral medication error and 38% had uncorrected errors at the time of discharge. After education and computerized order entry, significant reductions in medication error rates were observed compared to baseline rates; 36% of 315 admissions had at least one error and 31% had uncorrected errors at discharge. While the prevalence of antiretroviral errors in year 3 was similar to that of year 2 (37% of 276 admissions), there was a significant decrease in the prevalence of uncorrected errors at discharge (12%) with the use of prospective review and intervention. Interventions, such as education and guideline development, can aid in reducing ART medication errors, but a committed stewardship program is necessary to elicit the greatest impact. © 2016 Pharmacotherapy Publications, Inc.

Adaptive quaternion tracking with nonlinear extended state observer

NASA Astrophysics Data System (ADS)

Bai, Yu-liang; Wang, Xiao-gang; Xu, Jiang-tao; Cui, Nai-gang

2017-10-01

This paper addresses the problem of attitude tracking for spacecraft in the presence of uncertainties in moments of inertia and environmental disturbances. An adaptive quaternion tracking control is combined with a nonlinear extended state observer and the disturbances compensated for in each sampling period. The tracking controller is proved to asymptotically track a prescribed motion in the presence of these uncertainties. Simulations of a nano-spacecraft demonstrate a significant improvement in pointing accuracy and tracking error when compared to a conventional attitude controller. The proposed tracking control is completely deterministic, simple to implement, does not require knowledge of the uncertainties and does not suffer from chattering.

Personalized Medicine and Opioid Analgesic Prescribing for Chronic Pain: Opportunities and Challenges

PubMed Central

Bruehl, Stephen; Apkarian, A. Vania; Ballantyne, Jane C.; Berger, Ann; Borsook, David; Chen, Wen G.; Farrar, John T.; Haythornthwaite, Jennifer A.; Horn, Susan D.; Iadarola, Michael J.; Inturrisi, Charles E.; Lao, Lixing; Mackey, Sean; Mao, Jianren; Sawczuk, Andrea; Uhl, George R.; Witter, James; Woolf, Clifford J.; Zubieta, Jon-Kar; Lin, Yu

2013-01-01

Use of opioid analgesics for pain management has increased dramatically over the past decade, with corresponding increases in negative sequelae including overdose and death. There is currently no well-validated objective means of accurately identifying patients likely to experience good analgesia with low side effects and abuse risk prior to initiating opioid therapy. This paper discusses the concept of data-based personalized prescribing of opioid analgesics as a means to achieve this goal. Strengths, weaknesses, and potential synergism of traditional randomized placebo-controlled trial (RCT) and practice-based evidence (PBE) methodologies as means to acquire the clinical data necessary to develop validated personalized analgesic prescribing algorithms are overviewed. Several predictive factors that might be incorporated into such algorithms are briefly discussed, including genetic factors, differences in brain structure and function, differences in neurotransmitter pathways, and patient phenotypic variables such as negative affect, sex, and pain sensitivity. Currently available research is insufficient to inform development of quantitative analgesic prescribing algorithms. However, responder subtype analyses made practical by the large numbers of chronic pain patients in proposed collaborative PBE pain registries, in conjunction with follow-up validation RCTs, may eventually permit development of clinically useful analgesic prescribing algorithms. Perspective Current research is insufficient to base opioid analgesic prescribing on patient characteristics. Collaborative PBE studies in large, diverse pain patient samples in conjunction with follow-up RCTs may permit development of quantitative analgesic prescribing algorithms which could optimize opioid analgesic effectiveness, and mitigate risks of opioid-related abuse and mortality. PMID:23374939

Optimal joint measurements of complementary observables by a single trapped ion

NASA Astrophysics Data System (ADS)

Xiong, T. P.; Yan, L. L.; Ma, Z. H.; Zhou, F.; Chen, L.; Yang, W. L.; Feng, M.; Busch, P.

2017-06-01

The uncertainty relations, pioneered by Werner Heisenberg nearly 90 years ago, set a fundamental limitation on the joint measurability of complementary observables. This limitation has long been a subject of debate, which has been reignited recently due to new proposed forms of measurement uncertainty relations. The present work is associated with a new error trade-off relation for compatible observables approximating two incompatible observables, in keeping with the spirit of Heisenberg’s original ideas of 1927. We report the first direct test and confirmation of the tight bounds prescribed by such an error trade-off relation, based on an experimental realisation of optimal joint measurements of complementary observables using a single ultracold {}40{{{Ca}}}+ ion trapped in a harmonic potential. Our work provides a prototypical determination of ultimate joint measurement error bounds with potential applications in quantum information science for high-precision measurement and information security.

A systematic review of clinical pharmacist interventions in paediatric hospital patients.

PubMed

Drovandi, Aaron; Robertson, Kelvin; Tucker, Matthew; Robinson, Niechole; Perks, Stephen; Kairuz, Therése

2018-06-19

Clinical pharmacists provide beneficial services to adult patients, though their benefits for paediatric hospital patients are less defined. Five databases were searched using the MeSH terms 'clinical pharmacist', 'paediatric/paediatric', 'hospital', and 'intervention' for studies with paediatric patients conducted in hospital settings, and described pharmacist-initiated interventions, published between January 2000 and October 2017. The search strategy after full-text review identified 12 articles matching the eligibility criteria. Quality appraisal checklists from the Joanna Briggs Institute were used to appraise the eligible articles. Clinical pharmacist services had a positive impact on paediatric patient care. Medication errors intercepted by pharmacists included over- and under-dosing, missed doses, medication history gaps, allergies, and near-misses. Interventions to address these errors were positively received, and implemented by physicians, with an average acceptance rate of over 95%. Clinical pharmacist-initiated education resulted in improved medication understanding and adherence, improved patient satisfaction, and control of chronic medical conditions. This review found that clinical pharmacists in paediatric wards may reduce drug-related problems and improve patient outcomes. The benefits of pharmacist involvement appear greatest when directly involved in ward rounds, due to being able to more rapidly identify medication errors during the prescribing phase, and provide real-time advice and recommendations to prescribers. What is Known: • Complex paediatric conditions can require multiple pharmaceutical treatments, utilised in a safe manner to ensure good patient outcomes • The benefits of pharmacist interventions when using these treatments are well-documented in adult patients, though less so in paediatric patients What is New: • Pharmacists are adept at identifying and managing medication errors for paediatric patients, including incorrect doses, missed doses, and gaps in medication history • Interventions recommended by pharmacists are generally well-accepted by prescribing physicians, especially when recommendations can be made during the prescribing phase of treatment.

Parameter estimation in IMEX-trigonometrically fitted methods for the numerical solution of reaction-diffusion problems

NASA Astrophysics Data System (ADS)

D'Ambrosio, Raffaele; Moccaldi, Martina; Paternoster, Beatrice

2018-05-01

In this paper, an adapted numerical scheme for reaction-diffusion problems generating periodic wavefronts is introduced. Adapted numerical methods for such evolutionary problems are specially tuned to follow prescribed qualitative behaviors of the solutions, making the numerical scheme more accurate and efficient as compared with traditional schemes already known in the literature. Adaptation through the so-called exponential fitting technique leads to methods whose coefficients depend on unknown parameters related to the dynamics and aimed to be numerically computed. Here we propose a strategy for a cheap and accurate estimation of such parameters, which consists essentially in minimizing the leading term of the local truncation error whose expression is provided in a rigorous accuracy analysis. In particular, the presented estimation technique has been applied to a numerical scheme based on combining an adapted finite difference discretization in space with an implicit-explicit time discretization. Numerical experiments confirming the effectiveness of the approach are also provided.

Mathematical modelling of flow distribution in the human cardiovascular system

NASA Technical Reports Server (NTRS)

Sud, V. K.; Srinivasan, R. S.; Charles, J. B.; Bungo, M. W.

1992-01-01

The paper presents a detailed model of the entire human cardiovascular system which aims to study the changes in flow distribution caused by external stimuli, changes in internal parameters, or other factors. The arterial-venous network is represented by 325 interconnected elastic segments. The mathematical description of each segment is based on equations of hydrodynamics and those of stress/strain relationships in elastic materials. Appropriate input functions provide for the pumping of blood by the heart through the system. The analysis employs the finite-element technique which can accommodate any prescribed boundary conditions. Values of model parameters are from available data on physical and rheological properties of blood and blood vessels. As a representative example, simulation results on changes in flow distribution with changes in the elastic properties of blood vessels are discussed. They indicate that the errors in the calculated overall flow rates are not significant even in the extreme case of arteries and veins behaving as rigid tubes.

Non-medical prescribing in New Zealand: an overview of prescribing rights, service delivery models and training.

PubMed

Raghunandan, Rakhee; Tordoff, June; Smith, Alesha

2017-11-01

In this paper, we aim to provide an updated source of information for nonmedical prescribing (NMP) in New Zealand (NZ). A variety of NZ sources were used to collect data: legislation, policy documents and information from professional and regulatory organizations, and education providers. In NZ, the legal categories for prescribers include authorized, designated, and delegated prescribers. Authorized prescribers include dentists, midwives, nurse practitioners, and optometrist prescribers. Designated prescribers include pharmacist prescribers, registered nurse prescribers, and dietitian prescribers. There are no delegated prescribers in NZ at this time. There is variation in the regulation, educational programmes and prescribing competencies used by the different prescribing health professionals involved in NMP in NZ. This update collates relevant information relating to NMP in NZ into one consolidated document and provides policy makers with a current overview of prescribing rights, service delivery models, training requirements, and prescribing competencies used for NMP in NZ. As NMP in NZ continues to expand and evolve, this paper will form a baseline for future NMP research in NZ. NZ needs to develop overarching NMP policy to enable consistency in the various aspects of NMP, thereby delivering a safe and sustainable NMP service in NZ.

Medication regimens of frail older adults after discharge from home health care

PubMed Central

Lancaster, Rachelle; Marek, Karen Dorman; Bub, Linda Denison; Stetzer, Frank

2015-01-01

The purpose of this study was to examine the number and types of discrepancy errors present after discharge from home health care in older adults at risk for medication management problems following an episode of home healthcare. More than half of the 414 participants had at least one medication discrepancy error (53.2%, n=219) with the participant’s omission of a prescribed medication (n=118, 30.17%) occurring most frequently. The results of this study support the need for home health clinicians to perform frequent assessments of medication regimens to ensure that the older adults are aware of the regimen they are prescribed, and have systems in place to support them in managing their medications. PMID:25268528

Paediatric electronic infusion calculator: An intervention to eliminate infusion errors in paediatric critical care.

PubMed

Venkataraman, Aishwarya; Siu, Emily; Sadasivam, Kalaimaran

2016-11-01

Medication errors, including infusion prescription errors are a major public health concern, especially in paediatric patients. There is some evidence that electronic or web-based calculators could minimise these errors. To evaluate the impact of an electronic infusion calculator on the frequency of infusion errors in the Paediatric Critical Care Unit of The Royal London Hospital, London, United Kingdom. We devised an electronic infusion calculator that calculates the appropriate concentration, rate and dose for the selected medication based on the recorded weight and age of the child and then prints into a valid prescription chart. Electronic infusion calculator was implemented from April 2015 in Paediatric Critical Care Unit. A prospective study, five months before and five months after implementation of electronic infusion calculator, was conducted. Data on the following variables were collected onto a proforma: medication dose, infusion rate, volume, concentration, diluent, legibility, and missing or incorrect patient details. A total of 132 handwritten prescriptions were reviewed prior to electronic infusion calculator implementation and 119 electronic infusion calculator prescriptions were reviewed after electronic infusion calculator implementation. Handwritten prescriptions had higher error rate (32.6%) as compared to electronic infusion calculator prescriptions (<1%) with a p  < 0.001. Electronic infusion calculator prescriptions had no errors on dose, volume and rate calculation as compared to handwritten prescriptions, hence warranting very few pharmacy interventions. Use of electronic infusion calculator for infusion prescription significantly reduced the total number of infusion prescribing errors in Paediatric Critical Care Unit and has enabled more efficient use of medical and pharmacy time resources.

What doctors need to know: Prescribing or not for the oldest old.

PubMed

Kydd, Angela; Fleming, Anne

2016-08-01

Given the global increase in the number of people over the age of 85, there is a growing body of work concerning this group, termed the oldest old. Much of this work is confined to the literature specialising in geriatrics and the more generic health care papers refer to 'older people' with little definition of what is meant by 'older'. Iatrogenesis (ill health caused by doctors) is a major issue and general practitioners (GPs) need practical help in prescribing for the oldest old. This paper presents a narrative review of the literature on prescribing and the oldest old. The results showed that all papers sourced referred to prescribing for the 'old' as those aged over 65, with only scant mention of oldest old. Yet prescribing for the oldest old involves clinical judgement and knowledge of the patient. It includes weighing up what will do good, cause no harm and is acceptable to the individual. GPs have to make treatment choices mostly in isolation from colleagues, during time-limited consultations and with few relevant guidelines on managing multi-morbidities in the oldest old. A major issue in prescribing for people over the age of 85 is that guidelines for diseases are based on trials with younger adults, outline the best practice for one disease in isolation (i.e. not in the presence of other diseases) and take little account of the interactions between the drugs used in managing several diseases in frail older people. There is a growing body of work, however, calling for specialist services for the oldest old. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Minimizing Experimental Error in Thinning Research

Treesearch

C. B. Briscoe

1964-01-01

Many diverse approaches have been made prescribing and evaluating thinnings on an objective basis. None of the techniques proposed hasbeen widely accepted. Indeed. none has been proven superior to the others nor even widely applicable. There are at least two possible reasons for this: none of the techniques suggested is of any general utility and/or experimental error...

Medication errors: a prospective cohort study of hand-written and computerised physician order entry in the intensive care unit.

PubMed

Shulman, Rob; Singer, Mervyn; Goldstone, John; Bellingan, Geoff

2005-10-05

The study aimed to compare the impact of computerised physician order entry (CPOE) without decision support with hand-written prescribing (HWP) on the frequency, type and outcome of medication errors (MEs) in the intensive care unit. Details of MEs were collected before, and at several time points after, the change from HWP to CPOE. The study was conducted in a London teaching hospital's 22-bedded general ICU. The sampling periods were 28 weeks before and 2, 10, 25 and 37 weeks after introduction of CPOE. The unit pharmacist prospectively recorded details of MEs and the total number of drugs prescribed daily during the data collection periods, during the course of his normal chart review. The total proportion of MEs was significantly lower with CPOE (117 errors from 2429 prescriptions, 4.8%) than with HWP (69 errors from 1036 prescriptions, 6.7%) (p < 0.04). The proportion of errors reduced with time following the introduction of CPOE (p < 0.001). Two errors with CPOE led to patient harm requiring an increase in length of stay and, if administered, three prescriptions with CPOE could potentially have led to permanent harm or death. Differences in the types of error between systems were noted. There was a reduction in major/moderate patient outcomes with CPOE when non-intercepted and intercepted errors were combined (p = 0.01). The mean baseline APACHE II score did not differ significantly between the HWP and the CPOE periods (19.4 versus 20.0, respectively, p = 0.71). Introduction of CPOE was associated with a reduction in the proportion of MEs and an improvement in the overall patient outcome score (if intercepted errors were included). Moderate and major errors, however, remain a significant concern with CPOE.

The relationships among work stress, strain and self-reported errors in UK community pharmacy.

PubMed

Johnson, S J; O'Connor, E M; Jacobs, S; Hassell, K; Ashcroft, D M

2014-01-01

Changes in the UK community pharmacy profession including new contractual frameworks, expansion of services, and increasing levels of workload have prompted concerns about rising levels of workplace stress and overload. This has implications for pharmacist health and well-being and the occurrence of errors that pose a risk to patient safety. Despite these concerns being voiced in the profession, few studies have explored work stress in the community pharmacy context. To investigate work-related stress among UK community pharmacists and to explore its relationships with pharmacists' psychological and physical well-being, and the occurrence of self-reported dispensing errors and detection of prescribing errors. A cross-sectional postal survey of a random sample of practicing community pharmacists (n = 903) used ASSET (A Shortened Stress Evaluation Tool) and questions relating to self-reported involvement in errors. Stress data were compared to general working population norms, and regressed on well-being and self-reported errors. Analysis of the data revealed that pharmacists reported significantly higher levels of workplace stressors than the general working population, with concerns about work-life balance, the nature of the job, and work relationships being the most influential on health and well-being. Despite this, pharmacists were not found to report worse health than the general working population. Self-reported error involvement was linked to both high dispensing volume and being troubled by perceived overload (dispensing errors), and resources and communication (detection of prescribing errors). This study contributes to the literature by benchmarking community pharmacists' health and well-being, and investigating sources of stress using a quantitative approach. A further important contribution to the literature is the identification of a quantitative link between high workload and self-reported dispensing errors. Copyright © 2014 Elsevier Inc. All rights reserved.

Verification of an ensemble prediction system for storm surge forecast in the Adriatic Sea

NASA Astrophysics Data System (ADS)

Mel, Riccardo; Lionello, Piero

2014-12-01

In the Adriatic Sea, storm surges present a significant threat to Venice and to the flat coastal areas of the northern coast of the basin. Sea level forecast is of paramount importance for the management of daily activities and for operating the movable barriers that are presently being built for the protection of the city. In this paper, an EPS (ensemble prediction system) for operational forecasting of storm surge in the northern Adriatic Sea is presented and applied to a 3-month-long period (October-December 2010). The sea level EPS is based on the HYPSE (hydrostatic Padua Sea elevation) model, which is a standard single-layer nonlinear shallow water model, whose forcings (mean sea level pressure and surface wind fields) are provided by the ensemble members of the ECMWF (European Center for Medium-Range Weather Forecasts) EPS. Results are verified against observations at five tide gauges located along the Croatian and Italian coasts of the Adriatic Sea. Forecast uncertainty increases with the predicted value of the storm surge and with the forecast lead time. The EMF (ensemble mean forecast) provided by the EPS has a rms (root mean square) error lower than the DF (deterministic forecast), especially for short (up to 3 days) lead times. Uncertainty for short lead times of the forecast and for small storm surges is mainly caused by uncertainty of the initial condition of the hydrodynamical model. Uncertainty for large lead times and large storm surges is mainly caused by uncertainty in the meteorological forcings. The EPS spread increases with the rms error of the forecast. For large lead times the EPS spread and the forecast error substantially coincide. However, the EPS spread in this study, which does not account for uncertainty in the initial condition, underestimates the error during the early part of the forecast and for small storm surge values. On the contrary, it overestimates the rms error for large surge values. The PF (probability forecast) of the EPS has a clear skill in predicting the actual probability distribution of sea level, and it outperforms simple "dressed" PF methods. A probability estimate based on the single DF is shown to be inadequate. However, a PF obtained with a prescribed Gaussian distribution and centered on the DF value performs very similarly to the EPS-based PF.

Stemming the Tide of Antibiotic Resistance (STAR): A protocol for a trial of a complex intervention addressing the 'why' and 'how' of appropriate antibiotic prescribing in general practice

PubMed Central

Simpson, Sharon A; Butler, Christopher C; Hood, Kerry; Cohen, David; Dunstan, Frank; Evans, Meirion R; Rollnick, Stephen; Moore, Laurence; Hare, Monika; Bekkers, Marie-Jet; Evans, John

2009-01-01

Background After some years of a downward trend, antibiotic prescribing rates in the community have tended to level out in many countries. There is also wide variation in antibiotic prescribing between general practices, and between countries. There are still considerable further gains that could be made in reducing inappropriate antibiotic prescribing, but complex interventions are required. Studies to date have generally evaluated the effect of interventions on antibiotic prescribing in a single consultation and pragmatic evaluations that assess maintenance of new skills are rare. This paper describes the protocol for a pragmatic, randomized evaluation of a complex intervention aimed at reducing antibiotic prescribing by primary care clinicians. Methods and design We developed a Social Learning Theory based, blended learning program (on-line learning, a practice based seminar, and context bound learning) called the STAR Educational Program. The 'why of change' is addressed by providing clinicians in general practice with information on antibiotic resistance in urine samples submitted by their practice and their antibiotic prescribing data, and facilitating a practice-based seminar on the implications of this data. The 'how of change' is addressed through context-bound communication skills training and information on antibiotic indication and choice. This intervention will be evaluated in a trial involving 60 general practices, with general practice as the unit of randomization (clinicians from each practice to either receive the STAR Educational Program or not) and analysis. The primary outcome will be the number of antibiotic items dispensed over one year. An economic and process evaluation will also be conducted. Discussion This trial will be the first to evaluate the effectiveness of this type of theory-based, blended learning intervention aimed at reducing antibiotic prescribing by primary care clinicians. Novel aspects include feedback of practice level data on antimicrobial resistance and prescribing, use of principles from motivational interviewing, training in enhanced communication skills that incorporates context-bound experience and reflection, and using antibiotic dispensing over one year (as opposed to antibiotic prescribing in a single consultation) as the main outcome. Trial registration Current Controlled Trials ISRCTN63355948. PMID:19309493

Stemming the Tide of Antibiotic Resistance (STAR): a protocol for a trial of a complex intervention addressing the 'why' and 'how' of appropriate antibiotic prescribing in general practice.

PubMed

Simpson, Sharon A; Butler, Christopher C; Hood, Kerry; Cohen, David; Dunstan, Frank; Evans, Meirion R; Rollnick, Stephen; Moore, Laurence; Hare, Monika; Bekkers, Marie-Jet; Evans, John

2009-03-23

After some years of a downward trend, antibiotic prescribing rates in the community have tended to level out in many countries. There is also wide variation in antibiotic prescribing between general practices, and between countries. There are still considerable further gains that could be made in reducing inappropriate antibiotic prescribing, but complex interventions are required. Studies to date have generally evaluated the effect of interventions on antibiotic prescribing in a single consultation and pragmatic evaluations that assess maintenance of new skills are rare. This paper describes the protocol for a pragmatic, randomized evaluation of a complex intervention aimed at reducing antibiotic prescribing by primary care clinicians. We developed a Social Learning Theory based, blended learning program (on-line learning, a practice based seminar, and context bound learning) called the STAR Educational Program. The 'why of change' is addressed by providing clinicians in general practice with information on antibiotic resistance in urine samples submitted by their practice and their antibiotic prescribing data, and facilitating a practice-based seminar on the implications of this data. The 'how of change' is addressed through context-bound communication skills training and information on antibiotic indication and choice. This intervention will be evaluated in a trial involving 60 general practices, with general practice as the unit of randomization (clinicians from each practice to either receive the STAR Educational Program or not) and analysis. The primary outcome will be the number of antibiotic items dispensed over one year. An economic and process evaluation will also be conducted. This trial will be the first to evaluate the effectiveness of this type of theory-based, blended learning intervention aimed at reducing antibiotic prescribing by primary care clinicians. Novel aspects include feedback of practice level data on antimicrobial resistance and prescribing, use of principles from motivational interviewing, training in enhanced communication skills that incorporates context-bound experience and reflection, and using antibiotic dispensing over one year (as opposed to antibiotic prescribing in a single consultation) as the main outcome. Current Controlled Trials ISRCTN63355948.

Evaluation of drug administration errors in a teaching hospital

PubMed Central

2012-01-01

Background Medication errors can occur at any of the three steps of the medication use process: prescribing, dispensing and administration. We aimed to determine the incidence, type and clinical importance of drug administration errors and to identify risk factors. Methods Prospective study based on disguised observation technique in four wards in a teaching hospital in Paris, France (800 beds). A pharmacist accompanied nurses and witnessed the preparation and administration of drugs to all patients during the three drug rounds on each of six days per ward. Main outcomes were number, type and clinical importance of errors and associated risk factors. Drug administration error rate was calculated with and without wrong time errors. Relationship between the occurrence of errors and potential risk factors were investigated using logistic regression models with random effects. Results Twenty-eight nurses caring for 108 patients were observed. Among 1501 opportunities for error, 415 administrations (430 errors) with one or more errors were detected (27.6%). There were 312 wrong time errors, ten simultaneously with another type of error, resulting in an error rate without wrong time error of 7.5% (113/1501). The most frequently administered drugs were the cardiovascular drugs (425/1501, 28.3%). The highest risks of error in a drug administration were for dermatological drugs. No potentially life-threatening errors were witnessed and 6% of errors were classified as having a serious or significant impact on patients (mainly omission). In multivariate analysis, the occurrence of errors was associated with drug administration route, drug classification (ATC) and the number of patient under the nurse's care. Conclusion Medication administration errors are frequent. The identification of its determinants helps to undertake designed interventions. PMID:22409837

Evaluation of drug administration errors in a teaching hospital.

PubMed

Berdot, Sarah; Sabatier, Brigitte; Gillaizeau, Florence; Caruba, Thibaut; Prognon, Patrice; Durieux, Pierre

2012-03-12

Medication errors can occur at any of the three steps of the medication use process: prescribing, dispensing and administration. We aimed to determine the incidence, type and clinical importance of drug administration errors and to identify risk factors. Prospective study based on disguised observation technique in four wards in a teaching hospital in Paris, France (800 beds). A pharmacist accompanied nurses and witnessed the preparation and administration of drugs to all patients during the three drug rounds on each of six days per ward. Main outcomes were number, type and clinical importance of errors and associated risk factors. Drug administration error rate was calculated with and without wrong time errors. Relationship between the occurrence of errors and potential risk factors were investigated using logistic regression models with random effects. Twenty-eight nurses caring for 108 patients were observed. Among 1501 opportunities for error, 415 administrations (430 errors) with one or more errors were detected (27.6%). There were 312 wrong time errors, ten simultaneously with another type of error, resulting in an error rate without wrong time error of 7.5% (113/1501). The most frequently administered drugs were the cardiovascular drugs (425/1501, 28.3%). The highest risks of error in a drug administration were for dermatological drugs. No potentially life-threatening errors were witnessed and 6% of errors were classified as having a serious or significant impact on patients (mainly omission). In multivariate analysis, the occurrence of errors was associated with drug administration route, drug classification (ATC) and the number of patient under the nurse's care. Medication administration errors are frequent. The identification of its determinants helps to undertake designed interventions.

Error-Based Simulation for Error-Awareness in Learning Mechanics: An Evaluation

ERIC Educational Resources Information Center

Horiguchi, Tomoya; Imai, Isao; Toumoto, Takahito; Hirashima, Tsukasa

2014-01-01

Error-based simulation (EBS) has been developed to generate phenomena by using students' erroneous ideas and also offers promise for promoting students' awareness of errors. In this paper, we report the evaluation of EBS used in learning "normal reaction" in a junior high school. An EBS class, where students learned the concept…

Flight Investigation of Prescribed Simultaneous Independent Surface Excitations for Real-Time Parameter Identification

NASA Technical Reports Server (NTRS)

Moes, Timothy R.; Smith, Mark S.; Morelli, Eugene A.

2003-01-01

Near real-time stability and control derivative extraction is required to support flight demonstration of Intelligent Flight Control System (IFCS) concepts being developed by NASA, academia, and industry. Traditionally, flight maneuvers would be designed and flown to obtain stability and control derivative estimates using a postflight analysis technique. The goal of the IFCS concept is to be able to modify the control laws in real time for an aircraft that has been damaged in flight. In some IFCS implementations, real-time parameter identification (PID) of the stability and control derivatives of the damaged aircraft is necessary for successfully reconfiguring the control system. This report investigates the usefulness of Prescribed Simultaneous Independent Surface Excitations (PreSISE) to provide data for rapidly obtaining estimates of the stability and control derivatives. Flight test data were analyzed using both equation-error and output-error PID techniques. The equation-error PID technique is known as Fourier Transform Regression (FTR) and is a frequency-domain real-time implementation. Selected results were compared with a time-domain output-error technique. The real-time equation-error technique combined with the PreSISE maneuvers provided excellent derivative estimation in the longitudinal axis. However, the PreSISE maneuvers as presently defined were not adequate for accurate estimation of the lateral-directional derivatives.

Developing and Validating a Tablet Version of an Illness Explanatory Model Interview for a Public Health Survey in Pune, India

PubMed Central

Giduthuri, Joseph G.; Maire, Nicolas; Joseph, Saju; Kudale, Abhay; Schaetti, Christian; Sundaram, Neisha; Schindler, Christian; Weiss, Mitchell G.

2014-01-01

Background Mobile electronic devices are replacing paper-based instruments and questionnaires for epidemiological and public health research. The elimination of a data-entry step after an interview is a notable advantage over paper, saving investigator time, decreasing the time lags in managing and analyzing data, and potentially improving the data quality by removing the error-prone data-entry step. Research has not yet provided adequate evidence, however, to substantiate the claim of fewer errors for computerized interviews. Methodology We developed an Android-based illness explanatory interview for influenza vaccine acceptance and tested the instrument in a field study in Pune, India, for feasibility and acceptability. Error rates for tablet and paper were compared with reference to the voice recording of the interview as gold standard to assess discrepancies. We also examined the preference of interviewers for the classical paper-based or the electronic version of the interview and compared the costs of research with both data collection devices. Results In 95 interviews with household respondents, total error rates with paper and tablet devices were nearly the same (2.01% and 1.99% respectively). Most interviewers indicated no preference for a particular device; but those with a preference opted for tablets. The initial investment in tablet-based interviews was higher compared to paper, while the recurring costs per interview were lower with the use of tablets. Conclusion An Android-based tablet version of a complex interview was developed and successfully validated. Advantages were not compromised by increased errors, and field research assistants with a preference preferred the Android device. Use of tablets may be more costly than paper for small samples and less costly for large studies. PMID:25233212

Uncharted territory: measuring costs of diagnostic errors outside the medical record.

PubMed

Schwartz, Alan; Weiner, Saul J; Weaver, Frances; Yudkowsky, Rachel; Sharma, Gunjan; Binns-Calvey, Amy; Preyss, Ben; Jordan, Neil

2012-11-01

In a past study using unannounced standardised patients (USPs), substantial rates of diagnostic and treatment errors were documented among internists. Because the authors know the correct disposition of these encounters and obtained the physicians' notes, they can identify necessary treatment that was not provided and unnecessary treatment. They can also discern which errors can be identified exclusively from a review of the medical records. To estimate the avoidable direct costs incurred by physicians making errors in our previous study. In the study, USPs visited 111 internal medicine attending physicians. They presented variants of four previously validated cases that jointly manipulate the presence or absence of contextual and biomedical factors that could lead to errors in management if overlooked. For example, in a patient with worsening asthma symptoms, a complicating biomedical factor was the presence of reflux disease and a complicating contextual factor was inability to afford the currently prescribed inhaler. Costs of missed or unnecessary services were computed using Medicare cost-based reimbursement data. Fourteen practice locations, including two academic clinics, two community-based primary care networks with multiple sites, a core safety net provider, and three Veteran Administration government facilities. Contribution of errors to costs of care. Overall, errors in care resulted in predicted costs of approximately $174,000 across 399 visits, of which only $8745 was discernible from a review of the medical records alone (without knowledge of the correct diagnoses). The median cost of error per visit with an incorrect care plan differed by case and by presentation variant within case. Chart reviews alone underestimate costs of care because they typically reflect appropriate treatment decisions conditional on (potentially erroneous) diagnoses. Important information about patient context is often entirely missing from medical records. Experimental methods, including the use of USPs, reveal the substantial costs of these errors.

Non-medical prescribing in New Zealand: an overview of prescribing rights, service delivery models and training

PubMed Central

Raghunandan, Rakhee; Tordoff, June; Smith, Alesha

2017-01-01

Aim: In this paper, we aim to provide an updated source of information for nonmedical prescribing (NMP) in New Zealand (NZ). Methods: A variety of NZ sources were used to collect data: legislation, policy documents and information from professional and regulatory organizations, and education providers. Results: In NZ, the legal categories for prescribers include authorized, designated, and delegated prescribers. Authorized prescribers include dentists, midwives, nurse practitioners, and optometrist prescribers. Designated prescribers include pharmacist prescribers, registered nurse prescribers, and dietitian prescribers. There are no delegated prescribers in NZ at this time. There is variation in the regulation, educational programmes and prescribing competencies used by the different prescribing health professionals involved in NMP in NZ. Conclusion: This update collates relevant information relating to NMP in NZ into one consolidated document and provides policy makers with a current overview of prescribing rights, service delivery models, training requirements, and prescribing competencies used for NMP in NZ. As NMP in NZ continues to expand and evolve, this paper will form a baseline for future NMP research in NZ. NZ needs to develop overarching NMP policy to enable consistency in the various aspects of NMP, thereby delivering a safe and sustainable NMP service in NZ. PMID:29090084

Prescription errors before and after introduction of electronic medication alert system in a pediatric emergency department.

PubMed

Sethuraman, Usha; Kannikeswaran, Nirupama; Murray, Kyle P; Zidan, Marwan A; Chamberlain, James M

2015-06-01

Prescription errors occur frequently in pediatric emergency departments (PEDs).The effect of computerized physician order entry (CPOE) with electronic medication alert system (EMAS) on these is unknown. The objective was to compare prescription errors rates before and after introduction of CPOE with EMAS in a PED. The hypothesis was that CPOE with EMAS would significantly reduce the rate and severity of prescription errors in the PED. A prospective comparison of a sample of outpatient, medication prescriptions 5 months before and after CPOE with EMAS implementation (7,268 before and 7,292 after) was performed. Error types and rates, alert types and significance, and physician response were noted. Medication errors were deemed significant if there was a potential to cause life-threatening injury, failure of therapy, or an adverse drug effect. There was a significant reduction in the errors per 100 prescriptions (10.4 before vs. 7.3 after; absolute risk reduction = 3.1, 95% confidence interval [CI] = 2.2 to 4.0). Drug dosing error rates decreased from 8 to 5.4 per 100 (absolute risk reduction = 2.6, 95% CI = 1.8 to 3.4). Alerts were generated for 29.6% of prescriptions, with 45% involving drug dose range checking. The sensitivity of CPOE with EMAS in identifying errors in prescriptions was 45.1% (95% CI = 40.8% to 49.6%), and the specificity was 57% (95% CI = 55.6% to 58.5%). Prescribers modified 20% of the dosing alerts, resulting in the error not reaching the patient. Conversely, 11% of true dosing alerts for medication errors were overridden by the prescribers: 88 (11.3%) resulted in medication errors, and 684 (88.6%) were false-positive alerts. A CPOE with EMAS was associated with a decrease in overall prescription errors in our PED. Further system refinements are required to reduce the high false-positive alert rates. © 2015 by the Society for Academic Emergency Medicine.

An intravenous medication safety system: preventing high-risk medication errors at the point of care.

PubMed

Hatcher, Irene; Sullivan, Mark; Hutchinson, James; Thurman, Susan; Gaffney, F Andrew

2004-10-01

Improving medication safety at the point of care--particularly for high-risk drugs--is a major concern of nursing administrators. The medication errors most likely to cause harm are administration errors related to infusion of high-risk medications. An intravenous medication safety system is designed to prevent high-risk infusion medication errors and to capture continuous quality improvement data for best practice improvement. Initial testing with 50 systems in 2 units at Vanderbilt University Medical Center revealed that, even in the presence of a fully mature computerized prescriber order-entry system, the new safety system averted 99 potential infusion errors in 8 months.

Development and validation of an instrument to assess the prescribing readiness of medical students in Malaysia.

PubMed

Lai, Pauline Siew Mei; Sim, Si Mui; Chua, Siew Siang; Tan, Choo Hock; Ng, Chirk Jenn; Achike, Francis Ifejika; Teng, Cheong Lieng

2015-09-21

Prescribing incompetence is an important factor that contributes to prescribing error, and this is often due to inadequate training during medical schools. We therefore aimed to develop and validate an instrument to assess the prescribing readiness of medical students (PROMS) in Malaysia. The PROMS comprised of 26 items with four domains: undergraduate learning opportunities; hands-on clinical skills practice; information gathering behaviour; and factors affecting the learning of prescribing skills. The first three domains were adapted from an existing questionnaire, while items from the last domain were formulated based on findings from a nominal group discussion. Face and content validity was determined by an expert panel, pilot tested in a class of final year (Year 5) medical students, and assessed using the Flesch reading ease. To assess the reliability of the PROMS, the internal consistency and test-retest (at baseline and 2 weeks later) were assessed using the Wilcoxon Signed Ranks test and Spearman's rho. The discriminative validity of the PROMS was assessed using the Mann-Whitney U-test (to assess if the PROMS could discriminate between final year medical students from a public and a private university). A total of 119 medical students were recruited. Flesch reading ease was 46.9, indicating that the instrument was suitable for use in participants undergoing tertiary education. The overall Cronbach alpha value of the PROMS was 0.695, which was satisfactory. Test-retest showed no difference for 25/26 items, indicating that our instrument was reliable. Responses from the public and private university final year medical students were significantly different in 10/26 items, indicating that the PROMS was able to discriminate between these two groups. Medical students from the private university reported fewer learning opportunities and hands-on practice compared to those from the public university. On the other hand, medical students from the private university reported more frequent use of both web based and non-web-based resources compared to their public university counterparts. The PROMS instrument was found to be a reliable and valid tool for assessing medical students' readiness to prescribe in Malaysia. It may also inform on the adequacy of medical programmes in training prescribing skills.

Calculating radiotherapy margins based on Bayesian modelling of patient specific random errors

NASA Astrophysics Data System (ADS)

Herschtal, A.; te Marvelde, L.; Mengersen, K.; Hosseinifard, Z.; Foroudi, F.; Devereux, T.; Pham, D.; Ball, D.; Greer, P. B.; Pichler, P.; Eade, T.; Kneebone, A.; Bell, L.; Caine, H.; Hindson, B.; Kron, T.

2015-02-01

Collected real-life clinical target volume (CTV) displacement data show that some patients undergoing external beam radiotherapy (EBRT) demonstrate significantly more fraction-to-fraction variability in their displacement (‘random error’) than others. This contrasts with the common assumption made by historical recipes for margin estimation for EBRT, that the random error is constant across patients. In this work we present statistical models of CTV displacements in which random errors are characterised by an inverse gamma (IG) distribution in order to assess the impact of random error variability on CTV-to-PTV margin widths, for eight real world patient cohorts from four institutions, and for different sites of malignancy. We considered a variety of clinical treatment requirements and penumbral widths. The eight cohorts consisted of a total of 874 patients and 27 391 treatment sessions. Compared to a traditional margin recipe that assumes constant random errors across patients, for a typical 4 mm penumbral width, the IG based margin model mandates that in order to satisfy the common clinical requirement that 90% of patients receive at least 95% of prescribed RT dose to the entire CTV, margins be increased by a median of 10% (range over the eight cohorts -19% to +35%). This substantially reduces the proportion of patients for whom margins are too small to satisfy clinical requirements.

Adaptive radial basis function mesh deformation using data reduction

NASA Astrophysics Data System (ADS)

Gillebaart, T.; Blom, D. S.; van Zuijlen, A. H.; Bijl, H.

2016-09-01

Radial Basis Function (RBF) mesh deformation is one of the most robust mesh deformation methods available. Using the greedy (data reduction) method in combination with an explicit boundary correction, results in an efficient method as shown in literature. However, to ensure the method remains robust, two issues are addressed: 1) how to ensure that the set of control points remains an accurate representation of the geometry in time and 2) how to use/automate the explicit boundary correction, while ensuring a high mesh quality. In this paper, we propose an adaptive RBF mesh deformation method, which ensures the set of control points always represents the geometry/displacement up to a certain (user-specified) criteria, by keeping track of the boundary error throughout the simulation and re-selecting when needed. Opposed to the unit displacement and prescribed displacement selection methods, the adaptive method is more robust, user-independent and efficient, for the cases considered. Secondly, the analysis of a single high aspect ratio cell is used to formulate an equation for the correction radius needed, depending on the characteristics of the correction function used, maximum aspect ratio, minimum first cell height and boundary error. Based on the analysis two new radial basis correction functions are derived and proposed. This proposed automated procedure is verified while varying the correction function, Reynolds number (and thus first cell height and aspect ratio) and boundary error. Finally, the parallel efficiency is studied for the two adaptive methods, unit displacement and prescribed displacement for both the CPU as well as the memory formulation with a 2D oscillating and translating airfoil with oscillating flap, a 3D flexible locally deforming tube and deforming wind turbine blade. Generally, the memory formulation requires less work (due to the large amount of work required for evaluating RBF's), but the parallel efficiency reduces due to the limited bandwidth available between CPU and memory. In terms of parallel efficiency/scaling the different studied methods perform similarly, with the greedy algorithm being the bottleneck. In terms of absolute computational work the adaptive methods are better for the cases studied due to their more efficient selection of the control points. By automating most of the RBF mesh deformation, a robust, efficient and almost user-independent mesh deformation method is presented.

Liquid Medication Dosing Errors in Children: Role of Provider Counseling Strategies

PubMed Central

Yin, H. Shonna; Dreyer, Benard P.; Moreira, Hannah A.; van Schaick, Linda; Rodriguez, Luis; Boettger, Susanne; Mendelsohn, Alan L.

2014-01-01

Objective To examine the degree to which recommended provider counseling strategies, including advanced communication techniques and dosing instrument provision, are associated with reductions in parent liquid medication dosing errors. Methods Cross-sectional analysis of baseline data on provider communication and dosing instrument provision from a study of a health literacy intervention to reduce medication errors. Parents whose children (<9 years) were seen in two urban public hospital pediatric emergency departments (EDs) and were prescribed daily dose liquid medications self-reported whether they received counseling about their child’s medication, including advanced strategies (teachback, drawings/pictures, demonstration, showback) and receipt of a dosing instrument. Primary dependent variable: observed dosing error (>20% deviation from prescribed). Multivariate logistic regression analyses performed, controlling for: parent age, language, country, ethnicity, socioeconomic status, education, health literacy (Short Test of Functional Health Literacy in Adults); child age, chronic disease status; site. Results Of 287 parents, 41.1% made dosing errors. Advanced counseling and instrument provision in the ED were reported by 33.1% and 19.2%, respectively; 15.0% reported both. Advanced counseling and instrument provision in the ED were associated with decreased errors (30.5 vs. 46.4%, p=0.01; 21.8 vs. 45.7%, p=0.001). In adjusted analyses, ED advanced counseling in combination with instrument provision was associated with a decreased odds of error compared to receiving neither (AOR 0.3; 95% CI 0.1–0.7); advanced counseling alone and instrument alone were not significantly associated with odds of error. Conclusion Provider use of advanced counseling strategies and dosing instrument provision may be especially effective in reducing errors when used together. PMID:24767779

Liquid medication dosing errors in children: role of provider counseling strategies.

PubMed

Yin, H Shonna; Dreyer, Benard P; Moreira, Hannah A; van Schaick, Linda; Rodriguez, Luis; Boettger, Susanne; Mendelsohn, Alan L

2014-01-01

To examine the degree to which recommended provider counseling strategies, including advanced communication techniques and dosing instrument provision, are associated with reductions in parent liquid medication dosing errors. Cross-sectional analysis of baseline data on provider communication and dosing instrument provision from a study of a health literacy intervention to reduce medication errors. Parents whose children (<9 years) were seen in 2 urban public hospital pediatric emergency departments (EDs) and were prescribed daily dose liquid medications self-reported whether they received counseling about their child's medication, including advanced strategies (teachback, drawings/pictures, demonstration, showback) and receipt of a dosing instrument. The primary dependent variable was observed dosing error (>20% deviation from prescribed). Multivariate logistic regression analyses were performed, controlling for parent age, language, country, ethnicity, socioeconomic status, education, health literacy (Short Test of Functional Health Literacy in Adults); child age, chronic disease status; and site. Of 287 parents, 41.1% made dosing errors. Advanced counseling and instrument provision in the ED were reported by 33.1% and 19.2%, respectively; 15.0% reported both. Advanced counseling and instrument provision in the ED were associated with decreased errors (30.5 vs. 46.4%, P = .01; 21.8 vs. 45.7%, P = .001). In adjusted analyses, ED advanced counseling in combination with instrument provision was associated with a decreased odds of error compared to receiving neither (adjusted odds ratio 0.3; 95% confidence interval 0.1-0.7); advanced counseling alone and instrument alone were not significantly associated with odds of error. Provider use of advanced counseling strategies and dosing instrument provision may be especially effective in reducing errors when used together. Copyright © 2014 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Sampled-data H∞ filtering for Markovian jump singularly perturbed systems with time-varying delay and missing measurements

NASA Astrophysics Data System (ADS)

Yan, Yifang; Yang, Chunyu; Ma, Xiaoping; Zhou, Linna

2018-02-01

In this paper, sampled-data H∞ filtering problem is considered for Markovian jump singularly perturbed systems with time-varying delay and missing measurements. The sampled-data system is represented by a time-delay system, and the missing measurement phenomenon is described by an independent Bernoulli random process. By constructing an ɛ-dependent stochastic Lyapunov-Krasovskii functional, delay-dependent sufficient conditions are derived such that the filter error system satisfies the prescribed H∞ performance for all possible missing measurements. Then, an H∞ filter design method is proposed in terms of linear matrix inequalities. Finally, numerical examples are given to illustrate the feasibility and advantages of the obtained results.

Detection and avoidance of errors in computer software

NASA Technical Reports Server (NTRS)

Kinsler, Les

1989-01-01

The acceptance test errors of a computer software project to determine if the errors could be detected or avoided in earlier phases of development. GROAGSS (Gamma Ray Observatory Attitude Ground Support System) was selected as the software project to be examined. The development of the software followed the standard Flight Dynamics Software Development methods. GROAGSS was developed between August 1985 and April 1989. The project is approximately 250,000 lines of code of which approximately 43,000 lines are reused from previous projects. GROAGSS had a total of 1715 Change Report Forms (CRFs) submitted during the entire development and testing. These changes contained 936 errors. Of these 936 errors, 374 were found during the acceptance testing. These acceptance test errors were first categorized into methods of avoidance including: more clearly written requirements; detail review; code reading; structural unit testing; and functional system integration testing. The errors were later broken down in terms of effort to detect and correct, class of error, and probability that the prescribed detection method would be successful. These determinations were based on Software Engineering Laboratory (SEL) documents and interviews with the project programmers. A summary of the results of the categorizations is presented. The number of programming errors at the beginning of acceptance testing can be significantly reduced. The results of the existing development methodology are examined for ways of improvements. A basis is provided for the definition is a new development/testing paradigm. Monitoring of the new scheme will objectively determine its effectiveness on avoiding and detecting errors.

Translating Patient Safety Research Into Clinical Practice

DTIC Science & Technology

2005-01-01

AIM approach is being used to evaluate a pharmacy alert intervention designed to detect and correct medication prescribing errors for all patients ...Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Advances in Patient Safety: Vol. 2 164 patients .6, 9 Medication use in the ambulatory care...subjects and patients with chronic illnesses) and settings (e.g., schools, worksites, and medical clinics).32 We illustrate each of the RE-AIM dimensions

Prescribed Velocity Gradients for Highly Viscous SPH Fluids with Vorticity Diffusion.

PubMed

Peer, Andreas; Teschner, Matthias

2017-12-01

Working with prescribed velocity gradients is a promising approach to efficiently and robustly simulate highly viscous SPH fluids. Such approaches allow to explicitly and independently process shear rate, spin, and expansion rate. This can be used to, e.g., avoid interferences between pressure and viscosity solvers. Another interesting aspect is the possibility to explicitly process the vorticity, e.g., to preserve the vorticity. In this context, this paper proposes a novel variant of the prescribed-gradient idea that handles vorticity in a physically motivated way. In contrast to a less appropriate vorticity preservation that has been used in a previous approach, vorticity is diffused. The paper illustrates the utility of the vorticity diffusion. Therefore, comparisons of the proposed vorticity diffusion with vorticity preservation and additionally with vorticity damping are presented. The paper further discusses the relation between prescribed velocity gradients and prescribed velocity Laplacians which improves the intuition behind the prescribed-gradient method for highly viscous SPH fluids. Finally, the paper discusses the relation of the proposed method to a physically correct implicit viscosity formulation.

Medication-related clinical decision support in computerized provider order entry systems: a review.

PubMed

Kuperman, Gilad J; Bobb, Anne; Payne, Thomas H; Avery, Anthony J; Gandhi, Tejal K; Burns, Gerard; Classen, David C; Bates, David W

2007-01-01

While medications can improve patients' health, the process of prescribing them is complex and error prone, and medication errors cause many preventable injuries. Computer provider order entry (CPOE) with clinical decision support (CDS), can improve patient safety and lower medication-related costs. To realize the medication-related benefits of CDS within CPOE, one must overcome significant challenges. Healthcare organizations implementing CPOE must understand what classes of CDS their CPOE systems can support, assure that clinical knowledge underlying their CDS systems is reasonable, and appropriately represent electronic patient data. These issues often influence to what extent an institution will succeed with its CPOE implementation and achieve its desired goals. Medication-related decision support is probably best introduced into healthcare organizations in two stages, basic and advanced. Basic decision support includes drug-allergy checking, basic dosing guidance, formulary decision support, duplicate therapy checking, and drug-drug interaction checking. Advanced decision support includes dosing support for renal insufficiency and geriatric patients, guidance for medication-related laboratory testing, drug-pregnancy checking, and drug-disease contraindication checking. In this paper, the authors outline some of the challenges associated with both basic and advanced decision support and discuss how those challenges might be addressed. The authors conclude with summary recommendations for delivering effective medication-related clinical decision support addressed to healthcare organizations, application and knowledge base vendors, policy makers, and researchers.

Hypervitaminosis D associated with a vitamin D dispensing error.

PubMed

Jacobsen, Ryan B; Hronek, Brett W; Schmidt, Ginelle A; Schilling, Margo L

2011-10-01

To report a case of hypervitaminosis D resulting in hypercalcemia and acute kidney injury in a 70-year-old female who was prescribed a standard dose of vitamin D but given a toxic dose of vitamin D 50,000 IU (1.25 mg) daily resulting from a dispensing error. A 70-year-old female in her usual state of health was instructed to begin supplementation with vitamin D 1000 IU daily. Three months later she developed confusion, slurred speech, unstable gait, and increased fatigue. She was hospitalized for hypercalcemia and acute kidney injury secondary to hypervitaminosis D. All vitamin D supplementation was discontinued and 5 months after discharge, the patient's serum calcium and vitamin D concentrations, as well as renal function, had returned to baseline values. Upon review of the patient's records, it was discovered that she had been taking vitamin D 50,000 IU daily. There is an increased interest in vitamin D, resulting in more health care providers recommending--and patients taking--supplemental vitamin D. Hypervitaminosis D is rarely reported and generally only in the setting of gross excess of vitamin D. This report highlights a case of hypervitaminosis D in the setting of a prescribed standard dose of vitamin D that resulted in toxic ingestion of vitamin D 50,000 IU daily due to a dispensing error. As more and more people use vitamin D supplements, it is important to recognize that, while rare, hypervitaminosis D is a possibility and dosage conversion of vitamin D units can result in errors. Health care providers and patients should be educated on the advantages and risks associated with vitamin D supplementation and be informed of safety measures to avoid hypervitaminosis D. In addition, health care providers should understand dosage conversion regarding vitamin D and electronic prescribing and dispensing software should be designed to detect such errors.

Error Rates in Measuring Teacher and School Performance Based on Student Test Score Gains. NCEE 2010-4004

ERIC Educational Resources Information Center

Schochet, Peter Z.; Chiang, Hanley S.

2010-01-01

This paper addresses likely error rates for measuring teacher and school performance in the upper elementary grades using value-added models applied to student test score gain data. Using realistic performance measurement system schemes based on hypothesis testing, we develop error rate formulas based on OLS and Empirical Bayes estimators.…

A systematic review of educational interventions to change behaviour of prescribers in hospital settings, with a particular emphasis on new prescribers

PubMed Central

Brennan, Nicola; Mattick, Karen

2013-01-01

Aims Prescribing is a complex task and a high risk area of clinical practice. Poor prescribing occurs across staff grades and settings but new prescribers are attributed much of the blame. New prescribers may not be confident or even competent to prescribe and probably have different support and development needs than their more experienced colleagues. Unfortunately, little is known about what interventions are effective in this group. Previous systematic reviews have not distinguished between different grades of staff, have been narrow in scope and are now out of date. Therefore, to inform the design of educational interventions to change prescribing behaviour, particularly that of new prescibers, we conducted a systematic review of existing hospital-based interventions. Methods Embase, Medline, SIGLE, Cinahl and PsychINFO were searched for relevant studies published 1994–2010. Studies describing interventions to change the behaviour of prescribers in hospital settings were included, with an emphasis on new prescibers. The bibliographies of included papers were also searched for relevant studies. Interventions and effectiveness were classified using existing frameworks and the quality of studies was assessed using a validated instrument. Results Sixty-four studies were included in the review. Only 13% of interventions specifically targeted new prescribers. Most interventions (72%) were deemed effective in changing behaviour but no particular type stood out as most effective. Conclusion Very few studies have tailored educational interventions to meet needs of new prescribers, or distinguished between new and experienced prescribers. Educational development and research will be required to improve this important aspect of early clinical practice. PMID:22831632

Pharmacist independent prescribing in critical care: results of a national questionnaire to establish the 2014 UK position.

PubMed

Bourne, Richard S; Whiting, Paul; Brown, Lisa S; Borthwick, Mark

2016-04-01

Clinical pharmacist practice is well established in the safe and effective use of medicines in the critically ill patient. In the UK, independent pharmacist prescribers are generally recognised as a valuable and desirable resource. However, currently, there are only anecdotal reports of pharmacist-independent prescribing in critical care. The aim of this questionnaire was to determine the current and proposed future independent prescribing practice of UK clinical pharmacists working in adult critical care. The questionnaire was distributed electronically to UK Clinical Pharmacy Association members (closed August 2014). There were 134 responses to the questionnaire (response rate at least 33%). Over a third of critical care pharmacists were practising independent prescribers in the specialty, and 70% intended to be prescribers within the next 3 years. Pharmacists with ≥5 years critical care experience (P < 0.001) or worked in a team (P = 0.005) were more likely to be practising independent prescribers. Pharmacists reported significant positives to the use of independent prescribing in critical care both in patient care and job satisfaction. Independently, prescribing was routine in: dose adjustment for multi-organ failure, change in route or formulation, correction prescribing errors, therapeutic drug monitoring and chronic medication. The majority of pharmacist prescribers reported they spent ≤5% of their clinical time prescribing and accounted for ≤5% of new prescriptions in critical care patients. Most critical care pharmacists intend to be practising as independent prescribers within the next 3 years. The extent and scope of critical care pharmacist prescribing appear to be of relatively low volume and within niche prescribing areas. © 2015 Royal Pharmaceutical Society.

Performance analysis of Rogowski coils and the measurement of the total toroidal current in the ITER machine

NASA Astrophysics Data System (ADS)

Quercia, A.; Albanese, R.; Fresa, R.; Minucci, S.; Arshad, S.; Vayakis, G.

2017-12-01

The paper carries out a comprehensive study of the performances of Rogowski coils. It describes methodologies that were developed in order to assess the capabilities of the Continuous External Rogowski (CER), which measures the total toroidal current in the ITER machine. Even though the paper mainly considers the CER, the contents are general and relevant to any Rogowski sensor. The CER consists of two concentric helical coils which are wound along a complex closed path. Modelling and computational activities were performed to quantify the measurement errors, taking detailed account of the ITER environment. The geometrical complexity of the sensor is accurately accounted for and the standard model which provides the classical expression to compute the flux linkage of Rogowski sensors is quantitatively validated. Then, in order to take into account the non-ideality of the winding, a generalized expression, formally analogue to the classical one, is presented. Models to determine the worst case and the statistical measurement accuracies are hence provided. The following sources of error are considered: effect of the joints, disturbances due to external sources of field (the currents flowing in the poloidal field coils and the ferromagnetic inserts of ITER), deviations from ideal geometry, toroidal field variations, calibration, noise and integration drift. The proposed methods are applied to the measurement error of the CER, in particular in its high and low operating ranges, as prescribed by the ITER system design description documents, and during transients, which highlight the large time constant related to the shielding of the vacuum vessel. The analyses presented in the paper show that the design of the CER diagnostic is capable of achieving the requisite performance as needed for the operation of the ITER machine.

Paediatric Patient Safety and the Need for Aviation Black Box Thinking to Learn From and Prevent Medication Errors.

PubMed

Huynh, Chi; Wong, Ian C K; Correa-West, Jo; Terry, David; McCarthy, Suzanne

2017-04-01

Since the publication of To Err Is Human: Building a Safer Health System in 1999, there has been much research conducted into the epidemiology, nature and causes of medication errors in children, from prescribing and supply to administration. It is reassuring to see growing evidence of improving medication safety in children; however, based on media reports, it can be seen that serious and fatal medication errors still occur. This critical opinion article examines the problem of medication errors in children and provides recommendations for research, training of healthcare professionals and a culture shift towards dealing with medication errors. There are three factors that we need to consider to unravel what is missing and why fatal medication errors still occur. (1) Who is involved and affected by the medication error? (2) What factors hinder staff and organisations from learning from mistakes? Does the fear of litigation and criminal charges deter healthcare professionals from voluntarily reporting medication errors? (3) What are the educational needs required to prevent medication errors? It is important to educate future healthcare professionals about medication errors and human factors to prevent these from happening. Further research is required to apply aviation's 'black box' principles in healthcare to record and learn from near misses and errors to prevent future events. There is an urgent need for the black box investigations to be published and made public for the benefit of other organisations that may have similar potential risks for adverse events. International sharing of investigations and learning is also needed.

Medication Errors in Pediatric Anesthesia: A Report From the Wake Up Safe Quality Improvement Initiative.

PubMed

Lobaugh, Lauren M Y; Martin, Lizabeth D; Schleelein, Laura E; Tyler, Donald C; Litman, Ronald S

2017-09-01

Wake Up Safe is a quality improvement initiative of the Society for Pediatric Anesthesia that contains a deidentified registry of serious adverse events occurring in pediatric anesthesia. The aim of this study was to describe and characterize reported medication errors to find common patterns amenable to preventative strategies. In September 2016, we analyzed approximately 6 years' worth of medication error events reported to Wake Up Safe. Medication errors were classified by: (1) medication category; (2) error type by phase of administration: prescribing, preparation, or administration; (3) bolus or infusion error; (4) provider type and level of training; (5) harm as defined by the National Coordinating Council for Medication Error Reporting and Prevention; and (6) perceived preventability. From 2010 to the time of our data analysis in September 2016, 32 institutions had joined and submitted data on 2087 adverse events during 2,316,635 anesthetics. These reports contained details of 276 medication errors, which comprised the third highest category of events behind cardiac and respiratory related events. Medication errors most commonly involved opioids and sedative/hypnotics. When categorized by phase of handling, 30 events occurred during preparation, 67 during prescribing, and 179 during administration. The most common error type was accidental administration of the wrong dose (N = 84), followed by syringe swap (accidental administration of the wrong syringe, N = 49). Fifty-seven (21%) reported medication errors involved medications prepared as infusions as opposed to 1 time bolus administrations. Medication errors were committed by all types of anesthesia providers, most commonly by attendings. Over 80% of reported medication errors reached the patient and more than half of these events caused patient harm. Fifteen events (5%) required a life sustaining intervention. Nearly all cases (97%) were judged to be either likely or certainly preventable. Our findings characterize the most common types of medication errors in pediatric anesthesia practice and provide guidance on future preventative strategies. Many of these errors will be almost entirely preventable with the use of prefilled medication syringes to avoid accidental ampule swap, bar-coding at the point of medication administration to prevent syringe swap and to confirm the proper dose, and 2-person checking of medication infusions for accuracy.

Error Analysis for RADAR Neighbor Matching Localization in Linear Logarithmic Strength Varying Wi-Fi Environment

PubMed Central

Tian, Zengshan; Xu, Kunjie; Yu, Xiang

2014-01-01

This paper studies the statistical errors for the fingerprint-based RADAR neighbor matching localization with the linearly calibrated reference points (RPs) in logarithmic received signal strength (RSS) varying Wi-Fi environment. To the best of our knowledge, little comprehensive analysis work has appeared on the error performance of neighbor matching localization with respect to the deployment of RPs. However, in order to achieve the efficient and reliable location-based services (LBSs) as well as the ubiquitous context-awareness in Wi-Fi environment, much attention has to be paid to the highly accurate and cost-efficient localization systems. To this end, the statistical errors by the widely used neighbor matching localization are significantly discussed in this paper to examine the inherent mathematical relations between the localization errors and the locations of RPs by using a basic linear logarithmic strength varying model. Furthermore, based on the mathematical demonstrations and some testing results, the closed-form solutions to the statistical errors by RADAR neighbor matching localization can be an effective tool to explore alternative deployment of fingerprint-based neighbor matching localization systems in the future. PMID:24683349

Error analysis for RADAR neighbor matching localization in linear logarithmic strength varying Wi-Fi environment.

PubMed

Zhou, Mu; Tian, Zengshan; Xu, Kunjie; Yu, Xiang; Wu, Haibo

2014-01-01

This paper studies the statistical errors for the fingerprint-based RADAR neighbor matching localization with the linearly calibrated reference points (RPs) in logarithmic received signal strength (RSS) varying Wi-Fi environment. To the best of our knowledge, little comprehensive analysis work has appeared on the error performance of neighbor matching localization with respect to the deployment of RPs. However, in order to achieve the efficient and reliable location-based services (LBSs) as well as the ubiquitous context-awareness in Wi-Fi environment, much attention has to be paid to the highly accurate and cost-efficient localization systems. To this end, the statistical errors by the widely used neighbor matching localization are significantly discussed in this paper to examine the inherent mathematical relations between the localization errors and the locations of RPs by using a basic linear logarithmic strength varying model. Furthermore, based on the mathematical demonstrations and some testing results, the closed-form solutions to the statistical errors by RADAR neighbor matching localization can be an effective tool to explore alternative deployment of fingerprint-based neighbor matching localization systems in the future.

Nurse prescribing: reflections on safety in practice.

PubMed

Bradley, Eleanor; Hynam, Brian; Nolan, Peter

2007-08-01

This qualitative study explores how recently qualified nurse prescribers describe, and rate, the safety of their prescribing. Internationally, the costs of drug errors are enormous and they can have serious implications for staff and patients. Nurses are now undertaking extended prescribing practice throughout the UK. Nurse prescribers work across different work settings and although safe prescribing is a priority in all of them, it is essential to ascertain the conditions that foster the highest levels of safety and how nurses can be supported in practice. Thirty-one nurses form the West Midlands area of England agreed to participate in an in-depth interview which sought to elicit their responses to various aspects of their prescribing work. They came from a variety of specialities and from hospital, community and general practice backgrounds. On completion of their training nurses were acutely aware of the responsibility that prescribing imposed on them. Although this awareness was thought to encourage caution and safety, it may also account for the fact that 26% of the nurses (n=8) had not prescribed since qualifying. Nurses felt that the multidisciplinary team had a vital role to play in supporting their prescribing practice as did collaborative working. It is concluded that those working in specialty areas that are less well-defined in terms of scope of practice (e.g. older adult nursing and learning disability) would benefit in particular from ongoing mentoring relationships with experienced prescribers and the development of individual formularies.

Early experiences with E-prescribing.

PubMed

Halamka, John

2006-01-01

Most physicians understand that e-prescribing will reduce medical errors and will be perceived by patients as making the prescription process easier. However, they are skeptical about a number of things. They worry whether their office processes will be improved or streamlined; e-prescribing will interface seamlessly with their existing practice management software; training and support will be available; e-prescribing data will be seamlessly transferable to an electronic health record when they implement a more advanced clinical record system for their practice; and if they will achieve a return on investment. Early adopting clinicians in Massachusetts can convince the majority of clinicians to adopt e-prescribing by sharing their motivations for adopting e-prescribing, the challenges that they needed to overcome, the hardware and software requirements, and integration into their office workflow. Finally, interaction with the physicians and practice managers in the audience makes the adoption of e-prescribing seem both reasonable and exciting. Resources such as vendor lists, questions to ask, and hardware and software requirements also need to be readily available and in a form that non-technical staff can read and understand. Physicians who know the "why" would also like to know

Electronic prescribing in ambulatory practice: promises, pitfalls, and potential solutions.

PubMed

Papshev, D; Peterson, A M

2001-07-01

To examine advantages of and obstacles to electronic prescribing in the ambulatory care environment. MEDLINE and International Pharmaceutical Abstract searches were conducted for the period from January 1980 to September 2000. Key words were electronic prescribing, computerized physician order entry, prior authorization, drug utilization review, and consumer satisfaction. In September 2000, a public search engine (www.google.com) was used to find additional technical information. In addition, pertinent articles were cross-referenced to identify other resources. Articles, symposia proceedings, and organizational position statements published in the United States on electronic prescribing and automation in healthcare are cited. Electronic prescribing can eliminate the time gap between point of care and point of service, reduce medication errors, improve quality of care, and increase patient satisfaction. Considerable funding requirements, segmentation of healthcare markets, lack of technology standardization, providers' resistance to change, and regulatory indecisiveness create boundaries to the widespread use of automated prescribing. The potential solutions include establishing a standardizing warehouse or a router and gaining stakeholder support in implementation of the technology. Electronic prescribing can provide immense benefits to healthcare providers, patients, and managed care. Resolution of several obstacles that limit feasibility of this technology will determine its future.

How should teaching of undergraduates in clinical pharmacology and therapeutics be delivered and assessed?

PubMed Central

Maxwell, Simon R J

2012-01-01

Clinical pharmacology and therapeutics is the academic discipline that informs rational prescribing of medicines. There is accumulating evidence that a significant minority of prescriptions in the UK National Health Service contain errors. This comes at a time when the approach to and success of undergraduate education in this area has been called into question. Various stakeholders are now in agreement that this challenging area of undergraduate education needs to be strengthened. The principles that should form the basis of future educational strategy include greater visibility of clinical pharmacology and therapeutics in the curriculum, clear learning outcomes that are consistent with national guidance, strong and enthusiastic leadership, a student formulary, opportunities to practice prescribing, a robust assessment of prescribing competencies and external quality control. Important new developments in the UK are Prescribe, a repository of e-learning materials to support education in clinical pharmacology and prescribing, and the Prescribing Skills Assessment, a national online assessment designed to allow medical students to demonstrate that they have achieved the core competencies required to begin postgraduate training. PMID:22360965

Identifying fallacious arguments in a qualitative study of antipsychotic prescribing in dementia.

PubMed

Donyai, Parastou

2017-10-01

Dementia can result in cognitive, noncognitive and behavioural symptoms which are difficult to manage. Formal guidelines for the care and management of dementia in the UK state that antipsychotics should only be prescribed where fully justified. This is because inappropriate use, particularly problematic in care-home settings, can produce severe side effects including death. The aim of this study was to explore the use of fallacious arguments in professionals' deliberations about antipsychotic prescribing in dementia in care-home settings. Fallacious arguments have the potential to become unremarkable discourses that construct and validate practices which are counter to guidelines. This qualitative study involved interviews with 28 care-home managers and health professionals involved in caring for patients with dementia. Potentially fallacious arguments were identified using qualitative content analysis and a coding framework constructed from existing explanatory models of fallacious reasoning. Fallacious arguments were identified in a range of explanations and reasons that participants gave for in answer to questions about initiating, reducing doses of and stopping antipsychotics in dementia. The dominant fallacy was false dichotomy. Appeal to popularity, tradition, consequence, emotion, or fear, and the slippery slope argument was also identified. Fallacious arguments were often formulated to present convincing cases whereby prescribing antipsychotics or maintaining existing doses (versus not starting medication or reducing the dose, for example) appeared as the only acceptable decision but this is not always the case. The findings could help health professionals to recognise and mitigate the effect of logic-based errors in decisions about the prescribing of antipsychotics in dementia. © 2016 Royal Pharmaceutical Society.

Essential therapeutics skills required of junior doctors.

PubMed

Baldwin, Mathew J; Abouyannis, Michael; Butt, Tehreem F

2012-12-01

Junior doctors are responsible for the majority of in-hospital prescription errors. Little research has explored their confidence to prescribe, or practical therapeutics related tasks which they are required to perform in day-to-day practice. This survey aimed to explore these areas, gather feedback regarding therapeutics teaching at undergraduate level, and to apply findings to undergraduate training at University of Birmingham. Questionnaire-based survey of all first-year postgraduate doctors (PG1) attending teaching hospitals in the Birmingham and Worcester regions towards the end of the PG1 year. Doctors were asked about difficulties in prescribing, satisfaction with undergraduate training, and how frequently they undertook particular tasks pertaining to therapeutics. Qualitative data on suggestions for improving the curriculum were also collected. Difficulties were commonly encountered with prescribing warfarin, controlled drugs and syringe-driven drugs. Most (87.4 %) had been required to administer intravenous medications. Nearly all had prescribed to 'special groups' such as the elderly (100 %) and patients with renal disease (98.3 %). Thirty-seven percent were not satisfied with their undergraduate therapeutics teaching, and many (56.2 %) recommended making teaching more relevant to clinical practice. Many PG1s expressed difficulties in prescribing potentially dangerous medications. Although better than other UK surveys, significant numbers were not satisfied with undergraduate teaching. The strong opinion was for teaching to become more practical and more relevant. Prescriptions which PG1s are commonly asked to write have been described. Findings have guided improvements to undergraduate teaching and assessment in therapeutics at the University of Birmingham, and may offer guidance to other medical schools.

A Computer Prescribing Order Entry-Clinical Decision Support system designed for neonatal care: results of the 'preselected prescription' concept at the bedside.

PubMed

Gouyon, B; Iacobelli, S; Saliba, E; Quantin, C; Pignolet, A; Jacqz-Aigrain, E; Gouyon, J B

2017-02-01

The neonatal intensive care units (NICUs) are at the highest risk of drug dose error of all hospital wards. NICUs also have the most complicated prescription modalities. The computerization of the prescription process is currently recommended to decrease the risk of preventable adverse drug effects (pADEs) in NICUs. However, Computer Prescribing Order Entry-Clinical Decision Support (C.P.O.E./C.D.S.) systems have been poorly studied in NICUs, and their technical compatibility with neonatal specificities has been limited. We set up a performance study of the preselected prescription of drugs for neonates, which limited the role of the prescriber to choosing the drugs and their indications. A single 29 bed neonatal ward used this neonatal C.P.O.E./C.D.S. system for all prescriptions of all hospitalized newborns over an 18-month period. The preselected prescription of drugs was based on the indication, gestational age, body weight and post-natal age. The therapeutic protocols were provided by a formulary reference (330 drugs) that had been specifically designed for newborns. The preselected prescription also gave complete information about preparation and administration of drugs by nurses. The prescriber was allowed to modify the preselected prescription but alarms provided warning when the prescription was outside the recommended range. The main clinical characteristics and all items of each line of prescription were stored in a data warehouse, thus enabling this study to take place. Seven hundred and sixty successive newborns (from 24 to 42 weeks' gestation) were prescribed 52 392 lines of prescription corresponding to 65 drugs; About 30·4% of neonates had at least one out of licensed prescription; A prescription out of the recommended range for daily dose was recorded for 1·0% of all drug prescriptions. WHAT IS NEW?: The C.P.O.E./C.D.S. systems can currently provide a complete preselected prescription in NICUs according to dose rules, which are specific to newborns and also comply with local specificities (therapeutic protocols and formulation of drugs). The role of the prescriber is limited to the choice of drugs and their indications. The prescriber still retains the possibility of modifying each item of the prescription, with all other prescription items being calculated by the C.P.O.E. system. In these conditions, the prescribers rarely modified the preselected prescription and the rate of out of range prescription was low. A multicentric study is required to confirm and extend these observations. This study showed the feasibility of preselected prescription in NICUs and a low rate of out of range prescriptions. The preselected prescription could play a key role in lowering the dose error rate in NICUs. © 2016 John Wiley & Sons Ltd.

Systemic errors calibration in dynamic stitching interferometry

NASA Astrophysics Data System (ADS)

Wu, Xin; Qi, Te; Yu, Yingjie; Zhang, Linna

2016-05-01

The systemic error is the main error sauce in sub-aperture stitching calculation. In this paper, a systemic error calibration method is proposed based on pseudo shearing. This method is suitable in dynamic stitching interferometry for large optical plane. The feasibility is vibrated by some simulations and experiments.

The importance of interdisciplinary communication in the process of anticipatory prescribing.

PubMed

Wilson, Eleanor; Seymour, Jane

2017-03-16

In the UK there has been a widespread introduction of 'anticipatory prescribing' in community based palliative care. This involves general practitioners (GPs) writing prescriptions in anticipation of them being needed and has been encouraged to try to minimise the risk of patients suffering uncontrolled symptoms and distress; a key reason why terminally ill patients are admitted to hospital in contradiction of most people's preferences. This paper presents the findings from an ethnographic study of healthcare professionals across four care homes and four community sites in two regions (East Midlands and Lancashire/South Cumbria) of the UK. Data were collected from a range of community health professionals, resulting in 83 episodes of observation and 72 interviews. Findings highlight how essential good interdisciplinary communication is to the process of anticipatory prescribing and end-of-life care. This study found that when interdisciplinary communication worked well the anticipatory prescribing process could be carried out smoothly, optimising patient care.

Using Medications Safely

MedlinePlus

... health systems play an important role in preventing medication errors. To make sure you use medicines safely and effectively, ASHP recommends that you: Keep a list of all medications that you take (prescribed drugs, nonprescription medicines, herbal ...

Junior doctor-led ‘near-peer’ prescribing education for medical students

PubMed Central

Gibson, Kyle R; Qureshi, Zeshan U; Ross, Michael T; Maxwell, Simon R

2014-01-01

Aims Prescribing errors are common and inadequate preparation of prescribers appears to contribute. A junior doctor-led prescribing tutorial programme has been developed for Edinburgh final year medical students to increase exposure to common prescribing tasks. The aim of this study was to assess the impact of these tutorials on students and tutors. Methods One hundred and ninety-six tutorials were delivered to 183 students during 2010–2011. Each student completed a questionnaire after tutorial attendance which explored their previous prescribing experiences and the perceived benefits of tutorial attendance. Tutors completed a questionnaire which evaluated their teaching experiences and the impact on their prescribing practice. Student tutorial attendance was compared with end-of-year examination performance using linear regression analysis. Results The students reported increased confidence in their prescribing knowledge and skills after attending tutorials. Students who attended more tutorials also tended to perform better in end-of-year examinations (Drug prescribing: r = 0.16, P = 0.015; Fluid prescribing: r = 0.18, P = 0.007). Tutors considered that participation enhanced their own prescribing knowledge and skills. Although they were occasionally unable to address student uncertainties, 80% of tutors reported frequently correcting misconceptions and deficits in student knowledge. Ninety-five percent of students expressed a preference for prescribing training delivered by junior doctors over more senior doctors. Conclusions A ‘near-peer’ junior doctor-led approach to delivering prescribing training to medical students was highly valued by both students and tutors. Although junior doctors have relatively less clinical experience of prescribing, we believe that this can be addressed by training and academic supervision and is outweighed by the benefits of these tutorials. PMID:23617320

A Damping Grid Strapdown Inertial Navigation System Based on a Kalman Filter for Ships in Polar Regions.

PubMed

Huang, Weiquan; Fang, Tao; Luo, Li; Zhao, Lin; Che, Fengzhu

2017-07-03

The grid strapdown inertial navigation system (SINS) used in polar navigation also includes three kinds of periodic oscillation errors as common SINS are based on a geographic coordinate system. Aiming ships which have the external information to conduct a system reset regularly, suppressing the Schuler periodic oscillation is an effective way to enhance navigation accuracy. The Kalman filter based on the grid SINS error model which applies to the ship is established in this paper. The errors of grid-level attitude angles can be accurately estimated when the external velocity contains constant error, and then correcting the errors of the grid-level attitude angles through feedback correction can effectively dampen the Schuler periodic oscillation. The simulation results show that with the aid of external reference velocity, the proposed external level damping algorithm based on the Kalman filter can suppress the Schuler periodic oscillation effectively. Compared with the traditional external level damping algorithm based on the damping network, the algorithm proposed in this paper can reduce the overshoot errors when the state of grid SINS is switched from the non-damping state to the damping state, and this effectively improves the navigation accuracy of the system.

Utility of Equations to Estimate Peak Oxygen Uptake and Work Rate From a 6-Minute Walk Test in Patients With COPD in a Clinical Setting.

PubMed

Kirkham, Amy A; Pauhl, Katherine E; Elliott, Robyn M; Scott, Jen A; Doria, Silvana C; Davidson, Hanan K; Neil-Sztramko, Sarah E; Campbell, Kristin L; Camp, Pat G

2015-01-01

To determine the utility of equations that use the 6-minute walk test (6MWT) results to estimate peak oxygen uptake ((Equation is included in full-text article.)o2) and peak work rate with chronic obstructive pulmonary disease (COPD) patients in a clinical setting. This study included a systematic review to identify published equations estimating peak (Equation is included in full-text article.)o2 and peak work rate in watts in COPD patients and a retrospective chart review of data from a hospital-based pulmonary rehabilitation program. The following variables were abstracted from the records of 42 consecutively enrolled COPD patients: measured peak (Equation is included in full-text article.)o2 and peak work rate achieved during a cycle ergometer cardiopulmonary exercise test, 6MWT distance, age, sex, weight, height, forced expiratory volume in 1 second, forced vital capacity, and lung diffusion capacity. Estimated peak (Equation is included in full-text article.)o2 and peak work rate were estimated from 6MWT distance using published equations. The error associated with using estimated peak (Equation is included in full-text article.)o2 or peak work to prescribe aerobic exercise intensities of 60% and 80% was calculated. Eleven equations from 6 studies were identified. Agreement between estimated and measured values was poor to moderate (intraclass correlation coefficients = 0.11-0.63). The error associated with using estimated peak (Equation is included in full-text article.)o2 or peak work rate to prescribe exercise intensities of 60% and 80% of measured values ranged from mean differences of 12 to 35 and 16 to 47 percentage points, respectively. There is poor to moderate agreement between measured peak (Equation is included in full-text article.)o2 and peak work rate and estimations from equations that use 6MWT distance, and the use of the estimated values for prescription of aerobic exercise intensity would result in large error. Equations estimating peak (Equation is included in full-text article.)o2 and peak work rate are of low utility for prescribing exercise intensity in pulmonary rehabilitation programs.

Generation of a crowned pinion tooth surface by a surface of revolution

NASA Technical Reports Server (NTRS)

Litvin, F. L.; Zhang, J.; Handschuh, R. F.

1988-01-01

A method of generating crowned pinion tooth surfaces using a surface of revolution is developed. The crowned pinion meshes with a regular involute gear and has a prescribed parabolic type of transmission errors when the gears operate in the aligned mode. When the gears are misaligned the transmission error remains parabolic with the maximum level still remaining very small (less than 0.34 arc sec for the numerical examples). Tooth contact analysis (TCA) is used to simulate the conditions of meshing, determine the transmission error, and determine the bearing contact.

ANALYZING NUMERICAL ERRORS IN DOMAIN HEAT TRANSPORT MODELS USING THE CVBEM.

USGS Publications Warehouse

Hromadka, T.V.

1987-01-01

Besides providing an exact solution for steady-state heat conduction processes (Laplace-Poisson equations), the CVBEM (complex variable boundary element method) can be used for the numerical error analysis of domain model solutions. For problems where soil-water phase change latent heat effects dominate the thermal regime, heat transport can be approximately modeled as a time-stepped steady-state condition in the thawed and frozen regions, respectively. The CVBEM provides an exact solution of the two-dimensional steady-state heat transport problem, and also provides the error in matching the prescribed boundary conditions by the development of a modeling error distribution or an approximate boundary generation.

Laser Measurements Based for Volumetric Accuracy Improvement of Multi-axis Systems

NASA Astrophysics Data System (ADS)

Vladimir, Sokolov; Konstantin, Basalaev

The paper describes a new developed approach to CNC-controlled multi-axis systems geometric errors compensation based on optimal error correction strategy. Multi-axis CNC-controlled systems - machine-tools and CMM's are the basis of modern engineering industry. Similar design principles of both technological and measurement equipment allow usage of similar approaches to precision management. The approach based on geometric errors compensation are widely used at present time. The paper describes a system for compensation of geometric errors of multi-axis equipment based on the new approach. The hardware basis of the developed system is a multi-function laser interferometer. The principles of system's implementation, results of measurements and system's functioning simulation are described. The effectiveness of application of described principles to multi-axis equipment of different sizes and purposes for different machining directions and zones within workspace is presented. The concepts of optimal correction strategy is introduced and dynamic accuracy control is proposed.

Evolutionary algorithm for vehicle driving cycle generation.

PubMed

Perhinschi, Mario G; Marlowe, Christopher; Tamayo, Sergio; Tu, Jun; Wayne, W Scott

2011-09-01

Modeling transit bus emissions and fuel economy requires a large amount of experimental data over wide ranges of operational conditions. Chassis dynamometer tests are typically performed using representative driving cycles defined based on vehicle instantaneous speed as sequences of "microtrips", which are intervals between consecutive vehicle stops. Overall significant parameters of the driving cycle, such as average speed, stops per mile, kinetic intensity, and others, are used as independent variables in the modeling process. Performing tests at all the necessary combinations of parameters is expensive and time consuming. In this paper, a methodology is proposed for building driving cycles at prescribed independent variable values using experimental data through the concatenation of "microtrips" isolated from a limited number of standard chassis dynamometer test cycles. The selection of the adequate "microtrips" is achieved through a customized evolutionary algorithm. The genetic representation uses microtrip definitions as genes. Specific mutation, crossover, and karyotype alteration operators have been defined. The Roulette-Wheel selection technique with elitist strategy drives the optimization process, which consists of minimizing the errors to desired overall cycle parameters. This utility is part of the Integrated Bus Information System developed at West Virginia University.

Using aggregated, de-identified electronic health record data for multivariate pharmacosurveillance: a case study of azathioprine.

PubMed

Patel, Vishal N; Kaelber, David C

2014-12-01

To demonstrate the use of aggregated and de-identified electronic health record (EHR) data for multivariate post-marketing pharmacosurveillance in a case study of azathioprine (AZA). Using aggregated, standardized, normalized, and de-identified, population-level data from the Explore platform (Explorys, Inc.) we searched over 10 million individuals, of which 14,580 were prescribed AZA based on RxNorm drug orders. Based on logical observation identifiers names and codes (LOINC) and vital sign data, we examined the following side effects: anemia, cell lysis, fever, hepatotoxicity, hypertension, nephrotoxicity, neutropenia, and neutrophilia. Patients prescribed AZA were compared to patients prescribed one of 11 other anti-rheumatologic drugs to determine the relative risk of side effect pairs. Compared to AZA case report trends, hepatotoxicity (marked by elevated transaminases or elevated bilirubin) did not occur as an isolated event more frequently in patients prescribed AZA than other anti-rheumatic agents. While neutropenia occurred in 24% of patients (RR 1.15, 95% CI 1.07-1.23), neutrophilia was also frequent (45%) and increased in patients prescribed AZA (RR 1.28, 95% CI 1.22-1.34). After constructing a pairwise side effect network, neutropenia had no dependencies. A reduced risk of neutropenia was found in patients with co-existing elevations in total bilirubin or liver transaminases, supporting classic clinical knowledge that agranulocytosis is a largely unpredictable phenomenon. Rounding errors propagated in the statistically de-identified datasets for cohorts as small as 40 patients only contributed marginally to the calculated risk. Our work demonstrates that aggregated, standardized, normalized and de-identified population level EHR data can provide both sufficient insight and statistical power to detect potential patterns of medication side effect associations, serving as a multivariate and generalizable approach to post-marketing drug surveillance. Copyright © 2013 Elsevier Inc. All rights reserved.

Methodological Challenges in Describing Medication Dosing Errors in Children

DTIC Science & Technology

2005-01-01

recommendations. As an example, amoxicillin is the most commonly used medication in children. This one drug accounts for approximately 10 percent of...and a team intervention on prevention of serious medication errors. JAMA 1998;280(15):1311–6. 13. Bates DW, Teich JM, Lee J, et al. The impact of...barriers include prescribing medication that is not labeled for use in children, discrepancies in published dosing recommendations for many

An adaptive Hinfinity controller design for bank-to-turn missiles using ridge Gaussian neural networks.

PubMed

Lin, Chuan-Kai; Wang, Sheng-De

2004-11-01

A new autopilot design for bank-to-turn (BTT) missiles is presented. In the design of autopilot, a ridge Gaussian neural network with local learning capability and fewer tuning parameters than Gaussian neural networks is proposed to model the controlled nonlinear systems. We prove that the proposed ridge Gaussian neural network, which can be a universal approximator, equals the expansions of rotated and scaled Gaussian functions. Although ridge Gaussian neural networks can approximate the nonlinear and complex systems accurately, the small approximation errors may affect the tracking performance significantly. Therefore, by employing the Hinfinity control theory, it is easy to attenuate the effects of the approximation errors of the ridge Gaussian neural networks to a prescribed level. Computer simulation results confirm the effectiveness of the proposed ridge Gaussian neural networks-based autopilot with Hinfinity stabilization.

Effective Feedback to Improve Primary Care Prescribing Safety (EFIPPS) a pragmatic three-arm cluster randomised trial: designing the intervention (ClinicalTrials.gov registration NCT01602705).

PubMed

Barnett, Karen N; Bennie, Marion; Treweek, Shaun; Robertson, Christopher; Petrie, Dennis J; Ritchie, Lewis D; Guthrie, Bruce

2014-10-11

High-risk prescribing in primary care is common and causes considerable harm. Feedback interventions have small/moderate effects on clinical practice, but few trials explicitly compare different forms of feedback. There is growing recognition that intervention development should be theory-informed, and that comprehensive reporting of intervention design is required by potential users of trial findings. The paper describes intervention development for the Effective Feedback to Improve Primary Care Prescribing Safety (EFIPPS) study, a pragmatic three-arm cluster randomised trial in 262 Scottish general practices. The NHS chose to implement a feedback intervention to utilise a new resource, new Prescribing Information System (newPIS). The development phase required selection of high-risk prescribing outcome measures and design of intervention components: (1) educational material (the usual care comparison), (2) feedback of practice rates of high-risk prescribing received by both intervention arms and (3) a theory-informed behaviour change component to be received by one intervention arm. Outcome measures, educational material and feedback design, were developed with a National Health Service Advisory Group. The behaviour change component was informed by the Theory of Planned Behaviour and the Health Action Process Approach. A focus group elicitation study and an email Delphi study with general practitioners (GPs) identified key attitudes and barriers of responding to the prescribing feedback. Behaviour change techniques were mapped to the psychological constructs, and the content was informed by the results of the elicitation and Delphi study. Six high-risk prescribing measures were selected in a consensus process based on importance and feasibility. Educational material and feedback design were based on current NHS Scotland practice and Advisory Group recommendations. The behaviour change component was resource constrained in development, mirroring what is feasible in an NHS context. Four behaviour change interventions were developed and embedded in five quarterly rounds of feedback targeting attitudes, subjective norms, perceived behavioural control and action planning (2×). The paper describes a process which is feasible to use in the resource-constrained environment of NHS-led intervention development and documents the intervention to make its design and implementation explicit to potential users of the trial findings. ClinicalTrials.gov: NCT01602705.

What is the epidemiology of medication errors, error-related adverse events and risk factors for errors in adults managed in community care contexts? A systematic review of the international literature.

PubMed

Assiri, Ghadah Asaad; Shebl, Nada Atef; Mahmoud, Mansour Adam; Aloudah, Nouf; Grant, Elizabeth; Aljadhey, Hisham; Sheikh, Aziz

2018-05-05

To investigate the epidemiology of medication errors and error-related adverse events in adults in primary care, ambulatory care and patients' homes. Systematic review. Six international databases were searched for publications between 1 January 2006 and 31 December 2015. Two researchers independently extracted data from eligible studies and assessed the quality of these using established instruments. Synthesis of data was informed by an appreciation of the medicines' management process and the conceptual framework from the International Classification for Patient Safety. 60 studies met the inclusion criteria, of which 53 studies focused on medication errors, 3 on error-related adverse events and 4 on risk factors only. The prevalence of prescribing errors was reported in 46 studies: prevalence estimates ranged widely from 2% to 94%. Inappropriate prescribing was the most common type of error reported. Only one study reported the prevalence of monitoring errors, finding that incomplete therapeutic/safety laboratory-test monitoring occurred in 73% of patients. The incidence of preventable adverse drug events (ADEs) was estimated as 15/1000 person-years, the prevalence of drug-drug interaction-related adverse drug reactions as 7% and the prevalence of preventable ADE as 0.4%. A number of patient, healthcare professional and medication-related risk factors were identified, including the number of medications used by the patient, increased patient age, the number of comorbidities, use of anticoagulants, cases where more than one physician was involved in patients' care and care being provided by family physicians/general practitioners. A very wide variation in the medication error and error-related adverse events rates is reported in the studies, this reflecting heterogeneity in the populations studied, study designs employed and outcomes evaluated. This review has identified important limitations and discrepancies in the methodologies used and gaps in the literature on the epidemiology and outcomes of medication errors in community settings. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Generic drug names and social welfare.

PubMed

Lobo, Félix; Feldman, Roger

2013-06-01

This article studies how well International Nonproprietary Names (INNs), the "generic" names for pharmaceuticals, address the problems of imperfect information. Left in private hands, the identification of medicines leads to confusion and errors. Developed in the 1950s by the World Health Organization, INNs are a common, global, scientific nomenclature designed to overcome this failure. Taking stock after sixty years, we argue that the contribution of INNs to social welfare is paramount. They enhance public health by reducing errors and improving patient safety. They also contribute to economic efficiency by creating transparency as the foundation of competitive generic drug markets, reducing transaction costs, and favoring trade. The law in most countries requires manufacturers to designate pharmaceuticals with INNs in labeling and advertising. Generic substitution is also permitted or mandatory in many countries. But not all the benefits of INNs are fully realized because prescribers may not use them. We advocate strong incentives or even legally binding provisions to extend the use of INNs by prescribing physicians and dispensing pharmacists, but we do not recommend replacing brand names entirely with INNs. Instead, we propose dual use of brand names and INNs in prescribing, as in drug labeling.

Nurses' reported influence on the prescription and use of medication.

PubMed

Jutel, A; Menkes, D B

2010-03-01

To identify the activities senior nurses report undertaking that may influence the prescription and use of medicines. While much attention has focused on the role of nurse prescribing, little is known about the extent to which non-prescribing nurses influence medication decision making. The pharmaceutical industry recognizes this influence in its marketing strategies, and courts nurses by provision of promotional material and sponsorship of nursing professional development. We undertook parallel web- and paper-based surveys of 100 senior registered nurses employed by government-funded health boards in two distinct New Zealand regions. Only 2/96 (2%) of nurses had prescribing rights, yet 74/94 (79%) reported recommending treatments to the prescribing doctor, 74/95 (79%) stated they provided advice to patients about over-the-counter medications and 71/92 (77%) participated in the development of guidelines or policies that include the use of medications. All nurses in this sample reported influencing the prescription of medicines in one way or another. From actually writing prescriptions to providing feedback on treatment outcomes, there are many opportunities for nurses to influence the decision making of medical and other prescribers, which open nurses to exploitation from commercial forces. Policy and education regarding prescriber relationships with the pharmaceutical industry should also recognize the role of non-prescribing nurses.

Clinical Decision Support Improves Initial Dosing and Monitoring of Tobramycin and Amikacin

PubMed Central

Cox, Zachary L.; Nelsen, Cori L.; Waitman, Lemuel R.; McCoy, Jacob A.; Peterson, Josh F.

2010-01-01

Purpose Clinical decision support (CDS) systems could be valuable tools in reducing aminoglycoside prescribing errors. We evaluated the impact of CDS on initial dosing, interval, and pharmacokinetic outcomes of amikacin and tobramycin therapy. Methods A complex CDS advisor to provide guidance on initial dosing and monitoring, using both traditional and extended interval dosing strategies, was integrated into computerized provider order entry (CPOE) and compared to a control group which featured close pharmacy monitoring of all aminoglycoside orders. A random sample of 118 patients from an academic, tertiary care medical center prescribed amikacin and tobramycin prior to advisor implementation was compared to 98 patients admitted following advisor implementation. Primary outcome was an initial dose within 10% of a dose calculated to be adherent to published dose guidelines. Secondary outcomes were a guideline-adherent interval, trough and peak concentrations in goal range, and incidence of nephrotoxicity. Results Of 216 patients studied, 97 were prescribed amikacin and 119 were prescribed tobramycin. The primary outcome of initial dosing consistent with guideline-based care increased from 40% in the pre-advisor arm to 80% in the post-advisor arm (p<0.001), with a number needed to treat of 3 patients to prevent one incorrect dose. Correct initial interval based on renal function also increased from 63% to 87% (p<0.001). The changes in initial dosing and interval resulted in an increase of trough concentrations in the goal range from 59% pre-advisor to 89% post-advisor implementation (p=0.0004). There was no significant difference in peak concentrations in goal range or incidence of nephrotoxicity (25% vs. 17%, p=0.2). Conclusion An advisor for aminoglycoside dosing and monitoring integrated into CPOE significantly improves initial dosing, selection of interval, and trough concentrations at goal compared to unassisted physician dosing. PMID:21411805

Systematic literature review of hospital medication administration errors in children

PubMed Central

Ameer, Ahmed; Dhillon, Soraya; Peters, Mark J; Ghaleb, Maisoon

2015-01-01

Objective Medication administration is the last step in the medication process. It can act as a safety net to prevent unintended harm to patients if detected. However, medication administration errors (MAEs) during this process have been documented and thought to be preventable. In pediatric medicine, doses are usually administered based on the child’s weight or body surface area. This in turn increases the risk of drug miscalculations and therefore MAEs. The aim of this review is to report MAEs occurring in pediatric inpatients. Methods Twelve bibliographic databases were searched for studies published between January 2000 and February 2015 using “medication administration errors”, “hospital”, and “children” related terminologies. Handsearching of relevant publications was also carried out. A second reviewer screened articles for eligibility and quality in accordance with the inclusion/exclusion criteria. Key findings A total of 44 studies were systematically reviewed. MAEs were generally defined as a deviation of dose given from that prescribed; this included omitted doses and administration at the wrong time. Hospital MAEs in children accounted for a mean of 50% of all reported medication error reports (n=12,588). It was also identified in a mean of 29% of doses observed (n=8,894). The most prevalent type of MAEs related to preparation, infusion rate, dose, and time. This review has identified five types of interventions to reduce hospital MAEs in children: barcode medicine administration, electronic prescribing, education, use of smart pumps, and standard concentration. Conclusion This review has identified a wide variation in the prevalence of hospital MAEs in children. This is attributed to the definition and method used to investigate MAEs. The review also illustrated the complexity and multifaceted nature of MAEs. Therefore, there is a need to develop a set of safety measures to tackle these errors in pediatric practice. PMID:29354530

Adaptive fuzzy prescribed performance control for MIMO nonlinear systems with unknown control direction and unknown dead-zone inputs.

PubMed

Shi, Wuxi; Luo, Rui; Li, Baoquan

2017-01-01

In this study, an adaptive fuzzy prescribed performance control approach is developed for a class of uncertain multi-input and multi-output (MIMO) nonlinear systems with unknown control direction and unknown dead-zone inputs. The properties of symmetric matrix are exploited to design adaptive fuzzy prescribed performance controller, and a Nussbaum-type function is incorporated in the controller to estimate the unknown control direction. This method has two prominent advantages: it does not require the priori knowledge of control direction and only three parameters need to be updated on-line for this MIMO systems. It is proved that all the signals in the resulting closed-loop system are bounded and that the tracking errors converge to a small residual set with the prescribed performance bounds. The effectiveness of the proposed approach is validated by simulation results. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Wind Power Forecasting Error Distributions: An International Comparison; Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hodge, B. M.; Lew, D.; Milligan, M.

2012-09-01

Wind power forecasting is expected to be an important enabler for greater penetration of wind power into electricity systems. Because no wind forecasting system is perfect, a thorough understanding of the errors that do occur can be critical to system operation functions, such as the setting of operating reserve levels. This paper provides an international comparison of the distribution of wind power forecasting errors from operational systems, based on real forecast data. The paper concludes with an assessment of similarities and differences between the errors observed in different locations.

Do final‐year medical students have sufficient prescribing competencies? A systematic literature review

PubMed Central

Tichelaar, Jelle; Graaf, Sanne; Otten, René H. J.; Richir, Milan C.; van Agtmael, Michiel A.

2018-01-01

Aims Prescribing errors are an important cause of patient safety incidents and are frequently caused by junior doctors. This might be because the prescribing competence of final‐year medical students is poor as a result of inadequate clinical pharmacology and therapeutic (CPT) education. We reviewed the literature to investigate which prescribing competencies medical students should have acquired in order to prescribe safely and effectively, and whether these have been attained by the time they graduate. Methods PubMed, EMBASE and ERIC databases were searched from the earliest dates up to and including January 2017, using the terms ‘prescribing’, ‘competence’ and ‘medical students’ in combination. Articles describing or evaluating essential prescribing competencies of final‐year medical students were included. Results Twenty‐five articles describing, and 47 articles evaluating, the prescribing competencies of final‐year students were included. Although there seems to be some agreement, we found no clear consensus among CPT teachers on which prescribing competencies medical students should have when they graduate. Studies showed that students had a general lack of preparedness, self‐confidence, knowledge and skills, specifically regarding general and antimicrobial prescribing and pharmacovigilance. However, the results should be interpreted with caution, given the heterogeneity and methodological weaknesses of the included studies. Conclusions There is considerable evidence that final‐year students have insufficient competencies to prescribe safely and effectively, although there is a need for a greater consensus among CPT teachers on the required competencies. Changes in undergraduate CPT education are urgently required in order to improve the prescribing of future doctors. PMID:29315721

A primary care Web-based Intervention Modeling Experiment replicated behavior changes seen in earlier paper-based experiment.

PubMed

Treweek, Shaun; Francis, Jill J; Bonetti, Debbie; Barnett, Karen; Eccles, Martin P; Hudson, Jemma; Jones, Claire; Pitts, Nigel B; Ricketts, Ian W; Sullivan, Frank; Weal, Mark; MacLennan, Graeme

2016-12-01

Intervention Modeling Experiments (IMEs) are a way of developing and testing behavior change interventions before a trial. We aimed to test this methodology in a Web-based IME that replicated the trial component of an earlier, paper-based IME. Three-arm, Web-based randomized evaluation of two interventions (persuasive communication and action plan) and a "no intervention" comparator. The interventions were designed to reduce the number of antibiotic prescriptions in the management of uncomplicated upper respiratory tract infection. General practitioners (GPs) were invited to complete an online questionnaire and eight clinical scenarios where an antibiotic might be considered. One hundred twenty-nine GPs completed the questionnaire. GPs receiving the persuasive communication did not prescribe an antibiotic in 0.70 more scenarios (95% confidence interval [CI] = 0.17-1.24) than those in the control arm. For the action plan, GPs did not prescribe an antibiotic in 0.63 (95% CI = 0.11-1.15) more scenarios than those in the control arm. Unlike the earlier IME, behavioral intention was unaffected by the interventions; this may be due to a smaller sample size than intended. A Web-based IME largely replicated the findings of an earlier paper-based study, providing some grounds for confidence in the IME methodology. Copyright © 2016 Elsevier Inc. All rights reserved.

Research on correction algorithm of laser positioning system based on four quadrant detector

NASA Astrophysics Data System (ADS)

Gao, Qingsong; Meng, Xiangyong; Qian, Weixian; Cai, Guixia

2018-02-01

This paper first introduces the basic principle of the four quadrant detector, and a set of laser positioning experiment system is built based on the four quadrant detector. Four quadrant laser positioning system in the actual application, not only exist interference of background light and detector dark current noise, and the influence of random noise, system stability, spot equivalent error can't be ignored, so it is very important to system calibration and correction. This paper analyzes the various factors of system positioning error, and then propose an algorithm for correcting the system error, the results of simulation and experiment show that the modified algorithm can improve the effect of system error on positioning and improve the positioning accuracy.

[Determining factors for deciding whether or not to treat refractive errors and cataract in people with a learning disability].

PubMed

van Isterdael, C E D; Stilma, J S; Bezemer, P D; Tijmes, N T

2008-05-03

A study into the treatment of refractive errors and cataract in a selected population with learning disabilities. Design. Retrospective. In the years 1993-2003, 5205 people (mean age: 39 years) were referred to the visual advisory centre of Bartiméus (one of three institutes for the visually impaired in the Netherlands) by learning disability physicians and were assessed ophthalmologically. This assessment consisted of a measurement of visual acuity and refractive error, slitlamp examination and retinoscopy, and was performed at the client's accommodation. Advised treatment for spectacle prescriptions and referral for cataract surgery were registered. Refractive errors were found in 35% (1845/5205) of the patients with learning disabilities; 49% (905/1845) already wore spectacles; another 14% (265/1845) were prescribed spectacles for the first time. Of those with presbyopia, 12% (232/1865) had reading glasses and 10% (181/1865) were given a first prescription for spectacles. The most important determinant for not prescribing spectacles was: presence of severe learning disability (odds ratio (OR): 3.7). Cataract was present in 10% (497/5205) of the population; 399 patients were advised to be referred for surgery, 55% (219/399) were referred ofwhom 26% (57/219) had surgery. Moderately severe bilateral cataract was the only determinant of cataract surgery (OR: 7.8). Refractive errors and cataract were not always treated in this group. One of the reasons for non-treatment of refractive errors was a severe learning disability. The reason for treatment or non-treatment in patients with cataract was less clear.

PlayIt: Game Based Learning Approach for Teaching Programming Concepts

ERIC Educational Resources Information Center

Mathrani, Anuradha; Christian, Shelly; Ponder-Sutton, Agate

2016-01-01

This study demonstrates a game-based learning (GBL) approach to engage students in learning and enhance their programming skills. The paper gives a detailed narrative of how an educational game was mapped with the curriculum of a prescribed programming course in a computing diploma study programme. Two separate student cohorts were invited to…

Appropriating Professionalism: Restructuring the Official Knowledge Base of England's "Modernised" Teaching Profession

ERIC Educational Resources Information Center

Beck, John

2009-01-01

The present paper examines efforts by government and government agencies in England to prescribe and control the knowledge base of a teaching profession that has, under successive New Labour administrations since 1997, been subjected to "modernisation". A theoretical framework drawn from aspects of the work of Basil Bernstein, and of Rob…

Methods to Prescribe Particle Motion to Minimize Quadrature Error in Meshfree Methods

NASA Astrophysics Data System (ADS)

Templeton, Jeremy; Erickson, Lindsay; Morris, Karla; Poliakoff, David

2015-11-01

Meshfree methods are an attractive approach for simulating material systems undergoing large-scale deformation, such as spray break up, free surface flows, and droplets. Particles, which can be easily moved, are used as nodes and/or quadrature points rather than a relying on a fixed mesh. Most methods move particles according to the local fluid velocity that allows for the convection terms in the Navier-Stokes equations to be easily accounted for. However, this is a trade-off against numerical accuracy as the flow can often move particles to configurations with high quadrature error, and artificial compressibility is often required to prevent particles from forming undesirable regions of high and low concentrations. In this work, we consider the other side of the trade-off: moving particles based on reducing numerical error. Methods derived from molecular dynamics show that particles can be moved to minimize a surrogate for the solution error, resulting in substantially more accurate simulations at a fixed cost. Sandia National Laboratories is a multiprogram laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

An efficient computational method for characterizing the effects of random surface errors on the average power pattern of reflectors

NASA Technical Reports Server (NTRS)

Rahmat-Samii, Y.

1983-01-01

Based on the works of Ruze (1966) and Vu (1969), a novel mathematical model has been developed to determine efficiently the average power pattern degradations caused by random surface errors. In this model, both nonuniform root mean square (rms) surface errors and nonuniform illumination functions are employed. In addition, the model incorporates the dependence on F/D in the construction of the solution. The mathematical foundation of the model rests on the assumption that in each prescribed annular region of the antenna, the geometrical rms surface value is known. It is shown that closed-form expressions can then be derived, which result in a very efficient computational method for the average power pattern. Detailed parametric studies are performed with these expressions to determine the effects of different random errors and illumination tapers on parameters such as gain loss and sidelobe levels. The results clearly demonstrate that as sidelobe levels decrease, their dependence on the surface rms/wavelength becomes much stronger and, for a specified tolerance level, a considerably smaller rms/wavelength is required to maintain the low sidelobes within the required bounds.

Acute oxygen therapy: an audit of prescribing and delivery practices in a tertiary hospital in Perth, Western Australia.

PubMed

Kamran, Anam; Chia, Elisa; Tobin, Claire

2018-02-01

Oxygen is a widely used drug in the hospital setting. However, international audits suggest that oxygen administration practices are often not compliant with prescribed standards. This can place patients at risk and cause serious adverse events. To analyse data related to recent practices of oxygen prescription and administration at Royal Perth Hospital (RPH), Western Australia. The results of this audit aim to guide further research on possible interventional studies implementing key solutions. All patients who received care in the Acute Medical Unit at RPH between 1 September and 14 September 2015 were included in this audit. Patients who were given supplemental oxygen during their admission were selected for further review of records. Appropriate medically indicated target oxygen saturations for each patient were judged under consultation with a respiratory specialist. A total of 65 patients received oxygen supplementation within the study period; 36 of these patients (55.4%) had target oxygen saturations prescribed by doctors, and 25% of the prescribed targets were judged to be inappropriate. In total, 49 patients (75.4%) were exposed to a potential risk from oxygen therapy due to prescription error and/or delivery error. A real risk was identified in 19 patients (29.2%) as they received oxygen at levels outside their appropriate medically indicated target range. The current practices of oxygen prescription and administration within RPH are suboptimal. Patients are placed at risk of oxygen toxicity due to deviation from oxygen prescription guidelines. © 2017 Royal Australasian College of Physicians.

Soft-decision decoding techniques for linear block codes and their error performance analysis

NASA Technical Reports Server (NTRS)

Lin, Shu

1996-01-01

The first paper presents a new minimum-weight trellis-based soft-decision iterative decoding algorithm for binary linear block codes. The second paper derives an upper bound on the probability of block error for multilevel concatenated codes (MLCC). The bound evaluates difference in performance for different decompositions of some codes. The third paper investigates the bit error probability code for maximum likelihood decoding of binary linear codes. The fourth and final paper included in this report is concerns itself with the construction of multilevel concatenated block modulation codes using a multilevel concatenation scheme for the frequency non-selective Rayleigh fading channel.

An 802.11 n wireless local area network transmission scheme for wireless telemedicine applications.

PubMed

Lin, C F; Hung, S I; Chiang, I H

2010-10-01

In this paper, an 802.11 n transmission scheme is proposed for wireless telemedicine applications. IEEE 802.11n standards, a power assignment strategy, space-time block coding (STBC), and an object composition Petri net (OCPN) model are adopted. With the proposed wireless system, G.729 audio bit streams, Joint Photographic Experts Group 2000 (JPEG 2000) clinical images, and Moving Picture Experts Group 4 (MPEG-4) video bit streams achieve a transmission bit error rate (BER) of 10-7, 10-4, and 103 simultaneously. The proposed system meets the requirements prescribed for wireless telemedicine applications. An essential feature of this proposed transmission scheme is that clinical information that requires a high quality of service (QoS) is transmitted at a high power transmission rate with significant error protection. For maximizing resource utilization and minimizing the total transmission power, STBC and adaptive modulation techniques are used in the proposed 802.11 n wireless telemedicine system. Further, low power, direct mapping (DM), low-error protection scheme, and high-level modulation are adopted for messages that can tolerate a high BER. With the proposed transmission scheme, the required reliability of communication can be achieved. Our simulation results have shown that the proposed 802.11 n transmission scheme can be used for developing effective wireless telemedicine systems.

Recommendations for diagnosing effective radiative forcing from climate models for CMIP6

NASA Astrophysics Data System (ADS)

Smith, C. J.; Forster, P.; Richardson, T.; Myhre, G.; Pincus, R.

2016-12-01

The usefulness of previous Coupled Model Intercomparison Project (CMIP) exercises has been hampered by a lack of radiative forcing information. This has made it difficult to understand reasons for differences between model responses. Effective radiative forcing (ERF) is easier to diagnose than traditional radiative forcing in global climate models (GCMs) and is more representative of the ultimate climate response. Here we examine the different methods of computing ERF in two GCMs. We find that ERF computed from a fixed sea-surface temperature (SST) method (ERF_fSST) has much more certainty than regression-based methods. Thirty-year integrations are sufficient to reduce the standard error in global ERF to 0.05 Wm-2. For 2xCO2 ERF, 30 year integrations are needed to ensure that the signal is larger than the standard error over more than 90% of the globe. Within the ERF_fSST method there are various options for prescribing SSTs and sea-ice. We explore these and find that ERF is only weakly dependent on the methodological choices. Prescribing the monthly-averaged seasonally varying model's preindustrial climatology is recommended for its smaller random error and easier implementation. As part of CMIP6, the Radiative Forcing Model Intercomparison Project (RFMIP) asks models to conduct 30-year ERF_fSST experiments using the model's own preindustrial climatology of SST and sea-ice. The Aerosol and Chemistry Model intercomparison Project (AerChemMIP) will also mainly use this approach. We propose this as a standard method for diagnosing ERF in models and recommend that it be used across the climate modeling community to aid future comparisons.

Simulations using patient data to evaluate systematic errors that may occur in 4D treatment planning: a proof of concept study.

PubMed

St James, Sara; Seco, Joao; Mishra, Pankaj; Lewis, John H

2013-09-01

The purpose of this work is to present a framework to evaluate the accuracy of four-dimensional treatment planning in external beam radiation therapy using measured patient data and digital phantoms. To accomplish this, 4D digital phantoms of two model patients were created using measured patient lung tumor positions. These phantoms were used to simulate a four-dimensional computed tomography image set, which in turn was used to create a 4D Monte Carlo (4DMC) treatment plan. The 4DMC plan was evaluated by simulating the delivery of the treatment plan over approximately 5 min of tumor motion measured from the same patient on a different day. Unique phantoms accounting for the patient position (tumor position and thorax position) at 2 s intervals were used to represent the model patients on the day of treatment delivery and the delivered dose to the tumor was determined using Monte Carlo simulations. For Patient 1, the tumor was adequately covered with 95.2% of the tumor receiving the prescribed dose. For Patient 2, the tumor was not adequately covered and only 74.3% of the tumor received the prescribed dose. This study presents a framework to evaluate 4D treatment planning methods and demonstrates a potential limitation of 4D treatment planning methods. When systematic errors are present, including when the imaging study used for treatment planning does not represent all potential tumor locations during therapy, the treatment planning methods may not adequately predict the dose to the tumor. This is the first example of a simulation study based on patient tumor trajectories where systematic errors that occur due to an inaccurate estimate of tumor motion are evaluated.

Do final-year medical students have sufficient prescribing competencies? A systematic literature review.

PubMed

Brinkman, David J; Tichelaar, Jelle; Graaf, Sanne; Otten, René H J; Richir, Milan C; van Agtmael, Michiel A

2018-04-01

Prescribing errors are an important cause of patient safety incidents and are frequently caused by junior doctors. This might be because the prescribing competence of final-year medical students is poor as a result of inadequate clinical pharmacology and therapeutic (CPT) education. We reviewed the literature to investigate which prescribing competencies medical students should have acquired in order to prescribe safely and effectively, and whether these have been attained by the time they graduate. PubMed, EMBASE and ERIC databases were searched from the earliest dates up to and including January 2017, using the terms 'prescribing', 'competence' and 'medical students' in combination. Articles describing or evaluating essential prescribing competencies of final-year medical students were included. Twenty-five articles describing, and 47 articles evaluating, the prescribing competencies of final-year students were included. Although there seems to be some agreement, we found no clear consensus among CPT teachers on which prescribing competencies medical students should have when they graduate. Studies showed that students had a general lack of preparedness, self-confidence, knowledge and skills, specifically regarding general and antimicrobial prescribing and pharmacovigilance. However, the results should be interpreted with caution, given the heterogeneity and methodological weaknesses of the included studies. There is considerable evidence that final-year students have insufficient competencies to prescribe safely and effectively, although there is a need for a greater consensus among CPT teachers on the required competencies. Changes in undergraduate CPT education are urgently required in order to improve the prescribing of future doctors. © 2018 VU University Medical Centre. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.

Enhancing adaptive sparse grid approximations and improving refinement strategies using adjoint-based a posteriori error estimates

DOE PAGES

Jakeman, J. D.; Wildey, T.

2015-01-01

In this paper we present an algorithm for adaptive sparse grid approximations of quantities of interest computed from discretized partial differential equations. We use adjoint-based a posteriori error estimates of the interpolation error in the sparse grid to enhance the sparse grid approximation and to drive adaptivity. We show that utilizing these error estimates provides significantly more accurate functional values for random samples of the sparse grid approximation. We also demonstrate that alternative refinement strategies based upon a posteriori error estimates can lead to further increases in accuracy in the approximation over traditional hierarchical surplus based strategies. Throughout this papermore » we also provide and test a framework for balancing the physical discretization error with the stochastic interpolation error of the enhanced sparse grid approximation.« less

Best practice strategies to safeguard drug prescribing and drug administration: an anthology of expert views and opinions.

PubMed

Seidling, Hanna M; Stützle, Marion; Hoppe-Tichy, Torsten; Allenet, Benoît; Bedouch, Pierrick; Bonnabry, Pascal; Coleman, Jamie J; Fernandez-Llimos, Fernando; Lovis, Christian; Rei, Maria Jose; Störzinger, Dominic; Taylor, Lenka A; Pontefract, Sarah K; van den Bemt, Patricia M L A; van der Sijs, Heleen; Haefeli, Walter E

2016-04-01

While evidence on implementation of medication safety strategies is increasing, reasons for selecting and relinquishing distinct strategies and details on implementation are typically not shared in published literature. We aimed to collect and structure expert information resulting from implementing medication safety strategies to provide advice for decision-makers. Medication safety experts with clinical expertise from thirteen hospitals throughout twelve European and North American countries shared their experience in workshop meetings, on-site-visits and remote structured interviews. We performed an expert-based, in-depth assessment of implementation of best-practice strategies to improve drug prescribing and drug administration. Workflow, variability and recommended medication safety strategies in drug prescribing and drug administration processes. According to the experts, institutions chose strategies that targeted process steps known to be particularly error-prone in the respective setting. Often, the selection was channeled by local constraints such as the e-health equipment and critically modulated by national context factors. In our study, the experts favored electronic prescribing with clinical decision support and medication reconciliation as most promising interventions. They agreed that self-assessment and introduction of medication safety boards were crucial to satisfy the setting-specific differences and foster successful implementation. While general evidence for implementation of strategies to improve medication safety exists, successful selection and adaptation of a distinct strategy requires a thorough knowledge of the institute-specific constraints and an ongoing monitoring and adjustment of the implemented measures.

Optimized Assistive Human-Robot Interaction Using Reinforcement Learning.

PubMed

Modares, Hamidreza; Ranatunga, Isura; Lewis, Frank L; Popa, Dan O

2016-03-01

An intelligent human-robot interaction (HRI) system with adjustable robot behavior is presented. The proposed HRI system assists the human operator to perform a given task with minimum workload demands and optimizes the overall human-robot system performance. Motivated by human factor studies, the presented control structure consists of two control loops. First, a robot-specific neuro-adaptive controller is designed in the inner loop to make the unknown nonlinear robot behave like a prescribed robot impedance model as perceived by a human operator. In contrast to existing neural network and adaptive impedance-based control methods, no information of the task performance or the prescribed robot impedance model parameters is required in the inner loop. Then, a task-specific outer-loop controller is designed to find the optimal parameters of the prescribed robot impedance model to adjust the robot's dynamics to the operator skills and minimize the tracking error. The outer loop includes the human operator, the robot, and the task performance details. The problem of finding the optimal parameters of the prescribed robot impedance model is transformed into a linear quadratic regulator (LQR) problem which minimizes the human effort and optimizes the closed-loop behavior of the HRI system for a given task. To obviate the requirement of the knowledge of the human model, integral reinforcement learning is used to solve the given LQR problem. Simulation results on an x - y table and a robot arm, and experimental implementation results on a PR2 robot confirm the suitability of the proposed method.

A novel diagnosis method for a Hall plates-based rotary encoder with a magnetic concentrator.

PubMed

Meng, Bumin; Wang, Yaonan; Sun, Wei; Yuan, Xiaofang

2014-07-31

In the last few years, rotary encoders based on two-dimensional complementary metal oxide semiconductors (CMOS) Hall plates with a magnetic concentrator have been developed to measure contactless absolute angle. There are various error factors influencing the measuring accuracy, which are difficult to locate after the assembly of encoder. In this paper, a model-based rapid diagnosis method is presented. Based on an analysis of the error mechanism, an error model is built to compare minimum residual angle error and to quantify the error factors. Additionally, a modified particle swarm optimization (PSO) algorithm is used to reduce the calculated amount. The simulation and experimental results show that this diagnosis method is feasible to quantify the causes of the error and to reduce iteration significantly.

WE-H-BRC-09: Simulated Errors in Mock Radiotherapy Plans to Quantify the Effectiveness of the Physics Plan Review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gopan, O; Kalet, A; Smith, W

2016-06-15

Purpose: A standard tool for ensuring the quality of radiation therapy treatments is the initial physics plan review. However, little is known about its performance in practice. The goal of this study is to measure the effectiveness of physics plan review by introducing simulated errors into “mock” treatment plans and measuring the performance of plan review by physicists. Methods: We generated six mock treatment plans containing multiple errors. These errors were based on incident learning system data both within the department and internationally (SAFRON). These errors were scored for severity and frequency. Those with the highest scores were included inmore » the simulations (13 errors total). Observer bias was minimized using a multiple co-correlated distractor approach. Eight physicists reviewed these plans for errors, with each physicist reviewing, on average, 3/6 plans. The confidence interval for the proportion of errors detected was computed using the Wilson score interval. Results: Simulated errors were detected in 65% of reviews [51–75%] (95% confidence interval [CI] in brackets). The following error scenarios had the highest detection rates: incorrect isocenter in DRRs/CBCT (91% [73–98%]) and a planned dose different from the prescribed dose (100% [61–100%]). Errors with low detection rates involved incorrect field parameters in record and verify system (38%, [18–61%]) and incorrect isocenter localization in planning system (29% [8–64%]). Though pre-treatment QA failure was reliably identified (100%), less than 20% of participants reported the error that caused the failure. Conclusion: This is one of the first quantitative studies of error detection. Although physics plan review is a key safety measure and can identify some errors with high fidelity, others errors are more challenging to detect. This data will guide future work on standardization and automation. Creating new checks or improving existing ones (i.e., via automation) will help in detecting those errors with low detection rates.« less

Human-simulation-based learning to prevent medication error: A systematic review.

PubMed

Sarfati, Laura; Ranchon, Florence; Vantard, Nicolas; Schwiertz, Vérane; Larbre, Virginie; Parat, Stéphanie; Faudel, Amélie; Rioufol, Catherine

2018-01-31

In the past 2 decades, there has been an increasing interest in simulation-based learning programs to prevent medication error (ME). To improve knowledge, skills, and attitudes in prescribers, nurses, and pharmaceutical staff, these methods enable training without directly involving patients. However, best practices for simulation for healthcare providers are as yet undefined. By analysing the current state of experience in the field, the present review aims to assess whether human simulation in healthcare helps to reduce ME. A systematic review was conducted on Medline from 2000 to June 2015, associating the terms "Patient Simulation," "Medication Errors," and "Simulation Healthcare." Reports of technology-based simulation were excluded, to focus exclusively on human simulation in nontechnical skills learning. Twenty-one studies assessing simulation-based learning programs were selected, focusing on pharmacy, medicine or nursing students, or concerning programs aimed at reducing administration or preparation errors, managing crises, or learning communication skills for healthcare professionals. The studies varied in design, methodology, and assessment criteria. Few demonstrated that simulation was more effective than didactic learning in reducing ME. This review highlights a lack of long-term assessment and real-life extrapolation, with limited scenarios and participant samples. These various experiences, however, help in identifying the key elements required for an effective human simulation-based learning program for ME prevention: ie, scenario design, debriefing, and perception assessment. The performance of these programs depends on their ability to reflect reality and on professional guidance. Properly regulated simulation is a good way to train staff in events that happen only exceptionally, as well as in standard daily activities. By integrating human factors, simulation seems to be effective in preventing iatrogenic risk related to ME, if the program is well designed. © 2018 John Wiley & Sons, Ltd.

Implementation and evaluation of a community-based medication reconciliation (CMR) system at the hospital-community interface of care.

PubMed

Bailey, Allan L; Moe, Grace; Moe, Jessica; Oland, Ryan

2009-01-01

The WestView community-based medication reconciliation (CMR) aims to decrease medication error risk. A clinical pharmacist visits patients' homes within 72 hours of hospital discharge and compares medications in discharge orders, family physicians' charts, community pharmacy profiles and in the home. Discrepancies are discussed and reconciled with the dispenser, hospital prescriber and follow-up care provider. The CMR demonstrates successful integration that is patient-centred and standardized, bridging the hospital-community interface and improving information flow and communication channels across a family-physician-led multi-disciplinary team. A concurrent research study will evaluate the impact of CMR on health services utilization and to develop a risk prediction model.

Statistical analysis of modeling error in structural dynamic systems

NASA Technical Reports Server (NTRS)

Hasselman, T. K.; Chrostowski, J. D.

1990-01-01

The paper presents a generic statistical model of the (total) modeling error for conventional space structures in their launch configuration. Modeling error is defined as the difference between analytical prediction and experimental measurement. It is represented by the differences between predicted and measured real eigenvalues and eigenvectors. Comparisons are made between pre-test and post-test models. Total modeling error is then subdivided into measurement error, experimental error and 'pure' modeling error, and comparisons made between measurement error and total modeling error. The generic statistical model presented in this paper is based on the first four global (primary structure) modes of four different structures belonging to the generic category of Conventional Space Structures (specifically excluding large truss-type space structures). As such, it may be used to evaluate the uncertainty of predicted mode shapes and frequencies, sinusoidal response, or the transient response of other structures belonging to the same generic category.

Formal Verification of Safety Buffers for Sate-Based Conflict Detection and Resolution

NASA Technical Reports Server (NTRS)

Herencia-Zapana, Heber; Jeannin, Jean-Baptiste; Munoz, Cesar A.

2010-01-01

The information provided by global positioning systems is never totally exact, and there are always errors when measuring position and velocity of moving objects such as aircraft. This paper studies the effects of these errors in the actual separation of aircraft in the context of state-based conflict detection and resolution. Assuming that the state information is uncertain but that bounds on the errors are known, this paper provides an analytical definition of a safety buffer and sufficient conditions under which this buffer guarantees that actual conflicts are detected and solved. The results are presented as theorems, which were formally proven using a mechanical theorem prover.

Optimization of traffic data collection for specific pavement design applications.

DOT National Transportation Integrated Search

2006-05-01

The objective of this study is to establish the minimum traffic data collection effort required for pavement design applications satisfying a maximum acceptable error under a prescribed confidence level. The approach consists of simulating the traffi...

A Novel Error Model of Optical Systems and an On-Orbit Calibration Method for Star Sensors.

PubMed

Wang, Shuang; Geng, Yunhai; Jin, Rongyu

2015-12-12

In order to improve the on-orbit measurement accuracy of star sensors, the effects of image-plane rotary error, image-plane tilt error and distortions of optical systems resulting from the on-orbit thermal environment were studied in this paper. Since these issues will affect the precision of star image point positions, in this paper, a novel measurement error model based on the traditional error model is explored. Due to the orthonormal characteristics of image-plane rotary-tilt errors and the strong nonlinearity among these error parameters, it is difficult to calibrate all the parameters simultaneously. To solve this difficulty, for the new error model, a modified two-step calibration method based on the Extended Kalman Filter (EKF) and Least Square Methods (LSM) is presented. The former one is used to calibrate the main point drift, focal length error and distortions of optical systems while the latter estimates the image-plane rotary-tilt errors. With this calibration method, the precision of star image point position influenced by the above errors is greatly improved from 15.42% to 1.389%. Finally, the simulation results demonstrate that the presented measurement error model for star sensors has higher precision. Moreover, the proposed two-step method can effectively calibrate model error parameters, and the calibration precision of on-orbit star sensors is also improved obviously.

The design of delay-dependent wide-area DOFC with prescribed degree of stability α for damping inter-area low-frequency oscillations in power system.

PubMed

Sun, Miaoping; Nian, Xiaohong; Dai, Liqiong; Guo, Hua

2017-05-01

In this paper, the delay-dependent wide-area dynamic output feedback controller (DOFC) with prescribed degree of stability is proposed for interconnected power system to damp inter-area low-frequency oscillations. Here, the prescribed degree of stability α is used to maintain all the poles on the left of s=-α in the s-plane. Firstly, residue approach is adopted to select input-output control signals and the schur balanced truncation model reduction method is utilized to obtain the reduced power system model. Secondly, based on Lyapunov stability theory and transformation operation in complex plane, the sufficient condition of asymptotic stability for closed-loop power system with prescribed degree of stability α is derived. Then, a novel method based on linear matrix inequalities (LMIs) is presented to obtain the parameters of DOFC and calculate delay margin of the closed-loop system considering the prescribed degree of stability α. Finally, case studies are carried out on the two-area four-machine system, which is controlled by classical wide-area power system stabilizer (WAPSS) in reported reference and our proposed DOFC respectively. The effectiveness and advantages of the proposed method are verified by the simulation results under different operating conditions. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

A Comparison of Forecast Error Generators for Modeling Wind and Load Uncertainty

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Ning; Diao, Ruisheng; Hafen, Ryan P.

2013-12-18

This paper presents four algorithms to generate random forecast error time series, including a truncated-normal distribution model, a state-space based Markov model, a seasonal autoregressive moving average (ARMA) model, and a stochastic-optimization based model. The error time series are used to create real-time (RT), hour-ahead (HA), and day-ahead (DA) wind and load forecast time series that statistically match historically observed forecasting data sets, used for variable generation integration studies. A comparison is made using historical DA load forecast and actual load values to generate new sets of DA forecasts with similar stoical forecast error characteristics. This paper discusses and comparesmore » the capabilities of each algorithm to preserve the characteristics of the historical forecast data sets.« less

Greedy Sampling and Incremental Surrogate Model-Based Tailoring of Aeroservoelastic Model Database for Flexible Aircraft

NASA Technical Reports Server (NTRS)

Wang, Yi; Pant, Kapil; Brenner, Martin J.; Ouellette, Jeffrey A.

2018-01-01

This paper presents a data analysis and modeling framework to tailor and develop linear parameter-varying (LPV) aeroservoelastic (ASE) model database for flexible aircrafts in broad 2D flight parameter space. The Kriging surrogate model is constructed using ASE models at a fraction of grid points within the original model database, and then the ASE model at any flight condition can be obtained simply through surrogate model interpolation. The greedy sampling algorithm is developed to select the next sample point that carries the worst relative error between the surrogate model prediction and the benchmark model in the frequency domain among all input-output channels. The process is iterated to incrementally improve surrogate model accuracy till a pre-determined tolerance or iteration budget is met. The methodology is applied to the ASE model database of a flexible aircraft currently being tested at NASA/AFRC for flutter suppression and gust load alleviation. Our studies indicate that the proposed method can reduce the number of models in the original database by 67%. Even so the ASE models obtained through Kriging interpolation match the model in the original database constructed directly from the physics-based tool with the worst relative error far below 1%. The interpolated ASE model exhibits continuously-varying gains along a set of prescribed flight conditions. More importantly, the selected grid points are distributed non-uniformly in the parameter space, a) capturing the distinctly different dynamic behavior and its dependence on flight parameters, and b) reiterating the need and utility for adaptive space sampling techniques for ASE model database compaction. The present framework is directly extendible to high-dimensional flight parameter space, and can be used to guide the ASE model development, model order reduction, robust control synthesis and novel vehicle design of flexible aircraft.

Unsupervised Segmentation of Head Tissues from Multi-modal MR Images for EEG Source Localization.

PubMed

Mahmood, Qaiser; Chodorowski, Artur; Mehnert, Andrew; Gellermann, Johanna; Persson, Mikael

2015-08-01

In this paper, we present and evaluate an automatic unsupervised segmentation method, hierarchical segmentation approach (HSA)-Bayesian-based adaptive mean shift (BAMS), for use in the construction of a patient-specific head conductivity model for electroencephalography (EEG) source localization. It is based on a HSA and BAMS for segmenting the tissues from multi-modal magnetic resonance (MR) head images. The evaluation of the proposed method was done both directly in terms of segmentation accuracy and indirectly in terms of source localization accuracy. The direct evaluation was performed relative to a commonly used reference method brain extraction tool (BET)-FMRIB's automated segmentation tool (FAST) and four variants of the HSA using both synthetic data and real data from ten subjects. The synthetic data includes multiple realizations of four different noise levels and several realizations of typical noise with a 20% bias field level. The Dice index and Hausdorff distance were used to measure the segmentation accuracy. The indirect evaluation was performed relative to the reference method BET-FAST using synthetic two-dimensional (2D) multimodal magnetic resonance (MR) data with 3% noise and synthetic EEG (generated for a prescribed source). The source localization accuracy was determined in terms of localization error and relative error of potential. The experimental results demonstrate the efficacy of HSA-BAMS, its robustness to noise and the bias field, and that it provides better segmentation accuracy than the reference method and variants of the HSA. They also show that it leads to a more accurate localization accuracy than the commonly used reference method and suggest that it has potential as a surrogate for expert manual segmentation for the EEG source localization problem.

An Adaptive Buddy Check for Observational Quality Control

NASA Technical Reports Server (NTRS)

Dee, Dick P.; Rukhovets, Leonid; Todling, Ricardo; DaSilva, Arlindo M.; Larson, Jay W.; Einaudi, Franco (Technical Monitor)

2000-01-01

An adaptive buddy check algorithm is presented that adjusts tolerances for outlier observations based on the variability of surrounding data. The algorithm derives from a statistical hypothesis test combined with maximum-likelihood covariance estimation. Its stability is shown to depend on the initial identification of outliers by a simple background check. The adaptive feature ensures that the final quality control decisions are not very sensitive to prescribed statistics of first-guess and observation errors, nor on other approximations introduced into the algorithm. The implementation of the algorithm in a global atmospheric data assimilation is described. Its performance is contrasted with that of a non-adaptive buddy check, for the surface analysis of an extreme storm that took place in Europe on 27 December 1999. The adaptive algorithm allowed the inclusion of many important observations that differed greatly from the first guess and that would have been excluded on the basis of prescribed statistics. The analysis of the storm development was much improved as a result of these additional observations.

Essential competencies in prescribing: A first european cross-sectional study among 895 final-year medical students.

PubMed

Brinkman, D J; Tichelaar, J; Schutte, T; Benemei, S; Böttiger, Y; Chamontin, B; Christiaens, T; Likic, R; Maˇiulaitis, R; Marandi, T; Monteiro, E C; Papaioannidou, P; Pers, Y M; Pontes, C; Raskovic, A; Regenthal, R; Sanz, E J; Tamba, B I; Wilson, K; Vries, Tp de; Richir, M C; Agtmael, Ma van

2017-02-01

European medical students should have acquired adequate prescribing competencies before graduation, but it is not known whether this is the case. In this international multicenter study, we evaluated the essential knowledge, skills, and attitudes in clinical pharmacology and therapeutics (CPT) of final-year medical students across Europe. In a cross-sectional design, 26 medical schools from 17 European countries were asked to administer a standardized assessment and questionnaire to 50 final-year students. Although there were differences between schools, our results show an overall lack of essential prescribing competencies among final-year students in Europe. Students had a poor knowledge of drug interactions and contraindications, and chose inappropriate therapies for common diseases or made prescribing errors. Our results suggest that undergraduate teaching in CPT is inadequate in many European schools, leading to incompetent prescribers and potentially unsafe patient care. A European core curriculum with clear learning outcomes and assessments should be urgently developed. © 2016 The Authors. Clinical Pharmacology & Therapeutics published by Wiley Periodicals, Inc. on behalf of The American Society for Clinical Pharmacology and Therapeutics.

A paper form processing system with an error correcting function for reading handwritten Kanji strings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katsumi Marukawa; Kazuki Nakashima; Masashi Koga

1994-12-31

This paper presents a paper form processing system with an error correcting function for reading handwritten kanji strings. In the paper form processing system, names and addresses are important key data, and especially this paper takes up an error correcting method for name and address recognition. The method automatically corrects errors of the kanji OCR (Optical Character Reader) with the help of word dictionaries and other knowledge. Moreover, it allows names and addresses to be written in any style. The method consists of word matching {open_quotes}furigana{close_quotes} verification for name strings, and address approval for address strings. For word matching, kanjimore » name candidates are extracted by automaton-type word matching. In {open_quotes}furigana{close_quotes} verification, kana candidate characters recognized by the kana OCR are compared with kana`s searched from the name dictionary based on kanji name candidates, given by the word matching. The correct name is selected from the results of word matching and furigana verification. Also, the address approval efficiently searches for the right address based on a bottom-up procedure which follows hierarchical relations from a lower placename to a upper one by using the positional condition among the placenames. We ascertained that the error correcting method substantially improves the recognition rate and processing speed in experiments on 5,032 forms.« less

Nurse prescribing in general practice: a qualitative study of job satisfaction and work-related stress.

PubMed

Cousins, Rosanna; Donnell, Christine

2012-04-01

Studies examining the impact nurse prescribing have largely focused on the efficacy of the service. It was suggested in pro-prescribing policy arguments that extending the nursing role to include prescribing would increase job satisfaction. This assertion has not been fully explored. To investigate the impact of independent prescribing for experienced nurse practitioners (NPs) working in general practice. In-depth interviews were conducted with six NPs who each had at least 3 years experience of independent prescribing in a busy inner city general practice. Analysis of interview data yielded two main themes: as independent prescribers NPs experienced increased levels of both job satisfaction and work-related stress. Increased satisfaction was associated with having greater autonomy and being able to provide more holistic care. Increased work-related stress emerged from greater job demands, perceived insufficient support and perceived effort-reward imbalance that centred upon the enhanced role not being recognized in terms of an increase in grade and pay. Independent prescribing increases job satisfaction for NPs in general practice, but there is also evidence of stressors associated with the role. It is important that NPs in general practice are encouraged and supported towards providing the effective patient-centred care in the community envisaged by current UK government. We acknowledge that the results presented in this paper are based on a sample limited to one city; however, it provides information that has important implications for the well being of NPs and ultimately patient care.

[Refractive errors as causes of visual impairment in children from public schools of the Botucatu region - SP].

PubMed

Oliveira, Claudia Akemi Shiratori de; Hisatomi, Kenia Scrocaro; Leite, Cristiano Pinheiro; Schellini, Silvana Artioli; Padovani, Carlos Roberto; Padovani, Carlos Roberto Pereira

2009-01-01

To evaluate the refractive errors as cause of visual impairment in school children from the Botucatu region. A sectional study was conducted evaluating preschool and elementary school students, according to gender, refractive error, visual acuity and treatment. Four thousand six hundred and twenty-three (4,623) children were submitted to visual acuity evaluation and 8.1% of them were submitted to complete ocular examination. There were 63.2% hyperopic astigmatism, 15.7% myopic astigmatism, 12.5% astigmatism, 4.9% hyperopia and 3.7% myopia. Corrective lenses were prescribed for 48.7% of the evaluated children. The most frequent refractive error was hyperopic astigmatism and 50% of the children received treatment. The frequency of refractive errors was 3.9% of the studied population.

Effects of Artificial Viscosity on the Accuracy of High-reynolds-number Kappa-epsilon Turbulence Model

NASA Technical Reports Server (NTRS)

Chitsomboon, Tawit

1994-01-01

Wall functions, as used in the typical high Reynolds number k-epsilon turbulence model, can be implemented in various ways. A least disruptive method (to the flow solver) is to directly solve for the flow variables at the grid point next to the wall while prescribing the values of k and epsilon. For the centrally-differenced finite-difference scheme employing artificial viscocity (AV) as a stabilizing mechanism, this methodology proved to be totally useless. This is because the AV gives rise to a large error at the wall due to too steep a velocity gradient resulting from the use of a coarse grid as required by the wall function methodology. This error can be eliminated simply by extrapolating velocities at the wall, instead of using the physical values of the no-slip velocities (i.e. the zero value). The applicability of the technique used in this paper is demonstrated by solving a flow over a flat plate and comparing the results with those of experiments. It was also observed that AV gives rise to a velocity overshoot (about 1 percent) near the edge of the boundary layer. This small velocity error, however, can yield as much as 10 percent error in the momentum thickness. A method which integrates the boundary layer up to only the edge of the boundary (instead of infinity) was proposed and demonstrated to give better results than the standard method.

Perceptual Color Characterization of Cameras

PubMed Central

Vazquez-Corral, Javier; Connah, David; Bertalmío, Marcelo

2014-01-01

Color camera characterization, mapping outputs from the camera sensors to an independent color space, such as XY Z, is an important step in the camera processing pipeline. Until now, this procedure has been primarily solved by using a 3 × 3 matrix obtained via a least-squares optimization. In this paper, we propose to use the spherical sampling method, recently published by Finlayson et al., to perform a perceptual color characterization. In particular, we search for the 3 × 3 matrix that minimizes three different perceptual errors, one pixel based and two spatially based. For the pixel-based case, we minimize the CIE ΔE error, while for the spatial-based case, we minimize both the S-CIELAB error and the CID error measure. Our results demonstrate an improvement of approximately 3% for the ΔE error, 7% for the S-CIELAB error and 13% for the CID error measures. PMID:25490586

Insar Unwrapping Error Correction Based on Quasi-Accurate Detection of Gross Errors (quad)

NASA Astrophysics Data System (ADS)

Kang, Y.; Zhao, C. Y.; Zhang, Q.; Yang, C. S.

2018-04-01

Unwrapping error is a common error in the InSAR processing, which will seriously degrade the accuracy of the monitoring results. Based on a gross error correction method, Quasi-accurate detection (QUAD), the method for unwrapping errors automatic correction is established in this paper. This method identifies and corrects the unwrapping errors by establishing a functional model between the true errors and interferograms. The basic principle and processing steps are presented. Then this method is compared with the L1-norm method with simulated data. Results show that both methods can effectively suppress the unwrapping error when the ratio of the unwrapping errors is low, and the two methods can complement each other when the ratio of the unwrapping errors is relatively high. At last the real SAR data is tested for the phase unwrapping error correction. Results show that this new method can correct the phase unwrapping errors successfully in the practical application.

Implementation of an integrated computerized prescriber order-entry system for chemotherapy in a multisite safety-net health system.

PubMed

Chung, Clement; Patel, Shital; Lee, Rosetta; Fu, Lily; Reilly, Sean; Ho, Tuyet; Lionetti, Jason; George, Michael D; Taylor, Pam

2018-03-15

The development of a computerized prescriber order-entry (CPOE) system for chemotherapy in a multisite safety-net health system and the challenges to its successful implementation are described. Before CPOE for chemotherapy was first implemented and embedded in the electronic medical record system of Harris Health System (HHS), pharmacy personnel relied on regimen-specific preprinted order sets. However, due to differences in practice styles and workflow logistics, the paper orders across the 3 facilities were mostly site specific, with varying clinical content. Many of these order sets had not been approved by the oncology subcommittee. In addition, disparities in clinical knowledge and lack of communication contributed to inconsistencies in order set development. Led by medical directors from medical oncology departments at the 3 facilities, pharmacy administrators, and information technology representatives, HHS committed resources to supporting the adoption and use of a CPOE system for chemotherapy. Five practical lessons of broad applicability have been learned: engagement of interprofessional stakeholders, optimization of workflow before CPOE implementation, requirement of verification tool for CPOE, consolidation of protocols, and commitment to ongoing training and support. Evaluation of the CPOE system demonstrated a systemwide reduction in medication errors by 75% ( p < 0.05). Satisfaction with the CPOE system varied among sites and was unchanged institutionwide 6 months after the CPOE implementation. The development and implementation of CPOE for chemotherapy at a multisite safety-net health system created opportunities to optimize patient care and reduce variations through interprofessional collaborations. Initial evaluation suggested that CPOE reduced the medication-order error rate and improved user satisfaction in 1 of 3 facilities. Copyright © 2018 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Panel positioning error and support mechanism for a 30-m THz radio telescope

NASA Astrophysics Data System (ADS)

Yang, De-Hua; Okoh, Daniel; Zhou, Guo-Hua; Li, Ai-Hua; Li, Guo-Ping; Cheng, Jing-Quan

2011-06-01

A 30-m TeraHertz (THz) radio telescope is proposed to operate at 200 μm with an active primary surface. This paper presents sensitivity analysis of active surface panel positioning errors with optical performance in terms of the Strehl ratio. Based on Ruze's surface error theory and using a Monte Carlo simulation, the effects of six rigid panel positioning errors, such as piston, tip, tilt, radial, azimuthal and twist displacements, were directly derived. The optical performance of the telescope was then evaluated using the standard Strehl ratio. We graphically illustrated the various panel error effects by presenting simulations of complete ensembles of full reflector surface errors for the six different rigid panel positioning errors. Study of the panel error sensitivity analysis revealed that the piston error and tilt/tip errors are dominant while the other rigid errors are much less important. Furthermore, as indicated by the results, we conceived of an alternative Master-Slave Concept-based (MSC-based) active surface by implementating a special Series-Parallel Concept-based (SPC-based) hexapod as the active panel support mechanism. A new 30-m active reflector based on the two concepts was demonstrated to achieve correction for all the six rigid panel positioning errors in an economically feasible way.

An Algebraic Approach to Guarantee Harmonic Balance Method Using Gröbner Base

NASA Astrophysics Data System (ADS)

Yagi, Masakazu; Hisakado, Takashi; Okumura, Kohshi

Harmonic balance (HB) method is well known principle for analyzing periodic oscillations on nonlinear networks and systems. Because the HB method has a truncation error, approximated solutions have been guaranteed by error bounds. However, its numerical computation is very time-consuming compared with solving the HB equation. This paper proposes an algebraic representation of the error bound using Gröbner base. The algebraic representation enables to decrease the computational cost of the error bound considerably. Moreover, using singular points of the algebraic representation, we can obtain accurate break points of the error bound by collisions.

Model Error Budgets

NASA Technical Reports Server (NTRS)

Briggs, Hugh C.

2008-01-01

An error budget is a commonly used tool in design of complex aerospace systems. It represents system performance requirements in terms of allowable errors and flows these down through a hierarchical structure to lower assemblies and components. The requirements may simply be 'allocated' based upon heuristics or experience, or they may be designed through use of physics-based models. This paper presents a basis for developing an error budget for models of the system, as opposed to the system itself. The need for model error budgets arises when system models are a principle design agent as is increasingly more common for poorly testable high performance space systems.

Caveats in the proficient preparation of an APA-style research manuscript for publication.

PubMed

Cash, Thomas F

2009-01-01

Writing a scientific research paper for submission to a peer-reviewed journal requires compositional skill and attention to details. In evaluating submitted manuscripts, journal editors and reviewers often encounter recurrent mistakes in composition and in compliance with the stylistic requirements of the particular publication. This editorial article identifies core tenets of effective scientific writing in the social and behavioral sciences, and it delineates commonly committed errors in violation of the style prescribed by the American Psychological Association (APA). The editor organizes his advice in a user-friendly checklist to assist both authors and reviewers associated with this journal (Body Image: An International Journal of Research), as well as other journals that adhere to APA style. This advisory article may also assist research supervisors and instructors in academic training contexts.

Sources of Student Errors and Misconceptions in Algebra and Effectiveness of Classroom Practice Remediation in Machakos County--Kenya

ERIC Educational Resources Information Center

Mulungye, Mary M.; O'Connor, Miheso; Ndethiu, S.

2016-01-01

This paper is based on a study which sought to examine the various errors and misconceptions committed by students in algebra with the view to exposing the nature and origin of the errors and misconceptions in secondary schools in Machakos district. Teachers' knowledge on students' errors was investigated together with strategies for remedial…

Group Health’s Initiative To Avert Opioid Misuse And Overdose Among Patients With Chronic Noncancer Pain

PubMed Central

Trescott, Claire E.; Beck, Randi M.; Seelig, Michelle D.; Von Korff, Michael R.

2012-01-01

Increased opioid prescribing for chronic pain that is not due to cancer has been accompanied by large increases in abuse and overdose of prescription opioids. This paper describes how Group Health, a Seattle-based nonprofit health care system, implemented a major initiative to make opioid prescribing safer. In the initiative’s first nine months, clinicians developed documented care plans for almost 6,000 patients receiving long-term opioid therapy for chronic pain. Evaluation of the initiative’s effects on care processes and trends in adverse events is under way. PMID:21821559

Coordination of heterogeneous nonlinear multi-agent systems with prescribed behaviours

NASA Astrophysics Data System (ADS)

Tang, Yutao

2017-10-01

In this paper, we consider a coordination problem for a class of heterogeneous nonlinear multi-agent systems with a prescribed input-output behaviour which was represented by another input-driven system. In contrast to most existing multi-agent coordination results with an autonomous (virtual) leader, this formulation takes possible control inputs of the leader into consideration. First, the coordination was achieved by utilising a group of distributed observers based on conventional assumptions of model matching problem. Then, a fully distributed adaptive extension was proposed without using the input of this input-output behaviour. An example was given to verify their effectiveness.

A prescribed fire emission factors database for land management and air quality applications

Treesearch

E. Lincoln; WeiMin Hao; S. Baker; R. J. Yokelson; I. R. Burling; Shawn Urbanski; W. Miller; D. R. Weise; T. J. Johnson

2010-01-01

Prescribed fire is a significant emissions source in the U.S. and that needs to be adequately characterized in atmospheric transport/chemistry models. In addition, the Clean Air Act, its amendments, and air quality regulations require that prescribed fire managers estimate the quantity of emissions that a prescribed fire will produce. Several published papers contain a...

Differential-Drive Mobile Robot Control Design based-on Linear Feedback Control Law

NASA Astrophysics Data System (ADS)

Nurmaini, Siti; Dewi, Kemala; Tutuko, Bambang

2017-04-01

This paper deals with the problem of how to control differential driven mobile robot with simple control law. When mobile robot moves from one position to another to achieve a position destination, it always produce some errors. Therefore, a mobile robot requires a certain control law to drive the robot’s movement to the position destination with a smallest possible error. In this paper, in order to reduce position error, a linear feedback control is proposed with pole placement approach to regulate the polynoms desired. The presented work leads to an improved understanding of differential-drive mobile robot (DDMR)-based kinematics equation, which will assist to design of suitable controllers for DDMR movement. The result show by using the linier feedback control method with pole placement approach the position error is reduced and fast convergence is achieved.

A Dynamic Attitude Measurement System Based on LINS

PubMed Central

Li, Hanzhou; Pan, Quan; Wang, Xiaoxu; Zhang, Juanni; Li, Jiang; Jiang, Xiangjun

2014-01-01

A dynamic attitude measurement system (DAMS) is developed based on a laser inertial navigation system (LINS). Three factors of the dynamic attitude measurement error using LINS are analyzed: dynamic error, time synchronization and phase lag. An optimal coning errors compensation algorithm is used to reduce coning errors, and two-axis wobbling verification experiments are presented in the paper. The tests indicate that the attitude accuracy is improved 2-fold by the algorithm. In order to decrease coning errors further, the attitude updating frequency is improved from 200 Hz to 2000 Hz. At the same time, a novel finite impulse response (FIR) filter with three notches is designed to filter the dither frequency of the ring laser gyro (RLG). The comparison tests suggest that the new filter is five times more effective than the old one. The paper indicates that phase-frequency characteristics of FIR filter and first-order holder of navigation computer constitute the main sources of phase lag in LINS. A formula to calculate the LINS attitude phase lag is introduced in the paper. The expressions of dynamic attitude errors induced by phase lag are derived. The paper proposes a novel synchronization mechanism that is able to simultaneously solve the problems of dynamic test synchronization and phase compensation. A single-axis turntable and a laser interferometer are applied to verify the synchronization mechanism. The experiments results show that the theoretically calculated values of phase lag and attitude error induced by phase lag can both match perfectly with testing data. The block diagram of DAMS and physical photos are presented in the paper. The final experiments demonstrate that the real-time attitude measurement accuracy of DAMS can reach up to 20″ (1σ) and the synchronization error is less than 0.2 ms on the condition of three axes wobbling for 10 min. PMID:25177802

Set-up uncertainties: online correction with X-ray volume imaging.

PubMed

Kataria, Tejinder; Abhishek, Ashu; Chadha, Pranav; Nandigam, Janardhan

2011-01-01

To determine interfractional three-dimensional set-up errors using X-ray volumetric imaging (XVI). Between December 2007 and August 2009, 125 patients were taken up for image-guided radiotherapy using online XVI. After matching of reference and acquired volume view images, set-up errors in three translation directions were recorded and corrected online before treatment each day. Mean displacements, population systematic (Σ), and random (σ) errors were calculated and analyzed using SPSS (v16) software. Optimum clinical target volume (CTV) to planning target volume (PTV) margin was calculated using Van Herk's (2.5Σ + 0.7 σ) and Stroom's (2Σ + 0.7 σ) formula. Patients were grouped in 4 cohorts, namely brain, head and neck, thorax, and abdomen-pelvis. The mean vector displacement recorded were 0.18 cm, 0.15 cm, 0.36 cm, and 0.35 cm for brain, head and neck, thorax, and abdomen-pelvis, respectively. Analysis of individual mean set-up errors revealed good agreement with the proposed 0.3 cm isotropic margins for brain and 0.5 cm isotropic margins for head-neck. Similarly, 0.5 cm circumferential and 1 cm craniocaudal proposed margins were in agreement with thorax and abdomen-pelvic cases. The calculated mean displacements were well within CTV-PTV margin estimates of Van Herk (90% population coverage to minimum 95% prescribed dose) and Stroom (99% target volume coverage by 95% prescribed dose). Employing these individualized margins in a particular cohort ensure comparable target coverage as described in literature, which is further improved if XVI-aided set-up error detection and correction is used before treatment.

Assessment of legibility and completeness of handwritten and electronic prescriptions.

PubMed

Albarrak, Ahmed I; Al Rashidi, Eman Abdulrahman; Fatani, Rwaa Kamil; Al Ageel, Shoog Ibrahim; Mohammed, Rafiuddin

2014-12-01

To assess the legibility and completeness of handwritten prescriptions and compare with electronic prescription system for medication errors. Prospective study. King Khalid University Hospital (KKUH), Riyadh, Saudi Arabia. Handwritten prescriptions were received from clinical units of Medicine Outpatient Department (MOPD), Primary Care Clinic (PCC) and Surgery Outpatient Department (SOPD) whereas electronic prescriptions were collected from the pediatric ward. The handwritten prescription was assessed for completeness by the checklist designed according to the hospital prescription and evaluated for legibility by two pharmacists. The comparison between handwritten and electronic prescription errors was evaluated based on the validated checklist adopted from previous studies. Legibility and completeness of prescriptions. 398 prescriptions (199 handwritten and 199 e-prescriptions) were assessed. About 71 (35.7%) of handwritten and 5 (2.5%) of electronic prescription errors were identified. A significant statistical difference (P < 0.001) was observed between handwritten and e-prescriptions in omitted dose and omitted route of administration category of error distribution. The rate of completeness in patient identification in handwritten prescriptions was 80.97% in MOPD, 76.36% in PCC and 85.93% in SOPD clinic units. Assessment of medication prescription completeness was 91.48% in MOPD, 88.48% in PCC, and 89.28% in SOPD. This study revealed a high incidence of prescribing errors in handwritten prescriptions. The use of e-prescription system showed a significant decline in the incidence of errors. The legibility of handwritten prescriptions was relatively good whereas the level of completeness was very low.

Facilitators and barriers to non-medical prescribing - A systematic review and thematic synthesis.

PubMed

Graham-Clarke, Emma; Rushton, Alison; Noblet, Timothy; Marriott, John

2018-01-01

Non-medical prescribing has the potential to deliver innovative healthcare within limited finances. However, uptake has been slow, and a proportion of non-medical prescribers do not use the qualification. This systematic review aimed to describe the facilitators and barriers to non-medical prescribing in the United Kingdom. The systematic review and thematic analysis included qualitative and mixed methods papers reporting facilitators and barriers to independent non-medical prescribing in the United Kingdom. The following databases were searched to identify relevant papers: AMED, ASSIA, BNI, CINAHL, EMBASE, ERIC, MEDLINE, Open Grey, Open access theses and dissertations, and Web of Science. Papers published between 2006 and March 2017 were included. Studies were quality assessed using a validated tool (QATSDD), then underwent thematic analysis. The protocol was registered with PROSPERO (CRD42015019786). Of 3991 potentially relevant identified studies, 42 were eligible for inclusion. The studies were generally of moderate quality (83%), and most (71%) were published 2007-2012. The nursing profession dominated the studies (30/42). Thematic analysis identified three overarching themes: non-medical prescriber, human factors, and organisational aspects. Each theme consisted of several sub-themes; the four most highly mentioned were 'medical professionals', 'area of competence', 'impact on time' and 'service'. Sub-themes were frequently interdependent on each other, having the potential to act as a barrier or facilitator depending on circumstances. Addressing the identified themes and subthemes enables strategies to be developed to support and optimise non-medical prescribing. Further research is required to identify if similar themes are encountered by other non-medical prescribing groups than nurses and pharmacists.

Producing remote sensing-based emission estimates of prescribed burning in the contiguous United States for the U.S. Environmental Protection Agency 2011 National Emissions Inventory

NASA Astrophysics Data System (ADS)

McCarty, J. L.; Pouliot, G. A.; Soja, A. J.; Miller, M. E.; Rao, T.

2013-12-01

Prescribed fires in agricultural landscapes generally produce smaller burned areas than wildland fires but are important contributors to emissions impacting air quality and human health. Currently, there are a variety of available satellite-based estimates of crop residue burning, including the NOAA/NESDIS Hazard Mapping System (HMS) the Satellite Mapping Automated Reanalysis Tool for Fire Incident Reconciliation (SMARTFIRE 2), the Moderate Resolution Imaging Spectroradiometer (MODIS) Official Burned Area Product (MCD45A1)), the MODIS Direct Broadcast Burned Area Product (MCD64A1) the MODIS Active Fire Product (MCD14ML), and a regionally-tuned 8-day cropland differenced Normalized Burn Ratio product for the contiguous U.S. The purpose of this NASA-funded research was to refine the regionally-tuned product utilizing higher spatial resolution crop type data from the USDA NASS Cropland Data Layer and burned area training data from field work and high resolution commercial satellite data to improve the U.S. Environmental Protection Agency's (EPA) National Emissions Inventory (NEI). The final product delivered to the EPA included a detailed database of 25 different atmospheric emissions at the county level, emission distributions by crop type and seasonality, and GIS data. The resulting emission databases were shared with the U.S. EPA and regional offices, the National Wildfire Coordinating Group (NWGC) Smoke Committee, and all 48 states in the contiguous U.S., with detailed error estimations for Wyoming and Indiana and detailed analyses of results for Florida, Minnesota, North Dakota, Oklahoma, and Oregon. This work also provided opportunities in discovering the different needs of federal and state partners, including the various geospatial abilities and platforms across the many users and how to incorporate expert air quality, policy, and land management knowledge into quantitative earth observation-based estimations of prescribed fire emissions. Finally, this work created direct communication paths between federal and state partners to the scientists creating the remote sensing-based products, further improving the geospatial products and understanding of air quality impacts of prescribed burning at the state, regional, and national scales.

Crowned spur gears - Methods for generation and Tooth Contact Analysis. II - Generation of the pinion tooth surface by a surface of revolution

NASA Technical Reports Server (NTRS)

Litvin, F. L.; Handschuh, R. F.; Zhang, J.

1988-01-01

A method for generation of crowned pinion tooth surfaces using a surface of revolution is developed. The crowned pinion meshes with a regular involute gear and has a prescribed parabolic type of transmission errors when the gears operate in the aligned mode. When the gears are misaligned the transmission error remains parabolic with the maximum level still remaining very small (less than 0.34 arc second for the numerical examples). Tooth Contact Analysis (TCA) is used to simulate the conditions of meshing, determine the transmission error, and the bearing contact.

SU-F-BRD-05: Robustness of Dose Painting by Numbers in Proton Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Montero, A Barragan; Sterpin, E; Lee, J

Purpose: Proton range uncertainties may cause important dose perturbations within the target volume, especially when steep dose gradients are present as in dose painting. The aim of this study is to assess the robustness against setup and range errors for high heterogeneous dose prescriptions (i.e., dose painting by numbers), delivered by proton pencil beam scanning. Methods: An automatic workflow, based on MATLAB functions, was implemented through scripting in RayStation (RaySearch Laboratories). It performs a gradient-based segmentation of the dose painting volume from 18FDG-PET images (GTVPET), and calculates the dose prescription as a linear function of the FDG-uptake value on eachmore » voxel. The workflow was applied to two patients with head and neck cancer. Robustness against setup and range errors of the conventional PTV margin strategy (prescription dilated by 2.5 mm) versus CTV-based (minimax) robust optimization (2.5 mm setup, 3% range error) was assessed by comparing the prescription with the planned dose for a set of error scenarios. Results: In order to ensure dose coverage above 95% of the prescribed dose in more than 95% of the GTVPET voxels while compensating for the uncertainties, the plans with a PTV generated a high overdose. For the nominal case, up to 35% of the GTVPET received doses 5% beyond prescription. For the worst of the evaluated error scenarios, the volume with 5% overdose increased to 50%. In contrast, for CTV-based plans this 5% overdose was present only in a small fraction of the GTVPET, which ranged from 7% in the nominal case to 15% in the worst of the evaluated scenarios. Conclusion: The use of a PTV leads to non-robust dose distributions with excessive overdose in the painted volume. In contrast, robust optimization yields robust dose distributions with limited overdose. RaySearch Laboratories is sincerely acknowledged for providing us with RayStation treatment planning system and for the support provided.« less

Systematic Error Modeling and Bias Estimation

PubMed Central

Zhang, Feihu; Knoll, Alois

2016-01-01

This paper analyzes the statistic properties of the systematic error in terms of range and bearing during the transformation process. Furthermore, we rely on a weighted nonlinear least square method to calculate the biases based on the proposed models. The results show the high performance of the proposed approach for error modeling and bias estimation. PMID:27213386

A Hybrid Approach for Correcting Grammatical Errors

ERIC Educational Resources Information Center

Lee, Kiyoung; Kwon, Oh-Woog; Kim, Young-Kil; Lee, Yunkeun

2015-01-01

This paper presents a hybrid approach for correcting grammatical errors in the sentences uttered by Korean learners of English. The error correction system plays an important role in GenieTutor, which is a dialogue-based English learning system designed to teach English to Korean students. During the talk with GenieTutor, grammatical error…

Automatic Correction of Adverb Placement Errors for CALL

ERIC Educational Resources Information Center

Garnier, Marie

2012-01-01

According to recent studies, there is a persistence of adverb placement errors in the written productions of francophone learners and users of English at an intermediate to advanced level. In this paper, we present strategies for the automatic detection and correction of errors in the placement of manner adverbs, using linguistic-based natural…

Deep data fusion method for missile-borne inertial/celestial system

NASA Astrophysics Data System (ADS)

Zhang, Chunxi; Chen, Xiaofei; Lu, Jiazhen; Zhang, Hao

2018-05-01

Strap-down inertial-celestial integrated navigation system has the advantages of autonomy and high precision and is very useful for ballistic missiles. The star sensor installation error and inertial measurement error have a great influence for the system performance. Based on deep data fusion, this paper establishes measurement equations including star sensor installation error and proposes the deep fusion filter method. Simulations including misalignment error, star sensor installation error, IMU error are analyzed. Simulation results indicate that the deep fusion method can estimate the star sensor installation error and IMU error. Meanwhile, the method can restrain the misalignment errors caused by instrument errors.

SU-E-T-381: Evaluation of Calculated Dose Accuracy for Organs-At-Risk Located at Out-Of-Field in a Commercial Treatment Planning System for High Energy Photon Beams Produced From TrueBeam Accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, L; Ding, G

Purpose: Dose calculation accuracy for the out-of-field dose is important for predicting the dose to the organs-at-risk when they are located outside primary beams. The investigations on evaluating the calculation accuracy of treatment planning systems (TPS) on out-of-field dose in existing publications have focused on low energy (6MV) photon. This study evaluates out-of-field dose calculation accuracy of AAA algorithm for 15MV high energy photon beams. Methods: We used the EGSnrc Monte Carlo (MC) codes to evaluate the AAA algorithm in Varian Eclipse TPS (v.11). The incident beams start with validated Varian phase-space sources for a TrueBeam linac equipped with Millenniummore » 120 MLC. Dose comparisons between using AAA and MC for CT based realistic patient treatment plans using VMAT techniques for prostate and lung were performed and uncertainties of organ dose predicted by AAA at out-of-field location were evaluated. Results: The results show that AAA calculations under-estimate doses at the dose level of 1% (or less) of prescribed dose for CT based patient treatment plans using VMAT techniques. In regions where dose is only 1% of prescribed dose, although AAA under-estimates the out-of-field dose by 30% relative to the local dose, it is only about 0.3% of prescribed dose. For example, the uncertainties of calculated organ dose to liver or kidney that is located out-of-field is <0.3% of prescribed dose. Conclusion: For 15MV high energy photon beams, very good agreements (<1%) in calculating dose distributions were obtained between AAA and MC. The uncertainty of out-of-field dose calculations predicted by the AAA algorithm for realistic patient VMAT plans is <0.3% of prescribed dose in regions where the dose relative to the prescribed dose is <1%, although the uncertainties can be much larger relative to local doses. For organs-at-risk located at out-of-field, the error of dose predicted by Eclipse using AAA is negligible. This work was conducted in part using the resources of Varian research grant VUMC40590-R.« less

Sources of Error in Substance Use Prevalence Surveys

PubMed Central

Johnson, Timothy P.

2014-01-01

Population-based estimates of substance use patterns have been regularly reported now for several decades. Concerns with the quality of the survey methodologies employed to produce those estimates date back almost as far. Those concerns have led to a considerable body of research specifically focused on understanding the nature and consequences of survey-based errors in substance use epidemiology. This paper reviews and summarizes that empirical research by organizing it within a total survey error model framework that considers multiple types of representation and measurement errors. Gaps in our knowledge of error sources in substance use surveys and areas needing future research are also identified. PMID:27437511

[Medication errors in a neonatal unit: One of the main adverse events].

PubMed

Esqué Ruiz, M T; Moretones Suñol, M G; Rodríguez Miguélez, J M; Sánchez Ortiz, E; Izco Urroz, M; de Lamo Camino, M; Figueras Aloy, J

2016-04-01

Neonatal units are one of the hospital areas most exposed to the committing of treatment errors. A medication error (ME) is defined as the avoidable incident secondary to drug misuse that causes or may cause harm to the patient. The aim of this paper is to present the incidence of ME (including feeding) reported in our neonatal unit and its characteristics and possible causal factors. A list of the strategies implemented for prevention is presented. An analysis was performed on the ME declared in a neonatal unit. A total of 511 MEs have been reported over a period of seven years in the neonatal unit. The incidence in the critical care unit was 32.2 per 1000 hospital days or 20 per 100 patients, of which 0.22 per 1000 days had serious repercussions. The ME reported were, 39.5% prescribing errors, 68.1% administration errors, 0.6% were adverse drug reactions. Around two-thirds (65.4%) were produced by drugs, with 17% being intercepted. The large majority (89.4%) had no impact on the patient, but 0.6% caused permanent damage or death. Nurses reported 65.4% of MEs. The most commonly implicated causal factor was distraction (59%). Simple corrective action (alerts), and intermediate (protocols, clinical sessions and courses) and complex actions (causal analysis, monograph) were performed. It is essential to determine the current state of ME, in order to establish preventive measures and, together with teamwork and good practices, promote a climate of safety. Copyright © 2015 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.

Inappropriate Use of Medication by Elderly, Polymedicated, or Multipathological Patients with Chronic Diseases

PubMed Central

Pérez-Jover, Virtudes; Carratala-Munuera, Concepción; Gil-Guillen, Vicente F.; Basora, Josep; Orozco-Beltrán, Domingo

2018-01-01

The growth of the aging population leads to the increase of chronic diseases, of the burden of multimorbility, and of the complexity polypharmacy. The prevalence of medication errors rises in patients with polypharmacy in primary care, and this is a major concern to healthcare systems. This study reviews the published literature on the inappropriate use of medicines in order to articulate recommendations on how to reduce it in chronic patients, particularly in those who are elderly, polymedicated, or multipathological. A systematic review of articles published from January 2000 to October 2015 was performed using MEDLINE, EMBASE, PsychInfo, Scopus, The Cochrane Library, and Index Medicus databases. We selected 80 studies in order to analyse the content that addressed the question under consideration. Our literature review found that half of patients know what their prescribed treatment is; that most of elderly people take five or more medications a day; that in elderly, polymedicated people, the probability of a medication error occurring is higher; that new tools have been recently developed to reduce errors; that elderly patients can understand written information but the presentation and format is an important factor; and that a high percentage of patients have remaining doubts after their visit. Thus, strategies based on the evidence should be applied in order to reduce medication errors. PMID:29439425

Assessment of Rapid-Blood-Culture-Identification Result Interpretation and Antibiotic Prescribing Practices

PubMed Central

Campbell, W. Scott; Lyden, Elizabeth; Van Schooneveld, Trevor C.

2017-01-01

ABSTRACT Rapid pathogen identification can alter antibiotic prescribing practices if interpreted correctly. Microbiology reporting can be difficult to understand, and new technology has made it more challenging. Nebraska Medicine recently implemented the BioFire FilmArray blood culture identification panel (BCID) coupled with stewardship-based education on interpretation. Physician BCID result interpretation and prescribing were assessed via an electronic survey, with a response rate of 40.8% (156/382 surveys). Seven questions required respondents to interpret BCID results, identify the most likely pathogen, and then choose therapy based on the results. The tallied correct responses resulted in a knowledge score. General linear models evaluated the effect of role, specialty, and utilization of the BCID interpretation guide on the mean knowledge score. The specialties of the respondents included 55.7% internal medicine, 19.7% family medicine, and 24.6% other. Roles included 41.1% residents, 5.0% fellows, and 53.9% faculty. Most reported that they reviewed antimicrobial susceptibility results (89.4%) and adjusted therapy accordingly (81.6%), while only 60% stated that they adjusted therapy based on BCID results. The correct response rates ranged from 52 to 86% for the interpretation questions. The most common errors included misinterpretation of Enterobacteriaceae and Staphylococcus genus results. Neither role nor specialty was associated with total knowledge score in multivariate analysis (P = 0.13 and 0.47, respectively). In conclusion, physician interpretation of BCID results is suboptimal and can result in ineffective treatment or missed opportunity to narrow therapy. With the implementation of new technology, improved reporting practices of BCID results with clinical decision support tools providing interpretation guidance available at the point of care is recommended. PMID:28250000

Optimization of design and operating parameters of a space-based optical-electronic system with a distributed aperture.

PubMed

Tcherniavski, Iouri; Kahrizi, Mojtaba

2008-11-20

Using a gradient optimization method with objective functions formulated in terms of a signal-to-noise ratio (SNR) calculated at given values of the prescribed spatial ground resolution, optimization problems of geometrical parameters of a distributed optical system and a charge-coupled device of a space-based optical-electronic system are solved for samples of the optical systems consisting of two and three annular subapertures. The modulation transfer function (MTF) of the distributed aperture is expressed in terms of an average MTF taking residual image alignment (IA) and optical path difference (OPD) errors into account. The results show optimal solutions of the optimization problems depending on diverse variable parameters. The information on the magnitudes of the SNR can be used to determine the number of the subapertures and their sizes, while the information on the SNR decrease depending on the IA and OPD errors can be useful in design of a beam combination control system to produce the necessary requirements to its accuracy on the basis of the permissible deterioration in the image quality.

Statistical exchange-coupling errors and the practicality of scalable silicon donor qubits

NASA Astrophysics Data System (ADS)

Song, Yang; Das Sarma, S.

2016-12-01

Recent experimental efforts have led to considerable interest in donor-based localized electron spins in Si as viable qubits for a scalable silicon quantum computer. With the use of isotopically purified 28Si and the realization of extremely long spin coherence time in single-donor electrons, the recent experimental focus is on two-coupled donors with the eventual goal of a scaled-up quantum circuit. Motivated by this development, we simulate the statistical distribution of the exchange coupling J between a pair of donors under realistic donor placement straggles, and quantify the errors relative to the intended J value. With J values in a broad range of donor-pair separation ( 5 <|R |<60 nm), we work out various cases systematically, for a target donor separation R0 along the [001], [110] and [111] Si crystallographic directions, with |R0|=10 ,20 or 30 nm and standard deviation σR=1 ,2 ,5 or 10 nm. Our extensive theoretical results demonstrate the great challenge for a prescribed J gate even with just a donor pair, a first step for any scalable Si-donor-based quantum computer.

Volumetric error modeling, identification and compensation based on screw theory for a large multi-axis propeller-measuring machine

NASA Astrophysics Data System (ADS)

Zhong, Xuemin; Liu, Hongqi; Mao, Xinyong; Li, Bin; He, Songping; Peng, Fangyu

2018-05-01

Large multi-axis propeller-measuring machines have two types of geometric error, position-independent geometric errors (PIGEs) and position-dependent geometric errors (PDGEs), which both have significant effects on the volumetric error of the measuring tool relative to the worktable. This paper focuses on modeling, identifying and compensating for the volumetric error of the measuring machine. A volumetric error model in the base coordinate system is established based on screw theory considering all the geometric errors. In order to fully identify all the geometric error parameters, a new method for systematic measurement and identification is proposed. All the PIGEs of adjacent axes and the six PDGEs of the linear axes are identified with a laser tracker using the proposed model. Finally, a volumetric error compensation strategy is presented and an inverse kinematic solution for compensation is proposed. The final measuring and compensation experiments have further verified the efficiency and effectiveness of the measuring and identification method, indicating that the method can be used in volumetric error compensation for large machine tools.

Video error concealment using block matching and frequency selective extrapolation algorithms

NASA Astrophysics Data System (ADS)

P. K., Rajani; Khaparde, Arti

2017-06-01

Error Concealment (EC) is a technique at the decoder side to hide the transmission errors. It is done by analyzing the spatial or temporal information from available video frames. It is very important to recover distorted video because they are used for various applications such as video-telephone, video-conference, TV, DVD, internet video streaming, video games etc .Retransmission-based and resilient-based methods, are also used for error removal. But these methods add delay and redundant data. So error concealment is the best option for error hiding. In this paper, the error concealment methods such as Block Matching error concealment algorithm is compared with Frequency Selective Extrapolation algorithm. Both the works are based on concealment of manually error video frames as input. The parameter used for objective quality measurement was PSNR (Peak Signal to Noise Ratio) and SSIM(Structural Similarity Index). The original video frames along with error video frames are compared with both the Error concealment algorithms. According to simulation results, Frequency Selective Extrapolation is showing better quality measures such as 48% improved PSNR and 94% increased SSIM than Block Matching Algorithm.

Descriptive analysis of medication errors reported to the Egyptian national online reporting system during six months.

PubMed

Shehata, Zahraa Hassan Abdelrahman; Sabri, Nagwa Ali; Elmelegy, Ahmed Abdelsalam

2016-03-01

This study analyzes reports to the Egyptian medication error (ME) reporting system from June to December 2014. Fifty hospital pharmacists received training on ME reporting using the national reporting system. All received reports were reviewed and analyzed. The pieces of data analyzed were patient age, gender, clinical setting, stage, type, medication(s), outcome, cause(s), and recommendation(s). Over the course of 6 months, 12,000 valid reports were gathered and included in this analysis. The majority (66%) came from inpatient settings, while 23% came from intensive care units, and 11% came from outpatient departments. Prescribing errors were the most common type of MEs (54%), followed by monitoring (25%) and administration errors (16%). The most frequent error was incorrect dose (20%) followed by drug interactions, incorrect drug, and incorrect frequency. Most reports were potential (25%), prevented (11%), or harmless (51%) errors; only 13% of reported errors lead to patient harm. The top three medication classes involved in reported MEs were antibiotics, drugs acting on the central nervous system, and drugs acting on the cardiovascular system. Causes of MEs were mostly lack of knowledge, environmental factors, lack of drug information sources, and incomplete prescribing. Recommendations for addressing MEs were mainly staff training, local ME reporting, and improving work environment. There are common problems among different healthcare systems, so that sharing experiences on the national level is essential to enable learning from MEs. Internationally, there is a great need for standardizing ME terminology, to facilitate knowledge transfer. Underreporting, inaccurate reporting, and a lack of reporter diversity are some limitations of this study. Egypt now has a national database of MEs that allows researchers and decision makers to assess the problem, identify its root causes, and develop preventive strategies. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Operational use of prescribed fire in southern California chaparral

Treesearch

Ron Dougherty; Philip J. Riggan

1982-01-01

The use of prescribed fire in the chaparral could reduce the incidence and impacts of severe wildfires and enhance watershed re-sources. This paper describes the operational planning needed for a successful prescribed fire and discusses the recent experience with this technique on the Cleveland National Forest.

27 CFR 46.22 - Forms prescribed.

Code of Federal Regulations, 2010 CFR

2010-04-01

... CIGARETTE PAPERS AND TUBES Administrative Provisions § 46.22 Forms prescribed. (a) The appropriate TTB officer is authorized to prescribe all forms required by this part. You must furnish all of the..., and as required by this part. You must file each form in accordance with its instructions. (b) Forms...

Lead User Design: Medication Management in Electronic Medical Records.

PubMed

Price, Morgan; Weber, Jens H; Davies, Iryna; Bellwood, Paule

2015-01-01

Improvements in medication management may lead to a reduction of preventable errors. Usability and user experience issues are common and related to achieving benefits of Electronic Medical Records (EMRs). This paper reports on a novel study that combines the lead user method with a safety engineering review to discover an innovative design for the medication management module in EMRs in primary care. Eight lead users were recruited that represented prescribers and clinical pharmacists with expertise in EMR design, evidence-based medicine, medication safety and medication research. Eight separate medication management module designs were prototyped and validated, one with each lead user. A parallel safety review of medicaiton management was completed. The findings were synthesized into a single common set of goals, activities and one interactive, visual prototype. The lead user method with safety review proved to be an effective way to elicit diverse user goals and synthesize them into a common design. The resulting design ideas focus on meeting the goals of quality, efficiency, safety, reducing the cognitive load on the user, and improving communication wih the patient and the care team. Design ideas are being adapted to an existing EMR product, providing areas for further work.

A comparison of three methods of setting prescribing budgets, using data derived from defined daily dose analyses of historic patterns of use.

PubMed Central

Maxwell, M; Howie, J G; Pryde, C J

1998-01-01

BACKGROUND: Prescribing matters (particularly budget setting and research into prescribing variation between doctors) have been handicapped by the absence of credible measures of the volume of drugs prescribed. AIM: To use the defined daily dose (DDD) method to study variation in the volume and cost of drugs prescribed across the seven main British National Formulary (BNF) chapters with a view to comparing different methods of setting prescribing budgets. METHOD: Study of one year of prescribing statistics from all 129 general practices in Lothian, covering 808,059 patients: analyses of prescribing statistics for 1995 to define volume and cost/volume of prescribing for one year for 10 groups of practices defined by the age and deprivation status of their patients, for seven BNF chapters; creation of prescribing budgets for 1996 for each individual practice based on the use of target volume and cost statistics; comparison of 1996 DDD-based budgets with those set using the conventional historical approach; and comparison of DDD-based budgets with budgets set using a capitation-based formula derived from local cost/patient information. RESULTS: The volume of drugs prescribed was affected by the age structure of the practices in BNF Chapters 1 (gastrointestinal), 2 (cardiovascular), and 6 (endocrine), and by deprivation structure for BNF Chapters 3 (respiratory) and 4 (central nervous system). Costs per DDD in the major BNF chapters were largely independent of age, deprivation structure, or fundholding status. Capitation and DDD-based budgets were similar to each other, but both differed substantially from historic budgets. One practice in seven gained or lost more than 100,000 Pounds per annum using DDD or capitation budgets compared with historic budgets. The DDD-based budget, but not the capitation-based budget, can be used to set volume-specific prescribing targets. CONCLUSIONS: DDD-based and capitation-based prescribing budgets can be set using a simple explanatory model and generalizable methods. In this study, both differed substantially from historic budgets. DDD budgets could be created to accommodate new prescribing strategies and raised or lowered to reflect local intentions to alter overall prescribing volume or cost targets. We recommend that future work on setting budgets and researching prescribing variations should be based on DDD statistics. PMID:10024703

Enhancing the quality of antibiotic prescribing in Primary Care: Qualitative evaluation of a blended learning intervention

PubMed Central

2010-01-01

Background The Stemming the Tide of Antibiotic Resistance (STAR) Educational Program aims to enhance the quality of antibiotic prescribing and raise awareness about antibiotic resistance among general medical practitioners. It consists of a seven part, theory-based blended learning program that includes online reflection on clinicians' own practice, presentation of research evidence and guidelines, a practice-based seminar focusing on participants' own antibiotic prescribing and resistance rates in urine samples sent from their practice, communication skills training using videos of simulated patients in routine surgeries, and participation in a web forum. Effectiveness was evaluated in a randomised controlled trial in which 244 GPs and Nurse Practitioners and 68 general practices participated. This paper reports part of the process evaluation of that trial. Methods Semi-structured, digitally recorded, and transcribed telephone interviews with 31 purposively sampled trial participants analysed using thematic content analysis. Results The majority of participants reported increased awareness of antibiotic resistance, greater self-confidence in reducing antibiotic prescribing and at least some change in consultation style and antibiotic prescribing behaviour. Reported practical changes included adopting a practice-wide policy of antibiotic prescription reduction. Many GPs also reported increased insight into patients' expectations, ultimately contributing to improved doctor-patient rapport. The components of the intervention put forward as having the greatest influence on changing clinician behaviour were the up-to-date research evidence resources, simple and effective communication skills presented in on-line videos, and presentation of the practice's own antibiotic prescribing levels combined with an overview of local resistance data. Conclusion Participants regarded this complex blended learning intervention acceptable and feasible, and reported wide-ranging, positive changes in attitudes and clinical practice as a result of participating in the STAR Educational Program. Trial registration Current Controlled Trials ISRCTN63355948 PMID:20459655

Low Frequency Error Analysis and Calibration for High-Resolution Optical Satellite's Uncontrolled Geometric Positioning

NASA Astrophysics Data System (ADS)

Wang, Mi; Fang, Chengcheng; Yang, Bo; Cheng, Yufeng

2016-06-01

The low frequency error is a key factor which has affected uncontrolled geometry processing accuracy of the high-resolution optical image. To guarantee the geometric quality of imagery, this paper presents an on-orbit calibration method for the low frequency error based on geometric calibration field. Firstly, we introduce the overall flow of low frequency error on-orbit analysis and calibration, which includes optical axis angle variation detection of star sensor, relative calibration among star sensors, multi-star sensor information fusion, low frequency error model construction and verification. Secondly, we use optical axis angle change detection method to analyze the law of low frequency error variation. Thirdly, we respectively use the method of relative calibration and information fusion among star sensors to realize the datum unity and high precision attitude output. Finally, we realize the low frequency error model construction and optimal estimation of model parameters based on DEM/DOM of geometric calibration field. To evaluate the performance of the proposed calibration method, a certain type satellite's real data is used. Test results demonstrate that the calibration model in this paper can well describe the law of the low frequency error variation. The uncontrolled geometric positioning accuracy of the high-resolution optical image in the WGS-84 Coordinate Systems is obviously improved after the step-wise calibration.

Investigation on coupling error characteristics in angular rate matching based ship deformation measurement approach

NASA Astrophysics Data System (ADS)

Yang, Shuai; Wu, Wei; Wang, Xingshu; Xu, Zhiguang

2018-01-01

The coupling error in the measurement of ship hull deformation can significantly influence the attitude accuracy of the shipborne weapons and equipments. It is therefore important to study the characteristics of the coupling error. In this paper, an comprehensive investigation on the coupling error is reported, which has a potential of deducting the coupling error in the future. Firstly, the causes and characteristics of the coupling error are analyzed theoretically based on the basic theory of measuring ship deformation. Then, simulations are conducted for verifying the correctness of the theoretical analysis. Simulation results show that the cross-correlation between dynamic flexure and ship angular motion leads to the coupling error in measuring ship deformation, and coupling error increases with the correlation value between them. All the simulation results coincide with the theoretical analysis.

Identification and compensation of the temperature influences in a miniature three-axial accelerometer based on the least squares method

NASA Astrophysics Data System (ADS)

Grigorie, Teodor Lucian; Corcau, Ileana Jenica; Tudosie, Alexandru Nicolae

2017-06-01

The paper presents a way to obtain an intelligent miniaturized three-axial accelerometric sensor, based on the on-line estimation and compensation of the sensor errors generated by the environmental temperature variation. Taking into account that this error's value is a strongly nonlinear complex function of the values of environmental temperature and of the acceleration exciting the sensor, its correction may not be done off-line and it requires the presence of an additional temperature sensor. The proposed identification methodology for the error model is based on the least square method which process off-line the numerical values obtained from the accelerometer experimental testing for different values of acceleration applied to its axes of sensitivity and for different values of operating temperature. A final analysis of the error level after the compensation highlights the best variant for the matrix in the error model. In the sections of the paper are shown the results of the experimental testing of the accelerometer on all the three sensitivity axes, the identification of the error models on each axis by using the least square method, and the validation of the obtained models with experimental values. For all of the three detection channels was obtained a reduction by almost two orders of magnitude of the acceleration absolute maximum error due to environmental temperature variation.

Implementation fidelity of a computer-assisted intervention for children with speech sound disorders.

PubMed

McCormack, Jane; Baker, Elise; Masso, Sarah; Crowe, Kathryn; McLeod, Sharynne; Wren, Yvonne; Roulstone, Sue

2017-06-01

Implementation fidelity refers to the degree to which an intervention or programme adheres to its original design. This paper examines implementation fidelity in the Sound Start Study, a clustered randomised controlled trial of computer-assisted support for children with speech sound disorders (SSD). Sixty-three children with SSD in 19 early childhood centres received computer-assisted support (Phoneme Factory Sound Sorter [PFSS] - Australian version). Educators facilitated the delivery of PFSS targeting phonological error patterns identified by a speech-language pathologist. Implementation data were gathered via (1) the computer software, which recorded when and how much intervention was completed over 9 weeks; (2) educators' records of practice sessions; and (3) scoring of fidelity (intervention procedure, competence and quality of delivery) from videos of intervention sessions. Less than one-third of children received the prescribed number of days of intervention, while approximately one-half participated in the prescribed number of intervention plays. Computer data differed from educators' data for total number of days and plays in which children participated; the degree of match was lower as data became more specific. Fidelity to intervention procedures, competency and quality of delivery was high. Implementation fidelity may impact intervention outcomes and so needs to be measured in intervention research; however, the way in which it is measured may impact on data.

Decomposition of Composite Electric Field in a Three-Phase D-Dot Voltage Transducer Measuring System

PubMed Central

Hu, Xueqi; Wang, Jingang; Wei, Gang; Deng, Xudong

2016-01-01

In line with the wider application of non-contact voltage transducers in the engineering field, transducers are required to have better performance for different measuring environments. In the present study, the D-dot voltage transducer is further improved based on previous research in order to meet the requirements for long-distance measurement of electric transmission lines. When measuring three-phase electric transmission lines, problems such as synchronous data collection and composite electric field need to be resolved. A decomposition method is proposed with respect to the superimposed electric field generated between neighboring phases. The charge simulation method is utilized to deduce the decomposition equation of the composite electric field and the validity of the proposed method is verified by simulation calculation software. With the deduced equation as the algorithm foundation, this paper improves hardware circuits, establishes a measuring system and constructs an experimental platform for examination. Under experimental conditions, a 10 kV electric transmission line was tested for steady-state errors, and the measuring results of the transducer and the high-voltage detection head were compared. Ansoft Maxwell Stimulation Software was adopted to obtain the electric field intensity in different positions under transmission lines; its values and the measuring values of the transducer were also compared. Experimental results show that the three-phase transducer is characterized by a relatively good synchronization for data measurement, measuring results with high precision, and an error ratio within a prescribed limit. Therefore, the proposed three-phase transducer can be broadly applied and popularized in the engineering field. PMID:27754340

CREKID: A computer code for transient, gas-phase combustion of kinetics

NASA Technical Reports Server (NTRS)

Pratt, D. T.; Radhakrishnan, K.

1984-01-01

A new algorithm was developed for fast, automatic integration of chemical kinetic rate equations describing homogeneous, gas-phase combustion at constant pressure. Particular attention is paid to the distinguishing physical and computational characteristics of the induction, heat-release and equilibration regimes. The two-part predictor-corrector algorithm, based on an exponentially-fitted trapezoidal rule, includes filtering of ill-posed initial conditions, automatic selection of Newton-Jacobi or Newton iteration for convergence to achieve maximum computational efficiency while observing a prescribed error tolerance. The new algorithm was found to compare favorably with LSODE on two representative test problems drawn from combustion kinetics.

AveBoost2: Boosting for Noisy Data

NASA Technical Reports Server (NTRS)

Oza, Nikunj C.

2004-01-01

AdaBoost is a well-known ensemble learning algorithm that constructs its constituent or base models in sequence. A key step in AdaBoost is constructing a distribution over the training examples to create each base model. This distribution, represented as a vector, is constructed to be orthogonal to the vector of mistakes made by the pre- vious base model in the sequence. The idea is to make the next base model's errors uncorrelated with those of the previous model. In previous work, we developed an algorithm, AveBoost, that constructed distributions orthogonal to the mistake vectors of all the previous models, and then averaged them to create the next base model s distribution. Our experiments demonstrated the superior accuracy of our approach. In this paper, we slightly revise our algorithm to allow us to obtain non-trivial theoretical results: bounds on the training error and generalization error (difference between training and test error). Our averaging process has a regularizing effect which, as expected, leads us to a worse training error bound for our algorithm than for AdaBoost but a superior generalization error bound. For this paper, we experimented with the data that we used in both as originally supplied and with added label noise-a small fraction of the data has its original label changed. Noisy data are notoriously difficult for AdaBoost to learn. Our algorithm's performance improvement over AdaBoost is even greater on the noisy data than the original data.

Theoretical Analysis of Novel Quasi-3D Microscopy of Cell Deformation

PubMed Central

Qiu, Jun; Baik, Andrew D.; Lu, X. Lucas; Hillman, Elizabeth M. C.; Zhuang, Zhuo; Guo, X. Edward

2012-01-01

A novel quasi-three-dimensional (quasi-3D) microscopy technique has been developed to enable visualization of a cell under dynamic loading in two orthogonal planes simultaneously. The three-dimensional (3D) dynamics of the mechanical behavior of a cell under fluid flow can be examined at a high temporal resolution. In this study, a numerical model of a fluorescently dyed cell was created in 3D space, and the cell was subjected to uniaxial deformation or unidirectional fluid shear flow via finite element analysis (FEA). Therefore, the intracellular deformation in the simulated cells was exactly prescribed. Two-dimensional fluorescent images simulating the quasi-3D technique were created from the cell and its deformed states in 3D space using a point-spread function (PSF) and a convolution operation. These simulated original and deformed images were processed by a digital image correlation technique to calculate quasi-3D-based intracellular strains. The calculated strains were compared to the prescribed strains, thus providing a theoretical basis for the measurement of the accuracy of quasi-3D and wide-field microscopy-based intracellular strain measurements against the true 3D strains. The signal-to-noise ratio (SNR) of the simulated quasi-3D images was also modulated using additive Gaussian noise, and a minimum SNR of 12 was needed to recover the prescribed strains using digital image correlation. Our computational study demonstrated that quasi-3D strain measurements closely recovered the true 3D strains in uniform and fluid flow cellular strain states to within 5% strain error. PMID:22707985

Error simulation of paired-comparison-based scaling methods

NASA Astrophysics Data System (ADS)

Cui, Chengwu

2000-12-01

Subjective image quality measurement usually resorts to psycho physical scaling. However, it is difficult to evaluate the inherent precision of these scaling methods. Without knowing the potential errors of the measurement, subsequent use of the data can be misleading. In this paper, the errors on scaled values derived form paired comparison based scaling methods are simulated with randomly introduced proportion of choice errors that follow the binomial distribution. Simulation results are given for various combinations of the number of stimuli and the sampling size. The errors are presented in the form of average standard deviation of the scaled values and can be fitted reasonably well with an empirical equation that can be sued for scaling error estimation and measurement design. The simulation proves paired comparison based scaling methods can have large errors on the derived scaled values when the sampling size and the number of stimuli are small. Examples are also given to show the potential errors on actually scaled values of color image prints as measured by the method of paired comparison.

Numerical simulation of fluid flow through simplified blade cascade with prescribed harmonic motion using discontinuous Galerkin method

NASA Astrophysics Data System (ADS)

Vimmr, Jan; Bublík, Ondřej; Prausová, Helena; Hála, Jindřich; Pešek, Luděk

2018-06-01

This paper deals with a numerical simulation of compressible viscous fluid flow around three flat plates with prescribed harmonic motion. This arrangement presents a simplified blade cascade with forward wave motion. The aim of this simulation is to determine the aerodynamic forces acting on the flat plates. The mathematical model describing this problem is formed by Favre-averaged system of Navier-Stokes equations in arbitrary Lagrangian-Eulerian (ALE) formulation completed by one-equation Spalart-Allmaras turbulence model. The simulation was performed using the developed in-house CFD software based on discontinuous Galerkin method, which offers high order of accuracy.

Identification of an updated set of prescribing-safety indicators for GPs

PubMed Central

Spencer, Rachel; Bell, Brian; Avery, Anthony J; Gookey, Gill; Campbell, Stephen M

2014-01-01

Background Medication error is an important contributor to patient morbidity and mortality and is associated with inadequate patient safety measures. However, prescribing-safety tools specifically designed for use in general practice are lacking. Aim To identify and update a set of prescribing-safety indicators for assessing the safety of prescribing in general practice, and to estimate the risk of harm to patients associated with each indicator. Design and setting RAND/UCLA consensus development of indicators in UK general practice. Method Prescribing indicators were identified from a systematic review and previous consensus exercise. The RAND Appropriateness Method was used to further identify and develop the indicators with an electronic-Delphi method used to rate the risk associated with them. Twelve GPs from all the countries of the UK participated in the RAND exercise, with 11 GPs rating risk using the electronic-Delphi approach. Results Fifty-six prescribing-safety indicators were considered appropriate for inclusion (overall panel median rating of 7–9, with agreement). These indicators cover hazardous prescribing across a range of therapeutic indications, hazardous drug–drug combinations and inadequate laboratory test monitoring. Twenty-three (41%) of these indicators were considered high risk or extreme risk by 80% or more of the participants. Conclusion This study identified a set of 56 indicators that were considered, by a panel of GPs, to be appropriate for assessing the safety of GP prescribing. Twenty-three of these indicators were considered to be associated with high or extreme risk to patients and should be the focus of efforts to improve patient safety. PMID:24686882

SEU induced errors observed in microprocessor systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Asenek, V.; Underwood, C.; Oldfield, M.

In this paper, the authors present software tools for predicting the rate and nature of observable SEU induced errors in microprocessor systems. These tools are built around a commercial microprocessor simulator and are used to analyze real satellite application systems. Results obtained from simulating the nature of SEU induced errors are shown to correlate with ground-based radiation test data.

Using mobile devices to improve the safety of medication administration processes.

PubMed

Navas, H; Graffi Moltrasio, L; Ares, F; Strumia, G; Dourado, E; Alvarez, M

2015-01-01

Within preventable medical errors, those related to medications are frequent in every stage of the prescribing cycle. Nursing is responsible for maintaining each patients safety and care quality. Moreover, nurses are the last people who can detect an error in medication before its administration. Medication administration is one of the riskiest tasks in nursing. The use of information and communication technologies is related to a decrease in these errors. Including mobile devices related to 2D code reading of patients and medication will decrease the possibility of error when preparing and administering medication by nurses. A cross-platform software (iOS and Android) was developed to ensure the five Rights of the medication administration process (patient, medication, dose, route and schedule). Deployment in November showed 39% use.

Sense and Sensibility When Prescribing 'Off-Label' to Psychiatric Patients.

PubMed

Baldwin, David S; Tiwari, Nupur; Gordon, Robert

2015-01-01

Pharmacological treatment forms part of much routine psychiatric practice. Many psychotropic drugs and psychotherapies are available for treating patients with mental disorders, but considerable numbers of individuals remain troubled by incapacitating symptoms even after a succession of evidence-based treatments. In this situation, many doctors consider prescribing a psychotropic medication outside the narrow terms of its market authorisation or 'product licence', in an attempt to optimise clinical outcomes and increase the chance of recovery. Despite expressed concerns about potential hazards and increased physician liability, many authorities agree that using a drug outside the narrow terms of its product licence can be an important part of clinical practice. This paper illustrates the nature and extent of the use of licensed drugs for unlicensed applications in psychiatric and other medical settings, indicates potential drawbacks and hazards, and makes recommendations for a suggested process when prescribing 'off-label', as an appropriate part of the overall management of individual patients.

Designing a Safer Interactive Healthcare System - The Impact of Authentic User Participation

NASA Astrophysics Data System (ADS)

Went, Kathryn L.; Gregor, Peter; Ricketts, Ian W.

Information technology has been widely promoted in the healthcare sector to improve current practice and patient safety. However, end users are seldom involved extensively in the design and development of healthcare systems, with lip service often paid to the idea of true user involvement. In this case study the impact of sustained authentic user participation was explored using an interdisciplinary team, consisting of experts both in interaction and healthcare design and consultant anaesthetists, nurses, and pharmacists, to create an electronic prescribing and administration system. This paper details the interface that was created and provides examples of the way in which the design evolved in response to the sustained authentic user participation methods. The working prototype both reduced the opportunity for user error and was preferred by its users to the existing manual system.

(N+1)-dimensional fractional reduced differential transform method for fractional order partial differential equations

NASA Astrophysics Data System (ADS)

Arshad, Muhammad; Lu, Dianchen; Wang, Jun

2017-07-01

In this paper, we pursue the general form of the fractional reduced differential transform method (DTM) to (N+1)-dimensional case, so that fractional order partial differential equations (PDEs) can be resolved effectively. The most distinct aspect of this method is that no prescribed assumptions are required, and the huge computational exertion is reduced and round-off errors are also evaded. We utilize the proposed scheme on some initial value problems and approximate numerical solutions of linear and nonlinear time fractional PDEs are obtained, which shows that the method is highly accurate and simple to apply. The proposed technique is thus an influential technique for solving the fractional PDEs and fractional order problems occurring in the field of engineering, physics etc. Numerical results are obtained for verification and demonstration purpose by using Mathematica software.

Rigorous derivation of the effective model describing a non-isothermal fluid flow in a vertical pipe filled with porous medium

NASA Astrophysics Data System (ADS)

Beneš, Michal; Pažanin, Igor

2018-03-01

This paper reports an analytical investigation of non-isothermal fluid flow in a thin (or long) vertical pipe filled with porous medium via asymptotic analysis. We assume that the fluid inside the pipe is cooled (or heated) by the surrounding medium and that the flow is governed by the prescribed pressure drop between pipe's ends. Starting from the dimensionless Darcy-Brinkman-Boussinesq system, we formally derive a macroscopic model describing the effective flow at small Brinkman-Darcy number. The asymptotic approximation is given by the explicit formulae for the velocity, pressure and temperature clearly acknowledging the effects of the cooling (heating) and porous structure. The theoretical error analysis is carried out to indicate the order of accuracy and to provide a rigorous justification of the effective model.

Translating the Prescribed into the Enacted Curriculum in College and School

ERIC Educational Resources Information Center

Edwards, Richard

2011-01-01

Drawing upon concepts from actor-network theory (ANT), this article explores how the principle of symmetry can provide alternative readings of the translations of the prescribed into the enacted curriculum, without reducing understanding to explanation. The paper explores the contrasting ways in which the prescribed curriculum is translated into…

Negotiating jurisdiction in the workplace: a multiple-case study of nurse prescribing in hospital settings.

PubMed

Kroezen, M; Mistiaen, P; van Dijk, L; Groenewegen, P P; Francke, A L

2014-09-01

This paper reports on a multiple-case study of prescribing by nurse specialists in Dutch hospital settings. Most analyses of interprofessional negotiations over professional boundaries take a macro sociological approach and ignore workplace jurisdictions. Yet boundary blurring takes place and healthcare professionals renegotiate formal policies in the workplace. This paper studies the division of jurisdictional control over prescribing between nurse specialists and medical specialists in the workplace, and examines the relationship between workplace jurisdiction and legal jurisdiction over prescribing. Data collection took place in the Netherlands during the first half of 2013. The study used in-depth interviews with fifteen nurse specialists and fourteen medical specialists, non-participant observation of nurse specialists' prescribing consultations and document analysis. Great variety was found in the extent to which and way in which nurse specialists' legal prescriptive authority had been implemented. These findings suggest that there is considerable discrepancy between the division of jurisdictional control over prescribing at the macro (legal) level and the division at the micro (workplace) level. Copyright © 2014 Elsevier Ltd. All rights reserved.

An Analysis of Plan Robustness for Esophageal Tumors: Comparing Volumetric Modulated Arc Therapy Plans and Spot Scanning Proton Planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warren, Samantha, E-mail: samantha.warren@oncology.ox.ac.uk; Partridge, Mike; Bolsi, Alessandra

Purpose: Planning studies to compare x-ray and proton techniques and to select the most suitable technique for each patient have been hampered by the nonequivalence of several aspects of treatment planning and delivery. A fair comparison should compare similarly advanced delivery techniques from current clinical practice and also assess the robustness of each technique. The present study therefore compared volumetric modulated arc therapy (VMAT) and single-field optimization (SFO) spot scanning proton therapy plans created using a simultaneous integrated boost (SIB) for dose escalation in midesophageal cancer and analyzed the effect of setup and range uncertainties on these plans. Methods andmore » Materials: For 21 patients, SIB plans with a physical dose prescription of 2 Gy or 2.5 Gy/fraction in 25 fractions to planning target volume (PTV){sub 50Gy} or PTV{sub 62.5Gy} (primary tumor with 0.5 cm margins) were created and evaluated for robustness to random setup errors and proton range errors. Dose–volume metrics were compared for the optimal and uncertainty plans, with P<.05 (Wilcoxon) considered significant. Results: SFO reduced the mean lung dose by 51.4% (range 35.1%-76.1%) and the mean heart dose by 40.9% (range 15.0%-57.4%) compared with VMAT. Proton plan robustness to a 3.5% range error was acceptable. For all patients, the clinical target volume D{sub 98} was 95.0% to 100.4% of the prescribed dose and gross tumor volume (GTV) D{sub 98} was 98.8% to 101%. Setup error robustness was patient anatomy dependent, and the potential minimum dose per fraction was always lower with SFO than with VMAT. The clinical target volume D{sub 98} was lower by 0.6% to 7.8% of the prescribed dose, and the GTV D{sub 98} was lower by 0.3% to 2.2% of the prescribed GTV dose. Conclusions: The SFO plans achieved significant sparing of normal tissue compared with the VMAT plans for midesophageal cancer. The target dose coverage in the SIB proton plans was less robust to random setup errors and might be unacceptable for certain patients. Robust optimization to ensure adequate target coverage of SIB proton plans might be beneficial.« less

An Analysis of Plan Robustness for Esophageal Tumors: Comparing Volumetric Modulated Arc Therapy Plans and Spot Scanning Proton Planning

PubMed Central

Warren, Samantha; Partridge, Mike; Bolsi, Alessandra; Lomax, Anthony J.; Hurt, Chris; Crosby, Thomas; Hawkins, Maria A.

2016-01-01

Purpose Planning studies to compare x-ray and proton techniques and to select the most suitable technique for each patient have been hampered by the nonequivalence of several aspects of treatment planning and delivery. A fair comparison should compare similarly advanced delivery techniques from current clinical practice and also assess the robustness of each technique. The present study therefore compared volumetric modulated arc therapy (VMAT) and single-field optimization (SFO) spot scanning proton therapy plans created using a simultaneous integrated boost (SIB) for dose escalation in midesophageal cancer and analyzed the effect of setup and range uncertainties on these plans. Methods and Materials For 21 patients, SIB plans with a physical dose prescription of 2 Gy or 2.5 Gy/fraction in 25 fractions to planning target volume (PTV)50Gy or PTV62.5Gy (primary tumor with 0.5 cm margins) were created and evaluated for robustness to random setup errors and proton range errors. Dose–volume metrics were compared for the optimal and uncertainty plans, with P<.05 (Wilcoxon) considered significant. Results SFO reduced the mean lung dose by 51.4% (range 35.1%-76.1%) and the mean heart dose by 40.9% (range 15.0%-57.4%) compared with VMAT. Proton plan robustness to a 3.5% range error was acceptable. For all patients, the clinical target volume D98 was 95.0% to 100.4% of the prescribed dose and gross tumor volume (GTV) D98 was 98.8% to 101%. Setup error robustness was patient anatomy dependent, and the potential minimum dose per fraction was always lower with SFO than with VMAT. The clinical target volume D98 was lower by 0.6% to 7.8% of the prescribed dose, and the GTV D98 was lower by 0.3% to 2.2% of the prescribed GTV dose. Conclusions The SFO plans achieved significant sparing of normal tissue compared with the VMAT plans for midesophageal cancer. The target dose coverage in the SIB proton plans was less robust to random setup errors and might be unacceptable for certain patients. Robust optimization to ensure adequate target coverage of SIB proton plans might be beneficial. PMID:27084641

An Analysis of Plan Robustness for Esophageal Tumors: Comparing Volumetric Modulated Arc Therapy Plans and Spot Scanning Proton Planning.

PubMed

Warren, Samantha; Partridge, Mike; Bolsi, Alessandra; Lomax, Anthony J; Hurt, Chris; Crosby, Thomas; Hawkins, Maria A

2016-05-01

Planning studies to compare x-ray and proton techniques and to select the most suitable technique for each patient have been hampered by the nonequivalence of several aspects of treatment planning and delivery. A fair comparison should compare similarly advanced delivery techniques from current clinical practice and also assess the robustness of each technique. The present study therefore compared volumetric modulated arc therapy (VMAT) and single-field optimization (SFO) spot scanning proton therapy plans created using a simultaneous integrated boost (SIB) for dose escalation in midesophageal cancer and analyzed the effect of setup and range uncertainties on these plans. For 21 patients, SIB plans with a physical dose prescription of 2 Gy or 2.5 Gy/fraction in 25 fractions to planning target volume (PTV)50Gy or PTV62.5Gy (primary tumor with 0.5 cm margins) were created and evaluated for robustness to random setup errors and proton range errors. Dose-volume metrics were compared for the optimal and uncertainty plans, with P<.05 (Wilcoxon) considered significant. SFO reduced the mean lung dose by 51.4% (range 35.1%-76.1%) and the mean heart dose by 40.9% (range 15.0%-57.4%) compared with VMAT. Proton plan robustness to a 3.5% range error was acceptable. For all patients, the clinical target volume D98 was 95.0% to 100.4% of the prescribed dose and gross tumor volume (GTV) D98 was 98.8% to 101%. Setup error robustness was patient anatomy dependent, and the potential minimum dose per fraction was always lower with SFO than with VMAT. The clinical target volume D98 was lower by 0.6% to 7.8% of the prescribed dose, and the GTV D98 was lower by 0.3% to 2.2% of the prescribed GTV dose. The SFO plans achieved significant sparing of normal tissue compared with the VMAT plans for midesophageal cancer. The target dose coverage in the SIB proton plans was less robust to random setup errors and might be unacceptable for certain patients. Robust optimization to ensure adequate target coverage of SIB proton plans might be beneficial. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Quality Control of High-Dose-Rate Brachytherapy: Treatment Delivery Analysis Using Statistical Process Control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Able, Charles M., E-mail: cable@wfubmc.edu; Bright, Megan; Frizzell, Bart

Purpose: Statistical process control (SPC) is a quality control method used to ensure that a process is well controlled and operates with little variation. This study determined whether SPC was a viable technique for evaluating the proper operation of a high-dose-rate (HDR) brachytherapy treatment delivery system. Methods and Materials: A surrogate prostate patient was developed using Vyse ordnance gelatin. A total of 10 metal oxide semiconductor field-effect transistors (MOSFETs) were placed from prostate base to apex. Computed tomography guidance was used to accurately position the first detector in each train at the base. The plan consisted of 12 needles withmore » 129 dwell positions delivering a prescribed peripheral dose of 200 cGy. Sixteen accurate treatment trials were delivered as planned. Subsequently, a number of treatments were delivered with errors introduced, including wrong patient, wrong source calibration, wrong connection sequence, single needle displaced inferiorly 5 mm, and entire implant displaced 2 mm and 4 mm inferiorly. Two process behavior charts (PBC), an individual and a moving range chart, were developed for each dosimeter location. Results: There were 4 false positives resulting from 160 measurements from 16 accurately delivered treatments. For the inaccurately delivered treatments, the PBC indicated that measurements made at the periphery and apex (regions of high-dose gradient) were much more sensitive to treatment delivery errors. All errors introduced were correctly identified by either the individual or the moving range PBC in the apex region. Measurements at the urethra and base were less sensitive to errors. Conclusions: SPC is a viable method for assessing the quality of HDR treatment delivery. Further development is necessary to determine the most effective dose sampling, to ensure reproducible evaluation of treatment delivery accuracy.« less

Inter- and Intrafraction Uncertainty in Prostate Bed Image-Guided Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Kitty; Palma, David A.; Department of Oncology, University of Western Ontario, London

2012-10-01

Purpose: The goals of this study were to measure inter- and intrafraction setup error and prostate bed motion (PBM) in patients undergoing post-prostatectomy image-guided radiotherapy (IGRT) and to propose appropriate population-based three-dimensional clinical target volume to planning target volume (CTV-PTV) margins in both non-IGRT and IGRT scenarios. Methods and Materials: In this prospective study, 14 patients underwent adjuvant or salvage radiotherapy to the prostate bed under image guidance using linac-based kilovoltage cone-beam CT (kV-CBCT). Inter- and intrafraction uncertainty/motion was assessed by offline analysis of three consecutive daily kV-CBCT images of each patient: (1) after initial setup to skin marks, (2)more » after correction for positional error/immediately before radiation treatment, and (3) immediately after treatment. Results: The magnitude of interfraction PBM was 2.1 mm, and intrafraction PBM was 0.4 mm. The maximum inter- and intrafraction prostate bed motion was primarily in the anterior-posterior direction. Margins of at least 3-5 mm with IGRT and 4-7 mm without IGRT (aligning to skin marks) will ensure 95% of the prescribed dose to the clinical target volume in 90% of patients. Conclusions: PBM is a predominant source of intrafraction error compared with setup error and has implications for appropriate PTV margins. Based on inter- and estimated intrafraction motion of the prostate bed using pre- and post-kV-CBCT images, CBCT IGRT to correct for day-to-day variances can potentially reduce CTV-PTV margins by 1-2 mm. CTV-PTV margins for prostate bed treatment in the IGRT and non-IGRT scenarios are proposed; however, in cases with more uncertainty of target delineation and image guidance accuracy, larger margins are recommended.« less

Propagation of angular errors in two-axis rotation systems

NASA Astrophysics Data System (ADS)

Torrington, Geoffrey K.

2003-10-01

Two-Axis Rotation Systems, or "goniometers," are used in diverse applications including telescope pointing, automotive headlamp testing, and display testing. There are three basic configurations in which a goniometer can be built depending on the orientation and order of the stages. Each configuration has a governing set of equations which convert motion between the system "native" coordinates to other base systems, such as direction cosines, optical field angles, or spherical-polar coordinates. In their simplest form, these equations neglect errors present in real systems. In this paper, a statistical treatment of error source propagation is developed which uses only tolerance data, such as can be obtained from the system mechanical drawings prior to fabrication. It is shown that certain error sources are fully correctable, partially correctable, or uncorrectable, depending upon the goniometer configuration and zeroing technique. The system error budget can be described by a root-sum-of-squares technique with weighting factors describing the sensitivity of each error source. This paper tabulates weighting factors at 67% (k=1) and 95% (k=2) confidence for various levels of maximum travel for each goniometer configuration. As a practical example, this paper works through an error budget used for the procurement of a system at Sandia National Laboratories.

Efficient detection of dangling pointer error for C/C++ programs

NASA Astrophysics Data System (ADS)

Zhang, Wenzhe

2017-08-01

Dangling pointer error is pervasive in C/C++ programs and it is very hard to detect. This paper introduces an efficient detector to detect dangling pointer error in C/C++ programs. By selectively leave some memory accesses unmonitored, our method could reduce the memory monitoring overhead and thus achieves better performance over previous methods. Experiments show that our method could achieve an average speed up of 9% over previous compiler instrumentation based method and more than 50% over previous page protection based method.

Enhancement of flow measurements using fluid-dynamic constraints

NASA Astrophysics Data System (ADS)

Egger, H.; Seitz, T.; Tropea, C.

2017-09-01

Novel experimental modalities acquire spatially resolved velocity measurements for steady state and transient flows which are of interest for engineering and biological applications. One of the drawbacks of such high resolution velocity data is their susceptibility to measurement errors. In this paper, we propose a novel filtering strategy that allows enhancement of the noisy measurements to obtain reconstruction of smooth divergence free velocity and corresponding pressure fields which together approximately comply to a prescribed flow model. The main step in our approach consists of the appropriate use of the velocity measurements in the design of a linearized flow model which can be shown to be well-posed and consistent with the true velocity and pressure fields up to measurement and modeling errors. The reconstruction procedure is then formulated as an optimal control problem for this linearized flow model. The resulting filter has analyzable smoothing and approximation properties. We briefly discuss the discretization of the approach by finite element methods and comment on the efficient solution by iterative methods. The capability of the proposed filter to significantly reduce data noise is demonstrated by numerical tests including the application to experimental data. In addition, we compare with other methods like smoothing and solenoidal filtering.

H∞ filter design for nonlinear systems with quantised measurements in finite frequency domain

NASA Astrophysics Data System (ADS)

El Hellani, D.; El Hajjaji, A.; Ceschi, R.

2017-04-01

This paper deals with the problem of finite frequency (FF) H∞ full-order fuzzy filter design for nonlinear discrete-time systems with quantised measurements, described by Takagi-Sugeno models. The measured signals are assumed to be quantised with a logarithmic quantiser. Using a fuzzy-basis-dependent Lyapunov function, the finite frequency ℓ2 gain definition, the generalised S-procedure, and Finsler's lemma, a set of sufficient conditions are established in terms of matrix inequalities, ensuring that the filtering error system is stable and the H∞ attenuation level, from disturbance to the estimation error, is smaller than a given value over a prescribed finite frequency domain of the external disturbances. With the aid of Finsler's lemma, a large number of slack variables are introduced to the design conditions, which provides extra degrees of freedom in optimising the guaranteed H∞ performance. This directly leads to performance improvement and reduction of conservatism. Finally, we give a simulation example to demonstrate the efficiency of the proposed design method, and we show that a lower H∞ attenuation level can be obtained by our developed approach in comparison with another result in the literature.

Commission errors of active intentions: the roles of aging, cognitive load, and practice.

PubMed

Boywitt, C Dennis; Rummel, Jan; Meiser, Thorsten

2015-01-01

Performing an intended action when it needs to be withheld, for example, when temporarily prescribed medication is incompatible with the other medication, is referred to as commission errors of prospective memory (PM). While recent research indicates that older adults are especially prone to commission errors for finished intentions, there is a lack of research on the effects of aging on commission errors for still active intentions. The present research investigates conditions which might contribute to older adults' propensity to perform planned intentions under inappropriate conditions. Specifically, disproportionally higher rates of commission errors for still active intentions were observed in older than in younger adults with both salient (Experiment 1) and non-salient (Experiment 2) target cues. Practicing the PM task in Experiment 2, however, helped execution of the intended action in terms of higher PM performance at faster ongoing-task response times but did not increase the rate of commission errors. The results have important implications for the understanding of older adults' PM commission errors and the processes involved in these errors.

Trends in antibiotic use and microbial diagnostics in periodontal treatment: comparing surveys of German dentists in a ten-year period.

PubMed

Falkenstein, Svenja; Stein, Jamal M; Henne, Karsten; Conrads, Georg

2016-11-01

The use of antibiotics and microbial tests in periodontal treatment among German dental practitioners was investigated in 2012-2013 and compared with 2002-2003 data. One thousand four hundred representative German practitioners received a postal questionnaire requesting their prescribing habits concerning type, dose, frequency, and sequence of antibiotics adjunctive to mechanical debridement. Additionally, the use of local antimicrobials and microbial tests were recorded. The response rate was 29.1 % (407 reports). Drug combinations, especially amoxicillin plus metronidazole, were prescribed most frequently (32.8 %) with an increase of 7.4 % during the past decade, followed by clindamycin (29.3 %). Amoxicillin monotherapy was used unexpectedly frequently (17.0 %) and doxycycline (2.8 %) very infrequently. Then, 24.7 % prescribed antibiotics prior to mechanical therapy, while most dentists followed the recommended sequence. The use of local antimicrobials increased by 6.2 % and of microbial diagnostics by 20.8 %. Positive trends regarding position-paper-conform prescribing habits including the scheduling of systemic antibiotics and increasing use of local antimicrobials and microbial tests were observed. However, deficits and malpractice still exist in German practices. Unexpected is the widespread and increasing use of clindamycin. Continuing educational campaigns and strictly expressed real guidelines are needed. Indication and choice of antibiotic agents in causal periodontal therapy among German dentists have changed between 2003 and 2013 toward a more position-paper-based concept, but inappropriate prescriptions of second choice antibiotics still remain conspicuous.

SAR System for UAV Operation with Motion Error Compensation beyond the Resolution Cell

PubMed Central

González-Partida, José-Tomás; Almorox-González, Pablo; Burgos-García, Mateo; Dorta-Naranjo, Blas-Pablo

2008-01-01

This paper presents an experimental Synthetic Aperture Radar (SAR) system that is under development in the Universidad Politécnica de Madrid. The system uses Linear Frequency Modulated Continuous Wave (LFM-CW) radar with a two antenna configuration for transmission and reception. The radar operates in the millimeter-wave band with a maximum transmitted bandwidth of 2 GHz. The proposed system is being developed for Unmanned Aerial Vehicle (UAV) operation. Motion errors in UAV operation can be critical. Therefore, this paper proposes a method for focusing SAR images with movement errors larger than the resolution cell. Typically, this problem is solved using two processing steps: first, coarse motion compensation based on the information provided by an Inertial Measuring Unit (IMU); and second, fine motion compensation for the residual errors within the resolution cell based on the received raw data. The proposed technique tries to focus the image without using data of an IMU. The method is based on a combination of the well known Phase Gradient Autofocus (PGA) for SAR imagery and typical algorithms for translational motion compensation on Inverse SAR (ISAR). This paper shows the first real experiments for obtaining high resolution SAR images using a car as a mobile platform for our radar. PMID:27879884

SAR System for UAV Operation with Motion Error Compensation beyond the Resolution Cell.

PubMed

González-Partida, José-Tomás; Almorox-González, Pablo; Burgos-Garcia, Mateo; Dorta-Naranjo, Blas-Pablo

2008-05-23

This paper presents an experimental Synthetic Aperture Radar (SAR) system that is under development in the Universidad Politécnica de Madrid. The system uses Linear Frequency Modulated Continuous Wave (LFM-CW) radar with a two antenna configuration for transmission and reception. The radar operates in the millimeter-wave band with a maximum transmitted bandwidth of 2 GHz. The proposed system is being developed for Unmanned Aerial Vehicle (UAV) operation. Motion errors in UAV operation can be critical. Therefore, this paper proposes a method for focusing SAR images with movement errors larger than the resolution cell. Typically, this problem is solved using two processing steps: first, coarse motion compensation based on the information provided by an Inertial Measuring Unit (IMU); and second, fine motion compensation for the residual errors within the resolution cell based on the received raw data. The proposed technique tries to focus the image without using data of an IMU. The method is based on a combination of the well known Phase Gradient Autofocus (PGA) for SAR imagery and typical algorithms for translational motion compensation on Inverse SAR (ISAR). This paper shows the first real experiments for obtaining high resolution SAR images using a car as a mobile platform for our radar.

Comprehensive Anti-error Study on Power Grid Dispatching Based on Regional Regulation and Integration

NASA Astrophysics Data System (ADS)

Zhang, Yunju; Chen, Zhongyi; Guo, Ming; Lin, Shunsheng; Yan, Yinyang

2018-01-01

With the large capacity of the power system, the development trend of the large unit and the high voltage, the scheduling operation is becoming more frequent and complicated, and the probability of operation error increases. This paper aims at the problem of the lack of anti-error function, single scheduling function and low working efficiency for technical support system in regional regulation and integration, the integrated construction of the error prevention of the integrated architecture of the system of dispatching anti - error of dispatching anti - error of power network based on cloud computing has been proposed. Integrated system of error prevention of Energy Management System, EMS, and Operation Management System, OMS have been constructed either. The system architecture has good scalability and adaptability, which can improve the computational efficiency, reduce the cost of system operation and maintenance, enhance the ability of regional regulation and anti-error checking with broad development prospects.

Improved Design of Stellarator Coils for Current Carrying Plasmas

NASA Astrophysics Data System (ADS)

Drevlak, M.; Strumberger, E.; Hirshman, S.; Boozer, A.; Brooks, A.; Valanju, P.

1998-11-01

The method of automatic optimization (P. Merkel, Nucl. Fus. 27), (1987) 867; P. Merkel, M. Drevlak, Proc 25th EPS Conf. on Cont. Fus. and Plas. Phys., Prague, in print. for the design of stellarator coils consists essentially of determining filaments such that the average relative field error int dS [ (B_coil + B_j) \\cdot n]^2/B^2_coil is minimized on the prescribed plasma boundary. Bj is the magnetic field produced by the plasma currents of the given finite β fixed boundary equilibrium. For equilibria of the W7-X type, Bj can be neglected, because of the reduced parallel plasma currents. This is not true for quasi-axisymmetric stellarator (QAS) configurations (A. Reiman, et al., to be published.) with large equilibrium and net plasma (bootstrap) currents. Although the coils for QAS exhibit low values of the field error, free boundary calculations indicate that the shape of the plasma is usually not accurately reproduced , particularly when saddle coils are used. We investigate if the surface reconstruction can be improved by introducing a modified measure of the field error based on a measure of the resonant components of the normal field.

Self-Powered Forward Error-Correcting Biosensor Based on Integration of Paper-Based Microfluidics and Self-Assembled Quick Response Codes.

PubMed

Yuan, Mingquan; Liu, Keng-Ku; Singamaneni, Srikanth; Chakrabartty, Shantanu

2016-10-01

This paper extends our previous work on silver-enhancement based self-assembling structures for designing reliable, self-powered biosensors with forward error correcting (FEC) capability. At the core of the proposed approach is the integration of paper-based microfluidics with quick response (QR) codes that can be optically scanned using a smart-phone. The scanned information is first decoded to obtain the location of a web-server which further processes the self-assembled QR image to determine the concentration of target analytes. The integration substrate for the proposed FEC biosensor is polyethylene and the patterning of the QR code on the substrate has been achieved using a combination of low-cost ink-jet printing and a regular ballpoint dispensing pen. A paper-based microfluidics channel has been integrated underneath the substrate for acquiring, mixing and flowing the sample to areas on the substrate where different parts of the code can self-assemble in presence of immobilized gold nanorods. In this paper we demonstrate the proof-of-concept detection using prototypes of QR encoded FEC biosensors.

A modified adjoint-based grid adaptation and error correction method for unstructured grid

NASA Astrophysics Data System (ADS)

Cui, Pengcheng; Li, Bin; Tang, Jing; Chen, Jiangtao; Deng, Youqi

2018-05-01

Grid adaptation is an important strategy to improve the accuracy of output functions (e.g. drag, lift, etc.) in computational fluid dynamics (CFD) analysis and design applications. This paper presents a modified robust grid adaptation and error correction method for reducing simulation errors in integral outputs. The procedure is based on discrete adjoint optimization theory in which the estimated global error of output functions can be directly related to the local residual error. According to this relationship, local residual error contribution can be used as an indicator in a grid adaptation strategy designed to generate refined grids for accurately estimating the output functions. This grid adaptation and error correction method is applied to subsonic and supersonic simulations around three-dimensional configurations. Numerical results demonstrate that the sensitive grids to output functions are detected and refined after grid adaptation, and the accuracy of output functions is obviously improved after error correction. The proposed grid adaptation and error correction method is shown to compare very favorably in terms of output accuracy and computational efficiency relative to the traditional featured-based grid adaptation.

Identifying medication error chains from critical incident reports: a new analytic approach.

PubMed

Huckels-Baumgart, Saskia; Manser, Tanja

2014-10-01

Research into the distribution of medication errors usually focuses on isolated stages within the medication use process. Our study aimed to provide a novel process-oriented approach to medication incident analysis focusing on medication error chains. Our study was conducted across a 900-bed teaching hospital in Switzerland. All reported 1,591 medication errors 2009-2012 were categorized using the Medication Error Index NCC MERP and the WHO Classification for Patient Safety Methodology. In order to identify medication error chains, each reported medication incident was allocated to the relevant stage of the hospital medication use process. Only 25.8% of the reported medication errors were detected before they propagated through the medication use process. The majority of medication errors (74.2%) formed an error chain encompassing two or more stages. The most frequent error chain comprised preparation up to and including medication administration (45.2%). "Non-consideration of documentation/prescribing" during the drug preparation was the most frequent contributor for "wrong dose" during the administration of medication. Medication error chains provide important insights for detecting and stopping medication errors before they reach the patient. Existing and new safety barriers need to be extended to interrupt error chains and to improve patient safety. © 2014, The American College of Clinical Pharmacology.

"Being In" and "Feeling Seen" in Professional Development as New Teachers: The Ontological Layer(ing) of Professional Development Practice

ERIC Educational Resources Information Center

Bills, Andrew M.; Giles, David; Rogers, Bev

2016-01-01

Dominant discourses on professional development for teachers internationally are increasingly geared to the priority of ensuring individual teachers are meeting prescribed standards-based performance benchmarks which we call "performativities" in this paper. While this intent is invariably played out in individualised performance…

Can a Competence or Standards Model Facilitate an Inclusive Approach to Teacher Education?

ERIC Educational Resources Information Center

Moran, Anne

2009-01-01

The paper seeks to determine whether programmes of initial teacher education (ITE) can contribute to the development of beginning teachers' inclusive attitudes, values and practices. The majority of ITE programmes are based on government prescribed competence or standards frameworks, which are underpinned by Codes of Professional Values. It is…

Active Learning through Online Quizzes: Better Learning and Less (Busy) Work

ERIC Educational Resources Information Center

Cook, Brian Robert; Babon, Andrea

2017-01-01

Active learning is increasingly promoted within institutions of higher education to assist students develop higher order thinking and link knowledge to meaning. In this paper, the authors evaluate the use of weekly online quizzes based on prescribed preparatory material as a tool to incentivize preparatory reading in order to enable and encourage…

A comparison of smartphones to paper-based questionnaires for routine influenza sentinel surveillance, Kenya, 2011-2012.

PubMed

Njuguna, Henry N; Caselton, Deborah L; Arunga, Geoffrey O; Emukule, Gideon O; Kinyanjui, Dennis K; Kalani, Rosalia M; Kinkade, Carl; Muthoka, Phillip M; Katz, Mark A; Mott, Joshua A

2014-12-24

For disease surveillance, manual data collection using paper-based questionnaires can be time consuming and prone to errors. We introduced smartphone data collection to replace paper-based data collection for an influenza sentinel surveillance system in four hospitals in Kenya. We compared the quality, cost and timeliness of data collection between the smartphone data collection system and the paper-based system. Since 2006, the Kenya Ministry of Health (MoH) with technical support from the Kenya Medical Research Institute/Centers for Disease Control and Prevention (KEMRI/CDC) conducted hospital-based sentinel surveillance for influenza in Kenya. In May 2011, the MOH replaced paper-based collection with an electronic data collection system using Field Adapted Survey Toolkit (FAST) on HTC Touch Pro2 smartphones at four sentinel sites. We compared 880 paper-based questionnaires dated Jan 2010-Jun 2011 and 880 smartphone questionnaires dated May 2011-Jun 2012 from the four surveillance sites. For each site, we compared the quality, cost and timeliness of each data collection system. Incomplete records were more likely seen in data collected using pen-and-paper compared to data collected using smartphones (adjusted incidence rate ratio (aIRR) 7, 95% CI: 4.4-10.3). Errors and inconsistent answers were also more likely to be seen in data collected using pen-and-paper compared to data collected using smartphones (aIRR: 25, 95% CI: 12.5-51.8). Smartphone data was uploaded into the database in a median time of 7 days while paper-based data took a median of 21 days to be entered (p < 0.01). It cost USD 1,501 (9.4%) more to establish the smartphone data collection system ($17,500) than the pen-and-paper system (USD $15,999). During two years, however, the smartphone data collection system was $3,801 (7%) less expensive to operate ($50,200) when compared to pen-and-paper system ($54,001). Compared to paper-based data collection, an electronic data collection system produced fewer incomplete data, fewer errors and inconsistent responses and delivered data faster. Although start-up costs were higher, the overall costs of establishing and running the electronic data collection system were lower compared to paper-based data collection system. Electronic data collection using smartphones has potential to improve timeliness, data integrity and reduce costs.

Evaluation of Infrared Target Discrimination Algorithms.

DTIC Science & Technology

1983-04-01

application of this work is embodied in a computer program called PALANTIR , which Ref. 2 also describes in some detail. From a given set of narrow band spectral...chan- nels PALANTIR chooses a prescribed number of channels, picking those that will provide the least error when used in connection with a minimum

Dental negligence.

PubMed

Tay, C S

2000-02-01

Medical and dental errors and negligence are again in the spotlight in recent news report. Dead because of doctor's bad handwriting Prescribing drug overdoses Germ-infested soap pumps--infections in hospitals This articles explains dental negligence including dental duty of care and the standard of care expected of dentists in relation to the Bolam principle.

77 FR 42419 - Airworthiness Directives; Honeywell International, Inc. Global Navigation Satellite Sensor Units

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-19

... following methods: Federal eRulemaking Portal: Go to http://www.regulations.gov . Follow the instructions... software problem is due to a mathematical rounding error, which results in misleading information. At this... air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds...

Assessment of legibility and completeness of handwritten and electronic prescriptions

PubMed Central

Albarrak, Ahmed I; Al Rashidi, Eman Abdulrahman; Fatani, Rwaa Kamil; Al Ageel, Shoog Ibrahim; Mohammed, Rafiuddin

2014-01-01

Objectives To assess the legibility and completeness of handwritten prescriptions and compare with electronic prescription system for medication errors. Design Prospective study. Setting King Khalid University Hospital (KKUH), Riyadh, Saudi Arabia. Subjects and methods Handwritten prescriptions were received from clinical units of Medicine Outpatient Department (MOPD), Primary Care Clinic (PCC) and Surgery Outpatient Department (SOPD) whereas electronic prescriptions were collected from the pediatric ward. The handwritten prescription was assessed for completeness by the checklist designed according to the hospital prescription and evaluated for legibility by two pharmacists. The comparison between handwritten and electronic prescription errors was evaluated based on the validated checklist adopted from previous studies. Main outcome measures Legibility and completeness of prescriptions. Results 398 prescriptions (199 handwritten and 199 e-prescriptions) were assessed. About 71 (35.7%) of handwritten and 5 (2.5%) of electronic prescription errors were identified. A significant statistical difference (P < 0.001) was observed between handwritten and e-prescriptions in omitted dose and omitted route of administration category of error distribution. The rate of completeness in patient identification in handwritten prescriptions was 80.97% in MOPD, 76.36% in PCC and 85.93% in SOPD clinic units. Assessment of medication prescription completeness was 91.48% in MOPD, 88.48% in PCC, and 89.28% in SOPD. Conclusions This study revealed a high incidence of prescribing errors in handwritten prescriptions. The use of e-prescription system showed a significant decline in the incidence of errors. The legibility of handwritten prescriptions was relatively good whereas the level of completeness was very low. PMID:25561864

A Comparison of Three Methods for Computing Scale Score Conditional Standard Errors of Measurement. ACT Research Report Series, 2013 (7)

ERIC Educational Resources Information Center

Woodruff, David; Traynor, Anne; Cui, Zhongmin; Fang, Yu

2013-01-01

Professional standards for educational testing recommend that both the overall standard error of measurement and the conditional standard error of measurement (CSEM) be computed on the score scale used to report scores to examinees. Several methods have been developed to compute scale score CSEMs. This paper compares three methods, based on…

Automated quality checks on repeat prescribing.

PubMed Central

Rogers, Jeremy E; Wroe, Christopher J; Roberts, Angus; Swallow, Angela; Stables, David; Cantrill, Judith A; Rector, Alan L

2003-01-01

BACKGROUND: Good clinical practice in primary care includes periodic review of repeat prescriptions. Markers of prescriptions that may need review have been described, but manually checking all repeat prescriptions against the markers would be impractical. AIM: To investigate the feasibility of computerising the application of repeat prescribing quality checks to electronic patient records in United Kingdom (UK) primary care. DESIGN OF STUDY: Software performance test against benchmark manual analysis of cross-sectional convenience sample of prescribing documentation. SETTING: Three general practices in Greater Manchester, in the north west of England, during a 4-month period in 2001. METHOD: A machine-readable drug information resource, based on the British National Formulary (BNF) as the 'gold standard' for valid drug indications, was installed in three practices. Software raised alerts for each repeat prescribed item where the electronic patient record contained no valid indication for the medication. Alerts raised by the software in two practices were analysed manually. Clinical reaction to the software was assessed by semi-structured interviews in three practices. RESULTS: There was no valid indication in the electronic medical records for 14.8% of repeat prescribed items. Sixty-two per cent of all alerts generated were incorrect. Forty-three per cent of all incorrect alerts were as a result of errors in the drug information resource, 44% to locally idiosyncratic clinical coding, 8% to the use of the BNF without adaptation as a gold standard, and 5% to the inability of the system to infer diagnoses that, although unrecorded, would be 'obvious' to a clinical reading the record. The interviewed clinicians supported the goals of the software. CONCLUSION: Using electronic records for secondary decision support purposes will benefit from (and may require) both more consistent electronic clinical data collection across multiple sites, and reconciling clinicians' willingness to infer unstated but 'obvious' diagnoses with the machine's inability to do the same. PMID:14702902

Online machining error estimation method of numerical control gear grinding machine tool based on data analysis of internal sensors

NASA Astrophysics Data System (ADS)

Zhao, Fei; Zhang, Chi; Yang, Guilin; Chen, Chinyin

2016-12-01

This paper presents an online estimation method of cutting error by analyzing of internal sensor readings. The internal sensors of numerical control (NC) machine tool are selected to avoid installation problem. The estimation mathematic model of cutting error was proposed to compute the relative position of cutting point and tool center point (TCP) from internal sensor readings based on cutting theory of gear. In order to verify the effectiveness of the proposed model, it was simulated and experimented in gear generating grinding process. The cutting error of gear was estimated and the factors which induce cutting error were analyzed. The simulation and experiments verify that the proposed approach is an efficient way to estimate the cutting error of work-piece during machining process.

Gaming against medical errors: methods and results from a design game on CPOE.

PubMed

Kanstrup, Anne Marie; Nøhr, Christian

2009-01-01

The paper presents design game as a technique for participatory design for a Computerized Decision Support System (CDSS) for minimizing medical errors. Design game is used as a technique for working with the skills of users, the complexity of the use practice and the negotiation of design here within the challenging domain of medication. The paper presents a developed design game based on game inspiration from a computer game, theoretical inspiration on electronic decision support, and empirical grounding in scenarios of medical errors. The game has been played in a two-hour workshop with six clinicians. The result is presented as a list of central themes for design of CDSS and derived design principles from these themes. These principles are currently under further exploration in follow up prototype based activities.

Mapping the absolute magnetic field and evaluating the quadratic Zeeman-effect-induced systematic error in an atom interferometer gravimeter

NASA Astrophysics Data System (ADS)

Hu, Qing-Qing; Freier, Christian; Leykauf, Bastian; Schkolnik, Vladimir; Yang, Jun; Krutzik, Markus; Peters, Achim

2017-09-01

Precisely evaluating the systematic error induced by the quadratic Zeeman effect is important for developing atom interferometer gravimeters aiming at an accuracy in the μ Gal regime (1 μ Gal =10-8m /s2 ≈10-9g ). This paper reports on the experimental investigation of Raman spectroscopy-based magnetic field measurements and the evaluation of the systematic error in the gravimetric atom interferometer (GAIN) due to quadratic Zeeman effect. We discuss Raman duration and frequency step-size-dependent magnetic field measurement uncertainty, present vector light shift and tensor light shift induced magnetic field measurement offset, and map the absolute magnetic field inside the interferometer chamber of GAIN with an uncertainty of 0.72 nT and a spatial resolution of 12.8 mm. We evaluate the quadratic Zeeman-effect-induced gravity measurement error in GAIN as 2.04 μ Gal . The methods shown in this paper are important for precisely mapping the absolute magnetic field in vacuum and reducing the quadratic Zeeman-effect-induced systematic error in Raman transition-based precision measurements, such as atomic interferometer gravimeters.

Synchronization of multiple 3-DOF helicopters under actuator faults and saturations with prescribed performance.

PubMed

Yang, Huiliao; Jiang, Bin; Yang, Hao; Liu, Hugh H T

2018-04-01

The distributed cooperative control strategy is proposed to make the networked nonlinear 3-DOF helicopters achieve the attitude synchronization in the presence of actuator faults and saturations. Based on robust adaptive control, the proposed control method can both compensate the uncertain partial loss of control effectiveness and deal with the system uncertainties. To address actuator saturation problem, the control scheme is designed to ensure that the saturation constraint on the actuation will not be violated during the operation in spite of the actuator faults. It is shown that with the proposed control strategy, both the tracking errors of the leading helicopter and the attitude synchronization errors of each following helicopter are bounded in the existence of faulty actuators and actuator saturations. Moreover, the state responses of the entire group would not exceed the predesigned performance functions which are totally independent from the underlaying interaction topology. Simulation results illustrate the effectiveness of the proposed control scheme. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Electronic Prescribing and Medication Management at a Residential Aged Care Facility: Uptake by General Practitioners and Qualitative Evaluation of the Benefits and Barriers.

PubMed

Elliott, Rohan A; Lee, Cik Yin; Hussainy, Safeera Y

2016-01-01

A cloud-based mobile electronic prescribing and medication management system (ePMMS), in which prescribers' orders directly populate residential aged care facility (RACF) medication administration records (MARs) and are communicated electronically to the RACF's pharmacy, may create efficiencies and improve patient safety when compared to the paper-based and hybrid paper-electronic medication management systems used in most Australian RACFs. Little is known about general-practitioners' (GPs'), nurses' and pharmacists' acceptance of, or experiences with, ePMMS. To explore the uptake of an ePMMS by GPs, and the experiences and perceptions of GPs, nurses and pharmacists, at a 90-bed RACF that tested a beta-version ePMMS. Retrospective audit to determine the proportion of medicines ordered by GPs via the ePMMS over a three-month period. Focus groups conducted three-to-four months after implementation: one with GPs (n=5), one with nurses (n=12); in-depth interview/survey of pharmacists (n=2). Qualitative data were analysed thematically. Three of seven GPs used the ePMMS to order medicines; 53/205(25.9%) medicines were ordered via the ePMMS by GPs. Two broad themes were identified: benefits of the ePMMS, and barriers/limitations. Benefits related to patient safety and workforce efficiency, and included GPs' ability to access and modify residents' MARs remotely, no need for nurses to fax orders to the pharmacy, and no need for pharmacy transcription of GPs' handwritten orders to create electronic MARs. Barriers and limitations related to inefficiency, low GP uptake and training/support, and included slower prescribing compared to written orders, the need for GP-signed paper copies of the MAR, lack of integration with GP clinic software, and low GP motivation to use the system, especially GPs with few patients at the RACF. GPs, nurses and pharmacists felt the ePMMS improved medication-safety and workforce-efficiency, however a number of barriers were identified that contributed to low GP-uptake and limited the benefits.

Local concurrent error detection and correction in data structures using virtual backpointers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, C.C.J.; Chen, P.P.; Fuchs, W.K.

1989-11-01

A new technique, based on virtual backpointers, is presented in this paper for local concurrent error detection and correction in linked data structures. Two new data structures utilizing virtual backpointers, the Virtual Double-Linked List and the B-Tree and Virtual Backpointers, are described. For these structures, double errors within a fixed-size checking window can be detected in constant time and single errors detected during forward moves can be corrected in constant time.

Waterjet and laser etching: the nonlinear inverse problem

NASA Astrophysics Data System (ADS)

Bilbao-Guillerna, A.; Axinte, D. A.; Billingham, J.; Cadot, G. B. J.

2017-07-01

In waterjet and laser milling, material is removed from a solid surface in a succession of layers to create a new shape, in a depth-controlled manner. The inverse problem consists of defining the control parameters, in particular, the two-dimensional beam path, to arrive at a prescribed freeform surface. Waterjet milling (WJM) and pulsed laser ablation (PLA) are studied in this paper, since a generic nonlinear material removal model is appropriate for both of these processes. The inverse problem is usually solved for this kind of process by simply controlling dwell time in proportion to the required depth of milling at a sequence of pixels on the surface. However, this approach is only valid when shallow surfaces are etched, since it does not take into account either the footprint of the beam or its overlapping on successive passes. A discrete adjoint algorithm is proposed in this paper to improve the solution. Nonlinear effects and non-straight passes are included in the optimization, while the calculation of the Jacobian matrix does not require large computation times. Several tests are performed to validate the proposed method and the results show that tracking error is reduced typically by a factor of two in comparison to the pixel-by-pixel approach and the classical raster path strategy with straight passes. The tracking error can be as low as 2-5% and 1-2% for WJM and PLA, respectively, depending on the complexity of the target surface.

Methods for Addressing Technology-induced Errors: The Current State.

PubMed

Borycki, E; Dexheimer, J W; Hullin Lucay Cossio, C; Gong, Y; Jensen, S; Kaipio, J; Kennebeck, S; Kirkendall, E; Kushniruk, A W; Kuziemsky, C; Marcilly, R; Röhrig, R; Saranto, K; Senathirajah, Y; Weber, J; Takeda, H

2016-11-10

The objectives of this paper are to review and discuss the methods that are being used internationally to report on, mitigate, and eliminate technology-induced errors. The IMIA Working Group for Health Informatics for Patient Safety worked together to review and synthesize some of the main methods and approaches associated with technology- induced error reporting, reduction, and mitigation. The work involved a review of the evidence-based literature as well as guideline publications specific to health informatics. The paper presents a rich overview of current approaches, issues, and methods associated with: (1) safe HIT design, (2) safe HIT implementation, (3) reporting on technology-induced errors, (4) technology-induced error analysis, and (5) health information technology (HIT) risk management. The work is based on research from around the world. Internationally, researchers have been developing methods that can be used to identify, report on, mitigate, and eliminate technology-induced errors. Although there remain issues and challenges associated with the methodologies, they have been shown to improve the quality and safety of HIT. Since the first publications documenting technology-induced errors in healthcare in 2005, we have seen in a short 10 years researchers develop ways of identifying and addressing these types of errors. We have also seen organizations begin to use these approaches. Knowledge has been translated into practice in a short ten years whereas the norm for other research areas is of 20 years.

Early Career Teachers' Ability to Focus on Typical Students Errors in Relation to the Complexity of a Mathematical Topic

ERIC Educational Resources Information Center

Pankow, Lena; Kaiser, Gabriele; Busse, Andreas; König, Johannes; Blömeke, Sigrid; Hoth, Jessica; Döhrmann, Martina

2016-01-01

The paper presents results from a computer-based assessment in which 171 early career mathematics teachers from Germany were asked to anticipate typical student errors on a given mathematical topic and identify them under time constraints. Fast and accurate perception and knowledge-based judgments are widely accepted characteristics of teacher…

On the Energy Efficiency of On-Off Keying Transmitters with Two Distinct Types of Batteries.

PubMed

Shen, Tingting; Wang, Tao; Sun, Yanzan; Wu, Yating; Jin, Yanliang

2018-04-23

As nodes in wireless sensor networks are usually powered by nonrenewable batteries, energy efficient design becomes critical. This paper considers a battery-powered transmitter using on-off keying (OOK) modulation and studies its energy efficiency in terms of the battery’s energy consumption for per bit transmission (BECPB). In particular, the transmitter may use one of two distinct types of batteries with battery utilization factor (BUF) depending on discharge current. The first has an instantaneous discharge current (IDC)-based BUF, while the second has a mean discharge current (MDC)-based BUF. For each type of battery, a closed-form BECPB expression is derived under a Rayleigh channel when a prescribed symbol error rate (SER) is guaranteed. Then theoretical analysis is made to study the impact of battery characteristic parameter γ , communication distance d and bandwidth B on the BECPB. Finally, the analysis is corroborated by numerical experimental results, which reveal that: the BECPB for each type of battery increases with γ and d ; the BECPB for the two batteries first decreases and then increases with B , and there exists the optimal bandwidth corresponding to the minimum BECPB; the battery with IDC-based BUF corresponds to a larger BECPB. When γ and d are large, the BECPB for each type of battery is significantly higher than that for the ideal battery whose BUF is aways 1. For instance, when γ = 0.015 , d = 90 m and B = 10 kHz, the BECPB for IDC-based and MDC-based battery is nearly 60% amd 25% higher than that of the ideal battery, respectively.

On the Energy Efficiency of On-Off Keying Transmitters with Two Distinct Types of Batteries

PubMed Central

Shen, Tingting; Wang, Tao; Sun, Yanzan; Wu, Yating; Jin, Yanliang

2018-01-01

As nodes in wireless sensor networks are usually powered by nonrenewable batteries, energy efficient design becomes critical. This paper considers a battery-powered transmitter using on-off keying (OOK) modulation and studies its energy efficiency in terms of the battery’s energy consumption for per bit transmission (BECPB). In particular, the transmitter may use one of two distinct types of batteries with battery utilization factor (BUF) depending on discharge current. The first has an instantaneous discharge current (IDC)-based BUF, while the second has a mean discharge current (MDC)-based BUF. For each type of battery, a closed-form BECPB expression is derived under a Rayleigh channel when a prescribed symbol error rate (SER) is guaranteed. Then theoretical analysis is made to study the impact of battery characteristic parameter γ, communication distance d and bandwidth B on the BECPB. Finally, the analysis is corroborated by numerical experimental results, which reveal that: the BECPB for each type of battery increases with γ and d; the BECPB for the two batteries first decreases and then increases with B, and there exists the optimal bandwidth corresponding to the minimum BECPB; the battery with IDC-based BUF corresponds to a larger BECPB. When γ and d are large, the BECPB for each type of battery is significantly higher than that for the ideal battery whose BUF is aways 1. For instance, when γ=0.015, d=90 m and B=10 kHz, the BECPB for IDC-based and MDC-based battery is nearly 60% amd 25% higher than that of the ideal battery, respectively. PMID:29690609

Evaluation of students' knowledge about paediatric dosage calculations.

PubMed

Özyazıcıoğlu, Nurcan; Aydın, Ayla İrem; Sürenler, Semra; Çinar, Hava Gökdere; Yılmaz, Dilek; Arkan, Burcu; Tunç, Gülseren Çıtak

2018-01-01

Medication errors are common and may jeopardize the patient safety. As paediatric dosages are calculated based on the child's age and weight, risk of error in dosage calculations is increasing. In paediatric patients, overdose drug prescribed regardless of the child's weight, age and clinical picture may lead to excessive toxicity and mortalities while low doses may delay the treatment. This study was carried out to evaluate the knowledge of nursing students about paediatric dosage calculations. This research, which is of retrospective type, covers a population consisting of all the 3rd grade students at the bachelor's degree in May, 2015 (148 students). Drug dose calculation questions in exam papers including 3 open ended questions on dosage calculation problems, addressing 5 variables were distributed to the students and their responses were evaluated by the researchers. In the evaluation of the data, figures and percentage distribution were calculated and Spearman correlation analysis was applied. Exam question on the dosage calculation based on child's age, which is the most common method in paediatrics, and which ensures right dosages and drug dilution was answered correctly by 87.1% of the students while 9.5% answered it wrong and 3.4% left it blank. 69.6% of the students was successful in finding the safe dose range, and 79.1% in finding the right ratio/proportion. 65.5% of the answers with regard to Ml/dzy calculation were correct. Moreover, student's four operation skills were assessed and 68.2% of the students were determined to have found the correct answer. When the relation among the questions on medication was examined, a significant relation (correlation) was determined between them. It is seen that in dosage calculations, the students failed mostly in calculating ml/dzy (decimal). This result means that as dosage calculations are based on decimal values, calculations may be ten times erroneous when the decimal point is placed wrongly. Moreover, it is also seen that students lack maths knowledge in respect of four operations and calculating safe dose range. Relations among the medications suggest that a student wrongly calculating a dosage may also make other errors. Additional courses, exercises or utilisation of different teaching techniques may be suggested to eliminate the deficiencies in terms of basic maths knowledge, problem solving skills and correct dosage calculation of the students. Copyright © 2017 Elsevier Ltd. All rights reserved.

Examining the accuracy of foodservice in a hospital setting.

PubMed

Glover, N S; Keane, T M

1984-09-01

Although a great deal of research has been conducted to determine the appropriate diets for the prevention and treatment of various illnesses, there is very little in the literature about research that directly assesses the accuracy of the prescribed diets served to patients in a hospital setting. The present study was designed to evaluate the accuracy of meals served to patients by identifying critical errors and more general errors on trays about to be served. The results indicated that the error rate was greater on weekends and holidays than during the week. Significantly, a correlational analysis revealed that error rate was inversely related to the total number of foodservice supervisors and more specifically to the number of food production supervisors and registered dietitians present. The implications of the results for possible interventions and training are discussed.

Use of an OSSE to Evaluate Background Error Covariances Estimated by the 'NMC Method'

NASA Technical Reports Server (NTRS)

Errico, Ronald M.; Prive, Nikki C.; Gu, Wei

2014-01-01

The NMC method has proven utility for prescribing approximate background-error covariances required by variational data assimilation systems. Here, untunedNMCmethod estimates are compared with explicitly determined error covariances produced within an OSSE context by exploiting availability of the true simulated states. Such a comparison provides insights into what kind of rescaling is required to render the NMC method estimates usable. It is shown that rescaling of variances and directional correlation lengths depends greatly on both pressure and latitude. In particular, some scaling coefficients appropriate in the Tropics are the reciprocal of those in the Extratropics. Also, the degree of dynamic balance is grossly overestimated by the NMC method. These results agree with previous examinations of the NMC method which used ensembles as an alternative for estimating background-error statistics.

A new retrieval algorithm for tropospheric temperature, humidity and pressure profiling based on GNSS radio occultation data

NASA Astrophysics Data System (ADS)

Kirchengast, Gottfried; Li, Ying; Scherllin-Pirscher, Barbara; Schwärz, Marc; Schwarz, Jakob; Nielsen, Johannes K.

2017-04-01

The GNSS radio occultation (RO) technique is an important remote sensing technique for obtaining thermodynamic profiles of temperature, humidity, and pressure in the Earth's troposphere. However, due to refraction effects of both dry ambient air and water vapor in the troposphere, retrieval of accurate thermodynamic profiles at these lower altitudes is challenging and requires suitable background information in addition to the RO refractivity information. Here we introduce a new moist air retrieval algorithm aiming to improve the quality and robustness of retrieving temperature, humidity and pressure profiles in moist air tropospheric conditions. The new algorithm consists of four steps: (1) use of prescribed specific humidity and its uncertainty to retrieve temperature and its associated uncertainty; (2) use of prescribed temperature and its uncertainty to retrieve specific humidity and its associated uncertainty; (3) use of the previous results to estimate final temperature and specific humidity profiles through optimal estimation; (4) determination of air pressure and density profiles from the results obtained before. The new algorithm does not require elaborated matrix inversions which are otherwise widely used in 1D-Var retrieval algorithms, and it allows a transparent uncertainty propagation, whereby the uncertainties of prescribed variables are dynamically estimated accounting for their spatial and temporal variations. Estimated random uncertainties are calculated by constructing error covariance matrices from co-located ECMWF short-range forecast and corresponding analysis profiles. Systematic uncertainties are estimated by empirical modeling. The influence of regarding or disregarding vertical error correlations is quantified. The new scheme is implemented with static input uncertainty profiles in WEGC's current OPSv5.6 processing system and with full scope in WEGC's next-generation system, the Reference Occultation Processing System (rOPS). Results from both WEGC systems, current OPSv5.6 and next-generation rOPS, are shown and discussed, based on both insights from individual profiles and statistical ensembles, and compared to moist air retrieval results from the UCAR Boulder and ROM-SAF Copenhagen centers. The results show that the new algorithmic scheme improves the temperature, humidity and pressure retrieval performance, in particular also the robustness including for integrated uncertainty estimation for large-scale applications, over the previous algorithms. The new rOPS-implemented algorithm will therefore be used in the first large-scale reprocessing towards a tropospheric climate data record 2001-2016 by the rOPS, including its integrated uncertainty propagation.

Risk of road accident associated with the use of drugs: a systematic review and meta-analysis of evidence from epidemiological studies.

PubMed

Elvik, Rune

2013-11-01

This paper is a corrigendum to a previously published paper where errors were detected. The errors have been corrected in this paper. The paper is otherwise identical to the previously published paper. A systematic review and meta-analysis of studies that have assessed the risk of accident associated with the use of drugs when driving is presented. The meta-analysis included 66 studies containing a total of 264 estimates of the effects on accident risk of using illicit or prescribed drugs when driving. Summary estimates of the odds ratio of accident involvement are presented for amphetamines, analgesics, anti-asthmatics, anti-depressives, anti-histamines, benzodiazepines, cannabis, cocaine, opiates, penicillin and zopiclone (a sleeping pill). For most of the drugs, small or moderate increases in accident risk associated with the use of the drugs were found. Information about whether the drugs were actually used while driving and about the doses used was often imprecise. Most studies that have evaluated the presence of a dose-response relationship between the dose of drugs taken and the effects on accident risk confirm the existence of a dose-response relationship. Use of drugs while driving tends to have a larger effect on the risk of fatal and serious injury accidents than on the risk of less serious accidents (usually property-damage-only accidents). The quality of the studies that have assessed risk varied greatly. There was a tendency for the estimated effects of drug use on accident risk to be smaller in well-controlled studies than in poorly controlled studies. Evidence of publication bias was found for some drugs. The associations found cannot be interpreted as causal relationships, principally because most studies do not control very well for potentially confounding factors. Copyright © 2012 Elsevier Ltd. All rights reserved.

What do Australian consumers, pharmacists and prescribers think about documenting indications on prescriptions and dispensed medicines labels?: A qualitative study.

PubMed

Garada, Mona; McLachlan, Andrew J; Schiff, Gordon D; Lehnbom, Elin C

2017-11-15

Documenting the indication on prescriptions and dispensed medicines labels is not standard practice in Australia. However, previous studies that have focused on the content and design of dispensed medicines labels, have suggested including the indication as a safety measure. The aim of this study was to investigate the perspectives of Australian consumers, pharmacists and prescribers on documenting the indication on prescriptions and dispensed medicines labels. Semi-structured interviews were conducted and mock-up of dispensed medicines labels were designed for participants. Consumers (n = 19) and pharmacists (n = 7) were recruited by convenience sample at community pharmacies in Sydney (Australia) and prescribers (n = 8), including two medical students, were recruited through snowballing. Thirty-four participants were interviewed. Most participants agreed that documenting the indication would be beneficial especially for patients who are forgetful or take multiple medications. Participants also believed it would improve consumers' medication understanding and adherence. Prescribers and pharmacists believed it could help reduce prescribing and dispensing errors by matching the drug/dosage to the correct indication. Prescribers refrained from documenting the indication to protect patients' privacy; however, most patients did not consider documenting the indication as a breach of privacy. Prescribers raised concerns about the extra time to include indications on prescriptions and best language to document indications, using plain language as opposed to medical terminology. All interviewed stakeholders identified numerous benefits of documenting the indication on prescriptions and dispensed medicines labels. Whether these potential benefits can be realized remains unknown and addressing prescribers' concern regarding the time involved in documenting the indication on prescriptions remains a challenge for vendors of electronic medication management systems.

Particle Filter with Novel Nonlinear Error Model for Miniature Gyroscope-Based Measurement While Drilling Navigation

PubMed Central

Li, Tao; Yuan, Gannan; Li, Wang

2016-01-01

The derivation of a conventional error model for the miniature gyroscope-based measurement while drilling (MGWD) system is based on the assumption that the errors of attitude are small enough so that the direction cosine matrix (DCM) can be approximated or simplified by the errors of small-angle attitude. However, the simplification of the DCM would introduce errors to the navigation solutions of the MGWD system if the initial alignment cannot provide precise attitude, especially for the low-cost microelectromechanical system (MEMS) sensors operated in harsh multilateral horizontal downhole drilling environments. This paper proposes a novel nonlinear error model (NNEM) by the introduction of the error of DCM, and the NNEM can reduce the propagated errors under large-angle attitude error conditions. The zero velocity and zero position are the reference points and the innovations in the states estimation of particle filter (PF) and Kalman filter (KF). The experimental results illustrate that the performance of PF is better than KF and the PF with NNEM can effectively restrain the errors of system states, especially for the azimuth, velocity, and height in the quasi-stationary condition. PMID:26999130

Particle Filter with Novel Nonlinear Error Model for Miniature Gyroscope-Based Measurement While Drilling Navigation.

PubMed

Li, Tao; Yuan, Gannan; Li, Wang

2016-03-15

The derivation of a conventional error model for the miniature gyroscope-based measurement while drilling (MGWD) system is based on the assumption that the errors of attitude are small enough so that the direction cosine matrix (DCM) can be approximated or simplified by the errors of small-angle attitude. However, the simplification of the DCM would introduce errors to the navigation solutions of the MGWD system if the initial alignment cannot provide precise attitude, especially for the low-cost microelectromechanical system (MEMS) sensors operated in harsh multilateral horizontal downhole drilling environments. This paper proposes a novel nonlinear error model (NNEM) by the introduction of the error of DCM, and the NNEM can reduce the propagated errors under large-angle attitude error conditions. The zero velocity and zero position are the reference points and the innovations in the states estimation of particle filter (PF) and Kalman filter (KF). The experimental results illustrate that the performance of PF is better than KF and the PF with NNEM can effectively restrain the errors of system states, especially for the azimuth, velocity, and height in the quasi-stationary condition.

Information therapy: The strategic role of prescribed information in disease self-management.

PubMed

Mettler, Molly; Kemper, Donald W

2006-01-01

Imagine this: evidence-based medical information specifically written for and prescribed to a patient with chronic illness, targeted to that patient's specific "moment in care" and designed to help that patient manage his or her illness. Imagine "information therapy" built into every clinical encounter that a patient has with a physician or other health care service. Information therapy is defined as the timely prescription and availability of evidence-based health information to meet individuals' specific needs and support sound decision making. Information therapy is a new disease management tool that provides cost-effective disease management support to a much larger portion of the chronically ill population than is generally reached. This paper is a practical presentation of information therapy, its role in predictive modeling and disease self-management, and its potential for improving the outcomes of chronic care.

Reduction of low frequency error for SED36 and APS based HYDRA star trackers

NASA Astrophysics Data System (ADS)

Ouaknine, Julien; Blarre, Ludovic; Oddos-Marcel, Lionel; Montel, Johan; Julio, Jean-Marc

2017-11-01

In the frame of the CNES Pleiades satellite, a reduction of the star tracker low frequency error, which is the most penalizing error for the satellite attitude control, was performed. For that purpose, the SED36 star tracker was developed, with a design based on the flight qualified SED16/26. In this paper, the SED36 main features will be first presented. Then, the reduction process of the low frequency error will be developed, particularly the optimization of the optical distortion calibration. The result is an attitude low frequency error of 1.1" at 3 sigma along transverse axes. The implementation of these improvements to HYDRA, the new multi-head APS star tracker developed by SODERN, will finally be presented.

Estimating Bias Error Distributions

NASA Technical Reports Server (NTRS)

Liu, Tian-Shu; Finley, Tom D.

2001-01-01

This paper formulates the general methodology for estimating the bias error distribution of a device in a measuring domain from less accurate measurements when a minimal number of standard values (typically two values) are available. A new perspective is that the bias error distribution can be found as a solution of an intrinsic functional equation in a domain. Based on this theory, the scaling- and translation-based methods for determining the bias error distribution arc developed. These methods are virtually applicable to any device as long as the bias error distribution of the device can be sufficiently described by a power series (a polynomial) or a Fourier series in a domain. These methods have been validated through computational simulations and laboratory calibration experiments for a number of different devices.

Airborne data measurement system errors reduction through state estimation and control optimization

NASA Astrophysics Data System (ADS)

Sebryakov, G. G.; Muzhichek, S. M.; Pavlov, V. I.; Ermolin, O. V.; Skrinnikov, A. A.

2018-02-01

The paper discusses the problem of airborne data measurement system errors reduction through state estimation and control optimization. The approaches are proposed based on the methods of experiment design and the theory of systems with random abrupt structure variation. The paper considers various control criteria as applied to an aircraft data measurement system. The physics of criteria is explained, the mathematical description and the sequence of steps for each criterion application is shown. The formula is given for airborne data measurement system state vector posterior estimation based for systems with structure variations.

The Effect of an Electronic Checklist on Critical Care Provider Workload, Errors, and Performance.

PubMed

Thongprayoon, Charat; Harrison, Andrew M; O'Horo, John C; Berrios, Ronaldo A Sevilla; Pickering, Brian W; Herasevich, Vitaly

2016-03-01

The strategy used to improve effective checklist use in intensive care unit (ICU) setting is essential for checklist success. This study aimed to test the hypothesis that an electronic checklist could reduce ICU provider workload, errors, and time to checklist completion, as compared to a paper checklist. This was a simulation-based study conducted at an academic tertiary hospital. All participants completed checklists for 6 ICU patients: 3 using an electronic checklist and 3 using an identical paper checklist. In both scenarios, participants had full access to the existing electronic medical record system. The outcomes measured were workload (defined using the National Aeronautics and Space Association task load index [NASA-TLX]), the number of checklist errors, and time to checklist completion. Two independent clinician reviewers, blinded to participant results, served as the reference standard for checklist error calculation. Twenty-one ICU providers participated in this study. This resulted in the generation of 63 simulated electronic checklists and 63 simulated paper checklists. The median NASA-TLX score was 39 for the electronic checklist and 50 for the paper checklist (P = .005). The median number of checklist errors for the electronic checklist was 5, while the median number of checklist errors for the paper checklist was 8 (P = .003). The time to checklist completion was not significantly different between the 2 checklist formats (P = .76). The electronic checklist significantly reduced provider workload and errors without any measurable difference in the amount of time required for checklist completion. This demonstrates that electronic checklists are feasible and desirable in the ICU setting. © The Author(s) 2014.

Nurses' role in medication safety.

PubMed

Choo, Janet; Hutchinson, Alison; Bucknall, Tracey

2010-10-01

To explore the nurse's role in the process of medication management and identify the challenges associated with safe medication management in contemporary clinical practice. Medication errors have been a long-standing factor affecting consumer safety. The nursing profession has been identified as essential to the promotion of patient safety. A review of literature on medication errors and the use of electronic prescribing in medication errors. Medication management requires a multidisciplinary approach and interdisciplinary communication is essential to reduce medication errors. Information technologies can help to reduce some medication errors through eradication of transcription and dosing errors. Nurses must play a major role in the design of computerized medication systems to ensure a smooth transition to such as system. The nurses' roles in medication management cannot be over-emphasized. This is particularly true when designing a computerized medication system. The adoption of safety measures during decision making that parallel those of the aviation industry safety procedures can provide some strategies to prevent medication error. Innovations in information technology offer potential mechanisms to avert adverse events in medication management for nurses. © 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd.

Error analysis and experiments of attitude measurement using laser gyroscope

NASA Astrophysics Data System (ADS)

Ren, Xin-ran; Ma, Wen-li; Jiang, Ping; Huang, Jin-long; Pan, Nian; Guo, Shuai; Luo, Jun; Li, Xiao

2018-03-01

The precision of photoelectric tracking and measuring equipment on the vehicle and vessel is deteriorated by the platform's movement. Specifically, the platform's movement leads to the deviation or loss of the target, it also causes the jitter of visual axis and then produces image blur. In order to improve the precision of photoelectric equipment, the attitude of photoelectric equipment fixed with the platform must be measured. Currently, laser gyroscope is widely used to measure the attitude of the platform. However, the measurement accuracy of laser gyro is affected by its zero bias, scale factor, installation error and random error. In this paper, these errors were analyzed and compensated based on the laser gyro's error model. The static and dynamic experiments were carried out on a single axis turntable, and the error model was verified by comparing the gyro's output with an encoder with an accuracy of 0.1 arc sec. The accuracy of the gyroscope has increased from 7000 arc sec to 5 arc sec for an hour after error compensation. The method used in this paper is suitable for decreasing the laser gyro errors in inertial measurement applications.

A Vision-Based Self-Calibration Method for Robotic Visual Inspection Systems

PubMed Central

Yin, Shibin; Ren, Yongjie; Zhu, Jigui; Yang, Shourui; Ye, Shenghua

2013-01-01

A vision-based robot self-calibration method is proposed in this paper to evaluate the kinematic parameter errors of a robot using a visual sensor mounted on its end-effector. This approach could be performed in the industrial field without external, expensive apparatus or an elaborate setup. A robot Tool Center Point (TCP) is defined in the structural model of a line-structured laser sensor, and aligned to a reference point fixed in the robot workspace. A mathematical model is established to formulate the misalignment errors with kinematic parameter errors and TCP position errors. Based on the fixed point constraints, the kinematic parameter errors and TCP position errors are identified with an iterative algorithm. Compared to the conventional methods, this proposed method eliminates the need for a robot-based-frame and hand-to-eye calibrations, shortens the error propagation chain, and makes the calibration process more accurate and convenient. A validation experiment is performed on an ABB IRB2400 robot. An optimal configuration on the number and distribution of fixed points in the robot workspace is obtained based on the experimental results. Comparative experiments reveal that there is a significant improvement of the measuring accuracy of the robotic visual inspection system. PMID:24300597

A Mobile Heat Applicator for Simulating Prescribed Fire Intensities

Treesearch

Stephen S. Sackett; Darold E. Ward

1972-01-01

In testing the degree of tolerance or susceptibility of tree stems to heat from prescribed fires, it is desirable to apply controlled quantities of heat to the lower bole. This paper describes an infrared heater capable of simulating the intensities of prescribed fires and mobile enough for use in the field under natural conditions. Procedures for calibrating the unit...

Fuels planning: science synthesis and integration; economic uses fact sheet 08: prescribed fire costs

Treesearch

Rocky Mountain Research Station USDA Forest Service

2004-01-01

Although the use of prescribed fire as a management tool is widespread, there is great variability and uncertainty in the treatment costs. Given specific site variables and management objectives, how much will it cost to use prescribed fire? This paper describes the FASTRACS database, a tool that has been developed to aid managers in addressing this question.

Analysis of Errors and Misconceptions in the Learning of Calculus by Undergraduate Students

ERIC Educational Resources Information Center

Muzangwa, Jonatan; Chifamba, Peter

2012-01-01

This paper is going to analyse errors and misconceptions in an undergraduate course in Calculus. The study will be based on a group of 10 BEd. Mathematics students at Great Zimbabwe University. Data is gathered through use of two exercises on Calculus 1&2.The analysis of the results from the tests showed that a majority of the errors were due…

Intentionally flawed manuscripts as means for teaching students to critically evaluate scientific papers.

PubMed

Ferenc, Jaroslav; Červenák, Filip; Birčák, Erik; Juríková, Katarína; Goffová, Ivana; Gorilák, Peter; Huraiová, Barbora; Plavá, Jana; Demecsová, Loriana; Ďuríková, Nikola; Galisová, Veronika; Gazdarica, Matej; Puškár, Marek; Nagy, Tibor; Nagyová, Soňa; Mentelová, Lucia; Slaninová, Miroslava; Ševčovicová, Andrea; Tomáška, Ľubomír

2018-01-01

As future scientists, university students need to learn how to avoid making errors in their own manuscripts, as well as how to identify flaws in papers published by their peers. Here we describe a novel approach on how to promote students' ability to critically evaluate scientific articles. The exercise is based on instructing teams of students to write intentionally flawed manuscripts describing the results of simple experiments. The teams are supervised by instructors advising the students during manuscript writing, choosing the 'appropriate' errors, monitoring the identification of errors made by the other team and evaluating the strength of their arguments in support of the identified errors. We have compared the effectiveness of the method with a journal club-type seminar. Based on the results of our assessment we propose that the described seminar may effectively complement the existing approaches to teach critical scientific thinking. © 2017 by The International Union of Biochemistry and Molecular Biology, 46(1):22-30, 2018. © 2017 The International Union of Biochemistry and Molecular Biology.

Error model of geomagnetic-field measurement and extended Kalman-filter based compensation method

PubMed Central

Ge, Zhilei; Liu, Suyun; Li, Guopeng; Huang, Yan; Wang, Yanni

2017-01-01

The real-time accurate measurement of the geomagnetic-field is the foundation to achieving high-precision geomagnetic navigation. The existing geomagnetic-field measurement models are essentially simplified models that cannot accurately describe the sources of measurement error. This paper, on the basis of systematically analyzing the source of geomagnetic-field measurement error, built a complete measurement model, into which the previously unconsidered geomagnetic daily variation field was introduced. This paper proposed an extended Kalman-filter based compensation method, which allows a large amount of measurement data to be used in estimating parameters to obtain the optimal solution in the sense of statistics. The experiment results showed that the compensated strength of the geomagnetic field remained close to the real value and the measurement error was basically controlled within 5nT. In addition, this compensation method has strong applicability due to its easy data collection and ability to remove the dependence on a high-precision measurement instrument. PMID:28445508

Smartphone apps to support hospital prescribing and pharmacology education: a review of current provision

PubMed Central

Haffey, Faye; Brady, Richard R W; Maxwell, Simon

2014-01-01

Junior doctors write the majority of hospital prescriptions but many indicate they feel underprepared to assume this responsibility and around 10% of prescriptions contain errors. Medical smartphone apps are now widely used in clinical practice and present an opportunity to provide support to inexperienced prescribers. This study assesses the contemporary range of smartphone apps with prescribing or related content. Six smartphone app stores were searched for apps aimed at the healthcare professional with drug, pharmacology or prescribing content. Three hundred and six apps were identified. 34% appeared to be for use within the clinical environment in order to aid prescribing, 14% out with the clinical setting and 51% of apps were deemed appropriate for both clinical and non-clinical use. Apps with drug reference material, such as textbooks, manuals or medical apps with drug information were the commonest apps found (51%), followed by apps offering drug or infusion rate dose calculation (26%). 68% of apps charged for download, with a mean price of £14.25 per app and a range of £0.62–101.90. A diverse range of pharmacology-themed apps are available and there is further potential for the development of contemporary apps to improve prescribing performance. Personalized app stores may help universities/healthcare organizations offer high quality apps to students to aid in pharmacology education. Users of prescribing apps must be aware of the lack of information regarding the medical expertise of app developers. This will enable them to make informed choices about the use of such apps in their clinical practice. PMID:23488599

Smartphone apps to support hospital prescribing and pharmacology education: a review of current provision.

PubMed

Haffey, Faye; Brady, Richard R W; Maxwell, Simon

2014-01-01

Junior doctors write the majority of hospital prescriptions but many indicate they feel underprepared to assume this responsibility and around 10% of prescriptions contain errors. Medical smartphone apps are now widely used in clinical practice and present an opportunity to provide support to inexperienced prescribers. This study assesses the contemporary range of smartphone apps with prescribing or related content. Six smartphone app stores were searched for apps aimed at the healthcare professional with drug, pharmacology or prescribing content. Three hundred and six apps were identified. 34% appeared to be for use within the clinical environment in order to aid prescribing, 14% out with the clinical setting and 51% of apps were deemed appropriate for both clinical and non-clinical use. Apps with drug reference material, such as textbooks, manuals or medical apps with drug information were the commonest apps found (51%), followed by apps offering drug or infusion rate dose calculation (26%). 68% of apps charged for download, with a mean price of £14.25 per app and a range of £0.62-101.90. A diverse range of pharmacology-themed apps are available and there is further potential for the development of contemporary apps to improve prescribing performance. Personalized app stores may help universities/healthcare organizations offer high quality apps to students to aid in pharmacology education. Users of prescribing apps must be aware of the lack of information regarding the medical expertise of app developers. This will enable them to make informed choices about the use of such apps in their clinical practice. © 2013 The British Pharmacological Society.

Investigation of antimicrobial use pattern in the intensive treatment unit of a teaching hospital in western Nepal.

PubMed

Shankar, P Ravi; Partha, Praveen; Shenoy, Nagesh; Brahmadathan, K N

2003-11-01

Inappropriate use of antimicrobials is of special importance in the intensive treatment unit because of the large number of drugs prescribed, the chance for drug errors, and the likelihood of development of drug resistance. A total of 297 records of patients admitted to the intensive treatment unit of the Manipal teaching hospital, a tertiary care hospital in Pokhara, western Nepal, were studied to determine the prescribing frequency and rationality of use of antimicrobials. Patient outcome, duration of stay in the intensive treatment unit, and the age and sex distribution of the patients were also studied. Mean+/-SD drugs per patient was 3.4+/-1.8. About half (50.2%) of the patients received an antimicrobial; 84.6% of the antimicrobials were used without obtaining bacteriologic evidence of infection. The commonest organisms isolated on culture were Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae, and Staphylococcus aureus. A total of 28.9% of the antimicrobials were prescribed for lower respiratory tract infections on the basis of the putative site of infection; 61.9% of the antimicrobials were prescribed by the parenteral route and mainly the older generation of antimicrobials were used. In 39 of the 149 patients prescribed an antimicrobial, the use was irrational. Prescriber education to improve prescribing patterns and regular auditing of antimicrobial prescriptions to prevent their inappropriate use and unnecessary cost to the patients are required. The high percentage of inappropriate use of antimicrobials raises concerns about the development and spread of drug resistance, which must be addressed.

Ontological analysis of SNOMED CT.

PubMed

Héja, Gergely; Surján, György; Varga, Péter

2008-10-27

SNOMED CT is the most comprehensive medical terminology. However, its use for intelligent services based on formal reasoning is questionable. The analysis of the structure of SNOMED CT is based on the formal top-level ontology DOLCE. The analysis revealed several ontological and knowledge-engineering errors, the most important are errors in the hierarchy (mostly from an ontological point of view, but also regarding medical aspects) and the mixing of subsumption relations with other types (mostly 'part of'). The found errors impede formal reasoning. The paper presents a possible way to correct these problems.

The control algorithm of the system ‘frequency converter - asynchronous motor’ of the batcher

NASA Astrophysics Data System (ADS)

Lyapushkin, S. V.; Martyushev, N. V.; Shiryaev, S. Y.

2017-01-01

The paper is devoted to the solution of the problem of optimum batching of bulk mixtures according to the criterion of accuracy and maximally possible performance. This problem is solved for applied utilization when running the system ‘frequency converter - asynchronous motor’ having pulse-width modulation of a screw batcher of agricultural equipment. The developed control algorithm allows batching small components of a bulk mixture with the prescribed accuracy due to the weight consideration of the falling column of the material being in the air after the screw stoppage. The paper also shows that in order to reduce the influence of the mass of the ‘falling column’ on the accuracy of batching, it is necessary to specify the sequence of batching of components inside of the recipe beginning from the largest component ending with the least one. To exclude the variable error of batching, which arises owing to the mass of the material column, falling into the batcher-bunker, the algorithm of dynamic correction of the task is used in the control system.

A Quatro-Based 65-nm Flip-Flop Circuit for Soft-Error Resilience

NASA Astrophysics Data System (ADS)

Li, Y.-Q.; Wang, H.-B.; Liu, R.; Chen, L.; Nofal, I.; Shi, S.-T.; He, A.-L.; Guo, G.; Baeg, S. H.; Wen, S.-J.; Wong, R.; Chen, M.; Wu, Q.

2017-06-01

A flip-flop circuit hardened against soft errors is presented in this paper. This design is an improved version of Quatro for further enhanced soft-error resilience by integrating the guard-gate technique. The proposed design, as well as reference Quatro and regular flip-flops, was implemented and manufactured in a 65-nm CMOS bulk technology. Experimental characterization results of their alpha and heavy ions soft-error rates verified the superior hardening performance of the proposed design over the other two circuits.

Accuracy improvement of the H-drive air-levitating wafer inspection stage based on error analysis and compensation

NASA Astrophysics Data System (ADS)

Zhang, Fan; Liu, Pinkuan

2018-04-01

In order to improve the inspection precision of the H-drive air-bearing stage for wafer inspection, in this paper the geometric error of the stage is analyzed and compensated. The relationship between the positioning errors and error sources are initially modeled, and seven error components are identified that are closely related to the inspection accuracy. The most effective factor that affects the geometric error is identified by error sensitivity analysis. Then, the Spearman rank correlation method is applied to find the correlation between different error components, aiming at guiding the accuracy design and error compensation of the stage. Finally, different compensation methods, including the three-error curve interpolation method, the polynomial interpolation method, the Chebyshev polynomial interpolation method, and the B-spline interpolation method, are employed within the full range of the stage, and their results are compared. Simulation and experiment show that the B-spline interpolation method based on the error model has better compensation results. In addition, the research result is valuable for promoting wafer inspection accuracy and will greatly benefit the semiconductor industry.

The Need for Specialty Curricula Based on Core Competencies: A White Paper of the Conjoint Committee on Continuing Medical Education

ERIC Educational Resources Information Center

Jackson, Marcia J.; Gallis, Harry A.; Gilman, Stuart C.; Grossman, Michael; Holzman, Gerald B.; Marquis, Damon; Trusky, Sandra K.

2007-01-01

At present there is no curriculum to guide physician lifelong learning in a prescribed, deliberate manner. The Conjoint Committee on Continuing Medical Education, a group representing 16 major stakeholder organizations in continuing medical education, recommends that each specialty society and corresponding board reach consensus on the…

Kinesthetic and Interpersonal Learning: A Compendium of "Hands-On" and "Person-to-Person" Projects for Teaching International Accounting

ERIC Educational Resources Information Center

Riordan, Diane A.

2006-01-01

Prior researchers have described how individuals prefer to learn with different types of activities. Vincent and others (2002) have reported that business students prefer kinesthetic and interpersonal modes of learning and prescribe their use in the international business curriculum. Based on their findings, this paper presents a compendium of…

Implementing Projects in Calculus on a Large Scale at the University of South Florida

ERIC Educational Resources Information Center

Fox, Gordon A.; Campbell, Scott; Grinshpan, Arcadii; Xu, Xiaoying; Holcomb, John; Bénéteau, Catherine; Lewis, Jennifer E.; Ramachandran, Kandethody

2017-01-01

This paper describes the development of a program of project-based learning in Calculus courses at a large urban research university. In this program, students developed research projects in consultation with a faculty advisor in their major, and supervised by their calculus instructors. Students wrote up their projects in a prescribed format…

Quality of routine health data collected by health workers using smartphone at primary health care in Ethiopia.

PubMed

Medhanyie, Araya Abrha; Spigt, Mark; Yebyo, Henock; Little, Alex; Tadesse, Kidane; Dinant, Geert-Jan; Blanco, Roman

2017-05-01

Mobile phone based applications are considered by many as potentially useful for addressing challenges and improving the quality of data collection in developing countries. Yet very little evidence is available supporting or refuting the potential and widely perceived benefits on the use of electronic forms on smartphones for routine patient data collection by health workers at primary health care facilities. A facility based cross sectional study using a structured paper checklist was prepared to assess the completeness and accuracy of 408 electronic records completed and submitted to a central database server using electronic forms on smartphones by 25 health workers. The 408 electronic records were selected randomly out of a total of 1772 maternal health records submitted by the health workers to the central database over a period of six months. Descriptive frequencies and percentages of data completeness and error rates were calculated. When compared to paper records, the use of electronic forms significantly improved data completeness by 209 (8%) entries. Of a total 2622 entries checked for completeness, 2602 (99.2%) electronic record entries were complete, while 2393 (91.3%) paper record entries were complete. A very small percentage of error rates, which was easily identifiable, occurred in both electronic and paper forms although the error rate in the electronic records was more than double that of paper records (2.8% vs. 1.1%). More than half of entry errors in the electronic records related to entering a text value. With minimal training, supervision, and no incentives, health care workers were able to use electronic forms for patient assessment and routine data collection appropriately and accurately with a very small error rate. Minimising the number of questions requiring text responses in electronic forms would be helpful in minimizing data errors. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessment of Apixaban Prescribing Patterns for Nonvalvular Atrial Fibrillation in Hospitalized Patients.

PubMed

Gibson, Caitlin M; Smith, Carmen B; Davis, Sondra; Scalese, Michael J

2018-01-01

Apixaban is a direct oral anticoagulant (DOAC) for the prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation (NVAF). Other DOACs require renal dose adjustments based solely on creatinine clearance. Apixaban differs in that its dose adjustments are more complex, potentially leading to prescribing errors. To determine if adherence to Food and Drug Administration (FDA)-approved dosing for apixaban is maintained in hospitalized patients with NVAF. Patients ≥18 years old with NVAF who received apixaban during admission to 1 of 3 hospitals were evaluated. The primary outcome was to determine if providers order apixaban in accordance with FDA-approved dosages. Secondary outcomes included determining if pharmacist review increased the number of orders in accordance with FDA-approved dosing, which of the 3 criteria (age ≥80 years, body weight ≤60 kg, or serum creatinine ≥1.5 mg/dL) were met in patients receiving off-label dosing, and the rationale for off-label prescribing. A total of 556 patients met inclusion criteria. Apixaban was dosed according to FDA labeling by providers in 83.4% (n = 464) of orders. After pharmacist review, 87.0% (n = 484) of orders were at the approved dose, 12.2% (n = 68) were underdosed, and 0.7% (n = 4) were overdosed. Most patients who were underdosed met only 1 dose reduction criterion-most commonly age ≥80 years (56.0%). Reasons for off-label dosing included home dose continuation (39.0%), history of or perceived bleeding risk (30.5%), or unspecified/other (30.5%). The majority of apixaban orders for NVAF were based on FDA-approved dosages after provider entry and pharmacist review.

Solar Irradiance from GOES Albedo performance in a Hydrologic Model Simulation of Snowmelt Runoff

NASA Astrophysics Data System (ADS)

Sumargo, E.; Cayan, D. R.; McGurk, B. J.

2015-12-01

In many hydrologic modeling applications, solar radiation has been parameterized using commonly available measures, such as the daily temperature range, due to scarce in situ solar radiation measurement network. However, these parameterized estimates often produce significant biases. Here we test hourly solar irradiance derived from the Geostationary Operational Environmental Satellite (GOES) visible albedo product, using several established algorithms. Focusing on the Sierra Nevada and White Mountain in California, we compared the GOES irradiance and that from a traditional temperature-based algorithm with incoming irradiance from pyranometers at 19 stations. The GOES based estimates yielded 21-27% reduction in root-mean-squared error (average over 19 sites). The derived irradiance is then prescribed as an input to Precipitation-Runoff Modeling System (PRMS). We constrain our experiment to the Tuolumne River watershed and focus our attention on the winter and spring of 1996-2014. A root-mean-squared error reduction of 2-6% in daily inflow to Hetch Hetchy at the lower end of the Tuolumne catchment was achieved by incorporating the insolation estimates at only 8 out of 280 Hydrologic Response Units (HRUs) within the basin. Our ongoing work endeavors to apply satellite-derived irradiance at each individual HRU.

Towards a Collaborative Filtering Approach to Medication Reconciliation

PubMed Central

Hasan, Sharique; Duncan, George T.; Neill, Daniel B.; Padman, Rema

2008-01-01

A physician’s prescribing decisions depend on knowledge of the patient’s medication list. This knowledge is often incomplete, and errors or omissions could result in adverse outcomes. To address this problem, the Joint Commission recommends medication reconciliation for creating a more accurate list of a patient’s medications. In this paper, we develop techniques for automatic detection of omissions in medication lists, identifying drugs that the patient may be taking but are not on the patient’s medication list. Our key insight is that this problem is analogous to the collaborative filtering framework increasingly used by online retailers to recommend relevant products to customers. The collaborative filtering approach enables a variety of solution techniques, including nearest neighbor and co-occurrence approaches. We evaluate the effectiveness of these approaches using medication data from a long-term care center in the Eastern US. Preliminary results suggest that this framework may become a valuable tool for medication reconciliation. PMID:18998834

Towards a collaborative filtering approach to medication reconciliation.

PubMed

Hasan, Sharique; Duncan, George T; Neill, Daniel B; Padman, Rema

2008-11-06

A physicians prescribing decisions depend on knowledge of the patients medication list. This knowledge is often incomplete, and errors or omissions could result in adverse outcomes. To address this problem, the Joint Commission recommends medication reconciliation for creating a more accurate list of a patients medications. In this paper, we develop techniques for automatic detection of omissions in medication lists, identifying drugs that the patient may be taking but are not on the patients medication list. Our key insight is that this problem is analogous to the collaborative filtering framework increasingly used by online retailers to recommend relevant products to customers. The collaborative filtering approach enables a variety of solution techniques, including nearest neighbor and co-occurrence approaches. We evaluate the effectiveness of these approaches using medication data from a long-term care center in the Eastern US. Preliminary results suggest that this framework may become a valuable tool for medication reconciliation.

Fuzzy Adaptive Compensation Control of Uncertain Stochastic Nonlinear Systems With Actuator Failures and Input Hysteresis.

PubMed

Wang, Jianhui; Liu, Zhi; Chen, C L Philip; Zhang, Yun

2017-10-12

Hysteresis exists ubiquitously in physical actuators. Besides, actuator failures/faults may also occur in practice. Both effects would deteriorate the transient tracking performance, and even trigger instability. In this paper, we consider the problem of compensating for actuator failures and input hysteresis by proposing a fuzzy control scheme for stochastic nonlinear systems. Compared with the existing research on stochastic nonlinear uncertain systems, it is found that how to guarantee a prescribed transient tracking performance when taking into account actuator failures and hysteresis simultaneously also remains to be answered. Our proposed control scheme is designed on the basis of the fuzzy logic system and backstepping techniques for this purpose. It is proven that all the signals remain bounded and the tracking error is ensured to be within a preestablished bound with the failures of hysteretic actuator. Finally, simulations are provided to illustrate the effectiveness of the obtained theoretical results.

Chance-Constrained AC Optimal Power Flow for Distribution Systems With Renewables

DOE Office of Scientific and Technical Information (OSTI.GOV)

DallAnese, Emiliano; Baker, Kyri; Summers, Tyler

This paper focuses on distribution systems featuring renewable energy sources (RESs) and energy storage systems, and presents an AC optimal power flow (OPF) approach to optimize system-level performance objectives while coping with uncertainty in both RES generation and loads. The proposed method hinges on a chance-constrained AC OPF formulation where probabilistic constraints are utilized to enforce voltage regulation with prescribed probability. A computationally more affordable convex reformulation is developed by resorting to suitable linear approximations of the AC power-flow equations as well as convex approximations of the chance constraints. The approximate chance constraints provide conservative bounds that hold for arbitrarymore » distributions of the forecasting errors. An adaptive strategy is then obtained by embedding the proposed AC OPF task into a model predictive control framework. Finally, a distributed solver is developed to strategically distribute the solution of the optimization problems across utility and customers.« less

Home exercise programmes supported by video and automated reminders compared with standard paper-based home exercise programmes in patients with stroke: a randomized controlled trial.

PubMed

Emmerson, Kellie B; Harding, Katherine E; Taylor, Nicholas F

2017-08-01

To determine whether patients with stroke receiving rehabilitation for upper limb deficits using smart technology (video and reminder functions) demonstrate greater adherence to prescribed home exercise programmes and better functional outcomes when compared with traditional paper-based exercise prescription. Randomized controlled trial comparing upper limb home exercise programmes supported by video and automated reminders on smart technology, with standard paper-based home exercise programmes. A community rehabilitation programme within a large metropolitan health service. Patients with stroke with upper limb deficits, referred for outpatient rehabilitation. Participants were randomly assigned to the control (paper-based home exercise programme) or intervention group (home exercise programme filmed on an electronic tablet, with an automated reminder). Both groups completed their prescribed home exercise programme for four weeks. The primary outcome was adherence using a self-reported log book. Secondary outcomes were change in upper limb function and patient satisfaction. A total of 62 participants were allocated to the intervention ( n = 30) and control groups ( n = 32). There were no differences between the groups for measures of adherence (mean difference 2%, 95% CI -12 to 17) or change in the Wolf Motor Function Test log transformed time (mean difference 0.02 seconds, 95% CI -0.1 to 0.1). There were no between-group differences in how participants found instructions ( p = 0.452), whether they remembered to do their exercises ( p = 0.485), or whether they enjoyed doing their exercises ( p = 0.864). The use of smart technology was not superior to standard paper-based home exercise programmes for patients recovering from stroke. This trial design was registered prospectively with the Australian and New Zealand Clinical Trials Register, ID: ACTRN 12613000786796. http://www.anzctr.org.au/trialSearch.aspx.

Benefit of Modeling the Observation Error in a Data Assimilation Framework Using Vegetation Information Obtained From Passive Based Microwave Data

NASA Technical Reports Server (NTRS)

Bolten, John D.; Mladenova, Iliana E.; Crow, Wade; De Jeu, Richard

2016-01-01

A primary operational goal of the United States Department of Agriculture (USDA) is to improve foreign market access for U.S. agricultural products. A large fraction of this crop condition assessment is based on satellite imagery and ground data analysis. The baseline soil moisture estimates that are currently used for this analysis are based on output from the modified Palmer two-layer soil moisture model, updated to assimilate near-real time observations derived from the Soil Moisture Ocean Salinity (SMOS) satellite. The current data assimilation system is based on a 1-D Ensemble Kalman Filter approach, where the observation error is modeled as a function of vegetation density. This allows for offsetting errors in the soil moisture retrievals. The observation error is currently adjusted using Normalized Difference Vegetation Index (NDVI) climatology. In this paper we explore the possibility of utilizing microwave-based vegetation optical depth instead.

Nursing, Pharmacy, and Prescriber Knowledge and Perceptions of High-Alert Medications in a Large, Academic Medical Hospital

PubMed Central

Engels, Melanie J.

2015-01-01

Background: High-alert medications pose a greater risk of causing significant harm to patients if used in error. The Joint Commission requires that hospitals define institution-specific high-alert medications and implement processes to ensure safe medication use. Method: Nursing, pharmacy, and prescribers were asked to voluntarily complete a 34-question survey to assess their knowledge, experience, and perceptions regarding high-alert medications in an academic hospital. Results: The majority of respondents identified the organization’s high-alert medications, the consequences of an error involving a high-alert medication, and the reversal agent. Most of the risk-reduction strategies within the institution were viewed as being effective by respondents. Forty-five percent of the respondents utilized a high-alert medication in the previous 24 hours. Only 14.2% had experienced an error with a high-alert medication in the previous 12 months, with 46% being near misses. The survey found the 5 rights for medication administration were not being utilized consistently. Respondents indicated that work experience or hospital orientation is the preferred learning experience for high-alert medications. Conclusions: This study assessed all disciplines involved in the medication use process. Perceptions about high-alert medications differ between disciplines. Ongoing discipline-specific education is required to ensure that individuals accept accountability in the medication use process and to close knowledge gaps on high-alert medications and risk-reduction strategies. PMID:26446747

Two States Mapping Based Time Series Neural Network Model for Compensation Prediction Residual Error

NASA Astrophysics Data System (ADS)

Jung, Insung; Koo, Lockjo; Wang, Gi-Nam

2008-11-01

The objective of this paper was to design a model of human bio signal data prediction system for decreasing of prediction error using two states mapping based time series neural network BP (back-propagation) model. Normally, a lot of the industry has been applied neural network model by training them in a supervised manner with the error back-propagation algorithm for time series prediction systems. However, it still has got a residual error between real value and prediction result. Therefore, we designed two states of neural network model for compensation residual error which is possible to use in the prevention of sudden death and metabolic syndrome disease such as hypertension disease and obesity. We determined that most of the simulation cases were satisfied by the two states mapping based time series prediction model. In particular, small sample size of times series were more accurate than the standard MLP model.

Classification-Based Spatial Error Concealment for Visual Communications

NASA Astrophysics Data System (ADS)

Chen, Meng; Zheng, Yefeng; Wu, Min

2006-12-01

In an error-prone transmission environment, error concealment is an effective technique to reconstruct the damaged visual content. Due to large variations of image characteristics, different concealment approaches are necessary to accommodate the different nature of the lost image content. In this paper, we address this issue and propose using classification to integrate the state-of-the-art error concealment techniques. The proposed approach takes advantage of multiple concealment algorithms and adaptively selects the suitable algorithm for each damaged image area. With growing awareness that the design of sender and receiver systems should be jointly considered for efficient and reliable multimedia communications, we proposed a set of classification-based block concealment schemes, including receiver-side classification, sender-side attachment, and sender-side embedding. Our experimental results provide extensive performance comparisons and demonstrate that the proposed classification-based error concealment approaches outperform the conventional approaches.

Medicine and aviation: a review of the comparison.

PubMed

Randell, R

2003-01-01

This paper aims to understand the nature of medical error in highly technological environments and argues that a comparison with aviation can blur its real understanding. This study is a comparative study between the notion of error in health care and aviation based on the author's own ethnographic study in intensive care units and findings from the research literature on errors in aviation. Failures in the use of medical technology are common. In attempts to understand the area of medical error, much attention has focused on how we can learn from aviation. This paper argues that such a comparison is not always useful, on the basis that (i) the type of work and technology is very different in the two domains; (ii) different issues are involved in training and procurement; and (iii) attitudes to error vary between the domains. Therefore, it is necessary to look closely at the subject of medical error and resolve those questions left unanswered by the lessons of aviation.

Quantization-Based Adaptive Actor-Critic Tracking Control With Tracking Error Constraints.

PubMed

Fan, Quan-Yong; Yang, Guang-Hong; Ye, Dan

2018-04-01

In this paper, the problem of adaptive actor-critic (AC) tracking control is investigated for a class of continuous-time nonlinear systems with unknown nonlinearities and quantized inputs. Different from the existing results based on reinforcement learning, the tracking error constraints are considered and new critic functions are constructed to improve the performance further. To ensure that the tracking errors keep within the predefined time-varying boundaries, a tracking error transformation technique is used to constitute an augmented error system. Specific critic functions, rather than the long-term cost function, are introduced to supervise the tracking performance and tune the weights of the AC neural networks (NNs). A novel adaptive controller with a special structure is designed to reduce the effect of the NN reconstruction errors, input quantization, and disturbances. Based on the Lyapunov stability theory, the boundedness of the closed-loop signals and the desired tracking performance can be guaranteed. Finally, simulations on two connected inverted pendulums are given to illustrate the effectiveness of the proposed method.

Neural network-based model reference adaptive control system.

PubMed

Patino, H D; Liu, D

2000-01-01

In this paper, an approach to model reference adaptive control based on neural networks is proposed and analyzed for a class of first-order continuous-time nonlinear dynamical systems. The controller structure can employ either a radial basis function network or a feedforward neural network to compensate adaptively the nonlinearities in the plant. A stable controller-parameter adjustment mechanism, which is determined using the Lyapunov theory, is constructed using a sigma-modification-type updating law. The evaluation of control error in terms of the neural network learning error is performed. That is, the control error converges asymptotically to a neighborhood of zero, whose size is evaluated and depends on the approximation error of the neural network. In the design and analysis of neural network-based control systems, it is important to take into account the neural network learning error and its influence on the control error of the plant. Simulation results showing the feasibility and performance of the proposed approach are given.

Tests for detecting overdispersion in models with measurement error in covariates.

PubMed

Yang, Yingsi; Wong, Man Yu

2015-11-30

Measurement error in covariates can affect the accuracy in count data modeling and analysis. In overdispersion identification, the true mean-variance relationship can be obscured under the influence of measurement error in covariates. In this paper, we propose three tests for detecting overdispersion when covariates are measured with error: a modified score test and two score tests based on the proposed approximate likelihood and quasi-likelihood, respectively. The proposed approximate likelihood is derived under the classical measurement error model, and the resulting approximate maximum likelihood estimator is shown to have superior efficiency. Simulation results also show that the score test based on approximate likelihood outperforms the test based on quasi-likelihood and other alternatives in terms of empirical power. By analyzing a real dataset containing the health-related quality-of-life measurements of a particular group of patients, we demonstrate the importance of the proposed methods by showing that the analyses with and without measurement error correction yield significantly different results. Copyright © 2015 John Wiley & Sons, Ltd.

Analysis of case-only studies accounting for genotyping error.

PubMed

Cheng, K F

2007-03-01

The case-only design provides one approach to assess possible interactions between genetic and environmental factors. It has been shown that if these factors are conditionally independent, then a case-only analysis is not only valid but also very efficient. However, a drawback of the case-only approach is that its conclusions may be biased by genotyping errors. In this paper, our main aim is to propose a method for analysis of case-only studies when these errors occur. We show that the bias can be adjusted through the use of internal validation data, which are obtained by genotyping some sampled individuals twice. Our analysis is based on a simple and yet highly efficient conditional likelihood approach. Simulation studies considered in this paper confirm that the new method has acceptable performance under genotyping errors.

Changes in downed wood and forest structure after prescribed fire in ponderosa pine forests

Treesearch

Victoria Saab; Lisa Bate; John Lehmkuhl; Brett Dickson; Scott Story; Stephanie Jentsch; William Block

2006-01-01

Most prescribed fire plans focus on reducing wildfire hazards with little consideration given to effects on wildlife populations and their habitats. To evaluate effectiveness of prescribed burning in reducing fuels and to assess effects of fuels reduction on wildlife, we began a large-scale study known as the Birds and Burns Network in 2002. In this paper we analyze...

Building a state prescribed fire program: experiences and lessons learned in Ohio

Treesearch

Michael Bowden

2009-01-01

Science continues to show the need for the use of prescribed fire in oak-dominated forests of the eastern United States. Fire is necessary to reduce competition by thin-barked species, allowing for the development of oak advance regeneration. Many agencies are beginning to apply this science by using prescribed fire to manage their oak forests. This paper examines the...

Application of round grating angle measurement composite error amendment in the online measurement accuracy improvement of large diameter

NASA Astrophysics Data System (ADS)

Wang, Biao; Yu, Xiaofen; Li, Qinzhao; Zheng, Yu

2008-10-01

The paper aiming at the influence factor of round grating dividing error, rolling-wheel produce eccentricity and surface shape errors provides an amendment method based on rolling-wheel to get the composite error model which includes all influence factors above, and then corrects the non-circle measurement angle error of the rolling-wheel. We make soft simulation verification and have experiment; the result indicates that the composite error amendment method can improve the diameter measurement accuracy with rolling-wheel theory. It has wide application prospect for the measurement accuracy higher than 5 μm/m.

Analysis of Out Door Patients' Prescriptions According to World Health Organization (WHO) Prescribing Indicators Among Private Hospitals in Western India.

PubMed

Shelat, Prakash R; Kumbar, Shivaprasad Kalakappa

2015-03-01

Prescription is document through which doctor, patient and pharmacist are communicated. Many a times if these documents are not properly written or misinterpreted it can affect management of patients. WHO established prescribing indicators to analyse prescription and promoted rational use of drugs and better management of patients. To study the prescription pattern according to WHO prescribing indicators among private hospitals. The observational, prospective study carried out at different private hospitals at metro city in Western India to study the prescription pattern among private hospital. Study was conducted at different private hospitals of metro city. A total of 250 prescriptions of outdoor patients from various departments of private hospitals were collected for a period of three months (August to October) 2012 and evaluated. The study was analysed using Z-test. Patient details like age and gender was not written in all (100%) prescriptions. It was noticed that dose, direction of drug and duration of treatment was not completely written in 90%, 74% and 80% of prescriptions respectively. Abbreviations were used in all (100%) prescriptions. Doctor's medical registration number was mentioned in 0% prescriptions. Total 869 drugs were prescribed in 250 prescriptions. Average number of drug prescribed was 3.38±1.79 (Mean±SD). It was reported that Group II (3 to 4 encoutner) was significantly higher as compared to Group I (less than or equal to 2 encoutner) and Group III( more than four encounter). It was significantly (p<0.05) prescribed brand name prescriptions (93.33%) as compared to generic name prescriptions (6.7%). Percentage of encounter with antibiotics and injections was 54% and 18% respectively. Approximately 70% drugs were prescribed according to Essential Medicine List (EML) of State. Antibiotics accounted 30% of prescribed drugs which was significantly higher as compared to other group of prescribed drugs. Our study revealed that prescription errors were most commonly observed at private hospitals and antibiotics was commonly prescribed in private sector. Therefore, strict policy to good prescribing practice and strict antibiotic policy in outdoor patients are required to promote rational use of drugs.

Air Quality and Health Impacts of an Aviation Biofuel Supply Chain in the Northwestern United States

NASA Astrophysics Data System (ADS)

Ravi, V.; Lamb, B. K.

2016-12-01

The Northwest Advanced Renewables Alliance (NARA) is a multi-institutional program aimed at the development of a supply chain for aviation biofuel using woody residues from logging operations as a feedstock. In this paper, we present results based on a comprehensive regional air quality modelling framework (AIRPACT) showing the effects of reduced prescribed fires due to harvesting of the woody biomass feedstock and air quality impacts from the biofuel supply chain. We will present results from two different scenarios - (1) a biorefinery scenario with all emissions associated with supply chain (i.e. vehicular, logging-activity, and biorefinery operations) with two biorefineries in eastern and western Washington and (2) a prescribed burn scenario with all and reduced prescribed fire emissions. Prescribed fire activities peak during Oct-Nov in the region, and prescribed fire simulations for this period in 2011 show significant improvement in particulate air quality in western Oregon for the case with reduced fire emissions. Harvesting woody residue and reducing the amount of prescribed fire activity decreased PM2.5 by 10-20 µg/m3 at several locations. Using BenMAP, an air quality benefit mapping tool, we show that a decrease in PM2.5 concentrations due to reduced prescribed and slash burning activity is associated with decrease in several health end points analysed. Decreases in PM2.5 concentrations also help to improve visibility in protected natural environments, such as national parks. For the biofuel supply chain, summertime simulations were completed and initial results indicate only a small increase (≤1 ppbv) in hourly ozone concentration downwind of a large biorefinery near the Puget Sound region. Impacts from a smaller biorefinery located in eastern Washington are much smaller. Impacts from mobile sources for biomass hauling are negligible.

Modified Redundancy based Technique—a New Approach to Combat Error Propagation Effect of AES

NASA Astrophysics Data System (ADS)

Sarkar, B.; Bhunia, C. T.; Maulik, U.

2012-06-01

Advanced encryption standard (AES) is a great research challenge. It has been developed to replace the data encryption standard (DES). AES suffers from a major limitation of error propagation effect. To tackle this limitation, two methods are available. One is redundancy based technique and the other one is bite based parity technique. The first one has a significant advantage of correcting any error on definite term over the second one but at the cost of higher level of overhead and hence lowering the processing speed. In this paper, a new approach based on the redundancy based technique is proposed that would certainly speed up the process of reliable encryption and hence the secured communication.

Study on the calibration and optimization of double theodolites baseline

NASA Astrophysics Data System (ADS)

Ma, Jing-yi; Ni, Jin-ping; Wu, Zhi-chao

2018-01-01

For the double theodolites measurement system baseline as the benchmark of the scale of the measurement system and affect the accuracy of the system, this paper puts forward a method for calibration and optimization of the double theodolites baseline. Using double theodolites to measure the known length of the reference ruler, and then reverse the baseline formula. Based on the error propagation law, the analyses show that the baseline error function is an important index to measure the accuracy of the system, and the reference ruler position, posture and so on have an impact on the baseline error. The optimization model is established and the baseline error function is used as the objective function, and optimizes the position and posture of the reference ruler. The simulation results show that the height of the reference ruler has no effect on the baseline error; the posture is not uniform; when the reference ruler is placed at x=500mm and y=1000mm in the measurement space, the baseline error is the smallest. The experimental results show that the experimental results are consistent with the theoretical analyses in the measurement space. In this paper, based on the study of the placement of the reference ruler, for improving the accuracy of the double theodolites measurement system has a reference value.

Error-Rate Estimation Based on Multi-Signal Flow Graph Model and Accelerated Radiation Tests

PubMed Central

Wang, Yueke; Xing, Kefei; Deng, Wei; Zhang, Zelong

2016-01-01

A method of evaluating the single-event effect soft-error vulnerability of space instruments before launched has been an active research topic in recent years. In this paper, a multi-signal flow graph model is introduced to analyze the fault diagnosis and meantime to failure (MTTF) for space instruments. A model for the system functional error rate (SFER) is proposed. In addition, an experimental method and accelerated radiation testing system for a signal processing platform based on the field programmable gate array (FPGA) is presented. Based on experimental results of different ions (O, Si, Cl, Ti) under the HI-13 Tandem Accelerator, the SFER of the signal processing platform is approximately 10−3(error/particle/cm2), while the MTTF is approximately 110.7 h. PMID:27583533

Error-Rate Estimation Based on Multi-Signal Flow Graph Model and Accelerated Radiation Tests.

PubMed

He, Wei; Wang, Yueke; Xing, Kefei; Deng, Wei; Zhang, Zelong

2016-01-01

A method of evaluating the single-event effect soft-error vulnerability of space instruments before launched has been an active research topic in recent years. In this paper, a multi-signal flow graph model is introduced to analyze the fault diagnosis and meantime to failure (MTTF) for space instruments. A model for the system functional error rate (SFER) is proposed. In addition, an experimental method and accelerated radiation testing system for a signal processing platform based on the field programmable gate array (FPGA) is presented. Based on experimental results of different ions (O, Si, Cl, Ti) under the HI-13 Tandem Accelerator, the SFER of the signal processing platform is approximately 10-3(error/particle/cm2), while the MTTF is approximately 110.7 h.

A micro-UAS to start prescribed fires

USGS Publications Warehouse

Beachly, Evan; Higgins, James; Laney, Christian; Elbaum, Sebastian; Detweiler, Carrick; Allen, Craig R.; Twidwell, Dirac

2017-01-01

Prescribed fires have many benefits, but existing ignition methods are dangerous, costly, or inefficient. This paper presents the design and evaluation of a micro-UAS that can start a prescribed fire from the air, while being operated from a safe distance and without the costs associated with aerial ignition from a manned aircraft. We evaluate the performance of the system in extensive controlled tests indoors. We verify the capabilities of the system to perform interior ignitions, a normally dangerous task, through the ignition of two prescribed fires alongside wildland firefighters.

Assessment of phase based dose modulation for improved dose efficiency in cardiac CT on an anthropomorphic motion phantom

NASA Astrophysics Data System (ADS)

Budde, Adam; Nilsen, Roy; Nett, Brian

2014-03-01

State of the art automatic exposure control modulates the tube current across view angle and Z based on patient anatomy for use in axial full scan reconstructions. Cardiac CT, however, uses a fundamentally different image reconstruction that applies a temporal weighting to reduce motion artifacts. This paper describes a phase based mA modulation that goes beyond axial and ECG modulation; it uses knowledge of the temporal view weighting applied within the reconstruction algorithm to improve dose efficiency in cardiac CT scanning. Using physical phantoms and synthetic noise emulation, we measure how knowledge of sinogram temporal weighting and the prescribed cardiac phase can be used to improve dose efficiency. First, we validated that a synthetic CT noise emulation method produced realistic image noise. Next, we used the CT noise emulation method to simulate mA modulation on scans of a physical anthropomorphic phantom where a motion profile corresponding to a heart rate of 60 beats per minute was used. The CT noise emulation method matched noise to lower dose scans across the image within 1.5% relative error. Using this noise emulation method to simulate modulating the mA while keeping the total dose constant, the image variance was reduced by an average of 11.9% on a scan with 50 msec padding, demonstrating improved dose efficiency. Radiation dose reduction in cardiac CT can be achieved while maintaining the same level of image noise through phase based dose modulation that incorporates knowledge of the cardiac reconstruction algorithm.