Epidemiologic Evaluation of Measurement Data in the Presence of Detection Limits

PubMed Central

Lubin, Jay H.; Colt, Joanne S.; Camann, David; Davis, Scott; Cerhan, James R.; Severson, Richard K.; Bernstein, Leslie; Hartge, Patricia

2004-01-01

Quantitative measurements of environmental factors greatly improve the quality of epidemiologic studies but can pose challenges because of the presence of upper or lower detection limits or interfering compounds, which do not allow for precise measured values. We consider the regression of an environmental measurement (dependent variable) on several covariates (independent variables). Various strategies are commonly employed to impute values for interval-measured data, including assignment of one-half the detection limit to nondetected values or of “fill-in” values randomly selected from an appropriate distribution. On the basis of a limited simulation study, we found that the former approach can be biased unless the percentage of measurements below detection limits is small (5–10%). The fill-in approach generally produces unbiased parameter estimates but may produce biased variance estimates and thereby distort inference when 30% or more of the data are below detection limits. Truncated data methods (e.g., Tobit regression) and multiple imputation offer two unbiased approaches for analyzing measurement data with detection limits. If interest resides solely on regression parameters, then Tobit regression can be used. If individualized values for measurements below detection limits are needed for additional analysis, such as relative risk regression or graphical display, then multiple imputation produces unbiased estimates and nominal confidence intervals unless the proportion of missing data is extreme. We illustrate various approaches using measurements of pesticide residues in carpet dust in control subjects from a case–control study of non-Hodgkin lymphoma. PMID:15579415

Measuring the efficiency of Palestinian public hospitals during 2010-2015: an application of a two-stage DEA method.

PubMed

Sultan, Wasim I M; Crispim, José

2018-05-29

While health needs and expenditure in the Occupied Palestinian Territories (OPT) are growing, the international donations are declining and the economic situation is worsening. The purpose of this paper is twofold, to evaluate the productive efficiency of public hospitals in West Bank and to study contextual factors contributing to efficiency differences. This study examined technical efficiency among 11 public hospitals in West Bank from 2010 through 2015 targeting a total of 66 observations. Nationally representative data were extracted from the official annual health reports. We applied input-oriented Data Envelopment Analysis (DEA) models to estimate efficiency scores. To elaborate further on performance, we used Tobit regression to identify contextual factors whose impact on inefficient performance is statistically significant. Despite the increase in efficiency mean scores by 4% from 2010 to 2015, findings show potential savings of 14.5% of resource consumption without reducing the volume of the provided services. The significant Tobit model showed four predictors explaining the inefficient performance of a hospital (p <  0.01) are: bed occupancy rate (BOR); the outpatient-inpatient ratio (OPIPR); hospital's size (SIZE); and the availability of primary healthcare centers within the hospital's catchment area (PRC). There is a strong effect of OPIPR on efficiency differences between hospitals: A one unit increase in OPIPR will lead a decrease of 19.7% in the predicted inefficiency level holding all other factors constant. To date, no previous studies have examined the efficiency of public hospitals in the OPT. Our work identified their efficiency levels for potential improvements and the determinants of efficient performance. Based on the measurement of efficiency, the generated information may guide hospitals' managers, policymakers, and international donors improving the performance of the main national healthcare provider. The scope of this study is limited to public hospitals in West Bank. For a better understanding of the Palestinian market, further research on private hospitals and hospitals in Gaza Strip will be useful.

Modeling Outcomes with Floor or Ceiling Effects: An Introduction to the Tobit Model

ERIC Educational Resources Information Center

McBee, Matthew

2010-01-01

In gifted education research, it is common for outcome variables to exhibit strong floor or ceiling effects due to insufficient range of measurement of many instruments when used with gifted populations. Common statistical methods (e.g., analysis of variance, linear regression) produce biased estimates when such effects are present. In practice,…

Global Status, Intra-Institutional Stratification and Organizational Segmentation: A Time-Dynamic Tobit Analysis of ARWU Position among U.S. Universities

ERIC Educational Resources Information Center

Cantwell, Brendan; Taylor, Barrett J.

2013-01-01

Ranking systems such as "The Times Higher Education's World University Rankings" and Shanghai Jiao Tong University's "Academic Rankings of World Universities" simultaneously mark global status and stimulate global academic competition. As international ranking systems have become more prominent, researchers have begun to examine whether global…

Atrazine concentrations in near-surface aquifers: A censored regression approach

USGS Publications Warehouse

Liu, S.; Yen, S.T.; Kolpin, D.W.

1996-01-01

In 1991, the U.S. Geological Survey (USGS) conducted a study to investigate the occurrence of atrazine (2-chloro-4-ethylamino-6- isopropylamino-s-triazine) and other agricultural chemicals in near-surface aquifers in the midcontinental USA. Because about 83% of the atrazine concentrations from the USGS study were censored, standard statistical estimation procedures could not be used. To determine factors that affect atrazine concentrations in groundwater while accommodating the high degree of data censoring. Tobit models were used (normal homoscedastic, normal heteroscedastic, lognormal homoscedastic, and lognormal heteroscedastic). Empirical results suggest that the lognormal heteroscedastic Tobit model is the model of choice for this type of study. This model determined the following factors to have the strongest effect on atrazine concentrations in groundwater: percent of pasture within 3.2 km, percent of forest within 3.2 km (2 mi), mean open interval of the well, primary water use of a well, aquifer class (unconsolidated or bedrock), aquifer type (unconfined or confined), existence of a stream within 30 m (100 ft), existence of a stream within 30 m to 0.4 km (0.25 mi), and existence of a stream within 0.4 to 3.2 km. Examining the elasticities of the continuous explanatory factors provides further insight into their effects on atrazine concentrations in groundwater. This study documents a viable statistical method that can be used to accommodate the complicating presence of censured data, a feature that commonly occurs in environmental data.

INFLUENCES OF GENDER IDEOLOGY AND HOUSEWORK ALLOCATION ON WOMEN’S EMPLOYMENT OVER THE LIFE COURSE

PubMed Central

Cunningham, Mick

2008-01-01

The study investigates the influences of women’s attitudes about gender and couples’ housework allocation patterns on women’s employment status and work hours across the life course. The influence of these factors on the employment characteristics of continuously married women is investigated at four time points: 1977, 1980, 1985, and 1993. Data come from the Intergenerational Panel Study of Parents and Children and the analysis sample includes 556 continuously married women. Findings from structural equation, fixed effects, and tobit models offer consistent evidence of long-term positive influences of women’s egalitarian gender ideology and men’s participation in routine housework on women’s labor force participation. The results provide support for hypotheses based on the notion of lagged adaptation. PMID:19255608

Acceptability and willingness to pay for telemedicine services in Enugu state, southeast Nigeria

PubMed Central

Arize, Ifeyinwa; Onwujekwe, Obinna

2017-01-01

Background This study examines the level of awareness, acceptability and consumers’ willingness to pay (WTP) for telemedicine services using the contingent valuation method (CVM). This work is important as it elicits the value that consumers attach to telemedicine given there is a gap in this knowledge in many sub-Saharan countries such as in Nigeria. Methods The study was based on primary data obtained through an interviewer-administered questionnaire of 370 individuals including both males and females from 25 years and over, to collect data on respondents’ awareness of, acceptability of, and WTP for telemedicine, using the bidding game question format. A socioeconomic status (SES) index was created, based on information on household assets, and was used to categorize respondents into SES quartiles. The data were analyzed using a combination of descriptive techniques, logistics and the Tobit regression model (Tobit Type 1) methods. Results The study found that majority of the people (58.9%) had no knowledge of telemedicine. However, 48.7% of the respondents were willing to pay for telemedicine. The mean WTP for a telemedicine was US$2.04 for each visit. Tobit regression analysis showed that respondents’ socioeconomic status (SES) was the main statistically significant variable that explained their WTP for telemedicine. Conclusion The study has shown that there is a low-level awareness of and WTP for telemedicine services in Enugu State, South East of Nigeria. The finding of a positive relationship between SES and WTP implies that the poor may not be able to pay for telemedicine and may need government subsidies to be able to benefit from such service. Also, government and their partners need to undertake wide scale campaign before the introduction of telemedicine. PMID:29942606

Ownership and technical efficiency of hospitals: evidence from Ghana using data envelopment analysis.

PubMed

Jehu-Appiah, Caroline; Sekidde, Serufusa; Adjuik, Martin; Akazili, James; Almeida, Selassi D; Nyonator, Frank; Baltussen, Rob; Asbu, Eyob Zere; Kirigia, Joses Muthuri

2014-04-08

In order to measure and analyse the technical efficiency of district hospitals in Ghana, the specific objectives of this study were to (a) estimate the relative technical and scale efficiency of government, mission, private and quasi-government district hospitals in Ghana in 2005; (b) estimate the magnitudes of output increases and/or input reductions that would have been required to make relatively inefficient hospitals more efficient; and (c) use Tobit regression analysis to estimate the impact of ownership on hospital efficiency. In the first stage, we used data envelopment analysis (DEA) to estimate the efficiency of 128 hospitals comprising of 73 government hospitals, 42 mission hospitals, 7 quasi-government hospitals and 6 private hospitals. In the second stage, the estimated DEA efficiency scores are regressed against hospital ownership variable using a Tobit model. This was a retrospective study. In our DEA analysis, using the variable returns to scale model, out of 128 district hospitals, 31 (24.0%) were 100% efficient, 25 (19.5%) were very close to being efficient with efficiency scores ranging from 70% to 99.9% and 71 (56.2%) had efficiency scores below 50%. The lowest-performing hospitals had efficiency scores ranging from 21% to 30%.Quasi-government hospitals had the highest mean efficiency score (83.9%) followed by public hospitals (70.4%), mission hospitals (68.6%) and private hospitals (55.8%). However, public hospitals also got the lowest mean technical efficiency scores (27.4%), implying they have some of the most inefficient hospitals.Regarding regional performance, Northern region hospitals had the highest mean efficiency score (83.0%) and Volta Region hospitals had the lowest mean score (43.0%).From our Tobit regression, we found out that while quasi-government ownership is positively associated with hospital technical efficiency, private ownership negatively affects hospital efficiency. It would be prudent for policy-makers to examine the least efficient hospitals to correct widespread inefficiency. This would include reconsidering the number of hospitals and their distribution, improving efficiency and reducing duplication by closing or scaling down hospitals with efficiency scores below a certain threshold. For private hospitals with inefficiency related to large size, there is a need to break down such hospitals into manageable sizes.

Ownership and technical efficiency of hospitals: evidence from Ghana using data envelopment analysis

PubMed Central

2014-01-01

Background In order to measure and analyse the technical efficiency of district hospitals in Ghana, the specific objectives of this study were to (a) estimate the relative technical and scale efficiency of government, mission, private and quasi-government district hospitals in Ghana in 2005; (b) estimate the magnitudes of output increases and/or input reductions that would have been required to make relatively inefficient hospitals more efficient; and (c) use Tobit regression analysis to estimate the impact of ownership on hospital efficiency. Methods In the first stage, we used data envelopment analysis (DEA) to estimate the efficiency of 128 hospitals comprising of 73 government hospitals, 42 mission hospitals, 7 quasi-government hospitals and 6 private hospitals. In the second stage, the estimated DEA efficiency scores are regressed against hospital ownership variable using a Tobit model. This was a retrospective study. Results In our DEA analysis, using the variable returns to scale model, out of 128 district hospitals, 31 (24.0%) were 100% efficient, 25 (19.5%) were very close to being efficient with efficiency scores ranging from 70% to 99.9% and 71 (56.2%) had efficiency scores below 50%. The lowest-performing hospitals had efficiency scores ranging from 21% to 30%. Quasi-government hospitals had the highest mean efficiency score (83.9%) followed by public hospitals (70.4%), mission hospitals (68.6%) and private hospitals (55.8%). However, public hospitals also got the lowest mean technical efficiency scores (27.4%), implying they have some of the most inefficient hospitals. Regarding regional performance, Northern region hospitals had the highest mean efficiency score (83.0%) and Volta Region hospitals had the lowest mean score (43.0%). From our Tobit regression, we found out that while quasi-government ownership is positively associated with hospital technical efficiency, private ownership negatively affects hospital efficiency. Conclusions It would be prudent for policy-makers to examine the least efficient hospitals to correct widespread inefficiency. This would include reconsidering the number of hospitals and their distribution, improving efficiency and reducing duplication by closing or scaling down hospitals with efficiency scores below a certain threshold. For private hospitals with inefficiency related to large size, there is a need to break down such hospitals into manageable sizes. PMID:24708886

Hong Kong Hospital Authority resource efficiency evaluation: Via a novel DEA-Malmquist model and Tobit regression model.

PubMed

Guo, Hainan; Zhao, Yang; Niu, Tie; Tsui, Kwok-Leung

2017-01-01

The Hospital Authority (HA) is a statutory body managing all the public hospitals and institutes in Hong Kong (HK). In recent decades, Hong Kong Hospital Authority (HKHA) has been making efforts to improve the healthcare services, but there still exist some problems like unfair resource allocation and poor management, as reported by the Hong Kong medical legislative committee. One critical consequence of these problems is low healthcare efficiency of hospitals, leading to low satisfaction among patients. Moreover, HKHA also suffers from the conflict between limited resource and growing demand. An effective evaluation of HA is important for resource planning and healthcare decision making. In this paper, we propose a two-phase method to evaluate HA efficiency for reducing healthcare expenditure and improving healthcare service. Specifically, in Phase I, we measure the HKHA efficiency changes from 2000 to 2013 by applying a novel DEA-Malmquist index with undesirable factors. In Phase II, we further explore the impact of some exogenous factors (e.g., population density) on HKHA efficiency by Tobit regression model. Empirical results show that there are significant differences between the efficiencies of different hospitals and clusters. In particular, it is found that the public hospital serving in a richer district has a relatively lower efficiency. To a certain extent, this reflects the socioeconomic reality in HK that people with better economic condition prefers receiving higher quality service from the private hospitals.

Hong Kong Hospital Authority resource efficiency evaluation: Via a novel DEA-Malmquist model and Tobit regression model

PubMed Central

Guo, Hainan; Zhao, Yang; Niu, Tie; Tsui, Kwok-Leung

2017-01-01

The Hospital Authority (HA) is a statutory body managing all the public hospitals and institutes in Hong Kong (HK). In recent decades, Hong Kong Hospital Authority (HKHA) has been making efforts to improve the healthcare services, but there still exist some problems like unfair resource allocation and poor management, as reported by the Hong Kong medical legislative committee. One critical consequence of these problems is low healthcare efficiency of hospitals, leading to low satisfaction among patients. Moreover, HKHA also suffers from the conflict between limited resource and growing demand. An effective evaluation of HA is important for resource planning and healthcare decision making. In this paper, we propose a two-phase method to evaluate HA efficiency for reducing healthcare expenditure and improving healthcare service. Specifically, in Phase I, we measure the HKHA efficiency changes from 2000 to 2013 by applying a novel DEA-Malmquist index with undesirable factors. In Phase II, we further explore the impact of some exogenous factors (e.g., population density) on HKHA efficiency by Tobit regression model. Empirical results show that there are significant differences between the efficiencies of different hospitals and clusters. In particular, it is found that the public hospital serving in a richer district has a relatively lower efficiency. To a certain extent, this reflects the socioeconomic reality in HK that people with better economic condition prefers receiving higher quality service from the private hospitals. PMID:28886087

A smooth mixture of Tobits model for healthcare expenditure.

PubMed

Keane, Michael; Stavrunova, Olena

2011-09-01

This paper develops a smooth mixture of Tobits (SMTobit) model for healthcare expenditure. The model is a generalization of the smoothly mixing regressions framework of Geweke and Keane (J Econometrics 2007; 138: 257-290) to the case of a Tobit-type limited dependent variable. A Markov chain Monte Carlo algorithm with data augmentation is developed to obtain the posterior distribution of model parameters. The model is applied to the US Medicare Current Beneficiary Survey data on total medical expenditure. The results suggest that the model can capture the overall shape of the expenditure distribution very well, and also provide a good fit to a number of characteristics of the conditional (on covariates) distribution of expenditure, such as the conditional mean, variance and probability of extreme outcomes, as well as the 50th, 90th, and 95th, percentiles. We find that healthier individuals face an expenditure distribution with lower mean, variance and probability of extreme outcomes, compared with their counterparts in a worse state of health. Males have an expenditure distribution with higher mean, variance and probability of an extreme outcome, compared with their female counterparts. The results also suggest that heart and cardiovascular diseases affect the expenditure of males more than that of females. Copyright © 2011 John Wiley & Sons, Ltd.

Factors associated with job satisfaction among commune health workers: implications for human resource policies.

PubMed

Tran, Bach Xuan; Van Hoang, Minh; Nguyen, Hinh Duc

2013-01-30

Job satisfaction among health workers is an important indicator in assessing the performance and efficiency of health services. This study measured job satisfaction and determined associated factors among health workers in 38 commune health stations in an urban district and a rural district of Hanoi, Vietnam. A total of 252 health workers (36 medical doctors and 216 nurses and technicians; 74% female) were interviewed. A job satisfaction measure was developed using factor analysis, from which four dimensions emerged, namely 'benefits and prospects,' 'facility and equipment,' 'performance,' and 'professionals.' The results demonstrate that respondents were least satisfied with the following categories: salary and incentives (24.0%), benefit packages (25.1%), equipment (35.7%), and environment (41.8%). The average satisfaction score was moderate across four domains; it was the highest for 'performance' (66.6/100) and lowest for 'facility and equipment' (50.4/100). Tobit-censored regression models, constructed using stepwise selection, determined significant predictors of job satisfaction including age, areas of work and expertise, professional education, urban versus rural setting, and sufficient number of staff. The findings highlight the need to implement health policies that focus on incentives, working conditions, workloads, and personnel management at grassroots level.

Taxes and Bribes in Uganda.

PubMed

Jagger, Pamela; Shively, Gerald

Using data from 433 firms operating along Uganda's charcoal and timber supply chains we investigate patterns of bribe payment and tax collection between supply chain actors and government officials responsible for collecting taxes and fees. We examine the factors associated with the presence and magnitude of bribe and tax payments using a series of bivariate probit and Tobit regression models. We find empirical support for a number of hypotheses related to payments, highlighting the role of queuing, capital-at-risk, favouritism, networks, and role in the supply chain. We also find that taxes crowd-in bribery in the charcoal market.

Taxes and Bribes in Uganda

PubMed Central

Jagger, Pamela; Shively, Gerald

2016-01-01

Using data from 433 firms operating along Uganda’s charcoal and timber supply chains we investigate patterns of bribe payment and tax collection between supply chain actors and government officials responsible for collecting taxes and fees. We examine the factors associated with the presence and magnitude of bribe and tax payments using a series of bivariate probit and Tobit regression models. We find empirical support for a number of hypotheses related to payments, highlighting the role of queuing, capital-at-risk, favouritism, networks, and role in the supply chain. We also find that taxes crowd-in bribery in the charcoal market. PMID:27274568

Factors influencing the demand of the service of community based animal health care in Zimbabwe.

PubMed

Mutambara, J; Dube, I; Matangi, E; Majeke, F

2013-11-01

This study was done to find out about animal health service providers and factors that determined demand for community based veterinary service delivery in smallholder sector of Zimbabwe. Focus group discussions and a questionnaire was used to collect data on veterinary services providers and socio-economic factors related to animal health from a sample (N=333) smallholder livestock farmers from Gutu district of Masvingo province in Zimbabwe. Analytical techniques used were descriptive statistics, K-mean cluster analysis and Tobit regression model. Results showed that the majority of farmers (45%) obtained services from both Community Based Animal Health Workers (CBAHWs) and Department of Veterinary Service (DVS), 25% DVS only, 20% used CBAHWs while 10% did not seek any services. Further analysis showed that distance to CBAHW, distance to AHMC and employment status were significantly related to demand for CBAHWs with coefficients of -1.5, 0.7 and -10.3, respectively. The study thus concluded that CBAHW is an alternative animal health service delivery approach already practiced in smallholder farming sectors of Zimbabwe. Socio-economic factors significantly influenced the demand for CBAHW services. Given limited resources by state sponsored veterinary services, it is recommended that the CBAHWs approach should be encouraged as supplementary service provider especially in areas further DVS. These community organizations can be empowered by the state to deliver more improved services based on hygiene and modern science at a relatively low cost to farmers. Copyright © 2013 Elsevier B.V. All rights reserved.

Assessing household health expenditure with Box-Cox censoring models.

PubMed

Chaze, Jean-Paul

2005-09-01

In order to assess the combined presence of zero expenditures and a heavily skewed distribution of positive expenditures, the Box-Cox transformation with location parameter is used to define a set of models generalising the standard Tobit, Heckman selection and double-hurdle models. Extended flexibility with respect to previous specifications is introduced, notably regarding negative transformation parameters, which may prove necessary for medical expenditures, and corner-solution outcomes. An illustration is provided by the analysis of household health expenditure in Switzerland. Copyright (c) 2005 John Wiley & Sons, Ltd.

[Teacher sick leave: Prevalence, duration, reasons and covariates].

PubMed

Vercambre-Jacquot, M-N; Gilbert, F; Billaudeau, N

2018-02-01

Absences from work have considerable social and economic impact. In the education sector, the phenomenon is particularly worrying since teacher sick leave has an impact on the overall performance of the education system. Yet, available data are scarce. In April-June 2013, 2653 teachers responded to a population-based postal survey on their quality of life (enquête Qualité de vie des enseignants, MGEN Foundation/Ministry of education, response rate 53 %). Besides questions on work environment and health, teachers were asked to describe their eventual sick leave(s) since the beginning of the school year: duration, type and medical reasons. Self-reported information was reinforced by administrative data from ministerial databases and weighted to be extrapolated to all French teachers. Tobit models adjusted for individual factors of a private nature were used to investigate different occupational risk factors of teacher sick leave, taking into account both the estimated effect on the probability of sick leave and the length of it. More than one in three teachers (36 %) reported having had at least one day of sick leave since the beginning of the school year. Respiratory/ENT diseases were the leading reason for sick leave (37 %). However, and because sick leave duration depended on the underlying health problem, such diseases came in third place among justifications of sick leave days (14 %), far behind musculoskeletal problems (27 %) and neurological and psychological disorders (25 %). Tobit models suggested that some occupational factors significantly associated with the risk of sick leave may represent promising preventive targets, including high psychological demand, workplace violence and unfavorable socio-environmental context. Our study provides objective evidence about the issue of sick leave among French teachers, highlighting the usefulness of implementing actions to minimize its weight. To this end, the study findings point-out the importance of considering not only the probability of sick leave, but also its duration. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Wind power development in the United States: Effects of policies and electricity transmission congestion

NASA Astrophysics Data System (ADS)

Hitaj, Claudia

In this dissertation, I analyze the drivers of wind power development in the United States as well as the relationship between renewable power plant location and transmission congestion and emissions levels. I first examine the role of government renewable energy incentives and access to the electricity grid on investment in wind power plants across counties from 1998-2007. The results indicate that the federal production tax credit, state-level sales tax credit and production incentives play an important role in promoting wind power. In addition, higher wind power penetration levels can be achieved by bringing more parts of the electricity transmission grid under independent system operator regulation. I conclude that state and federal government policies play a significant role in wind power development both by providing financial support and by improving physical and procedural access to the electricity grid. Second, I examine the effect of renewable power plant location on electricity transmission congestion levels and system-wide emissions levels in a theoretical model and a simulation study. A new renewable plant takes the effect of congestion on its own output into account, but ignores the effect of its marginal contribution to congestion on output from existing plants, which results in curtailment of renewable power. Though pricing congestion removes the externality and reduces curtailment, I find that in the absence of a price on emissions, pricing congestion may in some cases actually increase system-wide emissions. The final part of my dissertation deals with an econometric issue that emerged from the empirical analysis of the drivers of wind power. I study the effect of the degree of censoring on random-effects Tobit estimates in finite sample with a particular focus on severe censoring, when the percentage of uncensored observations reaches 1 to 5 percent. The results show that the Tobit model performs well even at 5 percent uncensored observations with the bias in the Tobit estimates remaining at or below 5 percent. Under severe censoring (1 percent uncensored observations), large biases appear in the estimated standard errors and marginal effects. These are generally reduced as the sample size increases in both N and T.

The effect of environmental factors on technical and scale efficiency of primary health care providers in Greece.

PubMed

Kontodimopoulos, Nick; Moschovakis, Giorgos; Aletras, Vassilis H; Niakas, Dimitris

2007-11-17

The purpose of this study was to compare technical and scale efficiency of primary care centers from the two largest Greek providers, the National Health System (NHS) and the Social Security Foundation (IKA) and to determine if, and how, efficiency is affected by various exogenous factors such as catchment population and location. The sample comprised of 194 units (103 NHS and 91 IKA). Efficiency was measured with Data Envelopment Analysis (DEA) using three inputs, -medical staff, nursing/paramedical staff, administrative/other staff- and two outputs, which were the aggregated numbers of scheduled/emergency patient visits and imaging/laboratory diagnostic tests. Facilities were categorized as small, medium and large (<15,000, 15,000-30,000 and >30,000 respectively) to reflect catchment population and as urban/semi-urban or remote/island to reflect location. In a second stage analysis, technical and scale efficiency scores were regressed against facility type (NHS or IKA), size and location using multivariate Tobit regression. Regarding technical efficiency, IKA performed better than the NHS (84.9% vs. 70.1%, Mann-Whitney P < 0.001), smaller units better than medium-sized and larger ones (84.2% vs. 72.4% vs. 74.3%, Kruskal-Wallis P < 0.01) and remote/island units better than urban centers (81.1% vs. 75.7%, Mann-Whitney P = 0.103). As for scale efficiency, IKA again outperformed the NHS (89.7% vs. 85.9%, Mann-Whitney P = 0.080), but results were reversed in respect to facility size and location. Specifically, larger units performed better (96.3% vs. 90.9% vs. 75.9%, Kruskal-Wallis P < 0.001), and urban units showed higher scale efficiency than remote ones (91.9% vs. 75.3%, Mann-Whitney P < 0.001). Interestingly 75% of facilities appeared to be functioning under increasing returns to scale. Within-group comparisons revealed significant efficiency differences between the two primary care providers. Tobit regression models showed that facility type, size and location were significant explanatory variables of technical and scale efficiency. Variations appeared to exist in the productive performance of the NHS and IKA as the two main primary care providers in Greece. These variations reflect differences in primary care organization, economical incentives, financial constraints, sociodemographic and local peculiarities. In all technical efficiency comparisons, IKA facilities appeared to outperform NHS ones irrespective of facility size or location. In respect to scale efficiency, the results were to some extent inconclusive and observed differences were mostly insignificant, although again IKA appeared to perform better.

The moderating effect of leadership on the relationship between personality and performance.

PubMed

Yeh, Shu-Chuan Jennifer; Yuan, Kuo-Shu; Chen, Shih-Hua Sarah; Lo, Ying-Ying; Chou, Hsueh-Chih; Huang, Shan; Chiu, Herng-Chia; Wan, Thomas T H

2016-10-01

To examine how personality and leadership influence efficiency in the nursing service environment. Leadership and personality contribute to the success and failure of a unit. However, how they interact to influence performance is still understudied. We used matched pairs sample design to survey 135 head nurses and 1353 registered nurses on validated instruments of demographic characteristics, leadership styles and personality during June and July of 2014. Efficiency was calculated using Data Envelopment Analysis. Tobit regression was used for analysis. High conscientiousness and low neuroticism were significantly associated with higher efficiency. Particularly, under the initiating structure leadership style, high conscientiousness, high extraversion, high agreeableness, high openness and low neuroticism were related to higher efficiency. Openness would improve efficiency under a low consideration leadership style. Most personality traits were related to higher efficiency under the initiating leadership style. Only openness would improve leaders' efficiency under a high initiating structure and a low consideration leadership style. Considering personality as one factor of selecting head nurses, selecting the right person can improve the fit between individuals and organisations, which in turn, improves job performance. Training head nurses to develop better leadership styles in nurses is another way to enhance efficiency. © 2016 John Wiley & Sons Ltd.

Estimates of Median Flows for Streams on the 1999 Kansas Surface Water Register

USGS Publications Warehouse

Perry, Charles A.; Wolock, David M.; Artman, Joshua C.

2004-01-01

The Kansas State Legislature, by enacting Kansas Statute KSA 82a?2001 et. seq., mandated the criteria for determining which Kansas stream segments would be subject to classification by the State. One criterion for the selection as a classified stream segment is based on the statistic of median flow being equal to or greater than 1 cubic foot per second. As specified by KSA 82a?2001 et. seq., median flows were determined from U.S. Geological Survey streamflow-gaging-station data by using the most-recent 10 years of gaged data (KSA) for each streamflow-gaging station. Median flows also were determined by using gaged data from the entire period of record (all-available hydrology, AAH). Least-squares multiple regression techniques were used, along with Tobit analyses, to develop equations for estimating median flows for uncontrolled stream segments. The drainage area of the gaging stations on uncontrolled stream segments used in the regression analyses ranged from 2.06 to 12,004 square miles. A logarithmic transformation of the data was needed to develop the best linear relation for computing median flows. In the regression analyses, the significant climatic and basin characteristics, in order of importance, were drainage area, mean annual precipitation, mean basin permeability, and mean basin slope. Tobit analyses of KSA data yielded a model standard error of prediction of 0.285 logarithmic units, and the best equations using Tobit analyses of AAH data had a model standard error of prediction of 0.250 logarithmic units. These regression equations and an interpolation procedure were used to compute median flows for the uncontrolled stream segments on the 1999 Kansas Surface Water Register. Measured median flows from gaging stations were incorporated into the regression-estimated median flows along the stream segments where available. The segments that were uncontrolled were interpolated using gaged data weighted according to the drainage area and the bias between the regression-estimated and gaged flow information. On controlled segments of Kansas streams, the median flow information was interpolated between gaging stations using only gaged data weighted by drainage area. Of the 2,232 total stream segments on the Kansas Surface Water Register, 34.5 percent of the segments had an estimated median streamflow of less than 1 cubic foot per second when the KSA analysis was used. When the AAH analysis was used, 36.2 percent of the segments had an estimated median streamflow of less than 1 cubic foot per second. This report supercedes U.S. Geological Survey Water-Resources Investigations Report 02?4292.

Public willingness to pay for CO2 mitigation and the determinants under climate change: a case study of Suzhou, China.

PubMed

Yang, Jie; Zou, Liping; Lin, Tiansheng; Wu, Ying; Wang, Haikun

2014-12-15

This study explored the factors that influence respondents' willingness to pay (WTP) for CO2 mitigation under climate change. A questionnaire survey combined with contingent valuation and psychometric paradigm methods were conducted in the city of Suzhou, Jiangsu Province in China. Respondents' traditional demographic attributes, risk perception of greenhouse gas (GHG), and attitude toward the government's risk management practices were established using a Tobit model to analyze the determinants. The results showed that about 55% of the respondents refused to pay for CO2 mitigation, respondent's WTP increased with increasing CO2 mitigation percentage. Important factors influencing WTP include people's feeling of dread of GHGs, confidence in policy, the timeliness of governmental information disclosure, age, education and income level. Copyright © 2014 Elsevier Ltd. All rights reserved.

Price elasticity of on- and off-premises demand for alcoholic drinks: A Tobit analysis.

PubMed

Jiang, Heng; Livingston, Michael; Room, Robin; Callinan, Sarah

2016-06-01

Understanding how price policies will affect alcohol consumption requires estimates of the impact of price on consumption among different types of drinkers and across different consumption settings. This study aims to estimate how changes in price could affect alcohol demand across different beverages, different settings (on-premise, e.g., bars, restaurants and off-premise, e.g., liquor stores, supermarkets), and different levels of drinking and income. Tobit analysis is employed to estimate own- and cross-price elasticities of alcohol demand among 11 subcategories of beverage based on beverage type and on- or off-premise supply, using cross-sectional data from the Australian arm of the International Alcohol Control Survey 2013. Further elasticity estimates were derived for sub-groups of drinkers based on their drinking and income levels. The results suggest that demand for nearly every subcategory of alcohol significantly responds to its own price change, except for on-premise spirits and ready-to-drink spirits. The estimated demand for off-premise beverages is more strongly affected by own price changes than the same beverages in on-premise settings. Demand for off-premise regular beer and off-premise cask wine is more price responsive than demand for other beverages. Harmful drinkers and lower income groups appear more price responsive than moderate drinkers and higher income groups. Our findings suggest that alcohol price policies, such as increasing alcohol taxes or introducing a minimum unit price, can reduce alcohol demand. Price appears to be particularly effective for reducing consumption and as well as alcohol-related harm among harmful drinkers and lower income drinkers. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Evaluation of performance and impacts of maternal and child health hospital services using Data Envelopment Analysis in Guangxi Zhuang Autonomous Region, China: a comparison study among poverty and non-poverty county level hospitals.

PubMed

Wang, Xuan; Luo, Hongye; Qin, Xianjin; Feng, Jun; Gao, Hongda; Feng, Qiming

2016-08-23

As the core of the county-level Maternal and Child Health Hospitals (MCHH) in rural areas of China, the service efficiency affects the fairness and availability of healthcare services. This study aims to identify the determinants of hospital efficiency and explore how to improve the performance of MCHH in terms of productivity and efficiency. Data was collected from a sample of 32 county-level MCHHs of Guangxi in 2014. Firstly, we specified and measured the indicators of the inputs and outputs which represent hospital resources expended and its profiles respectively. Then we estimated the efficiency scores using Data Envelopment Analysis (DEA) for each hospital. Efficiency scores were decomposed into technical, scale and congestion components, and the potential output increases and/or input reductions were also estimated in this model, which would make relatively inefficient hospitals more efficient. In the second stage, the estimated efficiency scores are regressed against hospital external and internal environment factors using a Tobit model. We used DEAP (V2.1) and R for data analysis. The average scores of technical efficiency, net technical efficiency (managerial efficiency) and scale efficiency of the hospitals were 0.875, 0.922 and 0.945, respectively. Half of the hospitals were efficient, and 9.4 % and 40.6 % were weakly efficient and inefficient, respectively. Among the low-productiveness hospitals, 61.1 % came from poor counties (Poor counties in this article are in the list of key poverty-stricken counties at the national level, published by The State Council Leading Group Office of Poverty Alleviation and Development, 2012). The total input indicated that redundant medical resources in poverty areas were significantly higher than those in non-poverty areas. The Tobit regression model showed that the technical efficiency was proportional to the total annual incomes, the number of discharge patients, and the number of outpatient and emergency visits, while it was inversely proportional to total expenditure and the actual number of open beds. Technical efficiency was not associated with number of health care workers. The overall operational efficiency of the county-level MCHHs in Guangxi was low and needs to be improved. Regional economic differences affect the performances of hospitals. Health administrations should adjust and optimize the resource investments for the different areas. For the hospitals in poverty areas, policy-makers should not only consider the hardware facilities investment, but also the introduction of advanced techniques and high-level medical personnel to improve their technical efficiency.

Mindfulness, Physical Activity and Avoidance of Secondhand Smoke: A Study of College Students in Shanghai.

PubMed

Gao, Yu; Shi, Lu

2015-08-21

To better understand the documented link between mindfulness and longevity, we examine the association between mindfulness and conscious avoidance of secondhand smoke (SHS), as well as the association between mindfulness and physical activity. In Shanghai University of Finance and Economics (SUFE) we surveyed a convenience sample of 1516 college freshmen. We measured mindfulness, weekly physical activity, and conscious avoidance of secondhand smoke, along with demographic and behavioral covariates. We used a multilevel logistic regression to test the association between mindfulness and conscious avoidance of secondhand smoke, and used a Tobit regression model to test the association between mindfulness and metabolic equivalent hours per week. In both models the home province of the student respondent was used as the cluster variable, and demographic and behavioral covariates, such as age, gender, smoking history, household registration status (urban vs. rural), the perceived smog frequency in their home towns, and the asthma diagnosis. The logistic regression of consciously avoiding SHS shows that a higher level of mindfulness was associated with an increase in the odds ratio of conscious SHS avoidance (logged odds: 0.22, standard error: 0.07, p < 0.01). The Tobit regression shows that a higher level of mindfulness was associated with more metabolic equivalent hours per week (Tobit coefficient: 4.09, standard error: 1.13, p < 0.001). This study is an innovative attempt to study the behavioral issue of secondhand smoke from the perspective of the potential victim, rather than the active smoker. The observed associational patterns here are consistent with previous findings that mindfulness is associated with healthier behaviors in obesity prevention and substance use. Research designs with interventions are needed to test the causal link between mindfulness and these healthy behaviors.

Mindfulness, Physical Activity and Avoidance of Secondhand Smoke: A Study of College Students in Shanghai

PubMed Central

Gao, Yu; Shi, Lu

2015-01-01

Introduction: To better understand the documented link between mindfulness and longevity, we examine the association between mindfulness and conscious avoidance of secondhand smoke (SHS), as well as the association between mindfulness and physical activity. Method: In Shanghai University of Finance and Economics (SUFE) we surveyed a convenience sample of 1516 college freshmen. We measured mindfulness, weekly physical activity, and conscious avoidance of secondhand smoke, along with demographic and behavioral covariates. We used a multilevel logistic regression to test the association between mindfulness and conscious avoidance of secondhand smoke, and used a Tobit regression model to test the association between mindfulness and metabolic equivalent hours per week. In both models the home province of the student respondent was used as the cluster variable, and demographic and behavioral covariates, such as age, gender, smoking history, household registration status (urban vs. rural), the perceived smog frequency in their home towns, and the asthma diagnosis. Results: The logistic regression of consciously avoiding SHS shows that a higher level of mindfulness was associated with an increase in the odds ratio of conscious SHS avoidance (logged odds: 0.22, standard error: 0.07, p < 0.01). The Tobit regression shows that a higher level of mindfulness was associated with more metabolic equivalent hours per week (Tobit coefficient: 4.09, standard error: 1.13, p < 0.001). Discussion: This study is an innovative attempt to study the behavioral issue of secondhand smoke from the perspective of the potential victim, rather than the active smoker. The observed associational patterns here are consistent with previous findings that mindfulness is associated with healthier behaviors in obesity prevention and substance use. Research designs with interventions are needed to test the causal link between mindfulness and these healthy behaviors. PMID:26308029

Do High Consumers of Sugar-Sweetened Beverages Respond Differently to Price Changes? A Finite Mixture IV-Tobit Approach.

PubMed

Etilé, Fabrice; Sharma, Anurag

2015-09-01

This study compares the impact of sugar-sweetened beverages (SSBs) tax between moderate and high consumers in Australia. The key methodological contribution is that price response heterogeneity is identified while controlling for censoring of consumption at zero and endogeneity of expenditure by using a finite mixture instrumental variable Tobit model. The SSB price elasticity estimates show a decreasing trend across increasing consumption quantiles, from -2.3 at the median to -0.2 at the 95th quantile. Although high consumers of SSBs have a less elastic demand for SSBs, their very high consumption levels imply that a tax would achieve higher reduction in consumption and higher health gains. Our results also suggest that an SSB tax would represent a small fiscal burden for consumers whatever their pre-policy level of consumption, and that an excise tax should be preferred to an ad valorem tax. Copyright © 2015 John Wiley & Sons, Ltd.

Energy Markets in the United States: The Influence of Politics, Regulations, and Markets on Energy Development in the Oil and Gas and Wind Industries

NASA Astrophysics Data System (ADS)

Maguire, Karen Kay

2011-12-01

My dissertation focuses on the influence of politics, policies, and markets in determining oil and natural gas and wind energy development. In the first chapter, I examine the role of federal elected political influence and market factors in determining the acres of oil and natural gas leases issued on Bureau of Management (BLM) lands in the western United States between 1978 and 2008. I seek to determine if the political party and ideology of the federal political environment influence the number of acres that are leased and if there is disparate federal political influence in states that have a large amount of federal lands. Using a random effects Tobit model for a 17-state sample of the westernmost states in the contiguous United States, I find that more conservative federal political influence leads to additional leasing. The results are consistent across Senate committee leaders, Senate majority leadership, and the President's office. The further found that the influence of politics on leasing is not stronger in states with more federal lands. In the second chapter, I analyze the influence of state and federal political party changes and market factors on state oil and natural gas permitting. My findings, using a first-differenced empirical model for two samples, a 19-state sample, from 1990--2007, and a 14-state sample, from 1977--2007, indicate that the influence of state political party changes are trumped by economic factors. Oil and gas prices are the main drivers of permitting changes, while the state political party changes for the state legislatures and Governor's office are consistently not significant. In the third chapter I focus on the role of electricity markets and renewable energy regulation in wind development across the United States. My findings, using a random effects Tobit model with a 25-state sample, from 1994--2008, indicate that the implementation of state Renewables Portfolio Standards (RPS), the Federal Production Tax Credit (PTC), and Green Power Purchase Programs (GPP) positively influence a state's wind capacity. The influence of green power purchase programs continues to increase in the years after implementation, while for RPS it diminishes. The role of market factors is less significant.

How access to long-term care affects home health transfers.

PubMed

Kenney, G M

1993-01-01

This study examines the determinants of home health use after hospitalization for acute illness for eleven diagnosis-related groups (DRGs) in 1985, drawing on data from four primary sources: Medicare hospital bills, Medicare home health bills, the Medicare and Medicaid Automated Certification System files, and the American Hospital Association Survey. Separate Tobit models are estimated for each DRG. The analysis shows that transfers to home health care are heavily influenced by the hospital's long-term care arrangement and by conditions in local nursing home and home health care markets. Especially important is whether a hospital has its own long-term care unit, swing beds, or both, and whether nursing home beds are available in the local area. Patients discharged from hospitals are more likely to use home health care in areas with a low supply of nursing home beds and low Medicaid reimbursement levels for skilled nursing facilities. The results of this study have implications for proposals to extend Medicare's Prospective Payment System for hospital services to include postacute care. Proponents of a "bundled payment" that encompasses both acute and postacute services argue that the current system leads to inefficiencies and inequities. This analysis points to systematic relationships between home health and nursing home services, which should be factored into the development of a bundled payment policy.

Predictors of surgeons' efficiency in the operating rooms.

PubMed

Nakata, Yoshinori; Watanabe, Yuichi; Narimatsu, Hiroto; Yoshimura, Tatsuya; Otake, Hiroshi; Sawa, Tomohiro

2017-02-01

The sustainability of the Japanese healthcare system is questionable because of a huge fiscal debt. One of the solutions is to improve the efficiency of healthcare. The purpose of this study is to determine what factors are predictive of surgeons' efficiency scores. The authors collected data from all the surgical procedures performed at Teikyo University Hospital from April 1 through September 30 in 2013-2015. Output-oriented Charnes-Cooper-Rhodes model of data envelopment analysis was employed to calculate each surgeon's efficiency score. Seven independent variables that may predict their efficiency scores were selected: experience, medical school, surgical volume, gender, academic rank, surgical specialty, and the surgical fee schedule. Multiple regression analysis using random-effects Tobit model was used for our panel data. The data from total 8722 surgical cases were obtained in 18-month study period. The authors analyzed 134 surgeons. The only statistically significant coefficients were surgical specialty and surgical fee schedule (p = 0.000 and p = 0.016, respectively). Experience had some positive association with efficiency scores but did not reach statistical significance (p = 0.062). The other coefficients were not statistically significant. These results demonstrated that the surgical reimbursement system, not surgeons' personal characteristics, is a significant predictor of surgeons' efficiency.

Empirical analysis of pig welfare levels and their impact on pig breeding efficiency-Based on 773 pig farmers' survey data.

PubMed

Li, Yanling; Wu, Nanjun; Xu, Rong; Li, Liqing; Zhou, Wei; Zhou, Xianjun

2017-01-01

Few studies of the pig production efficiency are from the perspective of animal welfare. Therefore, this study conducted a comprehensive evaluation of pig welfare levels based on survey data from 773 pig farmers from 23 counties in the Chinese provinces of Hunan, Zhejiang, Guangdong, Guizhou, and Shanxi. This study used the Delphi method, Analytic Hierarchy Process (AHP), and Data Envelopment Analysis (DEA)-Tobit regression model to analyze farmers' pig production efficiency and its influencing factors. This paper found that most farmers' pig production efficiency is low, and the DEA is invalid. Only 2.9% of pig farmers' who breed pigs are at the optimal level in terms of welfare, and their production efficiency is relatively high. In contrast, 49.34% of the farmers are at the medium welfare level, and compared with the farmers at the optimal welfare level, these farmers' pig production efficiency is low. Additionally, the farmers' age, gender, and number of years of experience with pig breeding have a significant effect. Furthermore, the scale of pig breeding and feeding type, the agriculture facilities for the central treatment of waste in local areas, and the availability of local agricultural science and technology personnel have a considerable influence on pig production efficiency.

Are learning strategies linked to academic performance among adolescents in two States in India? A tobit regression analysis.

PubMed

Areepattamannil, Shaljan

2014-01-01

The results of the fourth cycle of the Program for International Student Assessment (PISA) revealed that an unacceptably large number of adolescent students in two states in India-Himachal Pradesh and Tamil Nadu-have failed to acquire basic skills in reading, mathematics, and science (Walker, 2011). Drawing on data from the PISA 2009 database and employing multivariate left-censored to bit regression as a data analytic strategy, the present study, therefore, examined whether or not the learning strategies-memorization, elaboration, and control strategies-of adolescent students in Himachal Pradesh (N = 1,616; Mean age = 15.81 years) and Tamil Nadu (N = 3,210; Mean age = 15.64 years) were linked to their performance on the PISA 2009 reading, mathematics, and science assessments. Tobit regression analyses, after accounting for student demographic characteristics, revealed that the self-reported use of control strategies was significantly positively associated with reading, mathematical, and scientific literacy of adolescents in Himachal Pradesh and Tamil Nadu. While the self-reported use of elaboration strategies was not significantly associated with reading literacy among adolescents in Himachal Pradesh and Tamil Nadu, it was significantly positively associated with mathematical literacy among adolescents in Himachal Pradesh and Tamil Nadu. Moreover, the self-reported use of elaboration strategies was significantly and positively linked to scientific literacy among adolescents in Himachal Pradesh alone. The self-reported use of memorization strategies was significantly negatively associated with reading, mathematical, and scientific literacy in Tamil Nadu, while it was significantly negatively associated with mathematical and scientific literacy alone in Himachal Pradesh. Implications of these findings are discussed.

Assessment of the risk of medium-term internal contamination in Minamisoma City, Fukushima, Japan, after the Fukushima Dai-ichi nuclear accident.

PubMed

Sugimoto, Amina; Gilmour, Stuart; Tsubokura, Masaharu; Nomura, Shuhei; Kami, Masahiro; Oikawa, Tomoyoshi; Kanazawa, Yukio; Shibuya, Kenji

2014-06-01

The Fukushima Dai-ichi nuclear disaster, the first level-7 major nuclear disaster since Chernobyl, raised concerns about the future health consequences of exposure to and intake of radionuclides. Factors determining the risk and level of internal radiation contamination after a nuclear accident, which are a key to understanding and improving current nuclear disaster management, are not well studied. We investigated both the prevalence and level of internal contamination in residents of Minamisoma, and identified factors determining the risk and levels of contamination. We implemented a program assessing internal radiation contamination using a whole body counter (WBC) measurement and a questionnaire survey in Minamisoma, between October 2011 and March 2012. Approximately 20% of the city's population (8,829 individuals) participated in the WBC measurement for internal contamination, of which 94% responded to the questionnaire. The proportion of participants with detectable internal contamination was 40% in adults and 9% in children. The level of internal contamination ranged from 2.3 to 196.5 Bq/kg (median, 11.3 Bq/kg). Tobit regression analysis identified two main risk factors: more time spent outdoors, and intake of potentially contaminated foods and water. Our findings suggest that, with sensible and reasonable precautions, people may be able to live continuously in radiation-affected areas with limited contamination risk. To enable this, nuclear disaster response should strictly enforce food and water controls and disseminate evidence-based and up-to-date information about avoidable contamination risks.

Health care costs in the elderly in Germany: an analysis applying Andersen’s behavioral model of health care utilization

PubMed Central

2014-01-01

Background To analyze the association of health care costs with predisposing, enabling, and need factors, as defined by Andersen’s behavioral model of health care utilization, in the German elderly population. Methods Using a cross-sectional design, cost data of 3,124 participants aged 57–84 years in the 8-year-follow-up of the ESTHER cohort study were analyzed. Health care utilization in a 3-month period was assessed retrospectively through an interview conducted by trained study physicians at respondents’ homes. Unit costs were applied to calculate health care costs from the societal perspective. Socio-demographic and health-related variables were categorized as predisposing, enabling, or need factors as defined by the Andersen model. Multimorbidity was measured by the Cumulative Illness Rating Scale for Geriatrics (CIRS-G). Mental health status was measured by the SF-12 mental component summary (MCS) score. Sector-specific costs were analyzed by means of multiple Tobit regression models. Results Mean total costs per respondent were 889 € for the 3-month period. The CIRS-G score and the SF-12 MCS score representing the need factor in the Andersen model were consistently associated with total, inpatient, outpatient and nursing costs. Among the predisposing factors, age was positively associated with outpatient costs, nursing costs, and total costs, and the BMI was associated with outpatient costs. Conclusions Multimorbidity and mental health status, both reflecting the need factor in the Andersen model, were the dominant predictors of health care costs. Predisposing and enabling factors had comparatively little impact on health care costs, possibly due to the characteristics of the German social health insurance system. Overall, the variables used in the Andersen model explained only little of the total variance in health care costs. PMID:24524754

Health care costs in the elderly in Germany: an analysis applying Andersen's behavioral model of health care utilization.

PubMed

Heider, Dirk; Matschinger, Herbert; Müller, Heiko; Saum, Kai-Uwe; Quinzler, Renate; Haefeli, Walter Emil; Wild, Beate; Lehnert, Thomas; Brenner, Hermann; König, Hans-Helmut

2014-02-14

To analyze the association of health care costs with predisposing, enabling, and need factors, as defined by Andersen's behavioral model of health care utilization, in the German elderly population. Using a cross-sectional design, cost data of 3,124 participants aged 57-84 years in the 8-year-follow-up of the ESTHER cohort study were analyzed. Health care utilization in a 3-month period was assessed retrospectively through an interview conducted by trained study physicians at respondents' homes. Unit costs were applied to calculate health care costs from the societal perspective. Socio-demographic and health-related variables were categorized as predisposing, enabling, or need factors as defined by the Andersen model. Multimorbidity was measured by the Cumulative Illness Rating Scale for Geriatrics (CIRS-G). Mental health status was measured by the SF-12 mental component summary (MCS) score. Sector-specific costs were analyzed by means of multiple Tobit regression models. Mean total costs per respondent were 889 € for the 3-month period. The CIRS-G score and the SF-12 MCS score representing the need factor in the Andersen model were consistently associated with total, inpatient, outpatient and nursing costs. Among the predisposing factors, age was positively associated with outpatient costs, nursing costs, and total costs, and the BMI was associated with outpatient costs. Multimorbidity and mental health status, both reflecting the need factor in the Andersen model, were the dominant predictors of health care costs. Predisposing and enabling factors had comparatively little impact on health care costs, possibly due to the characteristics of the German social health insurance system. Overall, the variables used in the Andersen model explained only little of the total variance in health care costs.

Technical and scale efficiency of public community hospitals in Eritrea: an exploratory study

PubMed Central

2013-01-01

Background Eritrean gross national income of Int$610 per capita is lower than the average for Africa (Int$1620) and considerably lower than the global average (Int$6977). It is therefore imperative that the country’s resources, including those specifically allocated to the health sector, are put to optimal use. The objectives of this study were (a) to estimate the relative technical and scale efficiency of public secondary level community hospitals in Eritrea, based on data generated in 2007, (b) to estimate the magnitudes of output increases and/or input reductions that would have been required to make relatively inefficient hospitals more efficient, and (c) to estimate using Tobit regression analysis the impact of institutional and contextual/environmental variables on hospital inefficiencies. Methods A two-stage Data Envelopment Analysis (DEA) method is used to estimate efficiency of hospitals and to explain the inefficiencies. In the first stage, the efficient frontier and the hospital-level efficiency scores are first estimated using DEA. In the second stage, the estimated DEA efficiency scores are regressed on some institutional and contextual/environmental variables using a Tobit model. In 2007 there were a total of 20 secondary public community hospitals in Eritrea, nineteen of which generated data that could be included in the study. The input and output data were obtained from the Ministry of Health (MOH) annual health service activity report of 2007. Since our study employs data that are five years old, the results are not meant to uncritically inform current decision-making processes, but rather to illustrate the potential value of such efficiency analyses. Results The key findings were as follows: (i) the average constant returns to scale technical efficiency score was 90.3%; (ii) the average variable returns to scale technical efficiency score was 96.9%; and (iii) the average scale efficiency score was 93.3%. In 2007, the inefficient hospitals could have become more efficient by either increasing their outputs by 20,611 outpatient visits and 1,806 hospital discharges, or by transferring the excess 2.478 doctors (2.85%), 9.914 nurses and midwives (0.98%), 9.774 laboratory technicians (9.68%), and 195 beds (10.42%) to primary care facilities such as health centres, health stations, and maternal and child health clinics. In the Tobit regression analysis, the coefficient for OPDIPD (outpatient visits as a proportion of inpatient days) had a negative sign, and was statistically significant; and the coefficient for ALOS (average length of stay) had a positive sign, and was statistically significant at 5% level of significance. Conclusions The findings from the first-stage analysis imply that 68% hospitals were variable returns to scale technically efficient; and only 42% hospitals achieved scale efficiency. On average, inefficient hospitals could have increased their outpatient visits by 5.05% and hospital discharges by 3.42% using the same resources. Our second-stage analysis shows that the ratio of outpatient visits to inpatient days and average length of inpatient stay are significantly correlated with hospital inefficiencies. This study shows that routinely collected hospital data in Eritrea can be used to identify relatively inefficient hospitals as well as the sources of their inefficiencies. PMID:23497525

Earnings and Expenditures on Household Services in Married and Cohabiting Unions

ERIC Educational Resources Information Center

Treas, Judith; de Ruijter, Esther

2008-01-01

Despite the rise in women's paid employment, little is known about how women and their partners allocate money to outsource domestic tasks, especially in unmarried unions. Tobit analyses of 6,170 married and cohabiting couples in the 1998 Consumer Expenditure Survey test hypotheses that recognize gender inequality between partners, gender typing…

Determinants of Student Attitudes toward Team Exams

ERIC Educational Resources Information Center

Reinig, Bruce A.; Horowitz, Ira; Whittenburg, Gene

2014-01-01

We examine how student attitudes toward their group, learning method, and perceived development of professional skills are initially shaped and subsequently evolve through multiple uses of team exams. Using a Tobit regression model to analyse a sequence of 10 team quizzes given in a graduate-level tax accounting course, we show that there is an…

Application of Fractal theory for crash rate prediction: Insights from random parameters and latent class tobit models.

PubMed

Chand, Sai; Dixit, Vinayak V

2018-03-01

The repercussions from congestion and accidents on major highways can have significant negative impacts on the economy and environment. It is a primary objective of transport authorities to minimize the likelihood of these phenomena taking place, to improve safety and overall network performance. In this study, we use the Hurst Exponent metric from Fractal Theory, as a congestion indicator for crash-rate modeling. We analyze one month of traffic speed data at several monitor sites along the M4 motorway in Sydney, Australia and assess congestion patterns with the Hurst Exponent of speed (H speed ). Random Parameters and Latent Class Tobit models were estimated, to examine the effect of congestion on historical crash rates, while accounting for unobserved heterogeneity. Using a latent class modeling approach, the motorway sections were probabilistically classified into two segments, based on the presence of entry and exit ramps. This will allow transportation agencies to implement appropriate safety/traffic countermeasures when addressing accident hotspots or inadequately managed sections of motorway. Copyright © 2017 Elsevier Ltd. All rights reserved.

HMO selection and Medicare costs: Bayesian MCMC estimation of a robust panel data tobit model with survival.

PubMed

Hamilton, B H

1999-08-01

The fraction of US Medicare recipients enrolled in health maintenance organizations (HMOs) has increased substantially over the past 10 years. However, the impact of HMOs on health care costs is still hotly debated. In particular, it is argued that HMOs achieve cost reduction through 'cream-skimming' and enrolling relatively healthy patients. This paper develops a Bayesian panel data tobit model of HMO selection and Medicare expenditures for recent US retirees that accounts for mortality over the course of the panel. The model is estimated using Markov Chain Monte Carlo (MCMC) simulation methods, and is novel in that a multivariate t-link is used in place of normality to allow for the heavy-tailed distributions often found in health care expenditure data. The findings indicate that HMOs select individuals who are less likely to have positive health care expenditures prior to enrollment. However, there is no evidence that HMOs disenrol high cost patients. The results also indicate the importance of accounting for survival over the panel, since high mortality probabilities are associated with higher health care expenditures in the last year of life.

Determinants of psychogeriatric inpatient length of stay and direct medical costs: a 6-year longitudinal study using a national database in Taiwan.

PubMed

Liu, Chin-Ming; Li, Chu-Shiu; Liu, Chwen-Chi; Tu, Chu-Chin

2012-08-01

This research examined factors related to the average length of hospital stay (LOS) and average direct medical costs (DMC) for 2291 psychogeriatric inpatients (aged 65 and over) admitted for the first time to a psychiatric ward in 2002. Hospitalization claim data of these inpatients were traced for the subsequent 6 years (2002-2007) from the dataset of Taiwan's National Health Insurance program. Analysis was carried out using the t-test, χ(2) -test and zero truncated Tobit regression. Mean LOS and mean DMC were significantly different according to sex, psychiatric diagnosis, institution type, ownership type, and number of hospitalizations, but age was the exception. Both LOS and DMC exhibited downward U-shape for the number of hospitalizations. Factors significantly associated with longer LOS and higher DMC were: male sex; schizophrenic and delusional disorders (compared with dementia); and public institution (compared with private hospital). Compared with dementia, organic mental and anxiety disorders had significantly shorter LOS, and affective disorders had shorter LOS but higher DMC. Community and psychiatric hospitals (compared with general hospital) significantly influenced LOS but not DMC. Our results can be used as a reference for providers and policymakers to improve psychiatric care efficiency and carry out National Health Insurance financial reform for psychogeriatric inpatients. © 2012 The Authors. Psychiatry and Clinical Neurosciences © 2012 Japanese Society of Psychiatry and Neurology.

The supply of general practitioners across local areas: accounting for spatial heterogeneity.

PubMed

McIsaac, Michelle; Scott, Anthony; Kalb, Guyonne

2015-10-03

The geographic distribution of general practitioners (GPs) remains persistently unequal in many countries despite notable increases in overall supply. This paper explores how the factors associated with the supply of general practitioners (GPs) are aligned with the arbitrary geographic boundaries imposed by the use of spatially referenced GP supply data. Data on GP supply in postcodes within Australia are matched to data on the population characteristics and levels of amenities in postcodes. Tobit regression models are used that examine the associations between GP supply and postcode characteristics, whilst accounting for spatial heterogeneity. The results demonstrate that GPs do not consider space in a one-dimensional sense. Location choice is related to both neighbourhood-specific factors, such as hospitals, and broader area factors, such as area income and proximity to private schools. Although the proportion of females and elderly were related to GPs supply, mortality rate was not. This paper represents the first attempt to map the factors influencing GP supply to the appropriate geographic level at which GPs may be considering that factor. We suggest that both neighbourhood and broader regional characteristics can influence GPs' locational choices. This finding is highly relevant to the design and evaluation of relocation incentive programmes.

What Criteria Should Policymakers Use for Assisting Households with Educational Expenditure? The Case of Urban Bangladesh

ERIC Educational Resources Information Center

Shafiq, M. Najeeb

2010-01-01

Low household expenditure on education compromises the learning and future labor market prospects of children. This study provides an empirical framework for determining the criteria that South Asian policymakers can use for assisting households with educational expenditure. A case study of urban Bangladesh using tobit and hurdle regression…

Efficiency and quality of care in nursing homes: an Italian case study.

PubMed

Garavaglia, Giulia; Lettieri, Emanuele; Agasisti, Tommaso; Lopez, Silvano

2011-03-01

This study investigates efficiency and quality of care in nursing homes. By means of Data Envelopment Analysis (DEA), the efficiency of 40 nursing homes that deliver their services in the north-western area of the Lombardy Region was assessed over a 3-year period (2005-2007). Lombardy is a very peculiar setting, since it is the only Region in Italy where the healthcare industry is organised as a quasi-market, in which the public authority buys health and nursing services from independent providers-establishing a reimbursement system for this purpose. The analysis is conducted by generating bootstrapped DEA efficiency scores for each nursing home (stage one), then regressing those scores on explanatory variables (stage two). Our DEA model employed two input (i.e. costs for health and nursing services and costs for residential services) and three output variables (case mix, extra nursing hours and residential charges). In the second-stage analysis, Tobit regressions and the Kruskall-Wallis tests of hypothesis to the efficiency scores were applied to define what are the factors that affect efficiency: (a) the ownership (private nursing houses outperform their public counterparts); and (b) the capability to implement strategies for labour cost and nursing costs containment, since the efficiency heavily depends upon the alignment of the costs to the public reimbursement system. Lastly, even though the public institutions are less efficient than the private ones, the results suggest that public nursing homes are moving towards their private counterparts, and thus competition is benefiting efficiency.

Determinants of Participation and Expenditure Patterns of Private Tuition Received by Primary School Students in Penang, Malaysia: An Exploratory Study

ERIC Educational Resources Information Center

Jelani, Juliana; Tan, Andrew K. G.

2012-01-01

In this exploratory study, the censored Tobit model is applied on primary data collected amongst parents of primary school students in Penang, Malaysia to examine the determinants of participation and expenditures on private tuition (PT). Results of the marginal effects indicate that socio-demographic characteristics--ethnicity, household income,…

Children’s Emotional and Behavioral Problems and Their Mothers’ Labor Supply

PubMed Central

Gaskin, Darrell J.; Alexandre, Pierre K.; Burke, Laura S.; Younis, Mustafa

2014-01-01

It has been documented that about 20% of children and adolescents suffer from a diagnosable mental or addictive disorder in the United States. The high prevalence of children’s emotional and behavioral problems (EBP) might have a negative effect on their mothers’ labor market outcomes because children with EBP require additional time for treatment. However, these children may require additional financial resources, which might promote mothers’ labor supply. Previous studies have only considered chronic conditions in analyzing the impact of children’s health on parental work activities. Moreover, most of these studies have not accounted for endogeneity in children’s health. This article estimates the effects of children’s EBP on their mothers’ labor supply by family structure while accounting for endogeneity in children’s health. We used the 1997 and 2002 Child Development Supplements (CDS) to the Panel Study of Income Dynamics (PSID). We used probit and bivariate probit models to estimate mothers’ probability of employment, and tobit and instrumental variable tobit models to estimate the effects of children’s EBP on their mothers’ work hours. Findings show negative effects of children’s EBP on their married mothers’ employment and on their single mothers’ work hours. PMID:25466413

Children's emotional and behavioral problems and their mothers' labor supply.

PubMed

Richard, Patrick; Gaskin, Darrell J; Alexandre, Pierre K; Burke, Laura S; Younis, Mustafa

2014-01-01

It has been documented that about 20% of children and adolescents suffer from a diagnosable mental or addictive disorder in the United States. The high prevalence of children's emotional and behavioral problems (EBP) might have a negative effect on their mothers' labor market outcomes because children with EBP require additional time for treatment. However, these children may require additional financial resources, which might promote mothers' labor supply. Previous studies have only considered chronic conditions in analyzing the impact of children's health on parental work activities. Moreover, most of these studies have not accounted for endogeneity in children's health. This article estimates the effects of children's EBP on their mothers' labor supply by family structure while accounting for endogeneity in children's health. We used the 1997 and 2002 Child Development Supplements (CDS) to the Panel Study of Income Dynamics (PSID). We used probit and bivariate probit models to estimate mothers' probability of employment, and tobit and instrumental variable tobit models to estimate the effects of children's EBP on their mothers' work hours. Findings show negative effects of children's EBP on their married mothers' employment and on their single mothers' work hours. © The Author(s) 2014.

What cigarette price is required for smokers to attempt to quit smoking? Findings from the ITC Korea Waves 2 and 3 Survey.

PubMed

Park, Eun-Ja; Park, Susan; Cho, Sung-il; Kim, Yeol; Seo, Hong Gwan; Driezen, Pete; Quah, Anne C K; Fong, Geoffrey T

2015-07-01

We assess the cigarette price that would motivate smokers to quit. We also explore the factors associated with the required price, including exposures to non-tax tobacco control policies. Cross-sectional analysis was conducted on data from 1257 male smokers, who participated in either Wave 2 or 3 of the ITC Korea Survey. Information was obtained on what cigarette price per pack would make them try to quit ('price to quit'). Tobit regression on log-transformed price and logistic regression on non-quitting were conducted to identify associated factors. The median price to quit was KRW5854 (US$5.31)/pack, given the current price of KRW2500 (US$2.27)/pack. Younger age, higher education, lack of concern about the health effects of smoking, lack of quit attempts and more cigarettes consumed per day were related to a higher price needed for a quit attempt. Exposures to combinations of non-tax policies were significantly associated with lower price levels to be motivated to quit. Considering the large price increase required for quit attempts, tax policy needs to be combined with other policies, particularly for certain groups, such as heavy smokers. Strengthening non-tax policies is likely to facilitate greater responsiveness to tax policy. 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.

[Environmental efficiency evaluation under carbon emission constraint in Western China].

PubMed

Rong, Jian-bo; Yan, Li-jiao; Huang, Shao-rong; Zhang, Ge

2015-06-01

This research used the SBM model based on undesirable outputs to measure the static environmental efficiency of Western China under carbon emission constraint from 2000 to 2012. The researchers also utilized the Malmquist index to further analyze the change tendency of environmental efficiency. Additionally, Tobit regression analysis was used to study the factors relevant to environmental efficiency. Practical solutions to improve environmental quality in Western China were put forward. The study showed that in Western China, environmental efficiency with carbon emission constraint was significantly lower than that without carbon emission constraint, and the difference could be described as an inverse U-shaped curve which increased at first and then decreased. Guang-xi and Inner Mongolia, the two provinces met the effective environmental efficiency levels all the time under carbon emission constraint. However, the five provinces of Guizhou, Gansu, Qinghai, Ningxia and Xinjiang did not. Furthermore, Ningxia had the lowest level of environmental efficiency, with a score between 0.281-0.386. Although the environmental efficiency of most provinces was currently at an ineffective level, the environmental efficiency quality was gradually improving at an average speed of 6.6%. Excessive CO2 emission and a large amount of energy consumption were the primary factors causing environmental inefficiency in Western China, and energy intensity had the most negative impact on the environmental efficiency. The increase of import and export trade reduced the environmental efficiency significantly in Western China, while the increase of foreign direct investment had a positive effect on its environmental efficiency.

"Why some consumers don't care": Heterogeneity in household responses to a food scandal.

PubMed

Rieger, Jörg; Weible, Daniela; Anders, Sven

2017-06-01

In the aftermath of food scandals, household perceptions about the health risks posed by failures in food safety play a central role in determining their mitigating behavior. A stream of literature has shown that factors including media coverage of a scandal, risk perceptions, trust in food safety information, and consumption habits matter. This paper deviates from the standard assumption of a homogeneous response to media information across all households exposed to a food scandal. Instead, we present an innovative multi-method approach to investigate the impacts of household heterogeneity in underlying psychological and behavioral, media usage patterns and consumption habits on poultry demand in the aftermath of the 2011 German dioxin scandal. The analysis employs weekly retail purchase and matching survey data for 6133 households covering pre and post scandal periods. The supplementary survey data elicits household respondent's risk perceptions and risk attitudes, product label and media information behavior. Initial factor and cluster analysis identify household segments based on psychographic and behavioral indicators. We then estimate a correlated random effect Tobit model to account for clustered household responses to quantify the influence of media effects distinguishing between short-term risk mitigation behavior and longer-term habit persistence. Our results confirm significant heterogeneity in household's media-induced risk-mitigation responses to the dioxin scandal across three clusters. However, we find that habit persistence in the form of consumption preferences for the affected products were able to largely compensate for demand-reducing media effects across household clusters. Considering heterogeneity in household's risk mitigation behaviors to food scandals holds implications for policy makers and food industry alike. Copyright © 2017 Elsevier Ltd. All rights reserved.

In Sickness and in Debt: Do Mounting Medical Bills Predict Payday Loan Debt?

PubMed

Bickham, Trey; Lim, Younghee

2015-01-01

Cash-strapped families sometimes turn to small, short-term loans with exorbitant fees—payday loans—to cope with mounting medical bills. Given that about three-fourths of payday loan customers are repeat borrowers, consumer advocates and policymakers have increasingly raised voices of concern about the use of payday loans to finance various household expenses, including, among other things, medical bills. The present study hypothesized that increases in medical debt are associated with increases in payday loan debt among a sample of Chapter 7 bankruptcy filers. The results of a multivariate tobit regression analysis showed that medical debt was associated with increased payday loan debt, controlling for various types of debt and other socioeconomic variables. This article concludes with implications of the results for social work policy- and direct-practice.

The Technical Efficiency of Earthquake Medical Rapid Response Teams Following Disasters: The Case of the 2010 Yushu Earthquake in China.

PubMed

Liu, Xu; Tang, Bihan; Yang, Hongyang; Liu, Yuan; Xue, Chen; Zhang, Lulu

2015-12-04

Performance assessments of earthquake medical rapid response teams (EMRRTs), particularly the first responders deployed to the hardest hit areas following major earthquakes, should consider efficient and effective use of resources. This study assesses the daily technical efficiency of EMRRTs in the emergency period immediately following the 2010 Yushu earthquake in China. Data on EMRRTs were obtained from official daily reports of the general headquarters for Yushu earthquake relief, the emergency office of the National Ministry of Health, and the Health Department of Qinghai Province, for a sample of data on 15 EMRRTs over 62 days. Data envelopment analysis was used to examine the technical efficiency in a constant returns to scale model, a variable returns to scale model, and the scale efficiency of EMRRTs. Tobit regression was applied to analyze the effects of corresponding influencing factors. The average technical efficiency scores under constant returns to scale, variable returns to scale, and the scale efficiency scores of the 62 units of analysis were 77.95%, 89.00%, and 87.47%, respectively. The staff-to-bed ratio was significantly related to global technical efficiency. The date of rescue was significantly related to pure technical efficiency. The type of institution to which an EMRRT belonged and the staff-to-bed ratio were significantly related to scale efficiency. This study provides evidence that supports improvements to EMRRT efficiency and serves as a reference for earthquake emergency medical rapid assistance leaders and teams.

The impact of healthcare reform on the efficiency of public county hospitals in China.

PubMed

Jiang, Shuai; Min, Rui; Fang, Peng-Qian

2017-12-20

The new round of Healthcare Reform in China has implemented over 3 years since 2009, and promoted greatly the development of public county hospitals. The purpose of this study is to evaluate county hospitals efficiency before and after the healthcare reform, and further assess the reform effectiveness through the comparative analysis of the efficiency. Data envelopment analysis (DEA) was employed to calculate the efficiency of 1105 sample hospitals which were selected from 31 provinces of China, also, Tobit regression was used to regress against those main external environmental factors. Our results show that the scales and amounts of service of hospitals had increased sharply, however, the efficiency was relatively low and decreased slightly from 2008 to 2012. Thirteen (1.18%) in 2008 and six (0.54%) hospitals in 2012 were defined as technically efficient, and the average scores were 0.2916 and 0.2503. The technical efficiency average score of the post-reform was significantly less than that of the pre-reform (p < 0.001), and the score of eastern region was highest and the western was lowest among three regions of China. It suggests the reform had not well improved county hospital efficiency although hospitals have reached a fair developing scale, and the corresponding policies and measures should be put into effect for improving efficiency, especially in the level and structure of health investment, operation and supervision mechanism of county hospitals.

Data on alcohol consumption and coronary artery calcification among asymptomatic middle-aged men for the ERA-JUMP study.

PubMed

Mahajan, Hemant; Choo, Jina; Masaki, Kamal; Fujiyoshi, Akira; Guo, Jingchuan; Hisamatsu, Takashi; Evans, Rhobert; Shangguan, Siyi; Willcox, Bradley; Okamura, Tomonori; Vishnu, Abhishek; Barinas-Mitchell, Emma; Ahuja, Vasudha; Miura, Katsuyuki; Kuller, Lewis; Shin, Chol; Ueshima, Hirotsugu; Sekikawa, Akira

2018-04-01

Data presented in this article are supplementary data to our primary article 'Association of Alcohol Consumption and Aortic Calcification in Healthy Men Aged 40-49 Years for the ERA JUMP Study' [1]. In this article, we have presented supplementary tables showing the independent association of alcohol consumption with coronary artery calcification using Tobit conditional regression and ordinal logistic regression.

Modeling willingness to pay for land conservation easements: treatment of zero and protest bids and application and policy implications

Treesearch

Seong-Hoon Cho; Steven T. Yen; J. Michael Bowker; David H. Newman

2008-01-01

This study compares an ordered probit model and a Tobit model with selection to take into account both true zero and protest zero bids while estimating the willingness to pay (WTP) for conservation easements in Macon County, NC. By comparing the two models, the ordered/Unordered selection issue of the protest responses is analyzed to demonstrate how the treatment of...

Is "Safety-in-numbers" theory applies to the pattern of pedestrian accidents in Seoul, South Korea.

NASA Astrophysics Data System (ADS)

Choi, Y.; Yoon, H.

2016-12-01

Every year, about 1.25 million people die of vehicle-related accidents, among which half are pedestrians with higher vulnerability: pedestrian, cyclists and motorcyclist (World Health Organization, 2016). This urges city governments in the world to strive for pedestrian safety and to apply diverse theories to transportation planning and design. The common belief is that the number of pedestrian accidents is directly and positively associated with the volume of pedestrian, however, another hypothesis, called "safety-in-numbers" effect, tells an opposite story in that accident rates declines with increase of the volume of pedestrian. In this study, we examine first, whether the safety-in-numbers theory applies to the pattern of pedestrian accidents in Seoul, and second, further investigate environmental factors that are associated with the pedestrian safety. On the first count, we use geospatial statistical analyses of the multi-year pedestrian accident data collected by Korea Road Traffic Authority (KoRoad) and the pedestrian volume data collected by SK Telecom (SKT). With Kernel Density Estimation and Bivariate Local Moran's I, we identify spatial clustering of pedestrian accidents in the city, and examine whether those locations match with concentrations of pedestrian volume. On the second count, we use statistical analysis, tobit, poisson and negative binomial regression to investigate relationships between pedestrian volume and number of pedestrian accident for the two types of geographic areas by the results of the aforementioned analysis; Area 1- locations of high volume of pedestrian with high number of accident, Area 2- locations of high volume of pedestrian with low number of accident. For environmental factors potentially explaining pedestrian accidents, we include land use composition, number of traffic lanes, crosswalk presence, pedestrian signal, traffic island and sidewalk width in our analysis. This research will be valuable in city governments' decision making with planning guidelines and political protocols for making safer pedestrian environment.

Dutch Tariff for the Five-Level Version of EQ-5D.

PubMed

M Versteegh, Matthijs; M Vermeulen, Karin; M A A Evers, Silvia; de Wit, G Ardine; Prenger, Rilana; A Stolk, Elly

2016-06-01

In 2009, a new version of the EuroQol five-dimensional questionnaire (EQ-5D) was introduced with five rather than three answer levels per dimension. This instrument is known as the EQ-5D-5L. To make the EQ-5D-5L suitable for use in economic evaluations, societal values need to be attached to all 3125 health states. To derive a Dutch tariff for the EQ-5D-5L. Health state values were elicited during face-to-face interviews in a general population sample stratified for age, sex, and education, using composite time trade-off (cTTO) and a discrete choice experiment (DCE). Data were modeled using ordinary least squares and tobit regression (for cTTO) and a multinomial conditional logit model (for DCE). Model performance was evaluated on the basis of internal consistency, parsimony, goodness of fit, handling of left-censored values, and theoretical considerations. A representative sample (N = 1003) of the Dutch population participated in the valuation study. Data of 979 and 992 respondents were included in the analysis of the cTTO and the DCE, respectively. The cTTO data were left-censored at -1. The tobit model was considered the preferred model for the tariff on the basis of its handling of the censored nature of the data, which was confirmed through comparison with the DCE data. The predicted values for the EQ-5D-5L ranged from -0.446 to 1. This study established a Dutch tariff for the EQ-5D-5L on the basis of cTTO. The values represent the preferences of the Dutch population. The tariff can be used to estimate the impact of health care interventions on quality of life, for example, in context of economic evaluations. Copyright © 2016 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Willingness to pay for adverse drug event regulatory actions.

PubMed

Bouvy, Jacoline; Weemers, Just; Schellekens, Huub; Koopmanschap, Marc

2011-11-01

Regulatory requirements for the pharmaceutical industry have become increasingly demanding with respect to the safety and effectiveness of drugs. The objective of this study was to determine the willingness to pay (WTP), of both the Dutch general public and dialysis patients, for regulatory requirements related to reducing the risk of pure red cell aplasia (PRCA) associated with epoetin alpha use. A survey was carried out in April 2009. The Dutch general public (n = 422) was approached through a survey sampling agency. Patients (n = 112) were included through several Dutch dialysis clinics because they are often treated with epoetin alpha and therefore were expected to have a higher WTP than the general public. The survey aimed to determine the WTP for reducing the risk of PRCA in epoetin alpha users from 4.5 to 0 per 10 000 patients per year, based on regulatory actions that have been taken by the European Medicines Agency (EMA). WTP was determined via a payment scale and an open-ended follow-up question. Patients were asked how much extra per year they would be willing to pay for their basic healthcare insurance. We used two censored regression models to test the association between WTP and a set of independent variables: a Tobit model with the stated WTP as the dependent variable and an interval regression model with the interval between the lower and upper bounds of the payment scale as the dependent variable. The patients' mean WTP was significantly higher (€46.52) than that of the general public (€24.40). The Tobit model showed significant associations (α = 0.05) with WTP for dialysis patients, risk perception and respondents' opinions on costs of healthcare. The interval regression model showed significant associations with WTP for the same variables as the Tobit model and for one additional variable (risk aversion). Income did not significantly affect WTP. A scenario with a 10-fold larger risk reduction did not increase WTP significantly. This study is, as far as we know, one of the first attempts to analyse the WTP for drug regulation and should in future be used in studies of the societal costs of drug regulation for epoetin alpha use. Our results indicate that the Dutch general public, especially Dutch dialysis patients, are willing to pay limited amounts to reduce the risk of serious adverse events associated with drug use.

Assessing the efficiency of hospital pharmacy services in Thai public district hospitals.

PubMed

Rattanachotphanit, Thananan; Limwattananon, Chulaporn; Limwattananon, Supon; Johns, Jeff R; Schommer, Jon C; Brown, Lawrence M

2008-07-01

The purpose of this study was to assess the efficiency of hospital pharmacy services and to determine the environmental factors affecting pharmacy service efficiency. The technical efficiency of a hospital pharmacy was assessed to evaluate the hospital's ability to use pharmacy manpower in order to produce the maximum output of the pharmacy service. Data Envelopment Analysis (DEA) was used as an efficiency measurement. The two labor inputs were pharmacists and support personnel and the ten outputs were from four pharmacy activities: drug dispensing, drug purchasing and inventory control, patient-oriented activities, and health consumer protection services. This was used to estimate technical efficiency. A Tobit regression model was used to determine the effect of the hospital size, location, input mix of pharmacy staff, working experience of pharmacists at the study hospitals, and use of technology on the pharmacy service efficiency. Data for pharmacy service input and output quantities were obtained from 155 respondents. Nineteen percent were found to have full efficiency with a technical efficiency score of 1.00. Thirty-six percent had a technical efficiency score of 0.80 or above and 27% had a low technical efficiency score (< 0.60). The average TE score increased in respect to the hospital size (0.60, 0.71, 0.75, and 0.83 in 10, 30, 60, and 90-120 bed hospitals, respectively). Hospital size and geographic location were significantly associated with pharmacy service efficiency.

Older adults' quality of life - Exploring the role of the built environment and social cohesion in community-dwelling seniors on low income.

PubMed

Engel, L; Chudyk, A M; Ashe, M C; McKay, H A; Whitehurst, D G T; Bryan, S

2016-09-01

The built environment and social cohesion are increasingly recognized as being associated with older adults' quality of life (QoL). However, limited research in this area still exists and the relationship has remained unexplored in the area of Metro Vancouver, Canada. This study examined the association between the built environment and social cohesion with QoL of 160 community-dwelling older adults (aged ≥ 65 years) on low income from Metro Vancouver. Cross-sectional data acquired from the Walk the Talk (WTT) study were used. Health-related QoL (HRQoL) and capability wellbeing were assessed using the EQ-5D-5L and the ICECAP-O, respectively. Measures of the environment comprised the NEWS-A (perceived built environment measure), the Street Smart Walk Score (objective built environment measure), and the SC-5PT (a measure of social cohesion). The primary analysis consists of Tobit regression models to explore the associations between environmental features and HRQoL as well as capability wellbeing. Key findings indicate that after adjusting for covariates, older adults' capability wellbeing was associated with street connectivity and social cohesion, while no statistically significant associations were found between environmental factors and HRQoL. Our results should be considered as hypothesis-generating and need confirmation in a larger longitudinal study. Copyright © 2016 Elsevier Ltd. All rights reserved.

Efficient Signal, Code, and Receiver Designs for MIMO Communication Systems

DTIC Science & Technology

2003-06-01

167 5-31 Concatenation of a tilted-QAM inner code with an LDPC outer code with a two component iterative soft-decision decoder. . . . . . . . . 168 5...for AWGN channels has long been studied. There are well-known soft-decision codes like the turbo codes and LDPC codes that can approach capacity to...bits) low density parity check ( LDPC ) code 1. 2. The coded bits are randomly interleaved so that bits nearby go through different sub-channels, and are

Mapping health outcome measures from a stroke registry to EQ-5D weights.

PubMed

Ghatnekar, Ola; Eriksson, Marie; Glader, Eva-Lotta

2013-03-07

To map health outcome related variables from a national register, not part of any validated instrument, with EQ-5D weights among stroke patients. We used two cross-sectional data sets including patient characteristics, outcome variables and EQ-5D weights from the national Swedish stroke register. Three regression techniques were used on the estimation set (n=272): ordinary least squares (OLS), Tobit, and censored least absolute deviation (CLAD). The regression coefficients for "dressing", "toileting", "mobility", "mood", "general health" and "proxy-responders" were applied to the validation set (n=272), and the performance was analysed with mean absolute error (MAE) and mean square error (MSE). The number of statistically significant coefficients varied by model, but all models generated consistent coefficients in terms of sign. Mean utility was underestimated in all models (least in OLS) and with lower variation (least in OLS) compared to the observed. The maximum attainable EQ-5D weight ranged from 0.90 (OLS) to 1.00 (Tobit and CLAD). Health states with utility weights <0.5 had greater errors than those with weights ≥ 0.5 (P<0.01). This study indicates that it is possible to map non-validated health outcome measures from a stroke register into preference-based utilities to study the development of stroke care over time, and to compare with other conditions in terms of utility.

Moderating roles of primary social influences in the relationship between adolescent self-reported exposure to antismoking messages and smoking intention.

PubMed

Paek, Hye-Jin

2008-11-01

This study explores moderating roles of primary social influences in the relationship between adolescent triers' and experimenters' self-reported exposure to antismoking messages and their smoking intentions. The theoretical arguments are drawn from primary socialization theory, group socialization theory, and the social development model, and the data are from the 2004 National Youth Tobacco Survey. The tobit regression models demonstrate that, as a primary social influence, peer smoking seems to be a strong risk factor for all of the adolescent segments' smoking intentions, whereas parental monitoring can be a significant counter-risk factor for middle-schoolers' smoking intentions. In addition, school intervention programs and parental monitoring against smoking appear to play a moderating role in the relationship between high-school triers' self-reported exposure to antismoking messages and their smoking intentions. The findings seem to suggest that campaigners should make more efforts to incorporate primary social influences to prevent adolescent smoking. The findings also suggest that campaigners should tailor antismoking programs to fit specific target audiences. In particular, middle-school experimenters deserve more attention from antismoking campaigners because they seem most vulnerable to future smoking.

[Technical efficiency in primary care for patients with diabetes].

PubMed

Salinas-Martínez, Ana María; Amaya-Alemán, María Agustina; Arteaga-García, Julio César; Núñez-Rocha, Georgina Mayela; Garza-Elizondo, María Eugenia

2009-01-01

To quantify the technical efficiency of diabetes care in family practice settings, characterize the provision of services and health results, and recognize potential sources of variation. We used data envelopment analysis with inputs and outputs for diabetes care from 47 family units within a social security agency in Nuevo Leon. Tobit regression models were also used. Seven units were technically efficient in providing services and nine in achieving health goals. Only two achieved both outcomes. The metropolitan location and the total number of consultations favored efficiency in the provision of services regardless of patient attributes; and the age of the doctor, the efficiency of health results. Performance varied within and among family units; some were efficient at providing services while others at accomplishing health goals. Sources of variation also differed. It is necessary to include both outputs in the study of efficiency of diabetes care in family practice settings.

Coordinated Analysis of Age, Sex, and Education Effects on Change in MMSE Scores

PubMed Central

2013-01-01

Objectives. We describe and compare the expected performance trajectories of older adults on the Mini-Mental Status Examination (MMSE) across six independent studies from four countries in the context of a collaborative network of longitudinal studies of aging. A coordinated analysis approach is used to compare patterns of change conditional on sample composition differences related to age, sex, and education. Such coordination accelerates evaluation of particular hypotheses. In particular, we focus on the effect of educational attainment on cognitive decline. Method. Regular and Tobit mixed models were fit to MMSE scores from each study separately. The effects of age, sex, and education were examined based on more than one centering point. Results. Findings were relatively consistent across studies. On average, MMSE scores were lower for older individuals and declined over time. Education predicted MMSE score, but, with two exceptions, was not associated with decline in MMSE over time. Conclusion. A straightforward association between educational attainment and rate of cognitive decline was not supported. Thoughtful consideration is needed when synthesizing evidence across studies, as methodologies adopted and sample characteristics, such as educational attainment, invariably differ. PMID:23033357

Coordinated analysis of age, sex, and education effects on change in MMSE scores.

PubMed

Piccinin, Andrea M; Muniz-Terrera, Graciela; Clouston, Sean; Reynolds, Chandra A; Thorvaldsson, Valgeir; Deary, Ian J; Deeg, Dorly J H; Johansson, Boo; Mackinnon, Andrew; Spiro, Avron; Starr, John M; Skoog, Ingmar; Hofer, Scott M

2013-05-01

We describe and compare the expected performance trajectories of older adults on the Mini-Mental Status Examination (MMSE) across six independent studies from four countries in the context of a collaborative network of longitudinal studies of aging. A coordinated analysis approach is used to compare patterns of change conditional on sample composition differences related to age, sex, and education. Such coordination accelerates evaluation of particular hypotheses. In particular, we focus on the effect of educational attainment on cognitive decline. Regular and Tobit mixed models were fit to MMSE scores from each study separately. The effects of age, sex, and education were examined based on more than one centering point. Findings were relatively consistent across studies. On average, MMSE scores were lower for older individuals and declined over time. Education predicted MMSE score, but, with two exceptions, was not associated with decline in MMSE over time. A straightforward association between educational attainment and rate of cognitive decline was not supported. Thoughtful consideration is needed when synthesizing evidence across studies, as methodologies adopted and sample characteristics, such as educational attainment, invariably differ.

Measurement and decomposition of energy efficiency of Northeast China-based on super efficiency DEA model and Malmquist index.

PubMed

Ma, Xiaojun; Liu, Yan; Wei, Xiaoxue; Li, Yifan; Zheng, Mengchen; Li, Yudong; Cheng, Chaochao; Wu, Yumei; Liu, Zhaonan; Yu, Yuanbo

2017-08-01

Nowadays, environment problem has become the international hot issue. Experts and scholars pay more and more attention to the energy efficiency. Unlike most studies, which analyze the changes of TFEE in inter-provincial or regional cities, TFEE is calculated with the ratio of target energy value and actual energy input based on data in cities of prefecture levels, which would be more accurate. Many researches regard TFP as TFEE to do analysis from the provincial perspective. This paper is intended to calculate more reliably by super efficiency DEA, observe the changes of TFEE, and analyze its relation with TFP, and it proves that TFP is not equal to TFEE. Additionally, the internal influences of the TFEE are obtained via the Malmquist index decomposition. The external influences of the TFFE are analyzed afterward based on the Tobit models. Analysis results demonstrate that Heilongjiang has the highest TFEE followed by Jilin, and Liaoning has the lowest TFEE. Eventually, some policy suggestions are proposed for the influences of energy efficiency and study results.

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

Van Ootegem, Luc; SHERPPA — Ghent University; Verhofstadt, Elsy

Depth–damage-functions, relating the monetary flood damage to the depth of the inundation, are commonly used in the case of fluvial floods (floods caused by a river overflowing). We construct four multivariate damage models for pluvial floods (caused by extreme rainfall) by differentiating on the one hand between ground floor floods and basement floods and on the other hand between damage to residential buildings and damage to housing contents. We do not only take into account the effect of flood-depth on damage, but also incorporate the effects of non-hazard indicators (building characteristics, behavioural indicators and socio-economic variables). By using a Tobit-estimationmore » technique on identified victims of pluvial floods in Flanders (Belgium), we take into account the effect of cases of reported zero damage. Our results show that the flood depth is an important predictor of damage, but with a diverging impact between ground floor floods and basement floods. Also non-hazard indicators are important. For example being aware of the risk just before the water enters the building reduces content damage considerably, underlining the importance of warning systems and policy in this case of pluvial floods. - Highlights: • Prediction of damage of pluvial floods using also non-hazard information • We include ‘no damage cases’ using a Tobit model. • The damage of flood depth is stronger for ground floor than for basement floods. • Non-hazard indicators are especially important for content damage. • Potential gain of policies that increase awareness of flood risks.« less

Mapping health outcome measures from a stroke registry to EQ-5D weights

PubMed Central

2013-01-01

Purpose To map health outcome related variables from a national register, not part of any validated instrument, with EQ-5D weights among stroke patients. Methods We used two cross-sectional data sets including patient characteristics, outcome variables and EQ-5D weights from the national Swedish stroke register. Three regression techniques were used on the estimation set (n = 272): ordinary least squares (OLS), Tobit, and censored least absolute deviation (CLAD). The regression coefficients for “dressing“, “toileting“, “mobility”, “mood”, “general health” and “proxy-responders” were applied to the validation set (n = 272), and the performance was analysed with mean absolute error (MAE) and mean square error (MSE). Results The number of statistically significant coefficients varied by model, but all models generated consistent coefficients in terms of sign. Mean utility was underestimated in all models (least in OLS) and with lower variation (least in OLS) compared to the observed. The maximum attainable EQ-5D weight ranged from 0.90 (OLS) to 1.00 (Tobit and CLAD). Health states with utility weights <0.5 had greater errors than those with weights ≥0.5 (P < 0.01). Conclusion This study indicates that it is possible to map non-validated health outcome measures from a stroke register into preference-based utilities to study the development of stroke care over time, and to compare with other conditions in terms of utility. PMID:23496957

How much can we gain from improved efficiency? An examination of performance of national HIV/AIDS programs and its determinants in low- and middle-income countries

PubMed Central

2012-01-01

Background The economic downturn exacerbates the inadequacy of resources for combating the worldwide HIV/AIDS pandemic and amplifies the need to improve the efficiency of HIV/AIDS programs. Methods We used data envelopment analysis (DEA) to evaluate efficiency of national HIV/AIDS programs in transforming funding into services and implemented a Tobit model to identify determinants of the efficiency in 68 low- and middle-income countries. We considered the change from the lowest quartile to the average value of a variable a "notable" increase. Results Overall, the average efficiency in implementing HIV/AIDS programs was moderate (49.8%). Program efficiency varied enormously among countries with means by quartile of efficiency of 13.0%, 36.4%, 54.4% and 96.5%. A country's governance, financing mechanisms, and economic and demographic characteristics influence the program efficiency. For example, if countries achieved a notable increase in "voice and accountability" (e.g., greater participation of civil society in policy making), the efficiency of their HIV/AIDS programs would increase by 40.8%. For countries in the lowest quartile of per capita gross national income (GNI), a notable increase in per capita GNI would increase the efficiency of AIDS programs by 45.0%. Conclusions There may be substantial opportunity for improving the efficiency of AIDS services, by providing more services with existing resources. Actions beyond the health sector could be important factors affecting HIV/AIDS service delivery. PMID:22443135

Assessment of the Risk of Medium-Term Internal Contamination in Minamisoma City, Fukushima, Japan, after the Fukushima Dai-ichi Nuclear Accident

PubMed Central

Gilmour, Stuart; Tsubokura, Masaharu; Nomura, Shuhei; Kami, Masahiro; Oikawa, Tomoyoshi; Kanazawa, Yukio; Shibuya, Kenji

2014-01-01

Background: The Fukushima Dai-ichi nuclear disaster, the first level-7 major nuclear disaster since Chernobyl, raised concerns about the future health consequences of exposure to and intake of radionuclides. Factors determining the risk and level of internal radiation contamination after a nuclear accident, which are a key to understanding and improving current nuclear disaster management, are not well studied. Objective: We investigated both the prevalence and level of internal contamination in residents of Minamisoma, and identified factors determining the risk and levels of contamination. Methods: We implemented a program assessing internal radiation contamination using a whole body counter (WBC) measurement and a questionnaire survey in Minamisoma, between October 2011 and March 2012. Results: Approximately 20% of the city’s population (8,829 individuals) participated in the WBC measurement for internal contamination, of which 94% responded to the questionnaire. The proportion of participants with detectable internal contamination was 40% in adults and 9% in children. The level of internal contamination ranged from 2.3 to 196.5 Bq/kg (median, 11.3 Bq/kg). Tobit regression analysis identified two main risk factors: more time spent outdoors, and intake of potentially contaminated foods and water. Conclusions: Our findings suggest that, with sensible and reasonable precautions, people may be able to live continuously in radiation-affected areas with limited contamination risk. To enable this, nuclear disaster response should strictly enforce food and water controls and disseminate evidence-based and up-to-date information about avoidable contamination risks. Citation: Sugimoto A, Gilmour S, Tsubokura M, Nomura S, Kami M, Oikawa T, Kanazawa Y, Shibuya K. 2014. Assessment of the risk of medium-term internal contamination in Minamisoma City, Fukushima, Japan, after the Fukushima Dai-ichi Nuclear accident. Environ Health Perspect 122:587–593; http://dx.doi.org/10.1289/ehp.1306848 PMID:24633072

[Offered income, salary expectations, and the economic activity of married women: an analytic model].

PubMed

Lollivier, S

1984-06-01

This study uses data from tax declarations for 40,000 French households for 1975 to propose a model that permits quantification of the effects of certain significant factors on the economic activity of married women. The PROBIT model of analysis of variance was used to determine the specific effect of several variables, including age of the woman, number of children under 25 years of age in the household, the age of the youngest child, husband's income and socioprofessional status, wife's level and type of education, size of community of residence and region of residence. The principal factors influencing activity rates were found to be educational level, age, and to those of childless women, but activity rates dropped by about 30% for mothers of 2 and even more for mothers of 3 or more children. Influence of the place of residence and the husband's income were associated with lesser disparities. The reasons for variations in female labor force participation can be viewed as analogous to a balance. Underlying factors can increase or decrease the income the woman hopes to earn (offered income) as well as the minimum income for which she will work (required salary). A TOBIT model was constructed in which income was a function of age, education, geographic location, and number of children, and salary required was a function of the variables related to the husband including income and socioprofessional status. For most of the effects considered, the observed variation in activity rates resulted from variations in offered income. The husband's income influences only the desired salary. The offered income decreases and the required salary increases when the number of children is 2 or more, reducing the rate of activity. More educated women have slightly greater salary expectations, but command much higher salaries, resulting in an increased rate of professional activity.

Agro-ecology, household economics and malaria in Uganda: empirical correlations between agricultural and health outcomes

PubMed Central

2014-01-01

Background This paper establishes empirical evidence relating the agriculture and health sectors in Uganda. The analysis explores linkages between agricultural management, malaria and implications for improving community health outcomes in rural Uganda. The goal of this exploratory work is to expand the evidence-base for collaboration between the agricultural and health sectors in Uganda. Methods The paper presents an analysis of data from the 2006 Uganda National Household Survey using a parametric multivariate Two-Limit Tobit model to identify correlations between agro-ecological variables including geographically joined daily seasonal precipitation records and household level malaria risk. The analysis of agricultural and environmental factors as they affect household malaria rates, disaggregated by age-group, is inspired by a complimentary review of existing agricultural malaria literature indicating a gap in evidence with respect to agricultural management as a form of malaria vector management. Crop choices and agricultural management practices may contribute to vector control through the simultaneous effects of reducing malaria transmission, improving housing and nutrition through income gains, and reducing insecticide resistance in both malaria vectors and agricultural pests. Results The econometric results show the existence of statistically significant correlations between crops, such as sweet potatoes/yams, beans, millet and sorghum, with household malaria risk. Local environmental factors are also influential- daily maximum temperature is negatively correlated with malaria, while daily minimum temperature is positively correlated with malaria, confirming trends in the broader literature are applicable to the Ugandan context. Conclusions Although not necessarily causative, the findings provide sufficient evidence to warrant purposefully designed work to test for agriculture health causation in vector management. A key constraint to modeling the agricultural basis of malaria transmission is the lack of data integrating both the health and agricultural information necessary to satisfy the differing methodologies used by the two sectors. A national platform for collaboration between the agricultural and health sectors could help align programs to achieve better measurements of agricultural interactions with vector reproduction and evaluate the potential for agricultural policy and programs to support rural malaria control. PMID:24990158

Association between social capital and health-related quality of life among left behind and not left behind older people in rural China.

PubMed

Zhong, Yaqin; Schön, Pär; Burström, Bo; Burström, Kristina

2017-12-16

The association between social capital and health-related quality of life (HRQoL) has not been thoroughly studied among older persons in rural China, especially among those who were left behind or not. This study investigates the association between social capital and HRQoL and examines possible differences of this association between being left behind or not in rural China. A cross-sectional survey of 825 people aged 60 years and older, residing in three rural counties in Jiangsu Province in China, was conducted in 2013. Factor analysis was performed to measure social capital. EQ-5D was used to measure HRQoL. Tobit regression analysis with upper censoring was conducted to explore the association between social capital and EQ-5D index. After controlling for individual characteristics, low social capital and being left behind were significantly associated with low HRQoL. Old people with low social capital had 0.055 lower EQ-5D index compared to those with high social capital. Old people being left behind had 0.040 lower EQ-5D index compared to those who were not left behind. For different dimensions of social capital, the main effects came from the domain of trust and reciprocity. There was a significant interaction between low social capital and being left behind on HRQoL, suggesting that low social capital was associated with low HRQoL among persons left behind. Our findings indicate that the left behind old people with low social capital were a potentially vulnerable group in rural China. Formulating and implementing initiatives and strategies which increase social capital may foster better HRQoL, especially for old people who were left behind.

Competitive Swimming and Racial Disparities in Drowning

PubMed Central

Myers, Samuel L.; Cuesta, Ana M.; Lai, Yufeng

2018-01-01

This paper provides compelling evidence of an inverse relationship between competitive swimming rates and drowning rates using Centers for Disease Control and Prevention (CDC) data on fatal drowning rates and membership rates from USA Swimming, the governing organization of competitive swimming in the United States. Tobit and Poisson regression models are estimated using panel data by state from 1999–2007 separately for males, females, African Americans and whites. The strong inverse relationship between competitive swimming rates and unintentional deaths through fatal drowning is most pronounced among African Americans males.

Message frames interact with motivational systems to determine depth of message processing.

PubMed

Shen, Lijiang; Dillard, James Price

2009-09-01

Although several theoretical perspectives predict that negatively framed messages will be processed more deeply than positively framed messages, a recent meta-analysis found no such difference. In this article, the authors explore 2 explanations for this inconsistency. One possibility is methodological: the statistics used in the primary studies underestimated framing effects on depth of message processing because the data were maldistributed. The other is theoretical: the absence of a main effect is veridical, but framing interacts with individual differences that predispose individuals to greater or lesser depth of processing. Data from 2 experiments (Ns = 286 and 252) were analyzed via tobit regression, a technique designed to overcome the limitations of maldistributed data. One study showed the predicted main effect for framing, but the other did not. Both studies showed the anticipated interaction: Depth of processing correlated positively with a measure of the behavioral activation system in the advantage framing condition, whereas depth of processing correlated positively with the behavioral inhibition system in the disadvantage framing condition.

Using Online Respondent Driven Sampling for Vietnamese Youths' Alcohol Use and Associated Risk Factors

PubMed Central

Zhang, Melvyn W. B.; Tran, Bach Xuan; Le, Huong Thi; Long, Nguyen Hoang; Le, Huong Thi; Hinh, Nguyen Duc; Tho, Tran Dinh; Le, Bao Nguyen; Thuc, Vu Thi Minh; Ngo, Chau; Tu, Nguyen Huu; Latkin, Carl A.; Ho, Roger CM

2017-01-01

Objectives The average alcohol consumption per capita among Vietnamese adults has consistently increased. Although alcohol-related disorders have been extensively studied, there is a paucity of research shedding light on this issue among Internet users. The study aimed to examine the severity of alcohol-related disorders and other associated factors that might predispose individuals towards alcohol usage in a sample of youths recruited online. Methods An online cross-sectional study was conducted with 1,080 Vietnamese youths. A standardized questionnaire was used. Respondent-driven sampling was applied to recruit participants. Multivariate logistic and Tobit regressions were utilized to identify the associated factors. Results About 59.5% of the males and 12.7% of the total youths declared that they were actively using alcohol. From the total sample, a cumulative total of 32.3% of the participants were drinking alcohol, with 21.8% and 25.0% of the participants being classified as drinking hazardously and binge drinkers, respectively. The majority of the participants (60.7%) were in the pre-contemplative stage. Conclusions A high prevalence of hazardous drinking was recognized among online Vietnamese youths. In addition, we found relationships between alcohol use disorder and other addictive disorders, such as tobacco smoking and water-pipe usage. Our results highlighted that the majority of the individuals are not receptive to the idea of changing their alcohol habits, and this would imply that there ought to be more government effort towards the implementation of effective alcohol control policies. PMID:28523209

Technical efficiency of nursing homes: do five-star quality ratings matter?

PubMed

Dulal, Rajendra

2017-02-28

This study investigates associations between five-star quality ratings and technical efficiency of nursing homes. The sample consists of a balanced panel of 338 nursing homes in California from 2009 through 2013 and uses two-stage data envelopment (DEA) analysis. The first-stage applies an input oriented variable returns to scale DEA analysis. The second-stage uses a left censored random-effect Tobit regression model. The five-star quality ratings i.e., health inspections, quality measures, staffing available on the Nursing Home Compare website are divided into two categories: outcome and structure form of quality. Results show that quality measures ratings and health inspection ratings, used as outcome form of quality, are not associated with mean technical efficiency. These quality ratings, however, do affect the technical efficiency of a particular nursing home and hence alter the ranking of nursing homes based on efficiency scores. Staffing rating, categorized as a structural form of quality, is negatively associated with mean technical efficiency. These findings show that quality dimensions are associated with technical efficiency in different ways, suggesting that multiple dimensions of quality should be included in the efficiency analysis of nursing homes. They also suggest that patient care can be enhanced through investing more in improving care delivery rather than simply raising the number of staff per resident.

Factors affecting the entry of for-profit providers into a price regulated market for formal long-term care services: a case study from Japan.

PubMed

Tokunaga, Mutsumi; Hashimoto, Hideki

2013-01-01

While the distinct behaviors of for-profit and non-profit providers in the healthcare market have been compared in the economic literature, their choices regarding market entry and exit have only recently been debated. Since 2000, when public Long-Term Care Insurance was introduced in Japan, for-profit providers have been able to provide formal long-term homecare services. The aim of this study is to determine which factors have affected market entry of for-profit providers under price regulation and in competition with existing non-profit providers. We used nation-wide panel data from 2002 to 2010, aggregated at the level of local public insurers (n = 1557), a basic area unit of service provision. The number of for-profit providers per elderly population in the area unit was regressed against factors related to local demand and service costs using first-difference linear regression, a fixed effects model, and Tobit regression for robustness checking. Results showed that demand (the number of eligible care recipients) and cost factors (population density and minimum wage) significantly influenced for-profit providers' choice of market entry. These findings indicate that for-profit providers will strategically choose a local market for maximizing profit. We believe that price regulation should be redesigned to incorporate quality of care and market conditions, regardless of the profit status of the providers, to ensure equal access to efficient delivery of long-term care across all regions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Factors affecting fruit and vegetable school lunch waste in Wisconsin elementary schools participating in Farm to School programmes.

PubMed

Bontrager Yoder, Andrea B; Foecke, Leah L; Schoeller, Dale A

2015-10-01

To examine characteristics potentially associated with school lunch fruit and vegetable waste, both overall and pre/post implementation of the Healthy, Hunger-Free Kids Act. Multi-year (2010-2013) cross-sectional study using pre- and post-meal digital photographs of students' school lunch trays to estimate fruit and vegetable availability and consumption. Fruit and vegetable items were categorized for factors suspected to impact waste: prior farm to school years, placement (main menu, salad bar), procurement (local, conventional), preparation (cooked, raw) and meal component (entrée, side, topping). Analyses to assess within-category differences in waste volume were performed using a Tobit model. Wisconsin elementary schools participating in farm to school programmes, USA. Children in third to fifth grade. Many within-factor differences were detected overall and/or across time. Cooked fruits were wasted less than raw, while cooked vegetables were wasted more than raw. Where identified, locally sourced items were wasted more than conventionally sourced (+0·1 cups, P<0·0001) and salad bar items more than main menu items (+0·01 cups, P<0·0001). Increasing prior farm to school years decreased waste (-0·02 cups, P<0·0001). Items previously tried were wasted at the same volume whether reported as liked or not. New school lunch meal pattern requirement implementation did not uniformly impact fruit and vegetable waste across all categories and there was no change in waste for seven of fifteen assessed categories. Many factors impact elementary students' school lunch waste. These factors may be helpful for school food-service authorities to consider when planning school menus.

Efficiency of private and public primary health facilities accredited by the National Health Insurance Authority in Ghana.

PubMed

Alhassan, Robert Kaba; Nketiah-Amponsah, Edward; Akazili, James; Spieker, Nicole; Arhinful, Daniel Kojo; Rinke de Wit, Tobias F

2015-01-01

Despite improvements in a number of health outcome indicators partly due to the National Health Insurance Scheme (NHIS), Ghana is unlikely to attain all its health-related millennium development goals before the end of 2015. Inefficient use of available limited resources has been cited as a contributory factor for this predicament. This study sought to explore efficiency levels of NHIS-accredited private and public health facilities; ascertain factors that account for differences in efficiency and determine the association between quality care and efficiency levels. The study is a cross-sectional survey of NHIS-accredited primary health facilities (n = 64) in two regions in southern Ghana. Data Envelopment Analysis was used to estimate technical efficiency of sampled health facilities while Tobit regression was employed to predict factors associated with efficiency levels. Spearman correlation test was performed to determine the association between quality care and efficiency. Overall, 20 out of the 64 health facilities (31 %) were optimally efficient relative to their peers. Out of the 20 efficient facilities, 10 (50 %) were Public/government owned facilities; 8 (40 %) were Private-for-profit facilities and 2 (10 %) were Private-not-for-profit/Mission facilities. Mission (Coef. = 52.1; p = 0.000) and Public (Coef. = 42.9; p = 0.002) facilities located in the Western region (predominantly rural) had higher odds of attaining the 100 % technical efficiency benchmark than those located in the Greater Accra region (largely urban). No significant association was found between technical efficiency scores of health facilities and many technical quality care proxies, except in overall quality score per the NHIS accreditation data (Coef. = -0.3158; p < 0.05) and SafeCare Essentials quality score on environmental safety for staff and patients (Coef. = -0.2764; p < 0.05) where the association was negative. The findings suggest some level of wastage of health resources in many healthcare facilities, especially those located in urban areas. The Ministry of Health and relevant stakeholders should undertake more effective need analysis to inform resource allocation, distribution and capacity building to promote efficient utilization of limited resources without compromising quality care standards.

Patients' willingness to pay for the treatment of tuberculosis in Nigeria: exploring own use and altruism.

PubMed

Ochonma, Ogbonnia G; Onwujekwe, Obinna E

2017-05-10

Although, current treatment services for Tuberculosis (TB) in Nigeria are provided free of charge in public facilities, the benefits (value) that patients attach to such service is not known. In addition, the prices that could be charged for treatment in case government and its partners withdraw from the provision of free services or inclusion of the services in health insurance plans are not known. Hence, there is a need to elicit the maximum amounts that patients are willing to pay for TB treatment services, both for themselves and for the very poor patients that may not be able to pay if some user fees are introduced (altruistic willingness to pay). A pretested interviewer-administered questionnaire was used to elicit the maximum willingness to pay (WTP) for TB treatment services from TB patients in a tertiary hospital in southeast Nigeria. WTP was elicited using the bidding game question format after a scenario was presented to the respondents. Data was analysed using tabulations. Tobit regression models were used to examine the validity of the elicited WTP for own use and altruistic WTP. The results show that those aged 30 years and below constituted more than two-fifth (43.2%) of the respondents. More than half of the respondents (52.8%) were not employed. 100 (80.0%) of the respondents were willing to pay for their own use of TB treatment services while 78(62.4%) of the respondents were willing to make altruistic contributions so that the very poor could benefit from the TB services. A Tobit regression analysis of maximum WTP for TB for own use shows that respondents were willing to pay maximum amounts at different statistically significant levels. The results equally show that altruistic WTP was positively and statistically significantly related to the employment status, distance from UNTH and global seriousness of TB. Most patients positively valued the provision of free TB services and were willing to pay for TB treatment for own use. The better-off ones were also willing to make altruistic contributions. Free provision of TB treatment services is potentially worthwhile, but there is potential scope for continuation of universal provision of TB treatment services, even if the government and donors scale down their financing of the services.

Technical Efficiency of Hospitals in Tehran, Iran.

PubMed

Kakeman, Edris; Rahimi Forushani, Abbas; Dargahi, Hossein

2016-04-01

Nowadays, restriction on access and optimum use of resources is the main challenge of development in all organizations. Therefore, the aim of this study was to determine the technical efficiency and its factors, influencing hospitals of Tehran. This research was a descriptive-analytical and retrospective study conducted in 2014-2015. Fifty two hospitals with public, private, and social security ownership type were selected for this study. The required data was collected by a researcher-made check list in 3 sections of background data, inputs and outputs. The data was analyzed by DEAP 1.0.2, and STATA-13 technique. Seventeen (31/48) of hospitals had the efficiency score of 1 as the highest technical efficiency. The highest average score of efficiency was related to social security hospitals as 84.32, and then the public and private hospitals with the average of 84.29 and 79.64 respectively. Tobit regression results showed that the size, type of practice, and ownership of hospitals were effective on the degree of their technical efficiency. However, there was no significant correlation between teaching / non-teaching hospitals with technical efficiency. Establishment of competition system among hospitals, constitution of medium size hospitals and allocation of budget to hospitals based on national accreditation system are recommended.

Risk Factor Differences in Calcified and Non-Calcified Aortic Plaque: The Framingham Heart Study

PubMed Central

Chuang, Michael L.; Gona, Philimon; Oyama-Manabe, Noriko; Manders, Emily S.; Salton, Carol J.; Hoffmann, Udo; Manning, Warren J.; O'Donnell, Christopher J.

2014-01-01

Objective Determine the prevalence and risk factor (RF) correlates of aortic plaque (AP) detected by cardiovascular magnetic resonance (CMR), which mainly shows noncalcified plaques, and by noncontrast computed tomography (CT), which best depicts calcified plaques, in community-dwelling adults. Approach and Results 1016 Framingham Offspring cohort members (64±9y, 474 men) underwent CMR and CT of the aorta. Potential RFs for AP (age; sex; BMI; blood pressure; LDL and HDL cholesterol; fasting glucose; C-reactive protein; prevalent hypertension, diabetes, smoking; use of antihypertensive, diabetes or lipid-lowering drugs) were compared between participants with zero versus nonzero AP by CMR and by CT. Candidate RFs attaining p<0.05 for difference with either imaging modality were entered into multivariable logistic regression models adjusting for age, sex and other RFs. Odds ratios were calculated for modality-specific prevalence of AP. Associations between RFs and continuous measures of AP were assessed using Tobit regression. Prevalences of CMR and CT AP were 49% and 82% respectively. AP burdens by CMR and CT were correlated, r=0.28, p<0.0001. Increasing age and smoking were associated with prevalent AP by both CMR and CT. Additionally, prevalent AP by CMR was associated with female sex and fasting glucose, prevalent AP by CT with hypertension treatment and with adverse lipid profile. Conclusions AP by CMR and CT are both associated with smoking and increasing age, but other risk factors differ between calcified and noncalcified AP. The relative predictive value of AP detected by CMR versus by CT for incident cardiovascular events remains to be determined. PMID:24833796

Willingness to pay and benefit-cost analysis of modern contraceptives in Nigeria.

PubMed

Onwujekwe, Obinna; Ogbonna, Chinwe; Ibe, Ogochukwu; Uzochukwu, Benjamin

2013-08-01

To determine the willingness to pay (WTP) and the benefit-cost of modern contraceptives delivered through the public sector in Nigeria. Data were collected from 4517 randomly selected households. The WTP for the 6 major contraceptive methods available in the public sector was elicited. Logistic regression was used to determine whether the decision to state a positive WTP amount was valid; Tobit regression was used to test the validity of the elicited WTP amounts. For each contraceptive, 3 BCR values were computed, based on the official unit price, the unit cost per couple-year of protection (CYP), and the average actual expenditure for contraceptives in the month preceding the interview. The mean WTP for the different contraceptives varied by socioeconomic status and geographic (urban versus rural) location (P<0.01). The BCR analysis showed that the benefits of providing contraceptives through the public sector far outweighed the costs, except for female condoms, where the CYP-based BCR was 0.9. The benefits of providing contraceptives outweigh the costs, making public sector investment worthwhile. The median WTP amounts, which reflect the ideal upper thresholds for pricing, indicate that cost recovery is feasible for all contraceptives. Copyright © 2013 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Seasonality of selected surface water constituents in the Indian River Lagoon, Florida.

PubMed

Qian, Y; Migliaccio, K W; Wan, Y; Li, Y C; Chin, D

2007-01-01

Seasonality is often the major exogenous effect that must be compensated for or removed to discern trends in water quality. Our objective was to provide a methodological example of trend analysis using water quality data with seasonality. Selected water quality constituents from 1979 to 2004 at three monitoring stations in southern Florida were evaluated for seasonality. The seasonal patterns of flow-weighted and log-transformed concentrations were identified by applying side-by-side boxplots and the Wilcoxon signed-rank test (p < 0.05). Seasonal and annual trends were determined by trend analysis (Seasonal Kendall or Tobit procedure) using the U.S. Geological Survey (USGS) Estimate TREND (ESTREND) program. Major water quality indicators (specific conductivity, turbidity, color, and chloride), except for turbidity at Station C24S49, exhibited significant seasonal patterns. Almost all nutrient species (NO(2)-N, NH(4)-N, total Kjeldahl N, PO(4)-P, and total P) had an identical seasonal pattern of concentrations significantly greater in the wet than in the dry season. Some water quality constituents were observed to exhibit significant annual or seasonal trends. In some cases, the overall annual trend was insignificant while opposing trends were present in different seasons. By evaluating seasonal trends separately from all data, constituents can be assessed providing a more accurate interpretation of water quality trends.

Lipoprotein(a) is strongly associated with coronary artery calcification in type-2 diabetic women

PubMed Central

Qasim, Atif N.; Martin, Seth S.; Mehta, Nehal N.; Wolfe, Megan L.; Park, James; Schwartz, Stanley; Schutta, Mark; Iqbal, Nayyar; Reilly, Muredach P.

2011-01-01

Background Lp(a), implicated in both atherogenesis and thrombosis pathways, varies significantly by demographic and metabolic factors, providing challenges for its use in Coronary Heart Disease (CHD) risk. The purpose of this study was to investigate whether type-2 diabetic subjects, relative to non-diabetics, might benefit more from Lp(a) measurement in the prediction of CHD risk, as measured by coronary artery calcium (CAC). Methods We performed cross sectional analyses in two community-based studies: the Penn Diabetes Heart Study [N=1299 with type-2 diabetes] and the Study of Inherited Risk of Coronary Atherosclerosis [N=860 without diabetes]. Results Blacks had 2–3 fold higher Lp(a) levels than whites in diabetic and non-diabetic samples. There was significant difference by gender (interaction p<0.001), but not race, in the association of Lp(a) with CAC in type-2 diabetic subjects. In age and race adjusted analysis of diabetic women, Lp(a) was associated with CAC [Tobit regression ratio 2.76 (95% CI 1.73–4.40), p<0.001]. Adjustment for exercise, medications, Framingham risk score, metabolic syndrome, BMI, CRP and hemoglobin A1c attenuated this effect, but the association of Lp(a) with CAC remained significant [2.25, (1.34–3.79), p=0.002]. This relationship was further maintained in women stratified by race, or by the use of HRT or lipid lowering drugs. In contrast, Lp(a) was not associated with CAC in diabetic men, nor in non-diabetic men and women. Conclusions Lp(a) is a strong independent predictor of CAC in type-2 diabetic women, regardless of race, but not in men. Lp(a) does not relate to CAC in men or women without type-2 diabetes. PMID:20303190

The relationship between shared decision-making and health-related quality of life among patients in Hong Kong SAR, China.

PubMed

Xu, Richard H; Cheung, Annie W L; Wong, Eliza L Y

2017-08-01

To elucidate the association between health-related quality of life and shared decision-making among patients in Hong Kong after adjustment for potential confounding variables. A telephone survey was conducted with patients attending all public specialist outpatient clinics in Hong Kong between July and December 2014. The Specialist Outpatient Patient Experience Questionnaire and EQ-5D questionnaire were used to evaluate shared decision-making and quality of life, respectively. We performed a Tobit regression analysis to examine the associations between shared decision-making and quality of life after adjustment for known social, economic and health-related factors. Twenty-six of the Hospital Authority's specialist outpatient clinics. Patients aged 18 years or older who attended one of the Hospital Authority's specialist outpatient clinics between July and November 2014. Shared decision-making and quality of life score. Overall, 13 966 patients completed the study. The group reporting partial involvement in decision-making had slightly higher EQ-5D scores than the 'not involved' group and the 'fully involved' group. EQ-5D scores were higher among subjects who were younger, male, and had a higher level of education. Respondents living alone and living in institutions scored lower on the EQ-5D than patients living with families. Important differences in the relationship between the attitudes towards shared decision-making and quality of life were identified among patients. These associations should be taken into consideration when promoting patient-centred care and improving health professional-patient communication. © 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

Linking local vulnerability to climatic hazard damage assessment for integrated river basin management

NASA Astrophysics Data System (ADS)

Hung, Hung-Chih; Liu, Yi-Chung; Chien, Sung-Ying

2015-04-01

1. Background Major portions of areas in Asia are expected to increase exposure and vulnerability to climate change and weather extremes due to rapid urbanization and overdevelopment in hazard-prone areas. To prepare and confront the potential impacts of climate change and related hazard risk, many countries have implemented programs of integrated river basin management. This has led to an impending challenge for the police-makers in many developing countries to build effective mechanism to assess how the vulnerability distributes over river basins, and to understand how the local vulnerability links to climatic (climate-related) hazard damages and risks. However, the related studies have received relatively little attention. This study aims to examine whether geographic localities characterized by high vulnerability experience significantly more damages owing to onset weather extreme events at the river basin level, and to explain what vulnerability factors influence these damages or losses. 2. Methods and data An indicator-based assessment framework is constructed with the goal of identifying composite indicators (including exposure, biophysical, socioeconomic, land-use and adaptive capacity factors) that could serve as proxies for attributes of local vulnerability. This framework is applied by combining geographical information system (GIS) techniques with multicriteria decision analysis (MCDA) to evaluate and map integrated vulnerability to climatic hazards across river basins. Furthermore, to explain the relationship between vulnerability factors and disaster damages, we develop a disaster damage model (DDM) based on existing disaster impact theory. We then synthesize a Zero-Inflated Poisson regression model with a Tobit regression analysis to identify and examine how the disaster impacts and vulnerability factors connect to typhoon disaster damages and losses. To illustrate the proposed methodology, the study collects data on the vulnerability attributes of the Kaoping, Tsengwen, and Taimali River basins in southern Taiwan, and on the disaster impacts and damages in these river basins due to Typhoon Morakot in 2009. The data was offered by the National Science and Technology Center for Disaster Reduction, Taiwan, as well as collected from the National Land Use Investigation, official census statistics and questionnaire surveys. 3. Results We use an MCDA to create a composite vulnerability index, and this index is incorporated into a GIS analysis to demonstrate the results of integrated vulnerability assessment throughout the river basins. Results of the vulnerability assessment indicate that the most vulnerable areas are almost all situated in the regions of middle and upper reaches of the river basins. Through the examining of DDM, it shows that the vulnerability factors play a critical role in determining disaster damages. Findings also present that the losses and casualties caused by Typhoon Morakot increase with elevation, urban and agricultural developments, proximity to rivers, and decrease with levels of income and adaptive capacity. Finally, we propose the adaptive options for minimizing vulnerability and risk, as well as for integrated river basin governance.

Factors associated with nicotine dependence during methadone maintenance treatment: findings from a multisite survey in Vietnam

PubMed Central

Do, Huyen Phuc; Nguyen, Long Hoang; Thi Nguyen, Nhung Phuong; Ngo, Chau; Thi Nguyen, Huong Lan; Le, Giang Tong; Nguyen, Linh Khanh; Nguyen, Cuong Tat; Tran, Bach Xuan; Le, Huong Thi; Vu, Thuc Minh Thi; Phan, Huong Thu Thi; Tran, Tho Dinh; Latkin, Carl A; Dunne, Michael P

2017-01-01

Objectives Smoking is associated with adverse health outcomes among drug users, including those in treatment. To date, however, there has been little evidence about smoking patterns among people receiving opioid-dependence treatment in developing countries. We examined self-reported nicotine dependence and associated factors in a large sample of opioid-dependent patients receiving methadone maintenance treatment (MMT) in northern Vietnam. Setting Five clinics in Hanoi (urban area) and Nam Dinh (rural area). Participants Patients receiving MMT in the settings during the study period. Primary and secondary outcome measures We collected data about smoking patterns, levels of nicotine dependence and other covariates such as socioeconomic status, health status, alcohol use and drug use. The Fagerström test was used to measure nicotine dependence (FTND). Logistic regression and Tobit regression were employed to examine relationships between the smoking rate, nicotine dependence and potentially associated variables. Results Among 1016 drug users undergoing MMT (98.7% male), 87.2% were current smokers. The mean FTND score was 4.5 (SD 2.4). Longer duration of MMT (OR 0.98, 95% CI 0.96 to 0.99) and being HIV-positive (OR 0.46, 95% CI 0.24 to 0.88) were associated with lower likelihood of smoking. Being employed, older age at first drug injection and having long duration of MMT were inversely related with FTND scores. Higher age and continuing drug and alcohol use were significantly associated with higher FTND scores. Conclusion Smoking prevalence is high among methadone maintenance drug users. Enhanced smoking cessation support should be integrated into MMT programmes in order to reduce risk factors for cigarette smoking and improve the health and well-being of people recovering from opiate dependence. PMID:28716791

Evaluating Food Safety Knowledge and Practices of Food Processors and Sellers Working in Food Facilities in Hanoi, Vietnam.

PubMed

Tran, Bach Xuan; DO, Hoa Thi; Nguyen, Luong Thanh; Boggiano, Victoria; LE, Huong Thi; LE, Xuan Thanh Thi; Trinh, Ngoc Bao; DO, Khanh Nam; Nguyen, Cuong Tat; Nguyen, Thanh Trung; Dang, Anh Kim; Mai, Hue Thi; Nguyen, Long Hoang; Than, Selena; Latkin, Carl A

2018-04-01

Consumption of fast food and street food is increasingly common among Vietnamese, particularly in large cities. The high daily demand for these convenient food services, together with a poor management system, has raised concerns about food hygiene and safety (FHS). This study aimed to examine the FHS knowledge and practices of food processors and sellers in food facilities in Hanoi, Vietnam, and to identify their associated factors. A cross-sectional study was conducted with 1,760 food processors and sellers in restaurants, fast food stores, food stalls, and street vendors in Hanoi in 2015. We assessed each participant's FHS knowledge using a self-report questionnaire and their FHS practices using a checklist. Tobit regression was used to determine potential factors associated with FHS knowledge and practices, including demographics, training experience, and frequency of health examination. Overall, we observed a lack of FHS knowledge among respondents across three domains, including standard requirements for food facilities (18%), food processing procedures (29%), and food poisoning prevention (11%). Only 25.9 and 38.1% of participants used caps and masks, respectively, and 12.8% of food processors reported direct hand contact with food. After adjusting for socioeconomic characteristics, these factors significantly predicted increased FHS knowledge and practice scores: (i) working at restaurants and food stalls, (ii) having FHS training, (iii) having had a physical examination, and (iv) having taken a stool test within the last year. These findings highlight the need of continuous training to improve FHS knowledge and practices among food processors and food sellers. Moreover, regular monitoring of food facilities, combined with medical examination of their staff, should be performed to ensure food safety.

Carbon nanotube and nanofiber exposure and sputum and blood biomarkers of early effect among U.S. workers.

PubMed

Beard, John D; Erdely, Aaron; Dahm, Matthew M; de Perio, Marie A; Birch, M Eileen; Evans, Douglas E; Fernback, Joseph E; Eye, Tracy; Kodali, Vamsi; Mercer, Robert R; Bertke, Stephen J; Schubauer-Berigan, Mary K

2018-07-01

Carbon nanotubes and nanofibers (CNT/F) are increasingly used for diverse applications. Although animal studies suggest CNT/F exposure may cause deleterious health effects, human epidemiological studies have typically been small, confined to single workplaces, and limited in exposure assessment. We conducted an industrywide cross-sectional epidemiological study of 108 workers from 12 U.S. sites to evaluate associations between occupational CNT/F exposure and sputum and blood biomarkers of early effect. We assessed CNT/F exposure via personal breathing zone, filter-based air sampling to measure background-corrected elemental carbon (EC) (a CNT/F marker) mass and microscopy-based CNT/F structure count concentrations. We measured 36 sputum and 37 blood biomarkers. We used factor analyses with varimax rotation to derive factors among sputum and blood biomarkers separately. We used linear, Tobit, and unconditional logistic regression models to adjust for potential confounders and evaluate associations between CNT/F exposure and individual biomarkers and derived factors. We derived three sputum and nine blood biomarker factors that explained 78% and 67%, respectively, of the variation. After adjusting for potential confounders, inhalable EC and total inhalable CNT/F structures were associated with the most sputum and blood biomarkers, respectively. Biomarkers associated with at least three CNT/F metrics were 72 kDa type IV collagenase/matrix metalloproteinase-2 (MMP-2), interleukin-18, glutathione peroxidase (GPx), myeloperoxidase, and superoxide dismutase (SOD) in sputum and MMP-2, matrix metalloproteinase-9, metalloproteinase inhibitor 1/tissue inhibitor of metalloproteinases 1, 8-hydroxy-2'-deoxyguanosine, GPx, SOD, endothelin-1, fibrinogen, intercellular adhesion molecule 1, vascular cell adhesion protein 1, and von Willebrand factor in blood, although directions of associations were not always as expected. Inhalable rather than respirable CNT/F was more consistently associated with fibrosis, inflammation, oxidative stress, and cardiovascular biomarkers. Published by Elsevier Ltd.

Routine assistance to parents: effects on daily mood and other stressors.

PubMed

Savla, Jyoti; Almeida, David M; Davey, Adam; Zarit, Steven H

2008-05-01

The present study examined the association of providing assistance to older parents amid everyday circumstances and short-term psychological consequences for adult children providing assistance. We explored this association using 824 daily diary interviews of 119 adult children providing assistance in the National Study of Daily Experiences by using a left-censored random effects tobit regression model that accounted for the clustered data and floor effects in reported psychological distress. Psychological distress was higher on days adult children provided assistance to their parent (b = 0.88, p <.05) even after we controlled for situational variables such as time spent on daily paid work, time spent on leisure activities, and assistance provided to individuals other than parents. Demographic and psychosocial variables such as having resident children (b = 2.14, p <.01), less education (b = -0.54, p <.05), and neuroticism (b = 2.08, p <.05), also predicted daily psychological distress. Even after we controlled for within-person (daily situational variables) and between-person factors (background characteristics), the act of providing assistance itself had immediate associations with daily mood for helpers, particularly for those with fewer resources and greater demands on time. Feasibility and success of programs that provide respite and relief services to older adults and their children should be assessed in light of daily living.

Routine Assistance to Parents: Effects on Daily Mood and Other Stressors

PubMed Central

Savla, Jyoti; Almeida, David M.; Davey, Adam; Zarit, Steven H.

2012-01-01

Objectives The present study examines the association of providing assistance to older parents amidst everyday circumstances and short-term psychological consequences for adult children providing assistance. Methods We explore this association using 824 daily diary interviews of 119 adult children providing assistance in the National Study of Daily Experiences by using a left-censored random effects tobit regression model that accounts for the clustered data and floor effects in reported psychological distress. Results Psychological distress was higher on days adult children provided assistance to their parent (b=0.88, p<0.05) even after controlling for situational variables such as time spent on daily paid work, leisure activities and assistance provided to individuals other than parents. Demographic and psychosocial variables such as having resident children (b=2.14, p<0.01), education (b=−0.54, p<0.05) and neuroticism (b=2.08, p<0.05) also predicted daily psychological distress. Discussion Even after controlling for within-person (daily situational variables) and between-person factors (background characteristics), the act of providing assistance itself has immediate associations with daily mood for helpers, particularly for those with fewer resources and greater demands on time. Feasibility and success of programs that provide respite and relief services to older adults and their children should be assessed in light of daily living. PMID:18559690

Estimating irrigation water demand in the Moroccan Drâa Valley using contingent valuation.

PubMed

Storm, Hugo; Heckelei, Thomas; Heidecke, Claudia

2011-10-01

Irrigation water management is crucial for agricultural production and livelihood security in Morocco as in many other parts of the world. For the implementation of an effective water management, knowledge about farmers' demand for irrigation water is crucial to assess reactions to water pricing policy, to establish a cost-benefit analysis of water supply investments or to determine the optimal water allocation between different users. Previously used econometric methods providing this information often have prohibitive data requirements. In this paper, the Contingent Valuation Method (CVM) is adjusted to derive a demand function for irrigation water along farmers' willingness to pay for one additional unit of surface water or groundwater. An application in the Middle Drâa Valley in Morocco shows that the method provides reasonable results in an environment with limited data availability. For analysing the censored survey data, the Least Absolute Deviation estimator was found to be a more suitable alternative to the Tobit model as errors are heteroscedastic and non-normally distributed. The adjusted CVM to derive demand functions is especially attractive for water scarce countries under limited data availability. Copyright © 2011 Elsevier Ltd. All rights reserved.

Food Insecurity is Associated with Poor HIV Outcomes Among Women in the United States.

PubMed

Spinelli, Matthew A; Frongillo, Edward A; Sheira, Lila A; Palar, Kartika; Tien, Phyllis C; Wilson, Tracey; Merenstein, Daniel; Cohen, Mardge; Adedimeji, Adebola; Wentz, Eryka; Adimora, Adaora A; Metsch, Lisa R; Turan, Janet M; Kushel, Margot B; Weiser, Sheri D

2017-12-01

Women in the general population experience more food insecurity than men. Few studies have examined food insecurity's impact on HIV treatment outcomes among women. We examined the association between food insecurity and HIV outcomes in a multi-site sample of HIV-infected women in the United States (n = 1154). Two-fifths (40%) of participants reported food insecurity. In an adjusted multivariable Tobit regression model, food insecurity was associated with 2.08 times higher viral load (95% confidence interval (CI): 1.04, 4.15) and lower CD4+ counts (- 42.10, CI: - 81.16, - 3.03). Integration of food insecurity alleviation into HIV programs may improve HIV outcomes in women.

Determinants of Allergen Concentrations in Apartments of Asthmatic Children Living in Public Housing

PubMed Central

Levy, Jonathan I.; Rogers, Christine A.; Burge, Harriet A.; Spengler, John D.

2007-01-01

There is growing evidence linking poor housing conditions and respiratory diseases, including asthma. The association between housing conditions and asthma in the inner city has been attributed in part to cockroach and mouse infestation and the resulting allergen exposures. Multiple social and behavioral factors can influence environmental exposures and health conditions, necessitating a thorough examination of such factors. As part of the Healthy Public Housing Initiative, we evaluated the association between physical and household characteristics and pest-related allergen levels in three public housing developments in Boston, MA. We detected cockroach allergens (Bla g 1 and Bla g 2) in bedroom air, bed, and especially high concentrations in kitchen samples. In multivariate Tobit regressions controlling for development and season, clutter and lack of cleanliness in the apartment were associated with a tenfold increase in Bla g 1 concentration in the air, a sevenfold increase in Bla g 1 and an eightfold increase in Bla g 2 concentrations in the bed, and an 11-fold increase in Bla g 2 in the kitchen (p<0.05 for all). Holes in the wall/ceiling were associated with a six- to 11-fold increase in kitchen cockroach allergen concentrations (p<0.05). Occupancy in an apartment unit of 2 years or more was also associated with increased cockroach allergen concentrations. In contrast, there were low concentrations of mouse urinary protein in this population. In conclusion, these results suggest that interventions in these homes should focus on reducing cockroach allergen concentrations and that building-wide interventions should be supplemented with targeted efforts focused on high-risk units. PMID:17216349

Efficiency and productivity assessment of public hospitals in Greece during the crisis period 2009-2012.

PubMed

Xenos, P; Yfantopoulos, J; Nektarios, M; Polyzos, N; Tinios, P; Constantopoulos, A

2017-01-01

This study is an initial effort to examine the dynamics of efficiency and productivity in Greek public hospitals during the first phase of the crisis 2009-2012. Data were collected by the Ministry of Health after several quality controls ensuring comparability and validity of hospital inputs and outputs. Productivity is estimated using the Malmquist Indicator, decomposing the estimated values into efficiency and technological change. Hospital efficiency and productivity growth are calculated by bootstrapping the non-parametric Malmquist analysis. The advantage of this method is the estimation efficiency and productivity through the corresponding confidence intervals. Additionally, a Random-effects Tobit model is explored to investigate the impact of contextual factors on the magnitude of efficiency. Findings reveal substantial variations in hospital productivity over the period from 2009 to 2012. The economic crisis of 2009 had a negative impact in productivity. The average Malmquist Productivity Indicator (MPI) score is 0.72 with unity signifying stable production. Approximately 91% of the hospitals score lower than unity. Substantial increase is observed between 2010 and 2011, as indicated by the average MPI score which fluctuates to 1.52. Moreover, technology change scored more than unity in more than 75% of hospitals. The last period (2011-2012) has shown stabilization in the expansionary process of productivity. The main factors contributing to overall productivity gains are increases in occupancy rates, type and size of the hospital. This paper attempts to offer insights in efficiency and productivity growth for public hospitals in Greece. The results suggest that the average hospital experienced substantial productivity growth between 2009 and 2012 as indicated by variations in MPI. Almost all of the productivity increase was due to technology change which could be explained by the concurrent managerial and financing healthcare reforms. Hospitals operating under decreasing returns to scale could achieve higher efficiency rates by reducing their capacity. However, certain social objectives should also be considered. Emphasis perhaps should be placed in utilizing and advancing managerial and organizational reforms, so that the benefits of technological improvements will have a continuing positive impact in the future.

Pathways from education to depression.

PubMed

Lee, Jinkook

2011-06-01

We examine educational gradients in depression and identify underlying mechanisms of how education might affect depression. We use a nationally representative sample of community-residing adults aged 45 and older from the 2006 Korean Longitudinal Study of Aging, which collected information about depressive symptoms and education. Using tobit regression, we estimate the effect of education on depression and examine what can explain the education gradients by controlling for proxy variables of different pathways linking education to depression. We found cognitive ability, economic resources, social status, social network, and health behavior explain all of the education gradients. Education affects depression through different underlying mechanisms, and the single most important pathway is through developing cognitive ability. Through these pathways, educational attainment influences not only depression for an individual but also for one's spouse, particularly for women, and parents.

Valuing Human Leptospirosis Prevention Using the Opportunity Cost of Labor

PubMed Central

Arbiol, Joseph; Borja, Maridel; Yabe, Mitsuyasu; Nomura, Hisako; Gloriani, Nina; Yoshida, Shinichi

2013-01-01

Leptospirosis is a serious public health concern in the Philippines, not only because of its increasing incidence rate, but also because of its significant health and economic impacts. Despite its relatively high seroprevalence, knowledge on the economic burden of disease, particularly on the value that the society places on disease prevention remains limited. Obtaining such information is important within the context of public health policy. This study was conducted in Metro Manila to determine the economic burden of leptospirosis, by asking respondents about their willingness to contribute to labor (WTCL) for the prevention of leptospirosis. The respondents pledged an average labor contribution of 10.66 h/month. The average WTCL corresponded to a monetary value of US$4.01 per month when valued using the opportunity cost of labor (leisure rate of time). From the monetized labor contribution, the total economic value of preventing leptospirosis was estimated at US$124.97 million per annum, which represents 1.13% of Metro Manila’s gross domestic product (GDP). Estimates from a Tobit regression model identified the respondents’ knowledge regarding leptospirosis, the susceptibility of their homes to flooding, and the proximity of their homes to sewers as significant factors to consider when developing resource contribution programs for leptospirosis prevention. More efforts need to be made in developing community level preventive programs, and in improving public’s knowledge and awareness about leptospirosis. PMID:23644831

Hospital electronic medical record enterprise application strategies: do they matter?

PubMed

Fareed, Naleef; Ozcan, Yasar A; DeShazo, Jonathan P

2012-01-01

Successful implementations and the ability to reap the benefits of electronic medical record (EMR) systems may be correlated with the type of enterprise application strategy that an administrator chooses when acquiring an EMR system. Moreover, identifying the most optimal enterprise application strategy is a task that may have important linkages with hospital performance. This study explored whether hospitals that have adopted differential EMR enterprise application strategies concomitantly differ in their overall efficiency. Specifically, the study examined whether hospitals with a single-vendor strategy had a higher likelihood of being efficient than those with a best-of-breed strategy and whether hospitals with a best-of-suite strategy had a higher probability of being efficient than those with best-of-breed or single-vendor strategies. A conceptual framework was used to formulate testable hypotheses. A retrospective cross-sectional approach using data envelopment analysis was used to obtain efficiency scores of hospitals by EMR enterprise application strategy. A Tobit regression analysis was then used to determine the probability of a hospital being inefficient as related to its EMR enterprise application strategy, while moderating for the hospital's EMR "implementation status" and controlling for hospital and market characteristics. The data envelopment analysis of hospitals suggested that only 32 hospitals were efficient in the study's sample of 2,171 hospitals. The results from the post hoc analysis showed partial support for the hypothesis that hospitals with a best-of-suite strategy were more likely to be efficient than those with a single-vendor strategy. This study underscores the importance of understanding the differences between the three strategies discussed in this article. On the basis of the findings, hospital administrators should consider the efficiency associations that a specific strategy may have compared with another prior to moving toward an enterprise application strategy.

Safety organizing, emotional exhaustion, and turnover in hospital nursing units.

PubMed

Vogus, Timothy J; Cooil, Bruce; Sitterding, Mary; Everett, Linda Q

2014-10-01

Prior research has found that safety organizing behaviors of registered nurses (RNs) positively impact patient safety. However, little research exists on how engaging in safety organizing affects caregivers. While we know that organizational processes can have divergent effects on organizational and employee outcomes, little research exists on the effects of pursuing highly reliable performance through safety organizing on caregivers. Specifically, we examined whether, and the conditions under which, safety organizing affects RN emotional exhaustion and nursing unit turnover rates. Subjects included 1352 RNs in 50 intensive care, internal medicine, labor, and surgery nursing units in 3 Midwestern acute-care hospitals who completed questionnaires between August and December 2011 and 50 Nurse Managers from the units who completed questionnaires in December 2012. Cross-sectional analyses of RN emotional exhaustion linked to survey data on safety organizing and hospital incident reporting system data on adverse event rates for the year before survey administration. Cross-sectional analysis of unit-level RN turnover rates for the year following the administration of the survey linked to survey data on safety organizing. Multilevel regression analysis indicated that safety organizing was negatively associated with RN emotional exhaustion on units with higher rates of adverse events and positively associated with RN emotional exhaustion with lower rates of adverse events. Tobit regression analyses indicated that safety organizing was associated with lower unit level of turnover rates over time. Safety organizing is beneficial to caregivers in multiple ways, especially on nursing units with high levels of adverse events and over time.

Estimation of indirect effect when the mediator is a censored variable.

PubMed

Wang, Jian; Shete, Sanjay

2017-01-01

A mediation model explores the direct and indirect effects of an initial variable ( X) on an outcome variable ( Y) by including a mediator ( M). In many realistic scenarios, investigators observe censored data instead of the complete data. Current research in mediation analysis for censored data focuses mainly on censored outcomes, but not censored mediators. In this study, we proposed a strategy based on the accelerated failure time model and a multiple imputation approach. We adapted a measure of the indirect effect for the mediation model with a censored mediator, which can assess the indirect effect at both the group and individual levels. Based on simulation, we established the bias in the estimations of different paths (i.e. the effects of X on M [ a], of M on Y [ b] and of X on Y given mediator M [ c']) and indirect effects when analyzing the data using the existing approaches, including a naïve approach implemented in software such as Mplus, complete-case analysis, and the Tobit mediation model. We conducted simulation studies to investigate the performance of the proposed strategy compared to that of the existing approaches. The proposed strategy accurately estimates the coefficients of different paths, indirect effects and percentages of the total effects mediated. We applied these mediation approaches to the study of SNPs, age at menopause and fasting glucose levels. Our results indicate that there is no indirect effect of association between SNPs and fasting glucose level that is mediated through the age at menopause.

How children with special health care needs affect the employment decisions of low-income parents.

PubMed

Loprest, Pamela; Davidoff, Amy

2004-09-01

To better understand the impact of having a child with special health care needs (CSHCN), on low-income parents' employment decisions. Using data from the 1999 and 2000 National Health Interview Survey (NHIS), we estimate multivariate statistical regressions (logit and tobit models) to estimate the relationship between having a CSHCN and the likelihood of employment and hours of employment for a sample-of low-income single parents. Controlling for differences in demographic and family characteristics, we find no significant association between having a CSHCN and the probability of work or the number of hours worked among low-income single-parent families. Separate analysis of different dimensions of special health care needs shows that parents of children with activity limitations are significantly less likely to work and work fewer hours. This result does not hold true for the group of children defined based on elevated or special service use, or for the group of children with specific chronic conditions. These results indicate that only a specific subset of children with special needs present difficulties for low-income parents' work. This suggests that policies to help low-income single parents of children with disabilities move into work should target this specific subset of children with special health care needs.

Amniotic fluid inflammatory cytokines: potential markers of immunologic dysfunction in autism spectrum disorders.

PubMed

Abdallah, Morsi W; Larsen, Nanna; Grove, Jakob; Nørgaard-Pedersen, Bent; Thorsen, Poul; Mortensen, Erik L; Hougaard, David M

2013-09-01

The aim of the study was to analyze cytokine profiles in amniotic fluid (AF) samples of children developing autism spectrum disorders (ASD) and controls, adjusting for maternal autoimmune disorders and maternal infections during pregnancy. AF samples of 331 ASD cases and 698 controls were analyzed for inflammatory cytokines using Luminex xMAP technology utilizing a historic birth cohort. Clinical data were retrieved from nationwide registers, and case-control differences in AF cytokine levels were assessed using chi-square tests, logistic and tobit regression models. Overall, individuals with ASD had significantly elevated AF levels of TNF-α and TNF-β compared to controls. Analyzing individuals diagnosed only with ICD-10 codes yielded significantly elevated levels of IL-4, IL-10, TNF-α and TNF-β in ASD patients. Restricting analysis to infantile autism cases showed significantly elevated levels of IL-4, TNF-α and TNF-β compared to controls with no psychiatric comorbidities. Elevated levels of IL-6 and IL-5 were found in individuals with other childhood psychiatric disorders (OCPD) when compared to controls with no psychiatric comorbidities. AF samples of individuals with ASD or OCPD showed differential cytokine profiles compared to frequency-matched controls. Further studies to examine the specificity of the reported cytokine profiles in ASD and OCPD are required.

The impact of weight misperception on health-related quality of life in Korean adults (KNHANES 2007–2014): a community-based cross-sectional study

PubMed Central

Park, Susan; Lee, Sejin; Hwang, Jinseub; Kwon, Jin-Won

2017-01-01

Background/objectives Weight perception, especially misperception, might affect health-related quality of life (HRQoL); however, related research is scarce and results remain equivocal. We examined the association between HRQoL and weight misperception by comparing obesity level as measured by body mass index (BMI) and weight perception in Korean adults. Methods Study subjects were 43 883 adults aged 19 years or older from cycles IV (2007–2009), V (2010–2012) and VI (2013–2014) of the Korean National Health and Nutrition Examination Survey. Multiple regression analyses comprising both logit and tobit models were conducted to evaluate the independent effect of obesity level as measured by BMI, weight perception and weight misperception on HRQoL after adjusting for demographics, socioeconomic status and number of chronic diseases. We also performed multiple regressions to explore the association between weight misperception and HRQoL stratified by BMI status. Results Obesity level as measured by BMI and weight perception were independently associated with low HRQoL in both separate and combined analyses. Weight misperception, including underestimation and overestimation, had a significantly negative impact on HRQoL. In subgroup analysis, subjects with BMI ranges from normal to overweight who misperceived their weight also had a high risk of low HRQoL. Overestimation of weight among obese subjects associated with low HRQoL, whereas underestimation of weight showed no significant association. Conclusions Both obesity level as measured by BMI and perceiving weight as fat were significant risk factors for low HRQoL. Subjects who incorrectly perceived their weight relative to their BMI status were more likely to report impaired HRQoL, particularly subjects with BMI in the normal to overweight range. Based on these findings, we recommend political and clinical efforts to better inform individuals about healthy weight status and promote accurate weight perception. PMID:28645975

Improving the effectiveness of service delivery in the public healthcare sector: the case of ophthalmology services in Malaysia.

PubMed

Foo, Chee Yoong; Lim, Ka Keat; Sivasampu, Sheamini; Dahian, Kamilah Binti; Goh, Pik Pin

2015-08-28

Rising demand of ophthalmology care is increasingly straining Malaysia's public healthcare sector due to its limited human and financial resources. Improving the effectiveness of ophthalmology service delivery can promote national policy goals of population health improvement and system sustainability. This study examined the performance variation of public ophthalmology service in Malaysia, estimated the potential output gain and investigated several factors that might explain the differential performance. Data for 2011 and 2012 on 36 ophthalmology centres operating in the Ministry of Health hospitals were used in this analysis. We first consulted a panel of ophthalmology service managers to understand the production of ophthalmology services and to verify the production model. We then assessed the relative performance of these centres using Data Envelopment Analysis (DEA). Efficiency scores (ES) were decomposed into technical, scale, and congestion component. Potential increase in service output was estimated. Sensitivity analysis of model changes was performed and stability of the result was assessed using bootstrap approach. Second stage Tobit regression was conducted to determine if hospital type, availability of day services and population characteristics were related to the DEA scores. In 2011, 33% of the ophthalmology centres were found to have ES > 1 (mean ES = 1.10). Potential output gains were 10% (SE ± 2.92), 7.4% (SE ± 2.06), 6.9% (SE ± 1.97) if the centres could overcome their technical, scale and congestion inefficiencies. More centres moved to the performance frontier in 2012 (mean ES = 1.07), with lower potential output gain. The model used has good stability. Robustness checks show that the DEA correctly identified low performing centres. Being in state hospital was significantly associated with better performance. Using DEA to benchmarking service performance of ophthalmology care could provide insights for policy makers and service managers to intuitively visualise the overall performance of resource use in an otherwise difficult to assess scenario. The considerable potential output gain estimated indicates that effort should be invested to understand what drove the performance variation and optimise them. Similar performance assessment should be undertaken for other healthcare services in the country in order to work towards a sustainable health system.

Risk factor differences in calcified and noncalcified aortic plaque: the Framingham Heart Study.

PubMed

Chuang, Michael L; Gona, Philimon; Oyama-Manabe, Noriko; Manders, Emily S; Salton, Carol J; Hoffmann, Udo; Manning, Warren J; O'Donnell, Christopher J

2014-07-01

The objective of this study was to determine the prevalence and risk factor (RF) correlates of aortic plaque (AP) detected by cardiovascular magnetic resonance (CMR), which mainly shows noncalcified plaques, and by noncontrast computed tomography (CT), which best depicts calcified plaques, in community-dwelling adults. A total of 1016 Framingham Heart Study Offspring cohort members (64 ± 9 years; 474 men) underwent CMR and CT of the aorta. Potential RFs for AP (age; sex; body mass index; blood pressure; low-density lipoprotein and high-density lipoprotein cholesterol; fasting glucose; C-reactive protein; prevalent hypertension, diabetes mellitus, smoking; use of antihypertensive, diabetes mellitus, or lipid-lowering drugs) were compared between participants, with zero versus nonzero AP by CMR and by CT. Candidate RFs attaining P<0.05 for difference with either imaging modality were entered into multivariable logistic regression models adjusting for age, sex, and other RFs. Odds ratios were calculated for modality-specific prevalence of AP. Associations between RFs and continuous measures of AP were assessed using Tobit regression. Prevalence of CMR and CT AP was 49% and 82%, respectively. AP burdens by CMR and CT were correlated, r=0.28, P<0.0001. Increasing age and smoking were associated with prevalent AP by both CMR and CT. Additionally, prevalent AP by CMR was associated with female sex and fasting glucose and prevalent AP by CT with hypertension treatment and adverse lipid profile. AP by CMR and CT are both associated with smoking and increasing age, but other RFs differ between calcified and noncalcified AP. The relative predictive value of AP detected by CMR versus by CT for incident cardiovascular events remains to be determined. © 2014 American Heart Association, Inc.

Neurologic, Functional and Cognitive Stroke Outcomes in Mexican Americans

PubMed Central

Lisabeth, Lynda D; Sánchez, Brisa N; Baek, Jonggyu; Skolarus, Lesli E; Smith, Melinda A; Garcia, Nelda; Brown, Devin L; Morgenstern, Lewis B

2014-01-01

Background and Purpose: Our objective was to compare neurologic, functional, and cognitive stroke outcomes in Mexican Americans (MAs) and non-Hispanic whites (NHWs) using data from a population-based study. Methods: Ischemic strokes (2008-2012) were identified from the Brain Attack Surveillance in Corpus Christi (BASIC) Project. Data were collected from patient or proxy interviews (conducted at baseline and 90 days post-stroke) and medical records. Ethnic differences in neurologic (National Institutes of Health Stroke Scale (NIHSS), range 0-44, higher scores worse), functional (activities of daily living (ADL)/instrumental activities of daily living (IADL) score, range 1-4, higher scores worse), and cognitive (Modified Mini-Mental State Examination (3MSE), range 0-100, lower scores worse) outcomes were assessed with Tobit or linear regression adjusted for demographics and clinical factors. Results: 513, 510, and 415 subjects had complete data for neurologic, functional and cognitive outcomes and covariates, respectively. Median age was 66 (IQR: 57-78); 64% were MA. In MAs, median NIHSS, ADL/IADL and 3MSE score were 3 (IQR: 1-6), 2.5 (IQR: 1.6-3.5) and 88 (IQR: 76-94), respectively. MAs scored 48% worse (95% CI: 23%-78%) on NIHSS, 0.36 points worse (95% CI: 0.16-0.57) on ADL/IADL score, and 3.39 points worse (95% CI: 0.35-6.43) on 3MSE than NHWs after multivariable adjustment. Conclusions: MAs scored worse than NHWs on all outcomes after adjustment for confounding factors; differences were only partially explained by ethnic differences in survival. These findings in combination with the increased stroke risk in MAs suggest that the public health burden of stroke in this growing population is substantial. PMID:24627112

Factors associated with nicotine dependence during methadone maintenance treatment: findings from a multisite survey in Vietnam.

PubMed

Do, Huyen Phuc; Nguyen, Long Hoang; Thi Nguyen, Nhung Phuong; Ngo, Chau; Thi Nguyen, Huong Lan; Le, Giang Tong; Nguyen, Linh Khanh; Nguyen, Cuong Tat; Tran, Bach Xuan; Le, Huong Thi; Vu, Thuc Minh Thi; Phan, Huong Thu Thi; Tran, Tho Dinh; Latkin, Carl A; Dunne, Michael P

2017-07-17

Smoking is associated with adverse health outcomes among drug users, including those in treatment. To date, however, there has been little evidence about smoking patterns among people receiving opioid-dependence treatment in developing countries. We examined self-reported nicotine dependence and associated factors in a large sample of opioid-dependent patients receiving methadone maintenance treatment (MMT) in northern Vietnam. Five clinics in Hanoi (urban area) and Nam Dinh (rural area). Patients receiving MMT in the settings during the study period. We collected data about smoking patterns, levels of nicotine dependence and other covariates such as socioeconomic status, health status, alcohol use and drug use. The Fagerström test was used to measure nicotine dependence (FTND). Logistic regression and Tobit regression were employed to examine relationships between the smoking rate, nicotine dependence and potentially associated variables. Among 1016 drug users undergoing MMT (98.7% male), 87.2% were current smokers. The mean FTND score was 4.5 (SD 2.4). Longer duration of MMT (OR 0.98, 95% CI 0.96 to 0.99) and being HIV-positive (OR 0.46, 95% CI 0.24 to 0.88) were associated with lower likelihood of smoking. Being employed, older age at first drug injection and having long duration of MMT were inversely related with FTND scores. Higher age and continuing drug and alcohol use were significantly associated with higher FTND scores. Smoking prevalence is high among methadone maintenance drug users. Enhanced smoking cessation support should be integrated into MMT programmes in order to reduce risk factors for cigarette smoking and improve the health and well-being of people recovering from opiate dependence. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Household social characteristics of the demand for alcoholic beverages among Spanish students.

PubMed

Gil-Lacruz, Ana Isabel; Gil-Lacruz, Marta

2013-03-01

This paper studies how household social capital affects adolescents' demand for alcoholic drinks. To that end, we focus on a theoretical framework that combines elements from the Model of Rational Addiction and the Model of Social Economics. For the empirical framework, we use a simultaneous Type II Tobit model, with data drawn from the Spanish National Survey on Drug Use in the School Population (2000, 2002, and 2004). The sample is comprised of 12,627 students aged 17 years old. Our results confirm that parents' decisions about drinking are even more decisive in their children's behavior than socioeconomic variables, such as parents' educative levels or working status. Parental responsibilities go beyond the endowment of health and educational goods and services; so, these results suggest the importance of designing family-drug use prevention programs. The study's limitations are noted.

Statistical modeling of crystalline silica exposure by trade in the construction industry using a database compiled from the literature.

PubMed

Sauvé, Jean-François; Beaudry, Charles; Bégin, Denis; Dion, Chantal; Gérin, Michel; Lavoué, Jérôme

2012-09-01

A quantitative determinants-of-exposure analysis of respirable crystalline silica (RCS) levels in the construction industry was performed using a database compiled from an extensive literature review. Statistical models were developed to predict work-shift exposure levels by trade. Monte Carlo simulation was used to recreate exposures derived from summarized measurements which were combined with single measurements for analysis. Modeling was performed using Tobit models within a multimodel inference framework, with year, sampling duration, type of environment, project purpose, project type, sampling strategy and use of exposure controls as potential predictors. 1346 RCS measurements were included in the analysis, of which 318 were non-detects and 228 were simulated from summary statistics. The model containing all the variables explained 22% of total variability. Apart from trade, sampling duration, year and strategy were the most influential predictors of RCS levels. The use of exposure controls was associated with an average decrease of 19% in exposure levels compared to none, and increased concentrations were found for industrial, demolition and renovation projects. Predicted geometric means for year 1999 were the highest for drilling rig operators (0.238 mg m(-3)) and tunnel construction workers (0.224 mg m(-3)), while the estimated exceedance fraction of the ACGIH TLV by trade ranged from 47% to 91%. The predicted geometric means in this study indicated important overexposure compared to the TLV. However, the low proportion of variability explained by the models suggests that the construction trade is only a moderate predictor of work-shift exposure levels. The impact of the different tasks performed during a work shift should also be assessed to provide better management and control of RCS exposure levels on construction sites.

Informal eldercare and work-related strain.

PubMed

Trukeschitz, Birgit; Schneider, Ulrike; Mühlmann, Richard; Ponocny, Ivo

2013-03-01

In light of an aging workforce, reconciling informal eldercare and paid work becomes increasingly pertinent. This article investigates the association between informal eldercare and work-related strain and tests for both the "competing demands" and "expansion" hypotheses. The sample of 938 Austrian employees consisted of employees caring for older relatives and a control group of employees without eldercare obligations. We ran a Tobit regression model on work-related strain with different measures of informal eldercare as explanatory variables and controls for both personal and workplace characteristics. Accounting for different characteristics of eldercare within one estimation model revealed that informal eldercare was associated with work-related strain in 2 ways, that is, it increased with both care hours and subjective care burden. However, after controlling for these burdensome attributes of eldercare, the carer status as such was found to be negatively associated with work-related strain. In addition and independently of care commitments, work-related factors, such as advanced skills and job motivation, reduced work-related strain. This article lends support to both the "competing demands" and the "expansion" hypotheses. Commitment to eldercare can enhance work-related outcomes but entails work-related problems if care burden and time demands of eldercare are substantial. Thus, workers with eldercare responsibilities cannot be considered less productive from the outset. An individual assessment of their situation, considering the care and work setting, is required. Findings from this study support the design of workplace initiatives to uphold workers' productivity in general and bring specific attention to policies alleviating workers' eldercare burden.

Time Out-of-Home and Cognitive, Physical, and Emotional Wellbeing of Older Adults: A Longitudinal Mixed Effects Model.

PubMed

Petersen, Johanna; Austin, Daniel; Mattek, Nora; Kaye, Jeffrey

2015-01-01

Time out-of-home has been linked with numerous health outcomes, including cognitive decline, poor physical ability and low emotional state. Comprehensive characterization of this important health metric would potentially enable objective monitoring of key health outcomes. The objective of this study is to determine the relationship between time out-of-home and cognitive status, physical ability and emotional state. Participants included 85 independent older adults, age 65-96 years (M = 86.36; SD = 6.79) who lived alone, from the Intelligent Systems for Assessing Aging Changes (ISAAC) and the ORCATECH Life Laboratory cohorts. Factors hypothesized to affect time out-of-home were assessed on three different temporal levels: yearly (cognitive status, loneliness, clinical walking speed), weekly (pain and mood) or daily (time out-of-home, in-home walking speed, weather, and season). Subject characteristics including age, race, and gender were assessed at baseline. Total daily time out-of-home in hours was assessed objectively and unobtrusively for up to one year using an in-home activity sensor platform. A longitudinal tobit mixed effects regression model was used to relate daily time out-of-home to cognitive status, physical ability and emotional state. More hours spend outside the home was associated with better cognitive function as assessed using the Clinical Dementia Rating (CDR) Scale, where higher scores indicate lower cognitive function (βCDR = -1.69, p<0.001). More hours outside the home was also associated with superior physical ability (βPain = -0.123, p<0.001) and improved emotional state (βLonely = -0.046, p<0.001; βLow mood = -0.520, p<0.001). Weather, season, and weekday also affected the daily time out-of-home. These results suggest that objective longitudinal monitoring of time out-of-home may enable unobtrusive assessment of cognitive, physical and emotional state. In addition, these results indicate that the factors affecting out-of-home behavior are complex, with factors such as living environment, weather and season significantly affecting time out-of-home. Studies investigating the relationship between time out-of-home and health outcomes may be optimized by taking into account the environment and life factors presented here.

A correlational study of suicidal ideation with psychological distress, depression, and demoralization in patients with cancer.

PubMed

Fang, Chun-Kai; Chang, Ming-Chih; Chen, Pei-Jan; Lin, Ching-Chi; Chen, Gon-Shen; Lin, Johnson; Hsieh, Ruey-Kuen; Chang, Yi-Fang; Chen, Hong-Wen; Wu, Chien-Liang; Lin, Kuan-Chia; Chiu, Yu-Jing; Li, Yu-Chan

2014-12-01

This study aims to study the effects of depression and demoralization on suicidal ideation and to determine the feasibility of the Distress Thermometer as a screening tool for patients with cancer who experience depression and demoralization, and thus to establish a model screening process for suicide prevention. Purposive sampling was used to invite inpatients and outpatients with lung cancer, leukemia, and lymphoma. Two hundred participants completed the questionnaire, which included the Distress Thermometer (DT), Patient Health Questionnaire-9 (PHQ-9), Demoralization Scale-Mandarin Version (DS-MV), and Beck Scale for Suicide Ideation. All data obtained were analyzed using SPSS 18.0 and SAS 9.3. Tobit regression analysis showed that demoralization influenced suicidal ideation more than depression did (t = 2.84, p < 0.01). When PHQ-9 ≥ 10 and DS-MV ≥42 were used as criteria for the DT, receiver operating characteristic analysis revealed that the AUC values were 0.77-0.79, with optimal cutoff points for both of DT ≥5; sensitivity 76.9 and 80.6 %, respectively; and specificity of 73.9 and 72.2 %, respectively. Demoralization had more influence on suicidal ideation than depression did. Therefore, attention should be paid to highly demoralized patients with cancer or high demoralization comorbid with depression for the purposes of suicide evaluation and prevention. The DT scale (with a cutoff of ≥5 points) has discriminative ability as a screening tool for demoralization or depression and can also be used in clinical settings for the preliminary screening of patients with cancer and high suicide risk.

Technical efficiency of women's health prevention programs in Bucaramanga, Colombia: a four-stage analysis.

PubMed

Ruiz-Rodriguez, Myriam; Rodriguez-Villamizar, Laura A; Heredia-Pi, Ileana

2016-10-13

Primary Health Care (PHC) is an efficient strategy to improve health outcomes in populations. Nevertheless, studies of technical efficiency in health care have focused on hospitals, with very little on primary health care centers. The objective of the present study was to use the Data Envelopment Analysis to estimate the technical efficiency of three women's health promotion and disease prevention programs offered by primary care centers in Bucaramanga, Colombia. Efficiency was measured using a four-stage data envelopment analysis with a series of Tobit regressions to account for the effect of quality outcomes and context variables. Input/output information was collected from the institutions' records, chart reviews and personal interviews. Information about contextual variables was obtained from databases from the primary health program in the municipality. A jackknife analysis was used to assess the robustness of the results. The analysis was based on data from 21 public primary health care centers. The average efficiency scores, after adjusting for quality and context, were 92.4 %, 97.5 % and 86.2 % for the antenatal care (ANC), early detection of cervical cancer (EDCC) and family planning (FP) programs, respectively. On each program, 12 of the 21 (57.1 %) health centers were found to be technically efficient; having had the best-practice frontiers. Adjusting for context variables changed the scores and reference rankings of the three programs offered by the health centers. The performance of the women's health prevention programs offered by the centers was found to be heterogeneous. Adjusting for context and health care quality variables had a significant effect on the technical efficiency scores and ranking. The results can serve as a guide to strengthen management and organizational and planning processes related to local primary care services operating within a market-based model such as the one in Colombia.

Employment of Low-Income African American and Latino Teens: Does Neighborhood Social Mix Matter?

PubMed Central

Santiago, Anna; Lucero, Jessica

2014-01-01

We quantify how teen employment outcomes for low-income African Americans and Latinos relate to their neighborhood conditions during ages 14–17. Data come from surveys of Denver Housing Authority (DHA) households who have lived in public housing scattered throughout Denver County. Because DHA household allocation mimics random assignment to neighborhood, this program represents a natural experiment for overcoming geographic selection bias. Our logistic and Tobit regression analyses found overall greater odds of teen employment and more hours worked for those who lived in neighborhoods with higher percentages of pre-1940 vintage housing, property crime rates and child abuse rates, though the strength of relationships was highly contingent on gender and ethnicity. Teen employment prospects of African Americans were especially diminished by residence in more socially vulnerable, violent neighborhoods, implying selective potential gains from social mixing alternatives. PMID:26273120

Mixed-effects location and scale Tobit joint models for heterogeneous longitudinal data with skewness, detection limits, and measurement errors.

PubMed

Lu, Tao

2017-01-01

The joint modeling of mean and variance for longitudinal data is an active research area. This type of model has the advantage of accounting for heteroscedasticity commonly observed in between and within subject variations. Most of researches focus on improving the estimating efficiency but ignore many data features frequently encountered in practice. In this article, we develop a mixed-effects location scale joint model that concurrently accounts for longitudinal data with multiple features. Specifically, our joint model handles heterogeneity, skewness, limit of detection, measurement errors in covariates which are typically observed in the collection of longitudinal data from many studies. We employ a Bayesian approach for making inference on the joint model. The proposed model and method are applied to an AIDS study. Simulation studies are performed to assess the performance of the proposed method. Alternative models under different conditions are compared.

The Interactive Effect of Diversification and Farming Scale on Productivity of Family Farm:Taking Rice Cultivation as An Example

NASA Astrophysics Data System (ADS)

Wei, Zhou

2017-05-01

Based on the diversification and cultivation scale, the rice cropping data of rural fixed observation points in 2011 were selected and the effect of diversification degree on rice productivity was analyzed by the Tobit model. The empirical results of the model show that diversification of sample farm will lead to loss of rice production efficiency. With the increase of rice planting scale, the loss of rice production efficiency will need to be further increased by diversification. Thus, we should stick to the family farm of specialized production operation. The transfer of land, the price and quantity of leasing, respecting the law of the market; the raising of funds can be considered non-subsidized capital market financing to help, while maintaining a certain degree of diversification, to avoid idle assets, low resource efficiency loss.

Plasma and serum L-selectin and clinical and subclinical the Multi-Ethnic Study of Atherosclerosis (MESA)cardiovascular disease

PubMed Central

BERARDI, CECILIA; DECKER, PAUL A.; KIRSCH, PHILLIP S.; DE ANDRADE, MARIZA; TSAI, MICHAEL Y.; PANKOW, JAMES S.; SALE, MICHELE M.; SICOTTE, HUGUES; TANG, WEIHONG; HANSON, NAOMI; POLAK, JOSEPH F.; BIELINSKI, SUZETTE J.

2014-01-01

L-selectin has been suggested to play a role in atherosclerosis. Previous studies on cardiovascular disease (CVD) and serum or plasma L-selectin are inconsistent. The association of serum L-selectin (sL-selectin) with carotid intima-media thickness, coronary artery calcium, ankle-brachial index (subclinical CVD) and incident CVD was assessed within 2403 participants in the Multi-Ethnic Study of Atherosclerosis (MESA). Regression analysis and the Tobit model were used to study subclinical disease; Cox Proportional Hazards regression for incident CVD. Mean age was 63 ± 10, 47% were males; mean sL-selectin was significantly different across ethnicities. Within each race/ethnicity, sL-selectin was associated with age and sex; among Caucasians and African Americans, it was associated with smoking status and current alcohol use. sL-selectin levels did not predict subclinical or clinical CVD after correction for multiple comparisons. Conditional logistic regression models were used to study plasma L-selectin and CVD within 154 incident CVD cases, occurred in a median follow up of 8.5 years, and 306 age-, sex-, and ethnicity-matched controls. L-selectin levels in plasma were significantly lower than in serum and the overall concordance was low. Plasma levels were not associated with CVD. In conclusion, this large multi-ethnic population, soluble L-selectin levels did not predict clinical or subclinical CVD. PMID:24631064

Multi-disease analysis of maternal antibody decay using non-linear mixed models accounting for censoring.

PubMed

Goeyvaerts, Nele; Leuridan, Elke; Faes, Christel; Van Damme, Pierre; Hens, Niel

2015-09-10

Biomedical studies often generate repeated measures of multiple outcomes on a set of subjects. It may be of interest to develop a biologically intuitive model for the joint evolution of these outcomes while assessing inter-subject heterogeneity. Even though it is common for biological processes to entail non-linear relationships, examples of multivariate non-linear mixed models (MNMMs) are still fairly rare. We contribute to this area by jointly analyzing the maternal antibody decay for measles, mumps, rubella, and varicella, allowing for a different non-linear decay model for each infectious disease. We present a general modeling framework to analyze multivariate non-linear longitudinal profiles subject to censoring, by combining multivariate random effects, non-linear growth and Tobit regression. We explore the hypothesis of a common infant-specific mechanism underlying maternal immunity using a pairwise correlated random-effects approach and evaluating different correlation matrix structures. The implied marginal correlation between maternal antibody levels is estimated using simulations. The mean duration of passive immunity was less than 4 months for all diseases with substantial heterogeneity between infants. The maternal antibody levels against rubella and varicella were found to be positively correlated, while little to no correlation could be inferred for the other disease pairs. For some pairs, computational issues occurred with increasing correlation matrix complexity, which underlines the importance of further developing estimation methods for MNMMs. Copyright © 2015 John Wiley & Sons, Ltd.

The efficiency of the public dental services (PDS) in Cyprus and selected determinants.

PubMed

Charalambous, Chrystalla; Maniadakis, Nikolaos; Polyzos, Nikolaos; Fragoulakis, Vassilis; Theodorou, Mamas

2013-10-18

Currently there is a dual system of oral healthcare delivery in Cyprus: the public dental system (PDS) run by the Government and the private system provided by private dental practitioners. Although 83% of the population is entitled to free treatment by the PDS only 10% of the population make use of them. As Cyprus faces now the challenges of the introduction of a new health care system and rising healthcare costs in general, surveys that examine, among other things, the efficiency of the PDS become very important as tools to make important cost savings. The aims of this study are to assess trends regarding the number of visits and the age distribution of patients using PDS from 2004 to 2007, to measure the technical efficiency of the PDS and to investigate various factors that may affect it. Non-parametric Data Envelopment Analysis (DEA) was employed to assess technical efficiency. Two separate cases were examined. Efficiency was calculated, firstly using as inputs the wages and the working hours of the personnel, and secondly the working hours of the personnel and the cost of the materials. As outputs, in both cases, the treatment offered (divided into primary, secondary and tertiary care) and the numbers of visits were used. In the second stage Tobit analysis was used to explore various predictors of efficiency (time per patient, location, age of dentists, age of patients and age of assistants). The study showed that whilst there was an increase in the number of patients using the PDS from 2004 to 2007, only a small proportion of the population (10%) make use of them. Women, middle and older aged patients, make more use of the PDS. Regarding efficiency, there were large differences between the units. The average Technical Efficiency score was 68% in the first model and 81% in the second. Urban areas and low time per patient are predictors of increased efficiency. The results suggest that many of the rural PDS are underperforming. Given that the option of shutting them down is undesirable, measures should be taken to reduce inputs (e.g. by reducing the personnel's working hours) and to increase outputs (remove barriers, make PDS more accessible and increase the number of patients).

The efficiency of the public dental services (PDS) in Cyprus and selected determinants

PubMed Central

2013-01-01

Background Currently there is a dual system of oral healthcare delivery in Cyprus: the public dental system (PDS) run by the Government and the private system provided by private dental practitioners. Although 83% of the population is entitled to free treatment by the PDS only 10% of the population make use of them. As Cyprus faces now the challenges of the introduction of a new health care system and rising healthcare costs in general, surveys that examine, among other things, the efficiency of the PDS become very important as tools to make important cost savings. The aims of this study are to assess trends regarding the number of visits and the age distribution of patients using PDS from 2004 to 2007, to measure the technical efficiency of the PDS and to investigate various factors that may affect it. Methods Non-parametric Data Envelopment Analysis (DEA) was employed to assess technical efficiency. Two separate cases were examined. Efficiency was calculated, firstly using as inputs the wages and the working hours of the personnel, and secondly the working hours of the personnel and the cost of the materials. As outputs, in both cases, the treatment offered (divided into primary, secondary and tertiary care) and the numbers of visits were used. In the second stage Tobit analysis was used to explore various predictors of efficiency (time per patient, location, age of dentists, age of patients and age of assistants). Results The study showed that whilst there was an increase in the number of patients using the PDS from 2004 to 2007, only a small proportion of the population (10%) make use of them. Women, middle and older aged patients, make more use of the PDS. Regarding efficiency, there were large differences between the units. The average Technical Efficiency score was 68% in the first model and 81% in the second. Urban areas and low time per patient are predictors of increased efficiency. Conclusion The results suggest that many of the rural PDS are underperforming. Given that the option of shutting them down is undesirable, measures should be taken to reduce inputs (e.g. by reducing the personnel’s working hours) and to increase outputs (remove barriers, make PDS more accessible and increase the number of patients). PMID:24139100

Water-Quality Trends in the Neuse River Basin, North Carolina, 1974-2003

NASA Astrophysics Data System (ADS)

Harned, D. A.

2003-12-01

Data from two U.S. Geological Survey (USGS) sites in the Neuse River basin were reviewed for trends in major ions, sediment, nutrients, and pesticides during the period 1974-2003. In 1997, the North Carolina Division of Water Quality implemented management rules to reduce nitrogen loading to the Neuse River by 30 percent by 2003. Therefore, the 1997-2003 period was reviewed for trends associated with the management changes. The Neuse River at Kinston basin (2,695 square miles) includes much of Raleigh, N.C., with 8-percent urban and 30-percent agricultural land use (1992 data). The Contentnea Creek basin (734 square miles), a Neuse River tributary, is 42-percent agricultural and 3-percent urban. Agricultural land uses in the Contentnea Creek basin have changed over the last decade from predominantly corn, soybean, and tobacco row crops to corn, soybeans, and cotton, with reduced tobacco acreages, and development of the hog industry. Data for this analysis were collected by the USGS for the National Stream Quality Accounting Network and National Water-Quality Assessment Program. Data were examined for trends using the Seasonal Kendall trend test or Tobit regression. The Seasonal Kendall test, which accounts for seasonal variability and adjusts for effects of streamflow on concentration with residuals from LOWESS (LOcally Weighted Sum of Squares) curves, was used to analyze trends in major ions, nutrients, and sediment. The Tobit test, appropriate for examining values with reporting limits, was used for the pesticide analysis. Monotonic trends are considered significant at the alpha < 0.05 probability level. Long-term (1974-2003) decreasing trends in the Neuse River at Kinston were detected for dissolved oxygen, silica, and sediment concentrations; increasing trends were detected for potassium, alkalinity, and chloride. Decreasing trends in Contentnea Creek were detected for silica, sulfate, and sediment concentrations during 1979-2003; increasing trends were detected for pH, hardness, and alkalinity. A pattern of increase until 1990 followed by little change or decline was observed for specific conductance, dissolved solids, hardness, and sulfate in the Neuse River and for potassium in Contentnea Creek. No significant recent (1997-2003) trends were detected for dissolved oxygen, pH, specific conductance, hardness, dissolved solids, or major ions. The Neuse River data indicated a recent declining trend in sediment concentration. Nitrogen concentrations in the form of ammonia, total ammonia and organic nitrogen, and nitrite plus nitrate have declined in both the Neuse River and Contentnea Creek. Total nitrogen concentrations increased in the Neuse River until about 1990 and then declined, primarily because of declines in nitrate. Recent declines are evident in nitrite plus nitrate in the Neuse River and in ammonia concentrations in Contentnea Creek. The data also show a reduction in variation of extreme values after 1990 in Contentnea Creek. Both observations suggest that the 1997 Neuse River management rules have had a detectable effect on nitrogen concentrations. Concentrations of dissolved and total phosphorus and orthophosphate reduced in a step trend in 1988 at both locations. This reflects the 1988 phosphate detergent ban in North Carolina. Orthophosphate concentrations have continued a recent decline in Contentnea Creek. Contentnea Creek has sufficient period of record (1994-2003) of concentrations of atrazine, deethyl atrazine, alachlor, carbaryl, diazinon, and prometon to test for trends. Both alachlor and prometon concentrations showed significant declines. Recent changes in agricultural practices coupled with a 5-year drought probably have affected pesticide use and transport to surface waters.

Comparison of Well-being of Older Adult Choir Singers and the General Population in Finland: A Case-Control Study.

PubMed

Johnson, Julene K; Louhivuori, Jukka; Siljander, Eero

2017-06-01

Previous research suggests that singing in a choir as an older adult is associated with better quality of life (QOL). However, the degree to which sociodemographic variables and level of engagement in hobbies contribute to this relationship is largely unknown. The aim of the study was to compare quality of life (QOL) of older adult choir singers with a matched sample of older adults from the general population in Finland, taking into consideration sociodemographic, satisfaction with health, and level of engagement in hobbies (active, inactive). Case-control methods were used to match a sample of 109 older adult singers with a sample of 307 older adults from the general population. Tobit regression analysis with sociodemographic covariates was used to explore observed group differences in QOL as measured by two WHOQOL-Bref domains (psychological and physical). Probit regression analysis was used to examine the effect of sociodemographic variables and engagement in hobbies and on overall QOL and satisfaction with health. As expected, sociodemographic variables were strongly associated with physical and psychological QOL. After controlling for sociodemographic variables, the older choir singers reported significantly higher ratings on physical QOL, but not psychological QOL, compared to matched controls. Additional adjustment for satisfaction for health attenuated the results. When considering level of engagement in hobbies, older adult choir singers reported significantly higher overall QOL and satisfaction with health when compared to either controls who were either actively engaged in hobbies or not active in hobbies. These results suggest that singing in a choir as an older adult may promote well-being, even after accounting for sociodemographic and level of engagement in hobbies.

Comparison of Well-being of Older Adult Choir Singers and the General Population in Finland: A Case-Control Study

PubMed Central

Johnson, Julene K; Louhivuori, Jukka; Siljander, Eero

2017-01-01

Previous research suggests that singing in a choir as an older adult is associated with better quality of life (QOL). However, the degree to which sociodemographic variables and level of engagement in hobbies contribute to this relationship is largely unknown. The aim of the study was to compare quality of life (QOL) of older adult choir singers with a matched sample of older adults from the general population in Finland, taking into consideration sociodemographic, satisfaction with health, and level of engagement in hobbies (active, inactive). Case-control methods were used to match a sample of 109 older adult singers with a sample of 307 older adults from the general population. Tobit regression analysis with sociodemographic covariates was used to explore observed group differences in QOL as measured by two WHOQOL-Bref domains (psychological and physical). Probit regression analysis was used to examine the effect of sociodemographic variables and engagement in hobbies and on overall QOL and satisfaction with health. As expected, sociodemographic variables were strongly associated with physical and psychological QOL. After controlling for sociodemographic variables, the older choir singers reported significantly higher ratings on physical QOL, but not psychological QOL, compared to matched controls. Additional adjustment for satisfaction for health attenuated the results. When considering level of engagement in hobbies, older adult choir singers reported significantly higher overall QOL and satisfaction with health when compared to either controls who were either actively engaged in hobbies or not active in hobbies. These results suggest that singing in a choir as an older adult may promote well-being, even after accounting for sociodemographic and level of engagement in hobbies. PMID:28736492

Indirect and direct costs of acute coronary syndromes with comorbid atrial fibrillation, heart failure, or both.

PubMed

Ghushchyan, Vahram; Nair, Kavita V; Page, Robert L

2015-01-01

The objective of this study was to determine the direct and indirect costs of acute coronary syndromes (ACS) alone and with common cardiovascular comorbidities. A retrospective analysis was conducted using the Medical Expenditure Panel Survey from 1998 to 2009. Four mutually exclusive cohorts were evaluated: ACS only, ACS with atrial fibrillation (AF), ACS with heart failure (HF), and ACS with both conditions. Direct costs were calculated for all-cause and cardiovascular-related health care resource utilization. Indirect costs were determined from productivity losses from missed days of work. Regression analysis was developed for each outcome controlling for age, US census region, insurance coverage, sex, race, ethnicity, education attainment, family income, and comorbidity burden. A negative binomial regression model was used for health care utilization variables. A Tobit model was utilized for health care costs and productivity loss variables. Total health care costs were greatest for those with ACS and both AF and HF ($38,484±5,191) followed by ACS with HF ($32,871±2,853), ACS with AF ($25,192±2,253), and ACS only ($17,954±563). Compared with the ACS only cohort, the mean all-cause adjusted health care costs associated with ACS with AF, ACS with HF, and ACS with AF and HF were $5,073 (95% confidence interval [CI] 719-9,427), $11,297 (95% CI 5,610-16,985), and $15,761 (95% CI 4,784-26,738) higher, respectively. Average wage losses associated with ACS with and without AF and/or HF amounted to $5,266 (95% CI -7,765, -2,767), when compared with patients without these conditions. ACS imposes a significant economic burden at both the individual and society level, particularly when with comorbid AF and HF.

Infants' indoor and outdoor residential exposure to benzene and respiratory health in a Spanish cohort.

PubMed

Ferrero, Amparo; Esplugues, Ana; Estarlich, Marisa; Llop, Sabrina; Cases, Amparo; Mantilla, Enrique; Ballester, Ferran; Iñiguez, Carmen

2017-03-01

Benzene exposure represents a potential risk for children's health. Apart from being a known carcinogen for humans (group 1 according to IARC), there is scientific evidence suggesting a relationship between benzene exposure and respiratory problems in children. But results are still inconclusive and inconsistent. This study aims to assess the determinants of exposure to indoor and outdoor residential benzene levels and its relationship with respiratory health in infants. Participants were 1-year-old infants (N = 352) from the INMA cohort from Valencia (Spain). Residential benzene exposure levels were measured inside and outside dwellings by means of passive samplers in a 15-day campaign. Persistent cough, low respiratory tract infections and wheezing during the first year of life, and covariates (dwelling traits, lifestyle factors and sociodemographic data) were obtained from parental questionnaires. Multiple Tobit regression and logistic regression models were performed to assess factors associated to residential exposure levels and health associations, respectively. Indoor levels were higher than outdoor ones (1.46 and 0.77 μg/m 3 , respectively; p < 0.01). A considerable percentage of dwellings, 42% and 21% indoors and outdoors respectively, surpassed the WHO guideline of 1.7 μg/m 3 derived from a lifetime risk of leukemia above 1/100 000. Monitoring season, maternal country of birth and parental tobacco consumption were associated with residential benzene exposure (indoor and outdoors). Additionally, indoor levels were associated with mother's age and type of heating, and outdoor levels were linked with zone of residence and distance from industrial areas. After adjustment for confounding factors, no significant associations were found between residential benzene exposure levels and respiratory health in infants. Hence, our study did not support the hypothesis for the benzene exposure effect on respiratory health in children. Even so, it highlights a public health concern related to the personal exposure levels, since a considerable number of children surpassed the abovementioned WHO guideline for benzene exposure. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

The future of nuclear power: A world-wide perspective

NASA Astrophysics Data System (ADS)

Aktar, Ismail

This study analyzes the future of commercial nuclear electric generation worldwide using the Environmental Kuznets Curve (EKC) concept. The Tobit panel data estimation technique is applied to analyze the data between 1980 and 1998 for 105 countries. EKC assumes that low-income countries increase their nuclear reliance in total electric production whereas high-income countries decrease their nuclear reliance. Hence, we expect that high-income countries should shut down existing nuclear reactors and/or not build any new ones. We encounter two reasons for shutdowns: economic or political/environmental concerns. To distinguish these two effects, reasons for shut down are also investigated by using the Hazard Model technique. Hence, the load factor of a reactor is used as an approximation for economic reason to shut down the reactor. If a shut downed reactor had high load factor, this could be attributable to political/environmental concern or else economic concern. The only countries with nuclear power are considered in this model. The two data sets are created. In the first data set, the single entry for each reactor is created as of 1998 whereas in the second data set, the multiple entries are created for each reactor beginning from 1980 to 1998. The dependent variable takes 1 if operational or zero if shut downed. The empirical findings provide strong evidence for EKC relationship for commercial nuclear electric generation. Furthermore, higher natural resources suggest alternative electric generation methods rather than nuclear power. Economic index as an institutional variable suggests higher the economic freedom, lower the nuclear electric generation as expected. This model does not support the idea to cut the carbon dioxide emission via increasing nuclear share. The Hazard Model findings suggest that higher the load factor is, less likely the reactor will shut down. However, if it is still permanently closed downed, then this could be attributable to political hostility against nuclear power. There are also some projections indicating which reactors are most/least likely to be shut downed from the logit model. We also project which countries are most likely to increase/decrease their nuclear reliance from the residuals of EKC model.

Antenatal Training with Music and Maternal Talk Concurrently May Reduce Autistic-Like Behaviors at around 3 Years of Age

PubMed Central

Ruan, Zeng-Liang; Liu, Li; Strodl, Esben; Fan, Li-Jun; Yin, Xiao-Na; Wen, Guo-Min; Sun, Deng-Li; Xian, Dan-Xia; Jiang, Hui; Jing, Jin; Jin, Yu; Wu, Chuan-An; Chen, Wei-Qing

2018-01-01

Antenatal training through music and maternal talk to the unborn fetus is a topic of general interest for parents-to-be in China, but we still lack a comprehensive assessment of their effects on the development of autistic-like behaviors during early childhood. During 2014–2016, 34,749 parents of children around the age of 3 years who were enrolled at kindergarten in the Longhua district of Shenzhen participated in this study. Self-administered questionnaires regarding demographics, antenatal music training, and maternal talk to the fetus during pregnancy were completed by the children’s primary caregivers. Autistic-like behaviors were assessed using the Autism Behavioral Checklist. Tobit regression analyses revealed that antenatal music training and maternal talk to the fetus was associated with a reduction in autistic-like behaviors in children, with a dose-dependent relationship. Furthermore, factorial analysis of covariance indicated a significant interaction effect between antenatal music training and maternal talk to the fetus on the autistic-like behaviors and found that children who often experienced antenatal music training and maternal talk concurrently had the lowest risk of autistic-like behaviors, while children who were never exposed to maternal talk and only sometimes experienced antenatal music training had the highest risk. Our results suggest that antenatal training through both music and maternal talk to the unborn fetus might reduce the risk of children’s autistic-like behaviors at around 3 years of age. PMID:29375407

Efficient rehabilitation care for joint replacement patients: skilled nursing facility or inpatient rehabilitation facility?

PubMed

Tian, Wenqiang; DeJong, Gerben; Horn, Susan D; Putman, Koen; Hsieh, Ching-Hui; DaVanzo, Joan E

2012-01-01

There has been lengthy debate as to which setting, skilled nursing facility (SNF) or inpatient rehabilitation facility (IRF), is more efficient in treating joint replacement patients. This study aims to determine the efficiency of rehabilitation care provided by SNF and IRF to joint replacement patients with respect to both payment and length of stay (LOS). This study used a prospective multisite observational cohort design. Tobit models were used to examine the association between setting of care and efficiency. The study enrolled 948 knee replacement patients and 618 hip replacement patients from 11 IRFs and 7 SNFs between February 2006 and February 2007. Output was measured by motor functional independence measure (FIM) score at discharge. Efficiency was measured in 3 ways: payment efficiency, LOS efficiency, and stochastic frontier analysis efficiency. IRF patients incurred higher expenditures per case but also achieved larger motor FIM gains in shorter LOS than did SNF patients. Setting of care was not a strong predictor of overall efficiency of rehabilitation care. Great variation in characteristics existed within IRFs or SNFs and severity groups. Medium-volume facilities among both SNFs and IRFs were most efficient. Early rehabilitation was consistently predictive of efficient treatment. The advantage of either setting is not clear-cut. Definition of efficiency depends in part on preference between cost and time. SNFs are more payment efficient; IRFs are more LOS efficient. Variation within SNFs and IRFs blurred setting differences; a simple comparison between SNF and IRF may not be appropriate.

Antenatal Training with Music and Maternal Talk Concurrently May Reduce Autistic-Like Behaviors at around 3 Years of Age.

PubMed

Ruan, Zeng-Liang; Liu, Li; Strodl, Esben; Fan, Li-Jun; Yin, Xiao-Na; Wen, Guo-Min; Sun, Deng-Li; Xian, Dan-Xia; Jiang, Hui; Jing, Jin; Jin, Yu; Wu, Chuan-An; Chen, Wei-Qing

2017-01-01

Antenatal training through music and maternal talk to the unborn fetus is a topic of general interest for parents-to-be in China, but we still lack a comprehensive assessment of their effects on the development of autistic-like behaviors during early childhood. During 2014-2016, 34,749 parents of children around the age of 3 years who were enrolled at kindergarten in the Longhua district of Shenzhen participated in this study. Self-administered questionnaires regarding demographics, antenatal music training, and maternal talk to the fetus during pregnancy were completed by the children's primary caregivers. Autistic-like behaviors were assessed using the Autism Behavioral Checklist. Tobit regression analyses revealed that antenatal music training and maternal talk to the fetus was associated with a reduction in autistic-like behaviors in children, with a dose-dependent relationship. Furthermore, factorial analysis of covariance indicated a significant interaction effect between antenatal music training and maternal talk to the fetus on the autistic-like behaviors and found that children who often experienced antenatal music training and maternal talk concurrently had the lowest risk of autistic-like behaviors, while children who were never exposed to maternal talk and only sometimes experienced antenatal music training had the highest risk. Our results suggest that antenatal training through both music and maternal talk to the unborn fetus might reduce the risk of children's autistic-like behaviors at around 3 years of age.

An examination of competition and efficiency for hospital industry in Turkey.

PubMed

Özgen Narcı, Hacer; Ozcan, Yasar A; Şahin, İsmet; Tarcan, Menderes; Narcı, Mustafa

2015-12-01

The two particular reforms that have been undertaken under the Health Transformation Program in Turkey are enhancing efficiency and increasing competition. However, there is a lack of information about the relationship between competition and hospital efficiency. The purpose of this paper is to analyze the effect of competition on technical efficiency for the hospital industry in Turkey. The target population included all public and private general hospitals that were open in 2010 in Turkey (n = 1,224). From these, 1,103 hospitals met the selection criteria and were included in the study. Data were obtained from the Turkish Statistical Institute, the Ministry of Health, and through a field survey. Technical efficiency of hospitals was estimated using Data Envelopment Analysis with five outputs and five inputs. The intensity of competition among hospitals was measured by objective and subjective measures. Objective competition was measured using the Hirschman-Herfindahl Index, and subjective competition was measured based on the perceptions of top level hospital managers. Multivariate Tobit regression was used to investigate the relationship between competition and efficiency while controlling the effects of demand and supply characteristics of the market and the hospital traits. Efficiency results showed that 17% of hospitals were technically efficient. Regression analyses portrayed that the degree of competition among general hospitals did not have a statistically significant relationship with hospitals' technical efficiency. To conclude, hospital efficiency in Turkey does not seem to be affected by the intensity of competition among hospitals.

Genetic influence on age at first birth of female twins born in the UK, 1919-68.

PubMed

Tropf, Felix C; Barban, Nicola; Mills, Melinda C; Snieder, Harold; Mandemakers, Jornt J

2015-01-01

Using a sample of monozygotic (945, 42 per cent) and dizygotic (1,329, 58 per cent) twin pairs born 1919-68 in the UK, we applied innovative tobit models to investigate genetic and environmental influences on age at first birth (AFB). We found that a substantial part (40 per cent) of the variation in AFB is caused by latent family characteristics. Genetic dispositions (26 per cent) play a more important role than the shared environment of siblings (14 per cent), with the non-shared environment/measurement error having the strongest influence (60 per cent). Like previous studies, this study reveals marked changes in estimates over time, and supports the idea that environmental constraints (war or economic crisis) suppress and normative freedom (sexual revolution) promotes the activation of genetic predispositions that affect fertility. We show that the exclusion of censored information (i.e., on the childless) by previous studies biased their results.

Estimating contaminant loads in rivers: An application of adjusted maximum likelihood to type 1 censored data

USGS Publications Warehouse

Cohn, Timothy A.

2005-01-01

This paper presents an adjusted maximum likelihood estimator (AMLE) that can be used to estimate fluvial transport of contaminants, like phosphorus, that are subject to censoring because of analytical detection limits. The AMLE is a generalization of the widely accepted minimum variance unbiased estimator (MVUE), and Monte Carlo experiments confirm that it shares essentially all of the MVUE's desirable properties, including high efficiency and negligible bias. In particular, the AMLE exhibits substantially less bias than alternative censored‐data estimators such as the MLE (Tobit) or the MLE followed by a jackknife. As with the MLE and the MVUE the AMLE comes close to achieving the theoretical Frechet‐Cramér‐Rao bounds on its variance. This paper also presents a statistical framework, applicable to both censored and complete data, for understanding and estimating the components of uncertainty associated with load estimates. This can serve to lower the cost and improve the efficiency of both traditional and real‐time water quality monitoring.

Time Out-of-Home and Cognitive, Physical, and Emotional Wellbeing of Older Adults: A Longitudinal Mixed Effects Model

PubMed Central

Petersen, Johanna

2015-01-01

Background Time out-of-home has been linked with numerous health outcomes, including cognitive decline, poor physical ability and low emotional state. Comprehensive characterization of this important health metric would potentially enable objective monitoring of key health outcomes. The objective of this study is to determine the relationship between time out-of-home and cognitive status, physical ability and emotional state. Methods and Findings Participants included 85 independent older adults, age 65–96 years (M = 86.36; SD = 6.79) who lived alone, from the Intelligent Systems for Assessing Aging Changes (ISAAC) and the ORCATECH Life Laboratory cohorts. Factors hypothesized to affect time out-of-home were assessed on three different temporal levels: yearly (cognitive status, loneliness, clinical walking speed), weekly (pain and mood) or daily (time out-of-home, in-home walking speed, weather, and season). Subject characteristics including age, race, and gender were assessed at baseline. Total daily time out-of-home in hours was assessed objectively and unobtrusively for up to one year using an in-home activity sensor platform. A longitudinal tobit mixed effects regression model was used to relate daily time out-of-home to cognitive status, physical ability and emotional state. More hours spend outside the home was associated with better cognitive function as assessed using the Clinical Dementia Rating (CDR) Scale, where higher scores indicate lower cognitive function (β CDR = -1.69, p<0.001). More hours outside the home was also associated with superior physical ability (β Pain = -0.123, p<0.001) and improved emotional state (β Lonely = -0.046, p<0.001; β Low mood = -0.520, p<0.001). Weather, season, and weekday also affected the daily time out-of-home. Conclusions These results suggest that objective longitudinal monitoring of time out-of-home may enable unobtrusive assessment of cognitive, physical and emotional state. In addition, these results indicate that the factors affecting out-of-home behavior are complex, with factors such as living environment, weather and season significantly affecting time out-of-home. Studies investigating the relationship between time out-of-home and health outcomes may be optimized by taking into account the environment and life factors presented here. PMID:26437228

Resource needs and gap analysis in achieving universal access to HIV/AIDS services: a data envelopment analysis of 45 countries.

PubMed

Zeng, Wu; Shepard, Donald S; Avila-Figueroa, Carlos; Ahn, Haksoon

2016-06-01

-To manage the human immunodeficiency virus and acquired immune deficiency syndrome (HIV/AIDS) epidemic, international donors have pledged unprecedented commitments for needed services. The Joint United Nations Programme on HIV/AIDS (UNAIDS) projected that low- and middle-income countries needed $25 billion to meet the 2010 HIV/AIDS goal of universal access to AIDS prevention and care, using the resource needs model (RNM). -Drawing from the results from its sister study, which used a data envelopment analysis (DEA) and a Tobit model to evaluate and adjust the technical efficiency of 61 countries in delivering HIV/AIDS services from 2002 to 2007, this study extended the DEA and developed an approach to estimate resource needs and decompose the performance gap into efficiency gap and resource gap. In the DEA, we considered national HIV/AIDS spending as the input and volume of voluntary counseling and testing (VCT), prevention of mother to child transmission (PMTCT) and antiretroviral treatment (ART) as the outputs. An input-oriented DEA model was constructed to project resource needs in achieving 2010 HIV/AIDS goal for 45 countries using the data in 2006, assuming that all study countries maximized efficiency. -The DEA approach demonstrated the potential to include efficiency of national HIV/AIDS programmes in resource needs estimation, using macro-level data. Under maximal efficiency, the annual projected resource needs for the 45 countries was $6.3 billion, ∼47% of their UNAIDS estimate of $13.5 billion. Given study countries' spending of $3.9 billion, improving efficiency could narrow the gap from $9.6 to $2.4 billion. The results suggest that along with continued financial commitment to HIV/AIDS, improving the efficiency of HIV/AIDS programmes would accelerate the pace to reach 2010 HIV/AIDS goals. The DEA approach provides a supplement to the AIDS RNM to inform policy making. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Quality of life and healthcare service utilization among methadone maintenance patients in a mountainous area of Northern Vietnam.

PubMed

Nguyen, Long Hoang; Nguyen, Lan Huong Thi; Boggiano, Victoria L; Hoang, Canh Dinh; Van Nguyen, Hung; Le, Huong Thi; Le, Hai Quan; Tran, Tho Dinh; Tran, Bach Xuan; Latkin, Carl A; Zary, Nabil; Vu, Minh Thuc Thi

2017-04-20

The expansion of methadone maintenance treatment in mountainous areas in still limited and little is known about its health impacts on drug users. This study aimed to examine health-related quality of life (HRQOL) and health care access among patients engaging in methadone maintenance treatment (MMT) in Tuyen Quang, a mountainous province in Vietnam. We conducted a cross-sectional survey with 241 patients conveniently recruited in two MMT clinics (Son Duong and Tuyen Quang). EuroQol-5 Dimensions - 5 levels (EQ-5D-5 L) and Visual analogue scale (VAS) were employed to measure HRQOL. Multivariate logistic and tobit regressions were used to determine the factors associated with HRQOL and health care utilization. The overall mean score of the EQ-5D index and EQ-VAS were 0.88 (SD = 0.20) and 81.8% (SD = 15.27%), respectively. Only 8.7% utilized inpatient services, and 14.9% used outpatient services. Being more highly educated, suffering acute diseases, and using health service within the last 12 months were associated with a decreased EQ-5D index. Individuals who were multiple substance abusers and those who recently had inpatient care were more likely to have a lower VAS. Older respondents, those taking their medications at the more impoverished clinic, substance abusers, and individuals who were struggling with anxiety/depression or their usual daily activities were more likely to use both inpatient and outpatient care. In summary, we observed good HRQOL, but high prevalence of anxiety/depression and low rates of service utilization among MMT patients in Tuyen Quang province. To improve the outcomes of MMT services in mountainous areas, it is necessary to introduce personalized and integrative services models with counseling and interventions on multiple substance use.

[Ecological compensation based on farmers' willingness: A case study of Jingsan County in Hubei Province, China].

PubMed

Yu, Liang-liang; Cai, Yin-ying

2015-01-01

Farmland protection is a pressing issue in China' s major agricultural regions because of the strategic importance of these regions for national food security. This study quantified the appropriate ecological compensation criteria for farmland protection by way of estimating farmers' opportunity cost and willingness to adopt environment-friendly farming practices. Based on survey data collected from Jingsan County, Hubei Province, a Tobit model was constructed to identify factors affecting farmers' willingness to accept (WTA). The result showed that with appropriate economic compensation for farmland protection, 77.1% and 64.7% of the surveyed households were willing to reduce usage of fertilizers and pesticides. When the reduced rates of fertilizer and pesticide increased from <10% to >50%, farmers' opportunity costs of production respectively increased from 1198 and 5850 yuan to 9698 and 9750 yuan per hectare per year, and their WTA increased from 4750 and 7313 yuan to 9781 and 12393 yuan per hectare per year. Farmers' opportunity cost and WTA in reducing pesticide inputs were larger than those in reducing the same rate of fertilizer inputs, and in each case farmers' WTA was greater than their opportunity cost. A farm' s distance from township, farmers' knowledge about the ecology of farmland, and their expectation to improve the ecological environment of farmland had positive, significant effect on the farmers' WTA to reducing fertilization, while farmers' education level and the overall economic condition of the village had significantly negative effect. The proportion of agriculture income, farmers' knowledge about the ecology of farmland, and their expectation to improve the ecological environment of farmland had positive, significant effect on the farmers' WTA to reducing pesticide, while household' cash income and the overall economic condition of the village had significantly negative effect.

Physician wages across specialties: informing the physician reimbursement debate.

PubMed

Leigh, J Paul; Tancredi, Daniel; Jerant, Anthony; Kravitz, Richard L

2010-10-25

Disparities in remuneration between primary care and other physician specialties may impede health care reform by undermining the sustainability of a primary care workforce. Previous studies have compared annual incomes across specialties unadjusted for work hours. Wage (earnings-per-hour) comparisons could better inform the physician payment debate. In a cross-sectional analysis of data from 6381 physicians providing patient care in the 2004-2005 Community Tracking Study (adjusted response rate, 53%), we compared wages across broad and narrow categories of physician specialties. Tobit and linear regressions were run. Four broad specialty categories (primary care, surgery, internal medicine and pediatric subspecialties, and other) and 41 specific specialties were analyzed together with demographic, geographic, and market variables. In adjusted analyses on broad categories, wages for surgery, internal medicine and pediatric subspecialties, and other specialties were 48%, 36%, and 45% higher, respectively, than for primary care specialties. In adjusted analyses for 41 specific specialties, wages were significantly lower for the following than for the reference group of general surgery (wage near median, $85.98): internal medicine and pediatrics combined (-$24.36), internal medicine (-$24.27), family medicine (-$23.70), and other pediatric subspecialties (-$23.44). Wage rankings were largely impervious to adjustment for control variables, including age, race, sex, and region. Wages varied substantially across physician specialties and were lowest for primary care specialties. The primary care wage gap was likely conservative owing to exclusion of radiologists, anesthesiologists, and pathologists. In light of low and declining medical student interest in primary care, these findings suggest the need for payment reform aimed at increasing incomes or reducing work hours for primary care physicians.

Pesticides present in migrant farmworker housing in North Carolina.

PubMed

Arcury, Thomas A; Lu, Chensheng; Chen, Haiying; Quandt, Sara A

2014-03-01

Migrant farmworkers are exposed to pesticides at work. Housing provided to migrant farmworkers may also expose them to pesticides, increasing their health risks. This analysis (1) describes the presence of organophosphorous (OP) and pyrethroid pesticides in North Carolina migrant farmworker houses, and (2) delineates associations of farmworker camp characteristics with pesticide detection and concentration. In 2010, 186 migrant farmworkers camps in NC were recruited (participation rate of 82.3%); pesticide wipe samples for 176 houses were analyzed. Tobacco is the predominant hand-harvested crop in this region. Two farmworkers per camp completed interviews; a third assisted with a housing inspection. Gas chromatography-mass spectrometry was used to detect OP and pyrethroid pesticides. Covariates of pesticide detection and concentration were determined with ANOVA and Tobit regression. OPs were found in 166 of 176 houses (average of 2.4/house); pyrethroids were found in 171 houses (average of 4.3/house). The number of different OPs detected in each camp and concentrations of these OPs were not associated with camp and housing characteristics. The number of different pyrethroids detected in each camp and concentrations of these pyrethroids were associated with camps having residents with H2-A visas, a posted North Carolina Department of Labor Certificate of Inspection, no barracks, fewer residents, no bedroom weather protection or floor violations, and no roaches. Farmworkers are exposed to pesticides where they live. Policy on removing pesticides from farmworker houses is needed. Reducing pesticides in farmworker houses will reduce one health risk confronted by this vulnerable population. © 2013 Wiley Periodicals, Inc.

Pesticides Present in Migrant Farmworker Housing in North Carolina

PubMed Central

Arcury, Thomas A.; Lu, Chensheng; Chen, Haiying; Quandt, Sara A.

2014-01-01

Background Migrant farmworkers are exposed to pesticides at work. Housing provided to migrant farmworkers may also expose them to pesticides, increasing their health risks. This analysis (1) describes the presence of organophosphorous (OP) and pyrethroid pesticides in North Carolina migrant farmworker houses, and (2) delineates associations of farmworker camp characteristics with pesticide detection and concentration. Methods In 2010, 186 migrant farmworkers camps in NC were recruited (participation rate of 82.3%); pesticide wipe samples for 176 houses were analyzed. Tobacco is the predominant hand-harvested crop in this region. Two farmworkers per camp completed interviews; a third assisted with a housing inspection. Gas chromatography–mass spectrometry was used to detect OP and pyrethroid pesticides. Covariates of pesticide detection and concentration were determined with ANOVA and Tobit regression. Results OPs were found in 166 of 176 houses (average of 2.4/house); pyrethroids were found in 171 houses (average of 4.3/house). The number of different OPs detected in each camp and concentrations of these OPs were not associated with camp and housing characteristics. The number of different pyrethroids detected in each camp and concentrations of these pyrethroids were associated with camps having residents with H2-A visas, a posted North Carolina Department of Labor Certificate of Inspection, no barracks, fewer residents, no bedroom weather protection or floor violations, and no roaches. Conclusions Farmworkers are exposed to pesticides where they live. Policy on removing pesticides from farmworker houses is needed. Reducing pesticides in farmworker houses will reduce one health risk confronted by this vulnerable population. PMID:24038176

Temporal trends in water-quality constituent concentrations and annual loads of chemical constituents in Michigan watersheds, 1998–2013

USGS Publications Warehouse

Hoard, Christopher J.; Fogarty, Lisa R.; Duris, Joseph W.

2018-02-21

In 1998, the Michigan Department of Environmental Quality and the U.S. Geological Survey began the Water Chemistry Monitoring Program for select streams in the State of Michigan. Objectives of this program were to provide assistance with (1) statewide water-quality assessments, (2) the National Pollutant Discharge Elimination System permitting process, and (3) water-resource management decisions. As part of this program, water-quality data collected from 1998 to 2013 were analyzed to identify potential trends for select constituents that were sampled. Sixteen water-quality constituents were analyzed at 32 stations throughout Michigan. Trend analysis on the various water-quality data was done using either the uncensored Seasonal Kendall test or through Tobit regression. In total, 79 trends were detected in the constituents analyzed for 32 river stations sampled for the study period—53 downward trends and 26 upward trends were detected. The most prevalent trend detected throughout the State was for ammonia, with 11 downward trends and 1 upward trend estimated.In addition to trends, constituent loads were estimated for 31 stations from 2002 to 2013 for stations that were sampled 12 times per year. Loads were computed using the Autobeale load computation program, which used the Beale ratio estimator approach to estimate an annual load. Constituent loads were the largest in large watershed streams with the highest annual flows such as the Saginaw and Grand Rivers. Likewise, constituent loads were the smallest in smaller tributaries that were sampled as part of this program such as the Boardman and Thunder Bay Rivers.

Modeling Ghanaian cocoa farmers' decision to use pesticide and frequency of application: the case of Brong Ahafo Region.

PubMed

Denkyirah, Elisha Kwaku; Okoffo, Elvis Dartey; Adu, Derick Taylor; Aziz, Ahmed Abdul; Ofori, Amoako; Denkyirah, Elijah Kofi

2016-01-01

Pesticides are a significant component of the modern agricultural technology that has been widely adopted across the globe to control pests, diseases, weeds and other plant pathogens, in an effort to reduce or eliminate yield losses and maintain high product quality. Although pesticides are said to be toxic and exposes farmers to risk due to the hazardous effects of these chemicals, pesticide use among cocoa farmers in Ghana is still high. Furthermore, cocoa farmers do not apply pesticide on their cocoa farms at the recommended frequency of application. In view of this, the study assessed the factors influencing cocoa farmers' decision to use pesticide and frequency of pesticide application. A total of 240 cocoa farmers from six cocoa growing communities in the Brong Ahafo Region of Ghana were selected for the study using the multi-stage sampling technique. The Probit and Tobit regression models were used to estimate factors influencing farmers' decision to use pesticide and frequency of pesticide application, respectively. Results of the study revealed that the use of pesticide is still high among farmers in the Region and that cocoa farmers do not follow the Ghana Cocoa Board recommended frequency of pesticide application. In addition, cocoa farmers in the study area were found to be using both Ghana Cocoa Board approved/recommended and unapproved pesticides for cocoa production. Gender, age, educational level, years of farming experience, access to extension service, availability of agrochemical shop and access to credit significantly influenced farmers' decision to use pesticides. Also, educational level, years of farming experience, membership of farmer based organisation, access to extension service, access to credit and cocoa income significantly influenced frequency of pesticide application. Since access to extension service is one key factor that reduces pesticide use and frequency of application among cocoa farmers, it is recommended that policies by government and non-governmental organisations should be aimed at mobilizing resources towards the expansion of extension education. In addition, extension service should target younger farmers as well as provide information on alternative pest control methods in order to reduce pesticide use among cocoa farmers. Furthermore, extension service/agents should target cocoa farmers with less years of farming experience and encourage cocoa farmers to join farmer based organisations in order to decrease frequency of pesticide application.

Health related quality of life in patients with community-acquired pneumococcal pneumonia in France.

PubMed

Andrade, Luiz Flavio; Saba, Grèce; Ricard, Jean-Damien; Messika, Jonathan; Gaillat, Jacques; Bonnin, Pierre; Chidiac, Christian; Illes, Hajnal-Gabriela; Laurichesse, Henri; Detournay, Bruno; Petitpretz, Patrick; de Pouvourville, Gérard

2018-02-02

Community Acquired Pneumococcal Pneumonia is a lung infection that causes serious health problems and can lead to complications and death. The aim of this study was to observe and analyze health related quality of life after a hospital episode for patients with community acquired pneumococcal pneumonia in France. A total of 524 individuals were enrolled prospectively in the study and were followed for 12 months after hospital discharge. Presence of streptococcus pneumoniae was confirmed by microbiological sampling. Quality of life was reported at four different points of time with the EQ-5D-3 L health states using the French reference tariff. Complete data on all four periods was available for 269 patients. We used descriptive and econometric analysis to assess quality of life over time during follow-up, and to identify factors that impact the utility indexes and their evolution through time. We used Tobit panel data estimators to deal with the bounded nature of utility values. Average age of patients was 63 and 55% of patients were men. Negative predictors of quality of life were the severity of the initial event, history of pneumonia, smokers, age and being male. On average, quality of life improved in the first 6 months after discharge and stabilized beyond. At month 1, mean utility index was 0.53 (SD: 0.34) for men and 0.45 (SD: 0.34) for women, versus mean of 0.69 (SD: 0.33) and 0.70 (SD: 0.35) at Month 12. "Usual activities" was the dimension the most impacted by the disease episode. Utilities for men were significantly higher than for women, although male patients were more severe. Individuals over 85 years old did not improve quality of life during follow-up, and quality of life did not improve or deteriorated for 34% of patients. We found that length of hospital stay was negatively correlated with quality of life immediately after discharge. This study provides with evidence that quality of life after an episode of community acquired pneumococcal pneumonia improves overall until the sixth month after hospital discharge, but older patients with previous history of pneumonia may not experience health gains after the initial episode.

Increasing access to modern contraceptives: the potential role of community solidarity through altruistic contributions.

PubMed

Onwujekwe, Obinna E; Ogbonna, Chinwe; Uguru, Nkoli; Uzochukwu, Benjamin S C; Lawson, Agathe; Ndyanabangi, Bannet

2012-07-06

There is an urgent need for universal access to modern contraceptives in Nigeria, to facilitate the achievement of the Millennium Development Goals and other national goals. This study provides information on the potential role of community solidarity in increasing access to contraceptives for the most-poor people through exploration of the role of altruism by determining level of altruistic willingness to pay (WTP) for modern contraceptives across different geographic contexts in Nigeria. It was a cross-sectional national survey which took place in six states spread across the six-geopolitical zones of the country. In each state, an urban and a rural area were selected for the study, giving a total of 6 urban and 6 rural sites. A pre-tested interviewer-administered questionnaire was used to collect information from at least 720 randomly selected householders from each state. The targeted respondent in a household was a female primary care giver of child bearing age (usually the wives), or in her absence, another female household member of child bearing age. A scenario on altruistic WTP was presented before the value was elicited using a binary with open-ended follow-up question format. Test of validity of elicited altruistic WTP was undertaken using Tobit regression. More than 50 % of the respondents across all the states were willing to contribute some money so that the very poor would be provided with modern contraceptives. The average amount of money that people were willing to contribute annually was 650 Naira (US$4.5). Mean altruistic WTP differed across SES quintiles and urban-rural divide (p < .01). Multiple regression analysis showed that age was negatively related to altruistic WTP (p < 0.05). However, years of schooling, being employed by government or being a big business person, prior experience of paying for contraceptives and socioeconomic status had statistically significant effects on altruistic WTP (p < 0.05). There is room for community solidarity to ensure that the very poor benefit from modern contraceptives and assure universal coverage with modern contraceptives. The factors that determine altruistic WTP should be harnessed to ensure that altruistic contributions are actually made. The challenge will be how to collect and pool the altruistic contributions for purchasing and delivering modern contraceptives to the most-poor, within the context of community financing.

Health-related quality of life in the Brazilian Amazon: a population-based cross-sectional study.

PubMed

Silva, Marcus Tolentino; Caicedo Roa, Monica; Galvao, Tais Freire

2017-08-14

To analyze perceptions of health-related quality of life and associated factors in populations from the Manaus Metropolitan Region. We conducted a population-based cross-sectional study from May to August 2015. Adults aged 18 years and older were selected using probabilistic three-phase cluster sampling and stratified by sex and age, based on official estimates. Quality of life data were collected using the European Quality of Life 5-Dimensions 3-Levels (EQ-5D-3L) along with socioeconomic, demographic, and health perception data. Utility scores were calculated using the Brazilian version of the EQ-5D-3L. Descriptive statistics were derived, and a multivariate Tobit regression model with correction for complex sampling was performed to identify the variables that influence utility levels. A total of 4001 participants were included. The average utility score was 0.886 (95% confidence interval [CI]: 0.881-0.890) with significant differences according to living area (the capital (0.882 ± 0.144) or inner cities (0.908 ± 0.122; p < 0.001)). The dimension for which the highest proportion of people reported moderate to severe problems was pain/discomfort (39%), followed by anxiety/depression (18%). Men had a higher quality of life than women (β = 0.041, p < 0.001). Not working was a factor that increased quality of life compared with being formally employed (β = 0.031, p = 0.037). The poorest people had a lower quality of life than the richest people (β = -0.118, p < 0.001). Better health perceptions increased utility scores (p < 0.001), while being separated decreased the scores (β = -0.052, p = 0.001). Health-related quality of life in the Manaus Metropolitan Region was high, as expected for the general population, and was higher among individuals who lived in the inner cities, men and those in higher social classes. Gender discrepancies and differences in quality of life between the capital and inner cities should be further investigated.

[The resilience and health status of primary caregivers of schizophrenia patients].

PubMed

Fan, Ya-Chi; Chen, Mei-Bih; Lin, Kuan-Chia; Bai, Ya-Mei; Wei, Shiow-Jing

2014-12-01

Resilience has been shown to have a positive effect on health status. However, little research has been conducted on the impact of resilience on the health of primary caregivers of schizophrenia patients. This study investigated the correlations between resilience and the health status of caregivers of schizophrenia patients. A cross-sectional, descriptive research design was used. Data collection was conducted using a set of questionnaires that included a demographic datasheet, the SOC-13 (Sense of Coherence), the DASS-21 (Depression Anxiety Stress Scales), and the SF-36 (short form). Seventy caregivers of schizophrenia patients were enrolled as participants at the psychiatric inpatient department of a medical center. SPSS 17.0 and SAS.9.2 statistical software packages were used to conduct descriptive analysis, the Sobel test, and Tobit model analysis. (1) The mean QOL (quality of life) scale score was 67.46 (SD = 17.74). Nearly one-fifth (18.6%) of caregivers were classified in the low to high depression range; 17.1% were classified in the low to high anxiety level; and 10% were classified in low to high stress level. (2) Duration of the caring period correlated negatively with caregiver QOL; having a concomitant disease significantly impacted QOL and resilience; and number of patient hospitalization days correlated negatively with level of caregiver anxiety. (3) The numbers of incidents of patient violence and patient suicide attempts correlated negatively with caregiver resilience and QOL. (4) Resilience was a mediator between care-giver demographic data and QOL. (5) Caregiver resilience was a predictor of QOL, depression, anxiety, and stress. The findings of the present study increase our understanding of the impact of resilience on the health status of caregivers of schizophrenia patients. The authors hope these finding may be referenced in the development of resilience-based nursing caring models in the future.

Adult active transport in the Netherlands: an analysis of its contribution to physical activity requirements.

PubMed

Fishman, Elliot; Böcker, Lars; Helbich, Marco

2015-01-01

Modern, urban lifestyles have engineered physical activity out of everyday life and this presents a major threat to human health. The Netherlands is a world leader in active travel, particularly cycling, but little research has sought to quantify the cumulative amount of physical activity through everyday walking and cycling. Using data collected as part of the Dutch National Travel Survey (2010 - 2012), this paper determines the degree to which Dutch walking and cycling contributes to meeting minimum level of physical activity of 150 minutes of moderate intensity aerobic activity throughout the week. The sample includes 74,465 individuals who recorded at least some travel on the day surveyed. As physical activity benefits are cumulative, all walking and cycling trips are analysed, including those to and from public transport. These trips are then converted into an established measure of physical activity intensity, known as metabolic equivalents of tasks. Multivariate Tobit regression models were performed on a range of socio-demographic, transport resources, urban form and meteorological characteristics. The results reveal that Dutch men and women participate in 24 and 28 minutes of daily physical activity through walking and cycling, which is 41% and 55% more than the minimum recommended level. It should be noted however that some 57% of the entire sample failed to record any walking or cycling, and an investigation of this particular group serves as an important topic of future research. Active transport was positively related with age, income, bicycle ownership, urban density and air temperature. Car ownership had a strong negative relationship with physically active travel. The results of this analysis demonstrate the significance of active transport to counter the emerging issue of sedentary lifestyle disease. The Dutch experience provides other countries with a highly relevant case study in the creation of environments and cultures that support healthy, active living.

Indirect and direct costs of acute coronary syndromes with comorbid atrial fibrillation, heart failure, or both

PubMed Central

Ghushchyan, Vahram; Nair, Kavita V; Page, Robert L

2015-01-01

Background The objective of this study was to determine the direct and indirect costs of acute coronary syndromes (ACS) alone and with common cardiovascular comorbidities. Methods A retrospective analysis was conducted using the Medical Expenditure Panel Survey from 1998 to 2009. Four mutually exclusive cohorts were evaluated: ACS only, ACS with atrial fibrillation (AF), ACS with heart failure (HF), and ACS with both conditions. Direct costs were calculated for all-cause and cardiovascular-related health care resource utilization. Indirect costs were determined from productivity losses from missed days of work. Regression analysis was developed for each outcome controlling for age, US census region, insurance coverage, sex, race, ethnicity, education attainment, family income, and comorbidity burden. A negative binomial regression model was used for health care utilization variables. A Tobit model was utilized for health care costs and productivity loss variables. Results Total health care costs were greatest for those with ACS and both AF and HF ($38,484±5,191) followed by ACS with HF ($32,871±2,853), ACS with AF ($25,192±2,253), and ACS only ($17,954±563). Compared with the ACS only cohort, the mean all-cause adjusted health care costs associated with ACS with AF, ACS with HF, and ACS with AF and HF were $5,073 (95% confidence interval [CI] 719–9,427), $11,297 (95% CI 5,610–16,985), and $15,761 (95% CI 4,784–26,738) higher, respectively. Average wage losses associated with ACS with and without AF and/or HF amounted to $5,266 (95% CI −7,765, −2,767), when compared with patients without these conditions. Conclusion ACS imposes a significant economic burden at both the individual and society level, particularly when with comorbid AF and HF. PMID:25565859

Longitudinal analysis of relationships between social support and general health in an Australian population cohort of young women.

PubMed

Holden, Libby; Lee, Christina; Hockey, Richard; Ware, Robert S; Dobson, Annette J

2015-02-01

The influence of social support on health and quality of life has been well documented. There is less evidence on whether health status affects social support, and little is known about longitudinal relationships between social support and health in early adulthood. This study investigates these associations using both concurrent and time-lagged measures at 5 time-points over 12 years during early adulthood. A population-based cohort of 9,758 young women from the Australian Longitudinal Study on Women's Health was used. Women were aged 22-27 in 2000 and 35-39 in 2012. The General Health subscale of the SF-36 and the MOS Social Support Survey 6-item Scale were used, with scores standardised to a range of 0-100. Longitudinal tobit models were used, because both social support and general health data were left skewed, with marked ceiling effects. All models were adjusted for status of the outcome of interest at the immediately previous survey. With both concurrent and time-lagged measures, there was a statistically significant difference in mean general health scores across social support quintiles after adjusting for demographic and behavioural covariates: lower general health was associated with lower social support. In reverse, social support mean scores were also significantly different across general health quintiles in both concurrent and time-lagged fully adjusted models. Social support is significantly associated with both current and subsequent general health in early adulthood. The significance of the reverse associations indicates that the two mutually influence each other. This study highlights the importance of social support as a health-related quality of life issue.

Water quality, compliance, and health outcomes among utilities implementing Water Safety Plans in France and Spain.

PubMed

Setty, Karen E; Kayser, Georgia L; Bowling, Michael; Enault, Jerome; Loret, Jean-Francois; Serra, Claudia Puigdomenech; Alonso, Jordi Martin; Mateu, Arnau Pla; Bartram, Jamie

2017-05-01

Water Safety Plans (WSPs), recommended by the World Health Organization since 2004, seek to proactively identify potential risks to drinking water supplies and implement preventive barriers that improve safety. To evaluate the outcomes of WSP application in large drinking water systems in France and Spain, we undertook analysis of water quality and compliance indicators between 2003 and 2015, in conjunction with an observational retrospective cohort study of acute gastroenteritis incidence, before and after WSPs were implemented at five locations. Measured water quality indicators included bacteria (E. coli, fecal streptococci, total coliform, heterotrophic plate count), disinfectants (residual free and total chlorine), disinfection by-products (trihalomethanes, bromate), aluminum, pH, turbidity, and total organic carbon, comprising about 240K manual samples and 1.2M automated sensor readings. We used multiple, Poisson, or Tobit regression models to evaluate water quality before and after the WSP intervention. The compliance assessment analyzed exceedances of regulated, recommended, or operational water quality thresholds using chi-squared or Fisher's exact tests. Poisson regression was used to examine acute gastroenteritis incidence rates in WSP-affected drinking water service areas relative to a comparison area. Implementation of a WSP generally resulted in unchanged or improved water quality, while compliance improved at most locations. Evidence for reduced acute gastroenteritis incidence following WSP implementation was found at only one of the three locations examined. Outcomes of WSPs should be expected to vary across large water utilities in developed nations, as the intervention itself is adapted to the needs of each location. The approach may translate to diverse water quality, compliance, and health outcomes. Copyright © 2017 Elsevier GmbH. All rights reserved.

Intergenerational transfers and informal care for disabled elderly persons in China: evidence from CHARLS.

PubMed

Liu, Xiaoting; Lu, Bei; Feng, Zhixin

2017-07-01

Aiming at 'ageing healthier and ageing better', a certain amount of high-quality informal care should be available for elderly persons with physical disability as formal care is barely accessible in China. The demographic transition and family structural changes have dramatically weakened traditional norms of filial piety and the structure of intergenerational transfers. This article employed nationwide representative data from the first wave (2011) of Chinese Health and Retirement Longitudinal Study (CHARLS) in order to identify the duration of informal care provision at home for frail elders (1122 in rural areas and 577 in urban areas, total 1699), measured in monthly hours, before estimating the associations between intergenerational transfers and the received time of informal care with Tobit Model analysis. Results showed that financial support from the younger generation was unexpectedly negatively associated with the monthly hours of care, implying a reduction of caring support along with increasing financial transfers towards older parents. The lack of informal care could not be compensated by having more children, co-residing with children, or increasing the parent-to-child/grandchild transfers. Spouses were shown to replace children as the major caregivers. In addition, the community-based long-term care system needs to be promoted to sustain and develop informal care, as the latter will become increasingly important with changing family dynamics. Finally, the received time of informal care, rather than the severity of physical disability measured by difficulty with ADLs or IADLs, was introduced to identify the actual demand for care by elders. The paper argues that it is important to reconceptualise and re-investigate the duration of care provision in the Chinese context in order to develop standards of payment as part of long-term care policies. © 2017 John Wiley & Sons Ltd.

Cognitive Predictors of Work Among Social Security Disability Insurance Beneficiaries With Psychiatric Disorders Enrolled in IPS Supported Employment.

PubMed

McGurk, Susan R; Drake, Robert E; Xie, Haiyi; Riley, Jarnee; Milfort, Roline; Hale, Thomas W; Frey, William

2018-01-13

Impaired cognitive functioning is a significant predictor of work dysfunction in schizophrenia. Less is known, however about relationships of cognition and work in people with less severe disorders with relatively normal cognitive functioning. This secondary analysis evaluated cognitive predictors of work in Social Security Disability Insurance (SSDI) beneficiaries with a recent work history who were randomized to receive mental health services, supported employment, and freedom from work disincentives over a 2-year study period in the Mental Health Treatment Study. Of the 1045 participants randomized to the treatment package, 945 (90.4%) received a cognitive assessment at study entry. Competitive work activity was evaluated using a computer-assisted timeline follow-back calendar at baseline and quarterly for 24 months. Mood disorders were the most common psychiatric diagnoses (64.9%), followed by schizophrenia or schizoaffective disorder (35.1%). Tobit regression analyses predicting the average number of hours worked per week, controlling for demographic characteristics, diagnosis, and work history indicated that the cognitive composite score (P < .01) and verbal learning subscale scores (P < .001) were associated with fewer hours of weekly work over the study period. Cognitive functioning predicted work over 2 years in SSDI beneficiaries with mood or schizophrenia-spectrum disorders who were receiving supported employment and mental health interventions, despite a relative absence of cognitive impairment in the study participants. The findings suggest cognitive functioning contributes to competitive work outcomes in persons with psychiatric disorders who have relatively unimpaired cognitive abilities, even under optimal conditions of treatment and vocational support. © The Author(s) 2017. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

[The life cycle of general practitioners' professional motivations: the case of prevention].

PubMed

Videau, Y; Batifoulier, P; Arrighi, Y; Gadreau, M; Ventelou, B

2010-10-01

The analysis of "professional motivations", mainly through the possible crowding-out effects between extrinsic and intrinsic motivations, has become an issue of great concern in the economic literature. This paper aims at applying this topic to the healthcare professions where the proper scaling up of pay-for-performance (P4P) policies by public authorities is at stake. We used a panel of 528 self-employed general practitioners in the "Provence-Alpes-Côte d'Azur" region in France to provide an interpersonal statistical decomposition between extrinsic and intrinsic motivations with regard to preventive actions. Then, we applied a Tobit model in order to specify the main explicative variables of the share of intrinsic motivations entering into physicians' total motivations. The relative share of intrinsic motivations was quite high among physicians paid with fixed fees. We found a significant effect of age on intrinsic motivations describing a U-shaped curve which can be interpreted as being the result of a "life cycle of medical motivations" or a generational effect. The cross-sectional nature of the data does not allow us to draw any conclusions concerning the predominance of the generational effect or the "life cycle effect" on the evolution of the relative share of physician's intrinsic motivations. Nevertheless, the U-shaped relation between intrinsic motivations and age questions the suitability of using uniformly P4P mechanisms. The generations or age groups of self-employed physicians who seem to be less responsive to extrinsic motivations are more likely to favour the introduction of other types of payment schemes (capitation or salary systems) or regulation tools such as clinical practice guidelines. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Matrix Gla Protein Polymorphisms are Associated with Coronary Artery Calcification in Men

PubMed Central

Crosier, Michael D.; Booth, Sarah L.; Peter, Inga; Dawson-Hughes, Bess; Price, Paul A.; O’Donnell, Christopher J.; Hoffmann, Udo; Williamson, Matthew K.; Ordovas, Jose M.

2009-01-01

Summary Matrix Gla protein (MGP) is a key regulator of vascular calcification. Genetic variation at the MGP locus could modulate the development of coronary artery calcification (CAC). Our aim was to examine the cross-sectional association between MGP single nucleotide polymorphisms (SNPs) [rs1800802 (T-138C), rs1800801 (G-7A), and rs4236 (Ala102Thr)] and CAC. CAC was measured by multidetector computed tomography (MDCT), in older men and women of European descent, (n = 386; 60 to 80 y of age). Serum MGP was measured by radioimmunoassay. Linear, Tobit and Ordinal regression analyses all revealed that in men, homozygous carriers of the minor allele of rs1800802 , rs1800801 , or rs4236 (minor allele frequency: 21, 38, and 40%, respectively) were associated with a decreased quantity of CAC, relative to major allele carriers. This association was not found in women. Although genetic variation in MGP was associated with serum MGP concentrations, there were no associations between serum MGP and CAC. The results of this study suggest a role for MGP genetic variants in coronary atherosclerosis among men that is not reflected in serum MGP concentrations. PMID:19352064

The willingness to pay of parties to traffic accidents for loss of productivity and consolation compensation.

PubMed

Jou, Rong-Chang; Chen, Tzu-Ying

2015-12-01

In this study, willingness to pay (WTP) for loss of productivity and consolation compensation by parties to traffic accidents is investigated using the Tobit model. In addition, WTP is compared to compensation determined by Taiwanese courts. The modelling results showed that variables such as education, average individual monthly income, traffic accident history, past experience of severe traffic accident injuries, the number of working days lost due to a traffic accident, past experience of accepting compensation for traffic accident-caused productivity loss and past experience of accepting consolation compensation caused by traffic accidents have a positive impact on WTP. In addition, average WTP for these two accident costs were obtained. We found that parties to traffic accidents were willing to pay more than 90% of the compensation determined by the court in the scenario of minor and moderate injuries. Parties were willing to pay approximately 80% of the compensation determined by the court for severe injuries, disability and fatality. Therefore, related agencies can use our study findings as the basis for determining the compensation that parties should pay for productivity losses caused by traffic accidents of different types. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Care preferences and spatial mobility : Factors influencing care-related willingness to move of elderly people in partnerships in a rural area].

PubMed

Rudel, Miriam; Abraham, Martin; Görtler, Edmund

2017-04-01

The availability of local support and care infrastructures at the place of residence is an important issue for the elderly living in rural areas. Spatial mobility can be seen as a strategy to cope with a lack of local care facilities. This study analyzes the preferences of older people living in long-term relationships concerning support and care arrangements. Furthermore, it is analyzed how far and under which circumstances older couples are willing to relocate their place of residence in response to regional care infrastructures. Using a quasi-experimental survey design, inhabitants of a small rural community aged over 50 years were interviewed and confronted with descriptions of fictitious situations with randomized options for moving residence. A Tobit model estimation method is applied to examine the determinants of older couples' care-related willingness to move their residence.The results show that most people prefer either the support of their own partner or outpatient care. Residential care is especially preferred by people aged 75 years and above, whereas new forms of support, such as senior cooperatives, are evaluated as attractive especially by younger age groups. Thus, information and advisory campaigns should address the target group in question even at an early stage in older peoples' life course. Care-related willingness to move home of couples aged 50 years and more is significantly determined by local provision of support and care infrastructures. The expansion of any care infrastructure at older peoples' place of residence can significantly reduce their willingness to move. In particular an increased availability of outpatient care is associated with a comparatively large reduction in couples' likelihood to move. In this way local commitment to rural areas can be sustained and rural depopulation can be prevented. At an alternative place of residence assisted living and residential care in particular can significantly enhance the willingness to relocate and can thus generate incentives to move for older couples.

Regression models for estimating concentrations of atrazine plus deethylatrazine in shallow groundwater in agricultural areas of the United States

USGS Publications Warehouse

Stackelberg, Paul E.; Barbash, Jack E.; Gilliom, Robert J.; Stone, Wesley W.; Wolock, David M.

2012-01-01

Tobit regression models were developed to predict the summed concentration of atrazine [6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine] and its degradate deethylatrazine [6-chloro-N-(1-methylethyl)-1,3,5,-triazine-2,4-diamine] (DEA) in shallow groundwater underlying agricultural settings across the conterminous United States. The models were developed from atrazine and DEA concentrations in samples from 1298 wells and explanatory variables that represent the source of atrazine and various aspects of the transport and fate of atrazine and DEA in the subsurface. One advantage of these newly developed models over previous national regression models is that they predict concentrations (rather than detection frequency), which can be compared with water quality benchmarks. Model results indicate that variability in the concentration of atrazine residues (atrazine plus DEA) in groundwater underlying agricultural areas is more strongly controlled by the history of atrazine use in relation to the timing of recharge (groundwater age) than by processes that control the dispersion, adsorption, or degradation of these compounds in the saturated zone. Current (1990s) atrazine use was found to be a weak explanatory variable, perhaps because it does not represent the use of atrazine at the time of recharge of the sampled groundwater and because the likelihood that these compounds will reach the water table is affected by other factors operating within the unsaturated zone, such as soil characteristics, artificial drainage, and water movement. Results show that only about 5% of agricultural areas have greater than a 10% probability of exceeding the USEPA maximum contaminant level of 3.0 μg L-1. These models are not developed for regulatory purposes but rather can be used to (i) identify areas of potential concern, (ii) provide conservative estimates of the concentrations of atrazine residues in deeper potential drinking water supplies, and (iii) set priorities among areas for future groundwater monitoring.

Branched-chain fatty acid composition of human milk and the impact of maternal diet: the Global Exploration of Human Milk (GEHM) Study1

PubMed Central

Dingess, Kelly A; Valentine, Christina J; Ollberding, Nicholas J; Davidson, Barbara S; Woo, Jessica G; Summer, Suzanne; Peng, Yongmei M; Guerrero, M Lourdes; Ruiz-Palacios, Guillermo M; Ran-Ressler, Rinat R; McMahon, Robert J; Brenna, J Thomas; Morrow, Ardythe L

2017-01-01

Background: An understudied component of the diet, branched-chain fatty acids (BCFAs) are distinctive saturated fatty acids that may have an important influence on health. Human-milk fatty acid composition is known to differ worldwide, but comparative data are lacking on BCFAs. Objective: We tested the hypotheses that concentrations of BCFAs in human milk differ between populations and are associated with maternal diet. Design: We surveyed the BCFA composition of samples collected as part of a standardized, prospective study of human-milk composition. Mothers were enrolled from 3 urban populations with differing diets: Cincinnati, Ohio; Shanghai, China; and Mexico City, Mexico. Enrollment was limited to healthy mothers of term singleton infants. We undertook a cross-sectional analysis of milk from all women with samples at postpartum week 4 (n = 359; ∼120 women/site). Fatty acids were extracted from milk by using a modified Bligh-Dyer technique and analyzed by gas chromatography. Statistical analysis was performed by ANOVA and Tobit regression. For Cincinnati mothers, 24-h diet recalls were analyzed in relation to the individual BCFA concentrations measured in milk samples. Results: Total BCFAs in milk differed by site, with the highest concentration in Cincinnati followed by Mexico City and Shanghai (mean ± SE: 7.90 ± 0.41, 6.10 ± 0.36, and 4.27 ± 0.25 mg/100 mL, respectively; P < 0.001). Site differences persisted after delivery mode, maternal age, and body mass index were controlled for. The individual concentrations of iso-14:0, iso-16:0, iso-18:0, anteiso-15:0, and anteiso-17:0 also differed between sites. Milk concentrations of iso-14:0 and anteiso-15:0 were associated with maternal intake of dairy; iso-16:0 was associated with maternal intakes of dairy and beef. Conclusions: BCFA concentrations in milk at 4 wk postpartum differed between mothers from Cincinnati, Shanghai, and Mexico City. Variations in human-milk BCFAs are influenced by diet. The impact of BCFAs on infant health warrants investigation. PMID:27903517

Branched-chain fatty acid composition of human milk and the impact of maternal diet: the Global Exploration of Human Milk (GEHM) Study.

PubMed

Dingess, Kelly A; Valentine, Christina J; Ollberding, Nicholas J; Davidson, Barbara S; Woo, Jessica G; Summer, Suzanne; Peng, Yongmei M; Guerrero, M Lourdes; Ruiz-Palacios, Guillermo M; Ran-Ressler, Rinat R; McMahon, Robert J; Brenna, J Thomas; Morrow, Ardythe L

2017-01-01

An understudied component of the diet, branched-chain fatty acids (BCFAs) are distinctive saturated fatty acids that may have an important influence on health. Human-milk fatty acid composition is known to differ worldwide, but comparative data are lacking on BCFAs. We tested the hypotheses that concentrations of BCFAs in human milk differ between populations and are associated with maternal diet. We surveyed the BCFA composition of samples collected as part of a standardized, prospective study of human-milk composition. Mothers were enrolled from 3 urban populations with differing diets: Cincinnati, Ohio; Shanghai, China; and Mexico City, Mexico. Enrollment was limited to healthy mothers of term singleton infants. We undertook a cross-sectional analysis of milk from all women with samples at postpartum week 4 (n = 359; ∼120 women/site). Fatty acids were extracted from milk by using a modified Bligh-Dyer technique and analyzed by gas chromatography. Statistical analysis was performed by ANOVA and Tobit regression. For Cincinnati mothers, 24-h diet recalls were analyzed in relation to the individual BCFA concentrations measured in milk samples. Total BCFAs in milk differed by site, with the highest concentration in Cincinnati followed by Mexico City and Shanghai (mean ± SE: 7.90 ± 0.41, 6.10 ± 0.36, and 4.27 ± 0.25 mg/100 mL, respectively; P < 0.001). Site differences persisted after delivery mode, maternal age, and body mass index were controlled for. The individual concentrations of iso-14:0, iso-16:0, iso-18:0, anteiso-15:0, and anteiso-17:0 also differed between sites. Milk concentrations of iso-14:0 and anteiso-15:0 were associated with maternal intake of dairy; iso-16:0 was associated with maternal intakes of dairy and beef. BCFA concentrations in milk at 4 wk postpartum differed between mothers from Cincinnati, Shanghai, and Mexico City. Variations in human-milk BCFAs are influenced by diet. The impact of BCFAs on infant health warrants investigation. © 2017 American Society for Nutrition.

Household water insecurity after a historic flood: Diarrhea and dehydration in the Bolivian Amazon.

PubMed

Rosinger, Asher Y

2018-01-01

While 884 million people worldwide lack access to clean water, millions live in flood-prone regions. Unexpected flooding increases risk of diarrheal diseases and is expected to occur with increased frequency in the 21st century. Water insecurity is linked to mental distress in water scarce regions, yet this construct has not been examined closely among populations living in flood-prone regions. This paper examines how differences in water sources and lifestyle among Tsimane' forager-horticulturalists in lowland Bolivia are related to water insecurity after a historic flood in 2014, and in turn, how water insecurity is associated with diarrhea and dehydration. Pre-flood data come from qualitative interviews with 36 household heads, anthropometrics, participant observation, and water quality analysis between September 2013-January 2014 used to create a locally-adapted water insecurity questionnaire. Water insecurity was measured after the historic flood; no pre-flood water insecurity measures are available. Post-flood data were collected through surveys, water quality analysis, and health exams using near-exhaustive sampling in two villages, yielding 118 adults and 115 children (aged 2-12 years) in 62 households between March-April 2014. Overall, 89% of adults reported medium or high water insecurity. Only hand-pumps tested negative for pathogenic bacteria both pre- and post-flood. Tobit regressions suggest that hand-pumps (when available) and adult age were associated with lower water insecurity scores. Multiple logistic regressions suggest that adults with high water insecurity were more likely to report diarrhea than adults with low (Odds Ratio [OR] 9.2; 95% CI: 1.27-67.1). Children from households with medium (OR: 6.8; 95% CI: 1.41-32.5) or high (OR: 14.0; 95% CI: 2.40-81.5) water insecurity had significantly higher odds of dehydration than children in households with low water insecurity. Catastrophic flooding may systematically increase dimensions of household water insecurity. This research suggests an experience-based measure of water insecurity is associated with objective health outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Willingness to pay for improved public health care services in Saudi Arabia: a contingent valuation study among heads of Saudi households.

PubMed

Al-Hanawi, Mohammed K; Alsharqi, Omar; Vaidya, Kirit

2018-06-04

The bulk of health care service provision in Saudi Arabia is undertaken by the public health care sector through the Ministry of Health, which is funded annually by the total government budget, which, in turn, is derived primarily from oil revenue. Public health care services in Saudi Arabia are characterised by an overload, overuse, and shortage of medical personnel, which can result in dissatisfaction with the quality of the current public health care services. This study uses a contingent valuation method to investigate the willingness of Saudi people to pay for improvements to the quality of public health care services. This study also determines the association between the willingness to pay for quality improvements and respondents' demographic and socioeconomic characteristics. A pre-tested interviewer-administered questionnaire was used to collect data from 1187 heads of household in Jeddah Province over a five-month period. Multi-stage sampling was employed to recruit participants. Partial Tobit regression and corresponding marginal effects analyses were used to analyse the data. These empirical analyses show that the majority of the sample was willing to pay for quality improvements in the public health care services. The results of this study might be of use to policymakers to help with both priority setting and fund allocation.

Village-level supply reliability of surface water irrigation in rural China: effects of climate change

NASA Astrophysics Data System (ADS)

Li, Yanrong; Wang, Jinxia

2018-06-01

Surface water, as the largest part of water resources, plays an important role on China's agricultural production and food security. And surface water is vulnerable to climate change. This paper aims to examine the status of the supply reliability of surface water irrigation, and discusses how it is affected by climate change in rural China. The field data we used in this study was collected from a nine-province field survey during 2012 and 2013. Climate data are offered by China's National Meteorological Information Center which contains temperature and precipitation in the past 30 years. A Tobit model (or censored regression model) was used to estimate the influence of climate change on supply reliability of surface water irrigation. Descriptive results showed that, surface water supply reliability was 74 % in the past 3 years. Econometric results revealed that climate variables significantly influenced the supply reliability of surface water irrigation. Specifically, temperature is negatively related with the supply reliability of surface water irrigation; but precipitation positively influences the supply reliability of surface water irrigation. Besides, climate influence differs by seasons. In a word, this paper improves our understanding of the impact of climate change on agriculture irrigation and water supply reliability in the micro scale, and provides a scientific basis for relevant policy making.

A Research Note on Time With Children in Different- and Same-Sex Two-Parent Families.

PubMed

Prickett, Kate C; Martin-Storey, Alexa; Crosnoe, Robert

2015-06-01

Public debate on same-sex marriage often focuses on the disadvantages that children raised by same-sex couples may face. On one hand, little evidence suggests any difference in the outcomes of children raised by same-sex parents and different-sex parents. On the other hand, most studies are limited by problems of sample selection and size, and few directly measure the parenting practices thought to influence child development. This research note demonstrates how the 2003-2013 American Time Use Survey (n=44,188) may help to address these limitations. Two-tier Cragg's Tobit alternative models estimated the amount of time that parents in different-sex and same-sex couples engaged in child-focused time. Women in same-sex couples were more likely than either women or men in different-sex couples to spend such time with children. Overall, women (regardless of the gender of their partners) and men coupled with other men spent significantly more time with children than men coupled with women, conditional on spending any child-focused time. These results support prior research that different-sex couples do not invest in children at appreciably different levels than same-sex couples. We highlight the potential for existing nationally representative data sets to provide preliminary insights into the developmental experiences of children in nontraditional families.

A Plate Waste Evaluation of the Farm to School Program.

PubMed

Kropp, Jaclyn D; Abarca-Orozco, Saul J; Israel, Glenn D; Diehl, David C; Galindo-Gonzalez, Sebastian; Headrick, Lauren B; Shelnutt, Karla P

2018-04-01

To investigate the impacts of the Farm to School (FTS) Program on the selection and consumption of fruits and vegetables. Plate waste data were recorded using the visual inspection method before and after implementation of the program. Six elementary schools in Florida: 3 treatment and 3 control schools. A total of 11,262 meal observations of National School Lunch Program (NSLP) participants in grades 1-5. The FTS Program, specifically local procurement of NSLP offerings, began in treatment schools in November, 2015 after the researchers collected preintervention data. The NSLP participants' selection and consumption of fruits and vegetables. Data were analyzed using Mann-Whitney U and proportions tests and difference-in-difference regressions. The NSLP participants at the treatment schools consumed, on average, 0.061 (P = .002) more servings of vegetables and 0.055 (P = .05) more servings of fruit after implementation of the FTS Program. When school-level fixed effects are included, ordinary least squares and tobit regression results indicated that NSLP participants at the treatment schools respectively consumed 0.107 (P < .001) and 0.086 (P < .001) more servings of vegetables, on average, after implementation of the FTS Program. Local procurement positively affected healthy eating. Copyright © 2017 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

The NHV rehabilitation services program improves long-term physical functioning in survivors of the 2008 Sichuan earthquake: a longitudinal quasi experiment.

PubMed

Zhang, Xia; Reinhardt, Jan D; Gosney, James E; Li, Jianan

2013-01-01

Long-term disability following natural disasters significantly burdens survivors and the impacted society. Nevertheless, medical rehabilitation programming has been historically neglected in disaster relief planning. 'NHV' is a rehabilitation services program comprised of non-governmental organizations (NGOs) (N), local health departments (H), and professional rehabilitation volunteers (V) which aims to improve long-term physical functioning in survivors of the 2008 Sichuan earthquake. We aimed to evaluate the effectiveness of the NHV program. 510 of 591 enrolled earthquake survivors participated in this longitudinal quasi-experimental study (86.3%). The early intervention group (NHV-E) consisted of 298 survivors who received institutional-based rehabilitation (IBR) followed by community-based rehabilitation (CBR); the late intervention group (NHV-L) was comprised of 101 survivors who began rehabilitation one year later. The control group of 111 earthquake survivors did not receive IBR/CBR. Physical functioning was assessed using the Barthel Index (BI). Data were analyzed with a mixed-effects Tobit regression model. Physical functioning was significantly increased in the NHV-E and NHV-L groups at follow-up but not in the control group after adjustment for gender, age, type of injury, and time to measurement. We found significant effects of both NHV (11.14, 95% CI 9.0-13.3) and sponaneaous recovery (5.03; 95% CI 1.73-8.34). The effect of NHV-E (11.3, 95% CI 9.0-13.7) was marginally greater than that of NHV-L (10.7, 95% CI 7.9-13.6). It could, however, not be determined whether specific IBR or CBR program components were effective since individual component exposures were not evaluated. Our analysis shows that the NHV improved the long-term physical functioning of Sichuan earthquake survivors with disabling injuries. The comprehensive rehabilitation program benefitted the individual and society, rehabilitation services in China, and international rehabilitation disaster relief planning. Similar IBR/CBR programs should therefore be considered for future large-scale rehabilitation disaster relief efforts.

Insurance against climate change and flood risk: Insurability and decision processes of insurers

NASA Astrophysics Data System (ADS)

Hung, Hung-Chih; Hung, Jia-Yi

2016-04-01

1. Background Major portions of the Asia-Pacific region is facing escalating exposure and vulnerability to climate change and flood-related extremes. This highlights an arduous challenge for public agencies to improve existing risk management strategies. Conventionally, governmental funding was majorly responsible and accountable for disaster loss compensation in the developing countries in Asia, such as Taiwan. This is often criticized as an ineffective and inefficient measure of dealing with flood risk. Flood insurance is one option within the toolkit of risk-sharing arrangement and adaptation strategy to flood risk. However, there are numerous potential barriers for insurance companies to cover flood damage, which would cause the flood risk is regarded as uninsurable. This study thus aims to examine attitudes within the insurers about the viability of flood insurance, the decision-making processes of pricing flood insurance and their determinants, as well as to examine potential solutions to encourage flood insurance. 2. Methods and data Using expected-utility theory, an insurance agent-based decision-making model was developed to examine the insurers' attitudes towards the insurability of flood risk, and to scrutinize the factors that influence their decisions on flood insurance premium-setting. This model particularly focuses on how insurers price insurance when they face either uncertainty or ambiguity about the probability and loss of a particular flood event occurring. This study considers the factors that are expected to affect insures' decisions on underwriting and pricing insurance are their risk perception, attitudes towards flood insurance, governmental measures (e.g., land-use planning, building codes, risk communication), expected probabilities and losses of devastating flooding events, as well as insurance companies' attributes. To elicit insurers' utilities about premium-setting for insurance coverage, the 'certainty equivalent,' 'probability equivalent,' and 'gamble tradeoff' methods were used. We then synthesized a Tobit and an OLS regression analysis to identify and examine the determinants of insurers' decisions on insurability and pricing for flood risk. Furthermore, the data were collected through a questionnaire survey, which was conducted with the assistance from the Non-life Underwriters Society, Taiwan and the Actuarial Institute, Taiwan. After pretesting, questionnaires were mailed to 410 randomly chosen commercial property-and-casualty insurance firms' actuaries and underwriters. The final sample consisted of 179 questionnaires for a 43.8% response rate. 3. Results Results of the questionnaire survey reveal that flood risk tends to be more uninsurable when there is ambiguity regarding the probability of a particular flood event loss. The presence of insurers' risk aversion appears to be robust. Insurers would charge a significantly higher price for a flood insurance policy than normal property insurance. The findings also show that the insurers who perceived higher levels of flood risk, or/and had a company with smaller size or higher financial leverage, would trigger a higher premium for flood insurance. Governmental risk management strategies, such as land-use planning, building codes, flood-hazard zone regulations, also played a prominent role in enhancing insurability and decreasing insurance premium. Therefore, appropriate incentives should be combined with better public risk communication and mitigation strategies to stimulate insurance coverage in reducing flood loss.

Review of Statistical Methods for Analysing Healthcare Resources and Costs

PubMed Central

Mihaylova, Borislava; Briggs, Andrew; O'Hagan, Anthony; Thompson, Simon G

2011-01-01

We review statistical methods for analysing healthcare resource use and costs, their ability to address skewness, excess zeros, multimodality and heavy right tails, and their ease for general use. We aim to provide guidance on analysing resource use and costs focusing on randomised trials, although methods often have wider applicability. Twelve broad categories of methods were identified: (I) methods based on the normal distribution, (II) methods following transformation of data, (III) single-distribution generalized linear models (GLMs), (IV) parametric models based on skewed distributions outside the GLM family, (V) models based on mixtures of parametric distributions, (VI) two (or multi)-part and Tobit models, (VII) survival methods, (VIII) non-parametric methods, (IX) methods based on truncation or trimming of data, (X) data components models, (XI) methods based on averaging across models, and (XII) Markov chain methods. Based on this review, our recommendations are that, first, simple methods are preferred in large samples where the near-normality of sample means is assured. Second, in somewhat smaller samples, relatively simple methods, able to deal with one or two of above data characteristics, may be preferable but checking sensitivity to assumptions is necessary. Finally, some more complex methods hold promise, but are relatively untried; their implementation requires substantial expertise and they are not currently recommended for wider applied work. Copyright © 2010 John Wiley & Sons, Ltd. PMID:20799344

Econometrics of inventory holding and shortage costs: the case of refined gasoline

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

Krane, S.D.

1985-01-01

This thesis estimates a model of a firm's optimal inventory and production behavior in order to investigate the link between the role of inventories in the business cycle and the microeconomic incentives for holding stocks of finished goods. The goal is to estimate a set of structural cost function parameters that can be used to infer the optimal cyclical response of inventories and production to shocks in demand. To avoid problems associated with the use of value based aggregate inventory data, an industry level physical unit data set for refined motor gasoline is examined. The Euler equations for a refiner'smore » multiperiod decision problem are estimated using restrictions imposed by the rational expectations hypothesis. The model also embodies the fact that, in most periods, the level of shortages will be zero, and even when positive, the shortages are not directly observable in the data set. These two concerns lead us to use a generalized method of moments estimation technique on a functional form that resembles the formulation of a Tobit problem. The estimation results are disappointing; the model and data yield coefficient estimates incongruous with the cost function interpretations of the structural parameters. These is only some superficial evidence that production smoothing is significant and that marginal inventory shortage costs increase at a faster rate than do marginal holding costs.« less

Residential area characteristics and disabilities among Dutch community-dwelling older adults.

PubMed

Etman, Astrid; Kamphuis, Carlijn B M; Pierik, Frank H; Burdorf, Alex; Van Lenthe, Frank J

2016-11-15

Living longer independently may be facilitated by an attractive and safe residential area, which stimulates physical activity. We studied the association between area characteristics and disabilities and whether this association is mediated by transport-related physical activity (TPA). Longitudinal data of 271 Dutch community-dwelling adults aged 65 years and older participating in the Elderly And their Neighbourhood (ELANE) study in 2011-2013 were used. Associations between objectively measured aesthetics (range 0-22), functional features (range 0-14), safety (range 0-16), and destinations (range 0-15) within road network buffers surrounding participants' residences, and self-reported disabilities in instrumental activities of daily living (range 0-8; measured twice over a 9 months period) were investigated by using longitudinal tobit regression analyses. Furthermore, it was investigated whether self-reported TPA mediated associations between area characteristics and disabilities. A one unit increase in aesthetics within the 400 m buffer was associated with 0.86 less disabilities (95% CI -1.47 to -0.25; p < 0.05), but other area characteristics were not related to disabilities. An increase in area aesthetics was associated with more TPA, and more minutes of TPA were associated with less disabilities. TPA however, only partly mediated the associated between area aesthetics and disabilities. Improving aesthetic features in the close by area around older persons' residences may help to prevent disability.

Dynamics of Urban Informal Labor Supply in the United States

PubMed Central

Gunter, Samara R.

2016-01-01

Objective This study provides the first panel data estimates of informal work in the US and explores relationships between informal- and regular-sector participation among urban parents of young children. Methods I examine determinants of informal-sector participation in five waves of data from the Fragile Families and Child Wellbeing Study using probit, pooled Tobit, and fixed effects OLS models. Results Approximately 53 percent of urban fathers and 32 percent of urban mothers with young children pursue informal work over a nine-year period. Informal work most often occurs in conjunction with regular work. Workers who work in both sectors in the same year are more likely to be non-minority race, higher education (mothers only), own credit cards, and work in skilled white- or blue-collar occupations. Workers who ever participate in only the informal sector are more likely to be younger, to have health limitations, and to have never worked in the regular sector. Informal participation spells are shorter than regular-sector participation spells and are associated with changes in regular-sector participation and occupation but not most other life events. Conclusion Consistent with past work, informal work among parents of young children is widespread across socioeconomic groups. Transitions in and out of the informal sector are strongly related to changes in regular-sector employment and occupation. The results suggest that regular-sector participation provides access to informal work opportunities. PMID:28439143

Dynamics of Urban Informal Labor Supply in the United States.

PubMed

Gunter, Samara R

2017-03-01

This study provides the first panel data estimates of informal work in the US and explores relationships between informal- and regular-sector participation among urban parents of young children. I examine determinants of informal-sector participation in five waves of data from the Fragile Families and Child Wellbeing Study using probit, pooled Tobit, and fixed effects OLS models. Approximately 53 percent of urban fathers and 32 percent of urban mothers with young children pursue informal work over a nine-year period. Informal work most often occurs in conjunction with regular work. Workers who work in both sectors in the same year are more likely to be non-minority race, higher education (mothers only), own credit cards, and work in skilled white- or blue-collar occupations. Workers who ever participate in only the informal sector are more likely to be younger, to have health limitations, and to have never worked in the regular sector. Informal participation spells are shorter than regular-sector participation spells and are associated with changes in regular-sector participation and occupation but not most other life events. Consistent with past work, informal work among parents of young children is widespread across socioeconomic groups. Transitions in and out of the informal sector are strongly related to changes in regular-sector employment and occupation. The results suggest that regular-sector participation provides access to informal work opportunities.

Estimates of Flow Duration, Mean Flow, and Peak-Discharge Frequency Values for Kansas Stream Locations

USGS Publications Warehouse

Perry, Charles A.; Wolock, David M.; Artman, Joshua C.

2004-01-01

Streamflow statistics of flow duration and peak-discharge frequency were estimated for 4,771 individual locations on streams listed on the 1999 Kansas Surface Water Register. These statistics included the flow-duration values of 90, 75, 50, 25, and 10 percent, as well as the mean flow value. Peak-discharge frequency values were estimated for the 2-, 5-, 10-, 25-, 50-, and 100-year floods. Least-squares multiple regression techniques were used, along with Tobit analyses, to develop equations for estimating flow-duration values of 90, 75, 50, 25, and 10 percent and the mean flow for uncontrolled flow stream locations. The contributing-drainage areas of 149 U.S. Geological Survey streamflow-gaging stations in Kansas and parts of surrounding States that had flow uncontrolled by Federal reservoirs and used in the regression analyses ranged from 2.06 to 12,004 square miles. Logarithmic transformations of climatic and basin data were performed to yield the best linear relation for developing equations to compute flow durations and mean flow. In the regression analyses, the significant climatic and basin characteristics, in order of importance, were contributing-drainage area, mean annual precipitation, mean basin permeability, and mean basin slope. The analyses yielded a model standard error of prediction range of 0.43 logarithmic units for the 90-percent duration analysis to 0.15 logarithmic units for the 10-percent duration analysis. The model standard error of prediction was 0.14 logarithmic units for the mean flow. Regression equations used to estimate peak-discharge frequency values were obtained from a previous report, and estimates for the 2-, 5-, 10-, 25-, 50-, and 100-year floods were determined for this report. The regression equations and an interpolation procedure were used to compute flow durations, mean flow, and estimates of peak-discharge frequency for locations along uncontrolled flow streams on the 1999 Kansas Surface Water Register. Flow durations, mean flow, and peak-discharge frequency values determined at available gaging stations were used to interpolate the regression-estimated flows for the stream locations where available. Streamflow statistics for locations that had uncontrolled flow were interpolated using data from gaging stations weighted according to the drainage area and the bias between the regression-estimated and gaged flow information. On controlled reaches of Kansas streams, the streamflow statistics were interpolated between gaging stations using only gaged data weighted by drainage area.

Trends in Water Quality in the Southeastern United States, 1973-2005

USGS Publications Warehouse

Harned, Douglas A.; Staub, Erik L.; Peak, Kelly L.; Tighe, Kirsten M.; Terziotti, Silvia

2009-01-01

As part of the U.S. Geological Survey National Water-Quality Assessment Program, water-quality data for 334 streams in eight States of the Southeastern United States were assessed for trends from 1973 to 2005. Forty-four U.S. Geological Survey sites were examined for trends in pH, specific conductance, and dissolved oxygen, and in concentrations of dissolved solids, suspended sediment, chloride, sodium, sulfate, silica, potassium, dissolved organic carbon, total nitrogen, total ammonia, total ammonia plus organic nitrogen, dissolved nitrite plus nitrate, and total phosphorus. An additional 290 sites from the U.S. Environmental Protection Agency Storage and Retrieval database were tested for trends in total nitrogen and phosphorus concentrations for the 1975-2004 and 1993-2004 periods. The seasonal Kendall test or Tobit regression was used to detect trends. Concentrations of dissolved constituents have increased in the Southeast during the last 30 years. Specific conductance increased at 62 percent and decreased at 3 percent of the sites, and pH increased at 31 percent and decreased at 11 percent of the sites. Decreasing trends in total nitrogen were detected at 49 percent of the sites, and increasing trends were detected at 10 percent of the sites. Ammonia concentrations decreased at 27 percent of the sites and increased at 6 percent of the sites. Nitrite plus nitrate concentrations increased at 29 percent of the sites and decreased at 10 percent of the sites. These results indicate that the changes in stream nitrogen concentrations generally coincided with improved municipal wastewater-treatment methods. Long-term decreasing trends in total phosphorus were detected at 56 percent of the sites, and increasing trends were detected at 8 percent of the sites. Concentrations of phosphorus have decreased over the last 35 years, which coincided with phosphate-detergent bans and improvements in wastewater treatment that were implemented beginning in 1972. Multiple regression analysis indicated a relation between changes in atmospheric inputs and agricultural practices, and changes in water quality. A long-term water-quality and landscape trends-assessment network for the Southeast is needed to assess changes in water quality over time in response to variations in population, agricultural, wastewater, and landscape variables.

Modelling protection behaviour towards micronutrient deficiencies: Case of iodine biofortified vegetable legumes as health intervention for school-going children

PubMed Central

De Steur, Hans; Gellynck, Xavier; Makokha, Anselimo

2016-01-01

BACKGROUND/OBJECTIVES Despite successes recorded in combating iodine deficiency, more than 2 billion people are still at risk of iodine deficiency disorders. Rural landlocked and mountainous areas of developing countries are the hardest hit, hence the need to explore and advance novel strategies such as biofortification. SUBJECTS/METHODS We evaluated adoption, purchase, and consumption of iodine biofortified vegetable legumes (IBVL) using the theory of protection motivations (PMT) integrated with an economic valuation technique. A total of 1,200 participants from three land-locked locations in East Africa were recruited via multi-stage cluster sampling, and data were collected using two, slightly distinct, questionnaires incorporating PMT constructs. The survey also elicited preferences for iodine biofortified foods when offered at a premium or discount. Determinants of protection motivations and preferences for iodine biofortified foods were assessed using path analysis modelling and two-limit Tobit regression, respectively. RESULTS Knowledge of iodine, iodine-health link, salt iodization, and biofortification was very low, albeit lower at the household level. Iodine and biofortification were not recognized as nutrient and novel approaches, respectively. On the other hand, severity, fear, occupation, knowledge, iodine status, household composition, and self-efficacy predicted the intention to consume biofortified foods at the household level; only vulnerability, self-efficacy, and location were the most crucial elements at the school level. In addition, results demonstrated a positive willingness-to-pay a premium or acceptance of a lesser discount for biofortification. Furthermore, preference towards iodine biofortified foods was a function of protection motivations, severity, vulnerability, fear, response efficacy, response cost, knowledge, iodine status, gender, age. and household head. CONCLUSIONS Results lend support for prevention of iodine deficiency in unprotected populations through biofortification; however 'threat' appraisal and socio-economic predictors are decisive in designing nutrition interventions and stimulating uptake of biofortification. In principle, the contribution is threefold: 1) Successful application of the integrated model to guide policy formulation; 2) Offer guidance to stakeholders to identify and tap niche markets; 3) stimulation of rural economic growth around school feeding programmes. PMID:26865917

Silica exposure during construction activities: statistical modeling of task-based measurements from the literature.

PubMed

Sauvé, Jean-François; Beaudry, Charles; Bégin, Denis; Dion, Chantal; Gérin, Michel; Lavoué, Jérôme

2013-05-01

Many construction activities can put workers at risk of breathing silica containing dusts, and there is an important body of literature documenting exposure levels using a task-based strategy. In this study, statistical modeling was used to analyze a data set containing 1466 task-based, personal respirable crystalline silica (RCS) measurements gathered from 46 sources to estimate exposure levels during construction tasks and the effects of determinants of exposure. Monte-Carlo simulation was used to recreate individual exposures from summary parameters, and the statistical modeling involved multimodel inference with Tobit models containing combinations of the following exposure variables: sampling year, sampling duration, construction sector, project type, workspace, ventilation, and controls. Exposure levels by task were predicted based on the median reported duration by activity, the year 1998, absence of source control methods, and an equal distribution of the other determinants of exposure. The model containing all the variables explained 60% of the variability and was identified as the best approximating model. Of the 27 tasks contained in the data set, abrasive blasting, masonry chipping, scabbling concrete, tuck pointing, and tunnel boring had estimated geometric means above 0.1mg m(-3) based on the exposure scenario developed. Water-fed tools and local exhaust ventilation were associated with a reduction of 71 and 69% in exposure levels compared with no controls, respectively. The predictive model developed can be used to estimate RCS concentrations for many construction activities in a wide range of circumstances.

Explaining differences in perceived health-related quality of life: a study within the Spanish population.

PubMed

Martín-Fernández, Jesús; Ariza-Cardiel, Gloria; Polentinos-Castro, Elena; Sanz-Cuesta, Teresa; Sarria-Santamera, Antonio; Del Cura-González, Isabel

2017-09-25

To assess the burden of several determinants on health-related quality of life (HRQOL) and to study its heterogeneity among the different Spanish regions. Cross-sectional study. Data were obtained from the Spanish National Health Survey (2012), and HRQOL was measured using the EQ-5D-5L questionnaire (utility and visual analogue scale -VAS- scores). Demographic variables, physical health condition, social variables, mental health status, and lifestyle were also analysed. Tobit regression models were employed to study the relationships between expressed HRQOL and personal characteristics. A total of 20,979 surveys were obtained. Of them, 62.4% expressed a utility score of 1, corresponding to perfect health (95%CI: 61.8%-63.2%), and 54.2% showed VAS scores ≥80 (95%CI: 53.5%-54.9%). HRQOL was mainly described as a function of age, chronic limitation in daily activities, and mental health status. Belonging to a higher-class strata and physical activity were related to better self-perceived HRQOL. Ageing worsened perceived HRQOL, but did not influence its determinants, and differences in HRQOL by regions were also not significant after model adjustment. HRQOL perception in the Spanish population varied slightly depending on the measure used (utilities index or VAS). Age, chronic limitations in daily life, and mental health status best explained the variability in perception, and no meaningful differences in HRQOL perception among regions were found after adjustment. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Success of commonly used operating room management tools in reducing tardiness of first case of the day starts: evidence from German hospitals.

PubMed

Ernst, Christian; Szczesny, Andrea; Soderstrom, Naomi; Siegmund, Frank; Schleppers, Alexander

2012-09-01

One of the declared objectives of surgical suite management in Germany is to increase operating room (OR) efficiency by reducing tardiness of first case of the day starts. We analyzed whether the introduction of OR management tools by German hospitals in response to increasing economic pressure was successful in achieving this objective. The OR management tools we considered were the appointment of an OR manager and the development and adoption of a surgical suite governance document (OR charter). We hypothesized that tardiness of first case starts was less in ORs that have adopted one or both of these tools. Using representative 2005 survey data from 107 German anesthesiology departments, we used a Tobit model to estimate the effect of the introduction of an OR manager or OR charter on tardiness of first case starts, while controlling for hospital size and surgical suite complexity. Adoption reduced tardiness of first case starts by at least 7 minutes (mean reduction 15 minutes, 95% confidence interval (CI): 7-22 minutes, P < 0.001). Reductions in tardiness of first case starts figure prominently the objectives of surgical suite management in Germany. Our results suggest that the appointment of an OR manager or the adoption of an OR charter support this objective. For short-term decision making on the day of surgery, this reduction in tardiness may have economic implications, because it reduced overutilized OR time.

Does Interdisciplinary Research Lead to Higher Citation Impact? The Different Effect of Proximal and Distal Interdisciplinarity

PubMed Central

Yegros-Yegros, Alfredo; Rafols, Ismael; D’Este, Pablo

2015-01-01

This article analyses the effect of degree of interdisciplinarity on the citation impact of individual publications for four different scientific fields. We operationalise interdisciplinarity as disciplinary diversity in the references of a publication, and rather than treating interdisciplinarity as a monodimensional property, we investigate the separate effect of different aspects of diversity on citation impact: i.e. variety, balance and disparity. We use a Tobit regression model to examine the effect of these properties of interdisciplinarity on citation impact, controlling for a range of variables associated with the characteristics of publications. We find that variety has a positive effect on impact, whereas balance and disparity have a negative effect. Our results further qualify the separate effect of these three aspects of diversity by pointing out that all three dimensions of interdisciplinarity display a curvilinear (inverted U-shape) relationship with citation impact. These findings can be interpreted in two different ways. On the one hand, they are consistent with the view that, while combining multiple fields has a positive effect in knowledge creation, successful research is better achieved through research efforts that draw on a relatively proximal range of fields, as distal interdisciplinary research might be too risky and more likely to fail. On the other hand, these results may be interpreted as suggesting that scientific audiences are reluctant to cite heterodox papers that mix highly disparate bodies of knowledge—thus giving less credit to publications that are too groundbreaking or challenging. PMID:26266805

Examining the relationship between the physical availability of medical marijuana and marijuana use across fifty California cities.

PubMed

Freisthler, Bridget; Gruenewald, Paul J

2014-10-01

The purpose of the current study is to assess statistical associations between individual demographic and personality characteristics, the city-level physical availability of medical marijuana (as measured through densities per roadway mile of storefront dispensaries and delivery services), and the incidence and prevalence of marijuana use. Individual level data on marijuana use were collected during a telephone survey of 8853 respondents living in 50 mid-size cities in California. Data on medical marijuana dispensaries and delivery services were obtained via six different websites and official city lists. Three outcome variables pertaining to lifetime, past year use, and frequency of past year use were analyzed using random effects logistic models (for lifetime and past year use) and random effects tobit models (for frequency of past 365-day use). The current study finds that the total physical availability of medical marijuana through dispensaries and delivery services per roadway mile at the city-level is positively related to current marijuana use and greater frequency of use, controlling for a variety of demographic and personality characteristics. As expected, current physical availability of medical marijuana was unrelated to lifetime use. Regulations on the number and densities of marijuana outlets may be a sufficient means to restrain overall levels of marijuana use within cities. However, alternative use of delivery services may also provide easy access to marijuana and mitigate these effects. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Does Interdisciplinary Research Lead to Higher Citation Impact? The Different Effect of Proximal and Distal Interdisciplinarity.

PubMed

Yegros-Yegros, Alfredo; Rafols, Ismael; D'Este, Pablo

2015-01-01

This article analyses the effect of degree of interdisciplinarity on the citation impact of individual publications for four different scientific fields. We operationalise interdisciplinarity as disciplinary diversity in the references of a publication, and rather than treating interdisciplinarity as a monodimensional property, we investigate the separate effect of different aspects of diversity on citation impact: i.e. variety, balance and disparity. We use a Tobit regression model to examine the effect of these properties of interdisciplinarity on citation impact, controlling for a range of variables associated with the characteristics of publications. We find that variety has a positive effect on impact, whereas balance and disparity have a negative effect. Our results further qualify the separate effect of these three aspects of diversity by pointing out that all three dimensions of interdisciplinarity display a curvilinear (inverted U-shape) relationship with citation impact. These findings can be interpreted in two different ways. On the one hand, they are consistent with the view that, while combining multiple fields has a positive effect in knowledge creation, successful research is better achieved through research efforts that draw on a relatively proximal range of fields, as distal interdisciplinary research might be too risky and more likely to fail. On the other hand, these results may be interpreted as suggesting that scientific audiences are reluctant to cite heterodox papers that mix highly disparate bodies of knowledge--thus giving less credit to publications that are too groundbreaking or challenging.

How much do physician-entrepreneurs contribute to new medical devices?

PubMed

Smith, Sheryl Winston; Sfekas, Andrew

2013-05-01

As recent public and private initiatives have sought to increase the transparency of physician-industry financial relationships (including calls for restricting collaboration), it is important to understand the extent of physicians' contributions to new medical devices. We quantify the contribution of information from physician-founded startup companies to 170 premarket approval (PMA) applications filed by 4 large incumbent medical device manufacturers over the period 1978-2007. We ask: Are incumbents more likely to incorporate information from physician-founded firms than nonphysician-founded firms? We matched the text in 4 incumbent medical device firms' PMAs (Medtronic, Johnson & Johnson, Boston Scientific, and Guidant) to the text in patent applications of 118 startup companies that received investment from these incumbents between 1978 and 2007. We use a text-matching algorithm to quantify the information contribution from physician and nonphysician-founded startups to incumbent firms' PMAs. We analyze correlates of backward citations and degree of overlap between incumbents' PMAs and startups' patents using negative binomial and tobit regressions. On average, physician-founded companies account for 11% of the information in PMAs, compared with 4% from nonphysician-founded companies. Regression results show that incumbents are significantly more likely to cite physician-founded companies' patents and to incorporate them into new devices. Physicians are an important source of medical device innovation. The results suggest that restrictions on financial relationships between providers and industry, while potentially improving patients' trust, may result in reduced medical innovation if physicians found fewer startups or if incumbent firms reduce investments in physician-founded startups.

Catastrophic out-of-pocket payments for health and poverty nexus: evidence from Senegal.

PubMed

Séne, Ligane Massamba; Cissé, Momath

2015-09-01

Out-of-pocket payments are the primary source through which health expenditure is met in Senegal. However, these payments are financial burdens that lead to impoverishment when they become catastrophic. The purpose of this study is to cast light on the determinants of catastrophic household out-of-pocket health expenditures and to assess their implications on poverty. The 2011 poverty monitoring survey is used in this study. This survey aims to draw poverty profiles and to highlight the socio-economic characteristics of different social groups. In line with the concerns raised by the new Supplemental Poverty Measure, poverty statistics are adjusted to take into account household health expenditures and to estimate their impoverishing effects. To identify the determinants of the magnitude of catastrophic health expenditure, we implement a seemingly unrelated equations system of Tobit regressions to take into account censoring through a conditional mixed-process estimator procedure. We identify major causes of catastrophic expenditures, such as the level of overall health spending, the expensiveness of health goods and services, the characteristics of health facilities, the health stock shocks, the lack of insurance, etc. Results show evidence that catastrophic health expenditures jeopardize household welfare for some people that fall into poverty as a result of negative effects on disposable income and disruption of the material living standards of households. Our findings warrant further policy improvements to minimize the financial risks of out-of-pocket health expenditures and increase the efficiency of health care system for more effective poverty reduction strategies.

EXAMINING THE RELATIONSHIP BETWEEN THE PHYSICAL AVAILABILITY OF MEDICAL MARIJUANA AND MARIJUANA USE ACROSS FIFTY CALIFORNIA CITIES

PubMed Central

Freisthler, Bridget; Gruenewald, Paul J.

2014-01-01

Background The purpose of the current study is to assess statistical associations between individual demographic and personality characteristics, the city-level physical availability of medical marijuana (as measured through densities per roadway mile of storefront dispensaries and delivery services), and the incidence and prevalence of marijuana use. Method Individual level data on marijuana use were collected during a telephone survey of 8,853 respondents living in 50 mid-size cities in California. Data on medical marijuana dispensaries and delivery services were obtained via six different websites and official city lists. Three outcome variables pertaining to lifetime, past year use, and frequency of past year use were analyzed using random effects logistic models (for lifetime and past year use) and random effects tobit models (for frequency of past 365-day use). Results The current study finds that the total physical availability of medical marijuana through dispensaries and delivery services per roadway mile at the city-level is positively related to current marijuana use and greater frequency of use, controlling for a variety of demographic and personality characteristics. As expected, current physical availability of medical marijuana was unrelated to lifetime use. Conclusions Regulations on the number and densities of marijuana outlets may be a sufficient means to restrain overall levels of marijuana use within cities. However, alternative use of delivery services may also provide easy access to marijuana and mitigate these effects. PMID:25156224

Limitations of on-site dairy farm regulatory debits as milk quality predictors.

PubMed

Borneman, Darand L; Stiegert, Kyle; Ingham, Steve

2015-03-01

In the United States, compliance with grade A raw fluid milk regulatory standards is assessed via laboratory milk quality testing and by on-site inspection of producers (farms). This study evaluated the correlation between on-site survey debits being marked and somatic cell count (SCC) or standard plate count (SPC) laboratory results for 1,301 Wisconsin grade A dairy farms in 2012. Debits recorded on the survey form were tested as predictors of laboratory results utilizing ordinary least squares regression to determine if results of the current method for on-site evaluation of grade A dairy farms accurately predict SCC and SPC test results. Such a correlation may indicate that current methods of on-site inspection serve the primary intended purpose of assuring availability of high-quality milk. A model for predicting SCC was estimated using ordinary least squares regression methods. Step-wise selected regressors of grouped debit items were able to predict SCC levels with some degree of accuracy (adjusted R2=0.1432). Specific debit items, seasonality, and farm size were the best predictors of SCC levels. The SPC data presented an analytical challenge because over 75% of the SPC observations were at or below a 25,000 cfu/mL threshold but were recorded by testing laboratories as at the threshold value. This classic censoring problem necessitated the use of a Tobit regression approach. Even with this approach, prediction of SPC values based on on-site survey criteria was much less successful (adjusted R2=0.034) and provided little support for the on-site survey system as a way to inform farmers about making improvements that would improve SPC. The lower level of correlation with SPC may indicate that factors affecting SPC are more varied and differ from those affecting SCC. Further, unobserved deficiencies in postmilking handling and storage sanitation could enhance bacterial growth and increase SPC, whereas postmilking sanitation will have no effect on SCC because somatic cells do not reproduce in stored milk. Results suggest that close examination, and perhaps redefinition, of survey debits, along with making the survey coincident with SCC and SPC sampling, could make the on-site survey a better tool for ensuring availability of high-quality milk. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Regression equations to estimate seasonal flow duration, n-day high-flow frequency, and n-day low-flow frequency at sites in North Dakota using data through water year 2009

USGS Publications Warehouse

Williams-Sether, Tara; Gross, Tara A.

2016-02-09

Seasonal mean daily flow data from 119 U.S. Geological Survey streamflow-gaging stations in North Dakota; the surrounding states of Montana, Minnesota, and South Dakota; and the Canadian provinces of Manitoba and Saskatchewan with 10 or more years of unregulated flow record were used to develop regression equations for flow duration, n-day high flow and n-day low flow using ordinary least-squares and Tobit regression techniques. Regression equations were developed for seasonal flow durations at the 10th, 25th, 50th, 75th, and 90th percent exceedances; the 1-, 7-, and 30-day seasonal mean high flows for the 10-, 25-, and 50-year recurrence intervals; and the 1-, 7-, and 30-day seasonal mean low flows for the 2-, 5-, and 10-year recurrence intervals. Basin and climatic characteristics determined to be significant explanatory variables in one or more regression equations included drainage area, percentage of basin drainage area that drains to isolated lakes and ponds, ruggedness number, stream length, basin compactness ratio, minimum basin elevation, precipitation, slope ratio, stream slope, and soil permeability. The adjusted coefficient of determination for the n-day high-flow regression equations ranged from 55.87 to 94.53 percent. The Chi2 values for the duration regression equations ranged from 13.49 to 117.94, whereas the Chi2 values for the n-day low-flow regression equations ranged from 4.20 to 49.68.

Patterns and trends in lead (Pb) concentrations in bald eagle (Haliaeetus leucocephalus) nestlings from the western Great Lakes region.

PubMed

Bruggeman, Jason E; Route, William T; Redig, Patrick T; Key, Rebecca L

2018-04-10

Most studies examining bald eagle (Haliaeetus leucocephalus) exposure to lead (Pb) have focused on adults that ingested spent Pb ammunition during the fall hunting season, often at clinical or lethal levels. We sampled live bald eagle nestlings along waterbodies to quantify Pb concentrations in 3 national park units and 2 nearby study areas in the western Great Lakes region. We collected 367 bald eagle nestling feather samples over 8 years during spring 2006-2015 and 188 whole blood samples over 4 years during spring 2010-2015. We used Tobit regression models to quantify relationships between Pb concentrations in nestling feathers and blood using study area, year, and nestling attributes as covariates. Pb in nestling feather samples decreased from 2006 to 2015, but there was no trend for Pb in blood samples. Pb concentrations in nestling feather and blood samples were significantly higher in study areas located closer to and within urban areas. Pb in feather and blood samples from the same nestling was positively correlated. Pb in feathers increased with nestling age, but this relationship was not observed for blood. Our results reflect how Pb accumulates in tissues as nestlings grow, with Pb in feathers and blood indexing exposure during feather development and before sampling, respectively. Some nestlings had Pb concentrations in blood that suggested a greater risk to sublethal effects from Pb exposure. Our data provides baselines for Pb concentrations in feathers and blood of nestling bald eagles from a variety of waterbody types spanning remote, lightly populated, and human-dominated landscapes.

Water quality of storm runoff and comparison of procedures for estimating storm-runoff loads, volume, event-mean concentrations, and the mean load for a storm for selected properties and constituents for Colorado Springs, southeastern Colorado, 1992

USGS Publications Warehouse

Von Guerard, Paul; Weiss, W.B.

1995-01-01

The U.S. Environmental Protection Agency requires that municipalities that have a population of 100,000 or greater obtain National Pollutant Discharge Elimination System permits to characterize the quality of their storm runoff. In 1992, the U.S. Geological Survey, in cooperation with the Colorado Springs City Engineering Division, began a study to characterize the water quality of storm runoff and to evaluate procedures for the estimation of storm-runoff loads, volume and event-mean concentrations for selected properties and constituents. Precipitation, streamflow, and water-quality data were collected during 1992 at five sites in Colorado Springs. Thirty-five samples were collected, seven at each of the five sites. At each site, three samples were collected for permitting purposes; two of the samples were collected during rainfall runoff, and one sample was collected during snowmelt runoff. Four additional samples were collected at each site to obtain a large enough sample size to estimate storm-runoff loads, volume, and event-mean concentrations for selected properties and constituents using linear-regression procedures developed using data from the Nationwide Urban Runoff Program (NURP). Storm-water samples were analyzed for as many as 186 properties and constituents. The constituents measured include total-recoverable metals, vola-tile-organic compounds, acid-base/neutral organic compounds, and pesticides. Storm runoff sampled had large concentrations of chemical oxygen demand and 5-day biochemical oxygen demand. Chemical oxygen demand ranged from 100 to 830 milligrams per liter, and 5.-day biochemical oxygen demand ranged from 14 to 260 milligrams per liter. Total-organic carbon concentrations ranged from 18 to 240 milligrams per liter. The total-recoverable metals lead and zinc had the largest concentrations of the total-recoverable metals analyzed. Concentrations of lead ranged from 23 to 350 micrograms per liter, and concentrations of zinc ranged from 110 to 1,400 micrograms per liter. The data for 30 storms representing rainfall runoff from 5 drainage basins were used to develop single-storm local-regression models. The response variables, storm-runoff loads, volume, and event-mean concentrations were modeled using explanatory variables for climatic, physical, and land-use characteristics. The r2 for models that use ordinary least-squares regression ranged from 0.57 to 0.86 for storm-runoff loads and volume and from 0.25 to 0.63 for storm-runoff event-mean concentrations. Except for cadmium, standard errors of estimate ranged from 43 to 115 percent for storm- runoff loads and volume and from 35 to 66 percent for storm-runoff event-mean concentrations. Eleven of the 30 concentrations collected during rainfall runoff for total-recoverable cadmium were censored (less than) concentrations. Ordinary least-squares regression should not be used with censored data; however, censored data can be included with uncensored data using tobit regression. Standard errors of estimate for storm-runoff load and event-mean concentration for total-recoverable cadmium, computed using tobit regression, are 247 and 171 percent. Estimates from single-storm regional-regression models, developed from the Nationwide Urban Runoff Program data base, were compared with observed storm-runoff loads, volume, and event-mean concentrations determined from samples collected in the study area. Single-storm regional-regression models tended to overestimate storm-runoff loads, volume, and event-mean con-centrations. Therefore, single-storm local- and regional-regression models were combined using model-adjustment procedures to take advantage of the strengths of both models while minimizing the deficiencies of each model. Procedures were used to develop single-stormregression equations that were adjusted using local data and estimates from single-storm regional-regression equations. Single-storm regression models developed using model- adjustment proce

Ethnic Differences in Poststroke Quality of Life in the Brain Attack Surveillance in Corpus Christi (BASIC) Project.

PubMed

Reeves, Sarah L; Brown, Devin L; Baek, Jonggyu; Wing, Jeffrey J; Morgenstern, Lewis B; Lisabeth, Lynda D

2015-10-01

Mexican Americans (MAs) have an increased risk of stroke and experience worse poststroke disability than non-Hispanic whites, which may translate into worse poststroke quality of life (QOL). We assessed ethnic differences in poststroke QOL, as well as potential modification of associations by age, sex, and initial stroke severity. Ischemic stroke survivors were identified through the biethnic, population-based Brain Attack Surveillance in Corpus Christi (BASIC) Project. Data were collected from medical records, baseline interviews, and 90-day poststroke interviews. Poststroke QOL was measured at ≈90 days by the validated short-form stroke-specific QOL in 3 domains: overall, physical, and psychosocial (range, 0-5; higher scores represent better QOL). Tobit regression was used to model associations between ethnicity and poststroke QOL scores, adjusted for demographics, clinical characteristics, and prestroke cognition and function. Among 290 eligible stroke survivors (66% MA, 34% non-Hispanic whites, median age=69 years), median scores for overall, physical, and psychosocial poststroke QOL were 3.3, 3.8, and 2.7, respectively. Poststroke QOL was lower for MAs than non-Hispanic whites both overall (mean difference, -0.30; 95% confidence interval, -0.59, -0.01) and in the physical domain (mean difference, -0.47; 95% confidence interval, -0.81, -0.14) after multivariable adjustment. No ethnic difference was found in the psychosocial domain. Age modified the associations between ethnicity and poststroke QOL such that differences were present in older but not in younger ages. Disparities exist in poststroke QOL for MAs and seem to be driven by differences in older stroke patients. Targeted interventions to improve outcomes among MA stroke survivors are urgently needed. © 2015 American Heart Association, Inc.

Ethnic Differences in Post-Stroke Quality of Life in the Brain Attack Surveillance in Corpus Christi (BASIC) Project

PubMed Central

Reeves, Sarah L; Brown, Devin L; Baek, Jonggyu; Wing, Jeffrey J; Morgenstern, Lewis B; Lisabeth, Lynda D

2015-01-01

Background and Purpose Mexican Americans (MAs) have an increased risk of stroke and experience worse post-stroke disability than non-Hispanic whites (NHWs), which may translate into worse post-stroke quality of life (QOL). We assessed ethnic differences in post-stroke QOL, as well as potential modification of associations by age, sex, and initial stroke severity. Methods Ischemic stroke survivors were identified through the biethnic, population-based Brain Attack Surveillance in Corpus Christi (BASIC) Project. Data were collected from medical records, baseline interviews, and 90-day post-stroke interviews. Post-stroke QOL was measured at approximately 90 days by the validated short-form stroke-specific QOL in 3 domains: overall, physical, and psychosocial (range 0–5; higher scores represent better QOL). Tobit regression was used to model associations between ethnicity and post-stroke QOL scores, adjusted for demographics, clinical characteristics, and pre-stroke cognition and function. Results Among 290 eligible stroke survivors (66% MA, 34% NHW, median age=69 years), median scores for overall, physical, and psychosocial post-stroke QOL were 3.3, 3.8 and 2.7, respectively. Overall post-stroke QOL was lower for MAs than NHWs (mean difference = −0.30, 95%CI:−0.59,−0.01) and in the physical domain (mean difference = −0.47, 95%CI:−0.81,−0.14) after multivariable adjustment. No ethnic difference was found in the psychosocial domain. Age modified the associations between ethnicity and post-stroke QOL such that differences were present in older but not younger ages. Conclusions Disparities exist in post-stroke QOL for MAs and appear to be driven by differences in older stroke patients. Targeted interventions to improve outcomes among MA stroke survivors are urgently needed. PMID:26286542

Regression models for explaining and predicting concentrations of organochlorine pesticides in fish from streams in the United States

USGS Publications Warehouse

Nowell, Lisa H.; Crawford, Charles G.; Gilliom, Robert J.; Nakagaki, Naomi; Stone, Wesley W.; Thelin, Gail; Wolock, David M.

2009-01-01

Empirical regression models were developed for estimating concentrations of dieldrin, total chlordane, and total DDT in whole fish from U.S. streams. Models were based on pesticide concentrations measured in whole fish at 648 stream sites nationwide (1992-2001) as part of the U.S. Geological Survey's National Water Quality Assessment Program. Explanatory variables included fish lipid content, estimates (or surrogates) representing historical agricultural and urban sources, watershed characteristics, and geographic location. Models were developed using Tobit regression methods appropriate for data with censoring. Typically, the models explain approximately 50 to 70% of the variability in pesticide concentrations measured in whole fish. The models were used to predict pesticide concentrations in whole fish for streams nationwide using the U.S. Environmental Protection Agency's River Reach File 1 and to estimate the probability that whole-fish concentrations exceed benchmarks for protection of fish-eating wildlife. Predicted concentrations were highest for dieldrin in the Corn Belt, Texas, and scattered urban areas; for total chlordane in the Corn Belt, Texas, the Southeast, and urbanized Northeast; and for total DDT in the Southeast, Texas, California, and urban areas nationwide. The probability of exceeding wildlife benchmarks for dieldrin and chlordane was predicted to be low for most U.S. streams. The probability of exceeding wildlife benchmarks for total DDT is higher but varies depending on the fish taxon and on the benchmark used. Because the models in the present study are based on fish data collected during the 1990s and organochlorine pesticide residues in the environment continue to decline decades after their uses were discontinued, these models may overestimate present-day pesticide concentrations in fish. ?? 2009 SETAC.

Work and family conflicts in employees with spinal cord injury and their caregiving partners.

PubMed

Fekete, C; Siegrist, J; Tough, H; Brinkhof, M W G

2018-01-01

Cross-sectional, observational. To investigate the association of conflicts between work and family life with indicators of health and to examine the antecedents of those conflicts in employees with spinal cord injury (SCI) and their caregiving partners. Community, Switzerland. Data from employed persons with SCI (n=79) and caregiving partners (n=93) who participated in the pro-WELL study were used. Logistic and tobit regressions were performed to assess the association of work-family and family-work conflicts with health indicators, namely mental health (36-item Short Form Health Survey (SF-36)), vitality (SF-36), well-being (WHOQoL BREF) and positive and negative affect (Positive and Negative Affect Scale short form (PANAS-S)). Own and partners' engagement in productive activities and socioeconomic circumstances were evaluated as potential antecedents of work-family and family-work conflicts using logistic regression. Work-family conflicts were related to reduced mental health (caregiving partners only), vitality and well-being. Family-work conflicts were linked to reduced mental health, vitality, well-being and positive affect in SCI and to reduced vitality in caregiving partners. Persons with lower income (SCI only) and lower subjective social position reported more conflicts than persons with higher income and higher subjective position. Higher workload increased work-family conflicts in caregiving partners and decreased family-work conflicts in SCI. Education, amount of caregiving, care-receiving and partners' employment status were not associated with the occurrence of conflicts. The optimal balance between work and family life is important to promote mental health, vitality and well-being in employees with SCI and their caregiving partners. This is especially true in employees perceiving their social position as low and in caregivers with a high workload.

Personal Care Product Use in Men and Urinary Concentrations of Select Phthalate Metabolites and Parabens: Results from the Environment And Reproductive Health (EARTH) Study.

PubMed

Nassan, Feiby L; Coull, Brent A; Gaskins, Audrey J; Williams, Michelle A; Skakkebaek, Niels E; Ford, Jennifer B; Ye, Xiaoyun; Calafat, Antonia M; Braun, Joseph M; Hauser, Russ

2017-08-18

Personal care products (PCPs) are exposure sources to phthalates and parabens; however, their contribution to men's exposure is understudied. We examined the association between PCP use and urinary concentrations of phthalate metabolites and parabens in men. In a prospective cohort, at multiple study visits, men self-reported their use of 14 PCPs and provided a urine sample (2004-2015, Boston, MA). We measured urinary concentrations of 9 phthalate metabolites and methylparaben, propylparaben, and butylparaben. We estimated the covariate-adjusted percent change in urinary concentrations associated with PCP use using linear mixed and Tobit mixed regressions. We also estimated weights for each PCP in a weighted binary score regression and modeled the resulting composite weighted PCP use. Four hundred men contributed 1,037 urine samples (mean of 3/man). The largest percent increase in monoethyl phthalate (MEP) was associated with use of cologne/perfume (83%, p -value<0.01) and deodorant (74%, p -value<0.01). In contrast, the largest percent increase for parabens was associated with the use of suntan/sunblock lotion (66-156%) and hand/body lotion (79-147%). Increases in MEP and parabens were generally greater with PCP use within 6 h of urine collection. A subset of 10 PCPs that were used within 6 h of urine collection contributed to at least 70% of the weighted score and predicted a 254-1,333% increase in MEP and parabens concentrations. Associations between PCP use and concentrations of the other phthalate metabolites were not statistically significant. We identified 10 PCPs of relevance and demonstrated that their use within 6 h of urine collection strongly predicted MEP and paraben urinary concentrations. https://doi.org/10.1289/EHP1374.

German Value Set for the EQ-5D-5L.

PubMed

Ludwig, Kristina; Graf von der Schulenburg, J-Matthias; Greiner, Wolfgang

2018-06-01

The objective of this study was to develop a value set for EQ-5D-5L based on the societal preferences of the German population. As the first country to do so, the study design used the improved EQ-5D-5L valuation protocol 2.0 developed by the EuroQol Group, including a feedback module as internal validation and a quality control process that was missing in the first wave of EQ-5D-5L valuation studies. A representative sample of the general German population (n = 1158) was interviewed using a composite time trade-off and a discrete choice experiment under close quality control. Econometric modeling was used to estimate values for all 3125 possible health states described by EQ-5D-5L. The value set was based on a hybrid model including all available information from the composite time trade-off and discrete choice experiment valuations without any exclusions due to data issues. The final German value set was constructed from a combination of a conditional logit model for the discrete choice experiment data and a censored at -1 Tobit model for the composite time trade-off data, correcting for heteroskedasticity. The value set had logically consistent parameter estimates (p < 0.001 for all coefficients). The predicted EQ-5D-5L index values ranged from -0.661 to 1. This study provided values for the health states of the German version of EQ-5D-5L representing the preferences of the German population. The study successfully employed for the first time worldwide the improved protocol 2.0. The value set enables the use of the EQ-5D-5L instrument in economic evaluations and in clinical studies.

Determinants of isocyanate exposures in auto body repair and refinishing shops.

PubMed

Woskie, S R; Sparer, J; Gore, R J; Stowe, M; Bello, D; Liu, Y; Youngs, F; Redlich, C; Eisen, E; Cullen, M

2004-07-01

As part of the Survey of Painters and Repairers of Auto bodies by Yale (SPRAY), the determinants of isocyanate exposure in auto body repair shops were evaluated. Measurements (n = 380) of hexamethylene diisocyanate-based monomer and polyisocyanate and isophorone diisocyanate-based polyisocyanate were collected from 33 auto body shops. The median total reactive isocyanate concentrations expressed as mass concentration of the NCO functional group were: 206 microg NCO/m3 for spray operations; 0.93 microg NCO/m3 for samples collected in the vicinity of spray operations done on the shop floor (near spray); 0.05 microg NCO/m3 for office or other shop areas adjacent to spray areas (workplace background); 0.17 microg NCO/m3 for paint mixing and gun cleaning operations (mixing); 0.27 microg NCO/m3 for sanding operations. Exposure determinants for the sample NCO mass load were identified using linear regression, tobit regression and logistic regression models. For spray samples in a spray booth the significant determinants were the number of milliliters of NCO applied, the gallons of clear coat used by the shop each month and the type of spray booth used (custom built crossdraft, prefabricated crossdraft or downdraft/semi-downdraft). For near spray (bystander) samples, outdoor temperature >65 degrees F (18 degrees C) and shop size >5000 feet2 (465 m2) were significant determinants of exposure levels. For workplace background samples the shop annual income was the most important determinant. For sanding samples, the shop annual income and outdoor temperature >65 degrees F (18 degrees C) were the most significant determinants. Identification of these key exposure determinants will be useful in targeting exposure evaluation and control efforts to reduce isocyanate exposures.

School readiness among children with behavior problems at entrance into kindergarten: results from a US national study.

PubMed

Montes, Guillermo; Lotyczewski, Bohdan S; Halterman, Jill S; Hightower, Alan D

2012-03-01

The impact of behavior problems on kindergarten readiness is not known. Our objective was to estimate the association between behavior problems and kindergarten readiness on a US national sample. In the US educational system, kindergarten is a natural point of entry into formal schooling at age 5 because fewer than half of the children enter kindergarten with prior formal preschool education. Parents of 1,200 children who were scheduled to enter kindergarten for the first time and were members of the Harris Interactive online national panel were surveyed. We defined behavior problems as an affirmative response to the question, "Has your child ever had behavior problems?" We validated this against attention deficit hyperactivity disorder diagnosis, scores on a reliable socioemotional scale, and child's receipt of early intervention services. We used linear, tobit, and logistic regression analyses to estimate the association between having behavior problems and scores in reliable scales of motor, play, speech and language, and school skills and an overall kindergarten readiness indicator. The sample included 176 children with behavior problems for a national prevalence of 14% (confidence interval, 11.5-17.5). Children with behavior problems were more likely to be male and live in households with lower income and parental education. We found that children with behavior problems entered kindergarten with lower speech and language, motor, play, and school skills, even after controlling for demographics and region. Delays were 0.6-1 SD below scores of comparable children without behavior problems. Parents of children with behavior problems were 5.2 times more likely to report their child was not ready for kindergarten. Childhood behavior problems are associated with substantial delays in motor, language, play, school, and socioemotional skills before entrance into kindergarten. Early screening and intervention is recommended.

Work and family conflicts in employees with spinal cord injury and their caregiving partners

PubMed Central

Fekete, C; Siegrist, J; Tough, H; Brinkhof, M W G

2018-01-01

Study design: Cross-sectional, observational. Objectives: To investigate the association of conflicts between work and family life with indicators of health and to examine the antecedents of those conflicts in employees with spinal cord injury (SCI) and their caregiving partners. Setting: Community, Switzerland. Methods: Data from employed persons with SCI (n=79) and caregiving partners (n=93) who participated in the pro-WELL study were used. Logistic and tobit regressions were performed to assess the association of work–family and family–work conflicts with health indicators, namely mental health (36-item Short Form Health Survey (SF-36)), vitality (SF-36), well-being (WHOQoL BREF) and positive and negative affect (Positive and Negative Affect Scale short form (PANAS-S)). Own and partners’ engagement in productive activities and socioeconomic circumstances were evaluated as potential antecedents of work–family and family–work conflicts using logistic regression. Results: Work–family conflicts were related to reduced mental health (caregiving partners only), vitality and well-being. Family–work conflicts were linked to reduced mental health, vitality, well-being and positive affect in SCI and to reduced vitality in caregiving partners. Persons with lower income (SCI only) and lower subjective social position reported more conflicts than persons with higher income and higher subjective position. Higher workload increased work–family conflicts in caregiving partners and decreased family–work conflicts in SCI. Education, amount of caregiving, care-receiving and partners’ employment status were not associated with the occurrence of conflicts. Conclusion: The optimal balance between work and family life is important to promote mental health, vitality and well-being in employees with SCI and their caregiving partners. This is especially true in employees perceiving their social position as low and in caregivers with a high workload. PMID:28853447

Coffee consumption and coronary artery calcium in young and middle-aged asymptomatic adults.

PubMed

Choi, Yuni; Chang, Yoosoo; Ryu, Seungho; Cho, Juhee; Rampal, Sanjay; Zhang, Yiyi; Ahn, Jiin; Lima, Joao A C; Shin, Hocheol; Guallar, Eliseo

2015-05-01

To investigate the association between regular coffee consumption and the prevalence of coronary artery calcium (CAC) in a large sample of young and middle-aged asymptomatic men and women. This cross-sectional study included 25 138 men and women (mean age 41.3 years) without clinically evident cardiovascular disease who underwent a health screening examination that included a validated food frequency questionnaire and a multidetector CT to determine CAC scores. We used robust Tobit regression analyses to estimate the CAC score ratios associated with different levels of coffee consumption compared with no coffee consumption and adjusted for potential confounders. The prevalence of detectable CAC (CAC score >0) was 13.4% (n=3364), including 11.3% prevalence for CAC scores 1-100 (n=2832), and 2.1% prevalence for CAC scores >100 (n=532). The mean ±SD consumption of coffee was 1.8±1.5 cups/day. The multivariate-adjusted CAC score ratios (95% CIs) comparing coffee drinkers of <1, 1-<3, 3-<5, and ≥5 cups/day to non-coffee drinkers were 0.77 (0.49 to 1.19), 0.66 (0.43 to 1.02), 0.59 (0.38 to 0.93), and 0.81 (0.46 to 1.43), respectively (p for quadratic trend=0.02). The association was similar in subgroups defined by age, sex, smoking status, alcohol consumption, status of obesity, diabetes, hypertension, and hypercholesterolaemia. In this large sample of men and women apparently free of clinically evident cardiovascular disease, moderate coffee consumption was associated with a lower prevalence of subclinical coronary atherosclerosis. 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.

Sugar-sweetened carbonated beverage consumption and coronary artery calcification in asymptomatic men and women.

PubMed

Chun, Sohyun; Choi, Yuni; Chang, Yoosoo; Cho, Juhee; Zhang, Yiyi; Rampal, Sanjay; Zhao, Di; Ahn, Jiin; Suh, Byung-Seong; Pastor-Barriuso, Roberto; Lima, Joao A C; Chung, Eun Chul; Shin, Hocheol; Guallar, Eliseo; Ryu, Seungho

2016-07-01

Sugar-sweetened carbonated beverage consumption has been linked to obesity, metabolic syndrome, type 2 diabetes, and clinically manifest coronary heart disease, but its association with subclinical coronary heart disease remains unclear. We investigated the relationship between sugar-sweetened carbonated beverage consumption and coronary artery calcium (CAC) in a large study of asymptomatic men and women. This was a cross-sectional study of 22,210 adult men and women who underwent a comprehensive health screening examination between 2011 and 2013 (median age 40 years). Sugar-sweetened carbonated beverage consumption was assessed using a validated food frequency questionnaire, and CAC was measured by cardiac computed tomography. Multivariable-adjusted CAC score ratios and 95% CIs were estimated from robust Tobit regression models for the natural logarithm (CAC score +1). The prevalence of detectable CAC (CAC score >0) was 11.7% (n = 2,604). After adjustment for age; sex; center; year of screening examination; education level; physical activity; smoking; alcohol intake; family history of cardiovascular disease; history of hypertension; history of hypercholesterolemia; and intake of total energy, fruits, vegetables, and red and processed meats, only the highest category of sugar-sweetened carbonated beverage consumption was associated with an increased CAC score compared with the lowest consumption category. The multivariable-adjusted CAC ratio comparing participants who consumed ≥5 sugar-sweetened carbonated beverages per week with nondrinkers was 1.70 (95% CI, 1.03-2.81). This association did not differ by clinical subgroup, including participants at low cardiovascular risk. Our findings suggest that high levels of sugar-sweetened carbonated beverage consumption are associated with a higher prevalence and degree of CAC in asymptomatic adults without a history of cardiovascular disease, cancer, or diabetes. Copyright © 2016 Elsevier Inc. All rights reserved.

Factor Analysis and Counseling Research

ERIC Educational Resources Information Center

Weiss, David J.

1970-01-01

Topics discussed include factor analysis versus cluster analysis, analysis of Q correlation matrices, ipsativity and factor analysis, and tests for the significance of a correlation matrix prior to application of factor analytic techniques. Techniques for factor extraction discussed include principal components, canonical factor analysis, alpha…

Using Horn's Parallel Analysis Method in Exploratory Factor Analysis for Determining the Number of Factors

ERIC Educational Resources Information Center

Çokluk, Ömay; Koçak, Duygu

2016-01-01

In this study, the number of factors obtained from parallel analysis, a method used for determining the number of factors in exploratory factor analysis, was compared to that of the factors obtained from eigenvalue and scree plot--two traditional methods for determining the number of factors--in terms of consistency. Parallel analysis is based on…

Determining the Number of Factors in P-Technique Factor Analysis

ERIC Educational Resources Information Center

Lo, Lawrence L.; Molenaar, Peter C. M.; Rovine, Michael

2017-01-01

Determining the number of factors is a critical first step in exploratory factor analysis. Although various criteria and methods for determining the number of factors have been evaluated in the usual between-subjects R-technique factor analysis, there is still question of how these methods perform in within-subjects P-technique factor analysis. A…

On the Relations among Regular, Equal Unique Variances, and Image Factor Analysis Models.

ERIC Educational Resources Information Center

Hayashi, Kentaro; Bentler, Peter M.

2000-01-01

Investigated the conditions under which the matrix of factor loadings from the factor analysis model with equal unique variances will give a good approximation to the matrix of factor loadings from the regular factor analysis model. Extends the results to the image factor analysis model. Discusses implications for practice. (SLD)

Application of Factor Analysis on the Financial Ratios of Indian Cement Industry and Validation of the Results by Cluster Analysis

NASA Astrophysics Data System (ADS)

De, Anupam; Bandyopadhyay, Gautam; Chakraborty, B. N.

2010-10-01

Financial ratio analysis is an important and commonly used tool in analyzing financial health of a firm. Quite a large number of financial ratios, which can be categorized in different groups, are used for this analysis. However, to reduce number of ratios to be used for financial analysis and regrouping them into different groups on basis of empirical evidence, Factor Analysis technique is being used successfully by different researches during the last three decades. In this study Factor Analysis has been applied over audited financial data of Indian cement companies for a period of 10 years. The sample companies are listed on the Stock Exchange India (BSE and NSE). Factor Analysis, conducted over 44 variables (financial ratios) grouped in 7 categories, resulted in 11 underlying categories (factors). Each factor is named in an appropriate manner considering the factor loads and constituent variables (ratios). Representative ratios are identified for each such factor. To validate the results of Factor Analysis and to reach final conclusion regarding the representative ratios, Cluster Analysis had been performed.

Monitoring and modeling to predict Escherichia coli at Presque Isle Beach 2, City of Erie, Erie County, Pennsylvania

USGS Publications Warehouse

Zimmerman, Tammy M.

2006-01-01

The Lake Erie shoreline in Pennsylvania spans nearly 40 miles and is a valuable recreational resource for Erie County. Nearly 7 miles of the Lake Erie shoreline lies within Presque Isle State Park in Erie, Pa. Concentrations of Escherichia coli (E. coli) bacteria at permitted Presque Isle beaches occasionally exceed the single-sample bathing-water standard, resulting in unsafe swimming conditions and closure of the beaches. E. coli concentrations and other water-quality and environmental data collected at Presque Isle Beach 2 during the 2004 and 2005 recreational seasons were used to develop models using tobit regression analyses to predict E. coli concentrations. All variables statistically related to E. coli concentrations were included in the initial regression analyses, and after several iterations, only those explanatory variables that made the models significantly better at predicting E. coli concentrations were included in the final models. Regression models were developed using data from 2004, 2005, and the combined 2-year dataset. Variables in the 2004 model and the combined 2004-2005 model were log10 turbidity, rain weight, wave height (calculated), and wind direction. Variables in the 2005 model were log10 turbidity and wind direction. Explanatory variables not included in the final models were water temperature, streamflow, wind speed, and current speed; model results indicated these variables did not meet significance criteria at the 95-percent confidence level (probabilities were greater than 0.05). The predicted E. coli concentrations produced by the models were used to develop probabilities that concentrations would exceed the single-sample bathing-water standard for E. coli of 235 colonies per 100 milliliters. Analysis of the exceedence probabilities helped determine a threshold probability for each model, chosen such that the correct number of exceedences and nonexceedences was maximized and the number of false positives and false negatives was minimized. Future samples with computed exceedence probabilities higher than the selected threshold probability, as determined by the model, will likely exceed the E. coli standard and a beach advisory or closing may need to be issued; computed exceedence probabilities lower than the threshold probability will likely indicate the standard will not be exceeded. Additional data collected each year can be used to test and possibly improve the model. This study will aid beach managers in more rapidly determining when waters are not safe for recreational use and, subsequently, when to issue beach advisories or closings.

A Review of CEFA Software: Comprehensive Exploratory Factor Analysis Program

ERIC Educational Resources Information Center

Lee, Soon-Mook

2010-01-01

CEFA 3.02(Browne, Cudeck, Tateneni, & Mels, 2008) is a factor analysis computer program designed to perform exploratory factor analysis. It provides the main properties that are needed for exploratory factor analysis, namely a variety of factoring methods employing eight different discrepancy functions to be minimized to yield initial…

Factor analysis of an instrument to measure the impact of disease on daily life.

PubMed

Pedrosa, Rafaela Batista Dos Santos; Rodrigues, Roberta Cunha Matheus; Padilha, Kátia Melissa; Gallani, Maria Cecília Bueno Jayme; Alexandre, Neusa Maria Costa

2016-01-01

to verify the structure of factors of an instrument to measure the Heart Valve Disease Impact on Daily Life (IDCV) when applied to coronary artery disease patients. the study included 153 coronary artery disease patients undergoing outpatient follow-up care. The IDCV structure of factors was initially assessed by means of confirmatory factor analysis and, subsequently, by exploratory factor analysis. The Varimax rotation method was used to estimate the main components of analysis, eigenvalues greater than one for extraction of factors, and factor loading greater than 0.40 for selection of items. Internal consistency was estimated using Cronbach's alpha coefficient. confirmatory factor analysis did not confirm the original structure of factors of the IDCV. Exploratory factor analysis showed three dimensions, which together explained 78% of the measurement variance. future studies with expansion of case selection are necessary to confirm the IDCV new structure of factors.

A comparison study on detection of key geochemical variables and factors through three different types of factor analysis

NASA Astrophysics Data System (ADS)

Hoseinzade, Zohre; Mokhtari, Ahmad Reza

2017-10-01

Large numbers of variables have been measured to explain different phenomena. Factor analysis has widely been used in order to reduce the dimension of datasets. Additionally, the technique has been employed to highlight underlying factors hidden in a complex system. As geochemical studies benefit from multivariate assays, application of this method is widespread in geochemistry. However, the conventional protocols in implementing factor analysis have some drawbacks in spite of their advantages. In the present study, a geochemical dataset including 804 soil samples collected from a mining area in central Iran in order to search for MVT type Pb-Zn deposits was considered to outline geochemical analysis through various fractal methods. Routine factor analysis, sequential factor analysis, and staged factor analysis were applied to the dataset after opening the data with (additive logratio) alr-transformation to extract mineralization factor in the dataset. A comparison between these methods indicated that sequential factor analysis has more clearly revealed MVT paragenesis elements in surface samples with nearly 50% variation in F1. In addition, staged factor analysis has given acceptable results while it is easy to practice. It could detect mineralization related elements while larger factor loadings are given to these elements resulting in better pronunciation of mineralization.

Exploratory Bi-factor Analysis: The Oblique Case.

PubMed

Jennrich, Robert I; Bentler, Peter M

2012-07-01

Bi-factor analysis is a form of confirmatory factor analysis originally introduced by Holzinger and Swineford (Psychometrika 47:41-54, 1937). The bi-factor model has a general factor, a number of group factors, and an explicit bi-factor structure. Jennrich and Bentler (Psychometrika 76:537-549, 2011) introduced an exploratory form of bi-factor analysis that does not require one to provide an explicit bi-factor structure a priori. They use exploratory factor analysis and a bifactor rotation criterion designed to produce a rotated loading matrix that has an approximate bi-factor structure. Among other things this can be used as an aid in finding an explicit bi-factor structure for use in a confirmatory bi-factor analysis. They considered only orthogonal rotation. The purpose of this paper is to consider oblique rotation and to compare it to orthogonal rotation. Because there are many more oblique rotations of an initial loading matrix than orthogonal rotations, one expects the oblique results to approximate a bi-factor structure better than orthogonal rotations and this is indeed the case. A surprising result arises when oblique bi-factor rotation methods are applied to ideal data.

A Brief History of the Philosophical Foundations of Exploratory Factor Analysis.

ERIC Educational Resources Information Center

Mulaik, Stanley A.

1987-01-01

Exploratory factor analysis derives its key ideas from many sources, including Aristotle, Francis Bacon, Descartes, Pearson and Yule, and Kant. The conclusions of exploratory factor analysis are never complete without subsequent confirmatory factor analysis. (Author/GDC)

Exploratory Bi-Factor Analysis: The Oblique Case

ERIC Educational Resources Information Center

Jennrich, Robert I.; Bentler, Peter M.

2012-01-01

Bi-factor analysis is a form of confirmatory factor analysis originally introduced by Holzinger and Swineford ("Psychometrika" 47:41-54, 1937). The bi-factor model has a general factor, a number of group factors, and an explicit bi-factor structure. Jennrich and Bentler ("Psychometrika" 76:537-549, 2011) introduced an exploratory form of bi-factor…

Extension Procedures for Confirmatory Factor Analysis

ERIC Educational Resources Information Center

Nagy, Gabriel; Brunner, Martin; Lüdtke, Oliver; Greiff, Samuel

2017-01-01

We present factor extension procedures for confirmatory factor analysis that provide estimates of the relations of common and unique factors with external variables that do not undergo factor analysis. We present identification strategies that build upon restrictions of the pattern of correlations between unique factors and external variables. The…

Old and New Ideas for Data Screening and Assumption Testing for Exploratory and Confirmatory Factor Analysis

PubMed Central

Flora, David B.; LaBrish, Cathy; Chalmers, R. Philip

2011-01-01

We provide a basic review of the data screening and assumption testing issues relevant to exploratory and confirmatory factor analysis along with practical advice for conducting analyses that are sensitive to these concerns. Historically, factor analysis was developed for explaining the relationships among many continuous test scores, which led to the expression of the common factor model as a multivariate linear regression model with observed, continuous variables serving as dependent variables, and unobserved factors as the independent, explanatory variables. Thus, we begin our paper with a review of the assumptions for the common factor model and data screening issues as they pertain to the factor analysis of continuous observed variables. In particular, we describe how principles from regression diagnostics also apply to factor analysis. Next, because modern applications of factor analysis frequently involve the analysis of the individual items from a single test or questionnaire, an important focus of this paper is the factor analysis of items. Although the traditional linear factor model is well-suited to the analysis of continuously distributed variables, commonly used item types, including Likert-type items, almost always produce dichotomous or ordered categorical variables. We describe how relationships among such items are often not well described by product-moment correlations, which has clear ramifications for the traditional linear factor analysis. An alternative, non-linear factor analysis using polychoric correlations has become more readily available to applied researchers and thus more popular. Consequently, we also review the assumptions and data-screening issues involved in this method. Throughout the paper, we demonstrate these procedures using an historic data set of nine cognitive ability variables. PMID:22403561

Factor Structure of the Social Appearance Anxiety Scale in Turkish Early Adolescents

ERIC Educational Resources Information Center

Sahin, Ertugrul; Topkaya, Nursel

2015-01-01

Although the Social Appearance Anxiety Scale (SAAS) is most often validated with the use of confirmatory factor analysis (CFA) on undergraduate students, exploratory factor analysis and multiple factor retention decision criteria necessitate the analysis of underlying factor structure to prevent over and under factoring as well as to reveal…

Factor Analysis via Components Analysis

ERIC Educational Resources Information Center

Bentler, Peter M.; de Leeuw, Jan

2011-01-01

When the factor analysis model holds, component loadings are linear combinations of factor loadings, and vice versa. This interrelation permits us to define new optimization criteria and estimation methods for exploratory factor analysis. Although this article is primarily conceptual in nature, an illustrative example and a small simulation show…

Mixture Factor Analysis for Approximating a Nonnormally Distributed Continuous Latent Factor with Continuous and Dichotomous Observed Variables

ERIC Educational Resources Information Center

Wall, Melanie M.; Guo, Jia; Amemiya, Yasuo

2012-01-01

Mixture factor analysis is examined as a means of flexibly estimating nonnormally distributed continuous latent factors in the presence of both continuous and dichotomous observed variables. A simulation study compares mixture factor analysis with normal maximum likelihood (ML) latent factor modeling. Different results emerge for continuous versus…

Estimating preferences for treatments in patients with localized prostate cancer.

PubMed

Ávila, Mónica; Becerra, Virginia; Guedea, Ferran; Suárez, José Francisco; Fernandez, Pablo; Macías, Víctor; Mariño, Alfonso; Hervás, Asunción; Herruzo, Ismael; Ortiz, María José; Ponce de León, Javier; Sancho, Gemma; Cunillera, Oriol; Pardo, Yolanda; Cots, Francesc; Ferrer, Montse

2015-02-01

Studies of patients' preferences for localized prostate cancer treatments have assessed radical prostatectomy and external radiation therapy, but none of them has evaluated brachytherapy. The aim of our study was to assess the preferences and willingness to pay of patients with localized prostate cancer who had been treated with radical prostatectomy, external radiation therapy, or brachytherapy, and their related urinary, sexual, and bowel side effects. This was an observational, prospective cohort study with follow-up until 5 years after treatment. A total of 704 patients with low or intermediate risk localized prostate cancer were consecutively recruited from 2003 to 2005. The estimation of preferences was conducted using time trade-off, standard gamble, and willingness-to-pay methods. Side effects were measured with the Expanded Prostate Index Composite (EPIC), a prostate cancer-specific questionnaire. Tobit models were constructed to assess the impact of treatment and side effects on patients' preferences. Propensity score was applied to adjust for treatment selection bias. Of the 580 patients reporting preferences, 165 were treated with radical prostatectomy, 152 with external radiation therapy, and 263 with brachytherapy. Both time trade-off and standard gamble results indicated that the preferences of patients treated with brachytherapy were 0.06 utilities higher than those treated with radical prostatectomy (P=.01). Similarly, willingness-to-pay responses showed a difference of €57/month (P=.004) between these 2 treatments. Severe urinary incontinence presented an independent impact on the preferences elicited (P<.05), whereas no significant differences were found by bowel and sexual side effects. Our findings indicate that urinary incontinence is the side effect with the highest impact on preferences and that brachytherapy and external radiation therapy are more valued than radical prostatectomy. These time trade-off and standard gamble preference assessments as well as the willingness-to-pay estimation could be useful to perform respectively cost-utility or cost-benefit analyses, which can guide health policy decisions. Copyright © 2015 Elsevier Inc. All rights reserved.

Estimating Preferences for Treatments in Patients With Localized Prostate Cancer

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

Ávila, Mónica; CIBER en Epidemiología y Salud Pública; Universitat Pompeu Fabra, Barcelona

Purpose: Studies of patients' preferences for localized prostate cancer treatments have assessed radical prostatectomy and external radiation therapy, but none of them has evaluated brachytherapy. The aim of our study was to assess the preferences and willingness to pay of patients with localized prostate cancer who had been treated with radical prostatectomy, external radiation therapy, or brachytherapy, and their related urinary, sexual, and bowel side effects. Methods and Materials: This was an observational, prospective cohort study with follow-up until 5 years after treatment. A total of 704 patients with low or intermediate risk localized prostate cancer were consecutively recruited from 2003more » to 2005. The estimation of preferences was conducted using time trade-off, standard gamble, and willingness-to-pay methods. Side effects were measured with the Expanded Prostate Index Composite (EPIC), a prostate cancer-specific questionnaire. Tobit models were constructed to assess the impact of treatment and side effects on patients' preferences. Propensity score was applied to adjust for treatment selection bias. Results: Of the 580 patients reporting preferences, 165 were treated with radical prostatectomy, 152 with external radiation therapy, and 263 with brachytherapy. Both time trade-off and standard gamble results indicated that the preferences of patients treated with brachytherapy were 0.06 utilities higher than those treated with radical prostatectomy (P=.01). Similarly, willingness-to-pay responses showed a difference of €57/month (P=.004) between these 2 treatments. Severe urinary incontinence presented an independent impact on the preferences elicited (P<.05), whereas no significant differences were found by bowel and sexual side effects. Conclusions: Our findings indicate that urinary incontinence is the side effect with the highest impact on preferences and that brachytherapy and external radiation therapy are more valued than radical prostatectomy. These time trade-off and standard gamble preference assessments as well as the willingness-to-pay estimation could be useful to perform respectively cost-utility or cost-benefit analyses, which can guide health policy decisions.« less

Formaldehyde exposure in U.S. industries from OSHA air sampling data.

PubMed

Lavoue, Jerome; Vincent, Raymond; Gerin, Michel

2008-09-01

National occupational exposure databanks have been cited as sources of exposure data for exposure surveillance and exposure assessment for occupational epidemiology. Formaldehyde exposure data recorded in the U.S Integrated Management Information System (IMIS) between 1979 and 2001 were collected to elaborate a multi-industry retrospective picture of formaldehyde exposures and to identify exposure determinants. Due to the database design, only detected personal measurement results (n = 5228) were analyzed with linear mixed-effect models, which explained 29% of the total variance. Short-term measurement results were higher than time-weighted average (TWA) data and decreased 18% per year until 1987 (TWA data 5% per year) and 5% per year (TWA data 4% per year) after that. Exposure varied across industries with maximal estimated TWA geometric means (GM) for 2001 in the reconstituted wood products, structural wood members, and wood dimension and flooring industries (GM = 0.20 mg/m(3). Highest short-term GMs estimated for 2001 were in the funeral service and crematory and reconstituted wood products industries (GM = 0.35 mg/m(3). Exposure levels in IMIS were marginally higher during nonprogrammed inspections compared with programmed inspections. An increasing exterior temperature tended to cause a decrease in exposure levels for cold temperatures (-5% per 5 degrees C for T < 15 degrees C) but caused an increase in exposure levels for warm temperatures (+15% per 5 degrees C for T >15 degrees C). Concentrations measured during the same inspection were correlated and varied differently across industries and sample type (TWA, short term). Sensitivity analyses using TOBIT regression suggested that the average bias caused by excluding non-detects is approximately 30%, being potentially higher for short-term data if many non-detects were actually short-term measurements. Although limited by availability of relevant exposure determinants and potential selection biases in IMIS, these results provide useful insight on formaldehyde occupational exposure in the United States in the last two decades. The authors recommend that more information on exposure determinants be recorded in IMIS.

Health-related quality of life inequalities by sexual orientation: Results from the Barcelona Health Interview Survey.

PubMed

Marti-Pastor, Marc; Perez, Gloria; German, Danielle; Pont, Angels; Garin, Olatz; Alonso, Jordi; Gotsens, Mercè; Ferrer, Montse

2018-01-01

Studies on health-related quality of life (HRQoL) inequalities according to sexual orientation are scarce. The aim of this study was to assess HRQoL inequalities between lesbian, gay, and bisexual (LGB) people and heterosexuals in the 2011 Barcelona population, to describe the extent to which sociodemographic characteristics, health-related behaviors, and chronic conditions could explain such inequalities, and to understand if they are sexual orientation inequities. In the 2011 Barcelona Health Interview Survey 3277 adults answered the EQ-5D, which measures five dimensions of HRQoL summarized into a single utility index (1 = perfect health, 0 = death). To assess HRQoL differences by sexual orientation we constructed Tobit models for the EQ-5D index, and Poisson regression models for the EQ-5D dimensions. In both cases, nested models were constructed to assess the mediator role of selected variables. After adjusting by socio-demographic variables, the LGB group presented a significantly lower EQ-5D index than heterosexuals, and higher prevalence ratios of problems in physical EQ-5D dimensions among both genders: adjusted prevalence ratio (aPR) = 1.70 for mobility (p = 0.046) and 2.11 for usual activities (p = 0.019). Differences in mental dimensions were only observed among men: aPR = 3.15 for pain/discomfort (p = 0.003) and 2.49 for anxiety/depression (p = 0.030). All these differences by sexual orientation disappeared after adding chronic conditions and health-related behaviors in the models. The LGB population presented worse HRQoL than heterosexuals in the EQ-5D index and most dimensions. Chronic conditions, health-related behaviors and gender play a major role in explaining HRQoL differences by sexual orientation. These findings support the need of including sexual orientation into the global agenda of health inequities.

An evaluation of early countermeasures to reduce the risk of internal radiation exposure after the Fukushima nuclear incident in Japan.

PubMed

Nomura, Shuhei; Tsubokura, Masaharu; Gilmour, Stuart; Hayano, Ryugo S; Watanabe, Yuni N; Kami, Masahiro; Kanazawa, Yukio; Oikawa, Tomoyoshi

2016-05-01

After a radiation-release incident, intake of radionuclides in the initial stage immediately following the incident may be the major contributor to total internal radiation exposure for individuals in affected areas. However, evaluation of early internal contamination risk is greatly lacking. This study assessed the relationship between initial stage evacuation/indoor sheltering and internal radiation contamination levels 4 months after the 2011 Fukushima nuclear incident in Japan and estimated potential pathways of the contamination. The study population comprised 525 participants in the internal radiation screening program at Minamisoma Municipal General Hospital, 23 km north of the Fukushima nuclear plant. The analysed dataset included the results of a screening performed in July 2011, 4 months after the incident, and of a questionnaire on early-incident response behaviours, such as sheltering indoors and evacuations, completed by participants. Association between such early countermeasures and internal contamination levels of cesium-134 were assessed using Tobit multiple regression analyses. Our study shows that individuals who evacuated to areas outside Fukushima Prefecture had similar contamination levels of cesium-134 to individuals who stayed in Fukushima (relative risk: 0.86; 95% confidence interval: 0.74-0.99). Time spent outdoors had no significant relationship with contamination levels. The effects of inhalation from radiological plumes released from the nuclear plant on total internal radiation contamination might be so low as to be undetectable by the whole-body counting unit used to examine participants. Given the apparent limited effectiveness of evacuation and indoor sheltering on internal contamination, the decision to implement such early responses to a radiation-release incident should be made by carefully balancing their potential benefits and health risks. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Personal Care Product Use in Men and Urinary Concentrations of Select Phthalate Metabolites and Parabens: Results from the Environment And Reproductive Health (EARTH) Study

PubMed Central

Coull, Brent A.; Gaskins, Audrey J.; Williams, Michelle A.; Skakkebaek, Niels E.; Ford, Jennifer B.; Ye, Xiaoyun; Calafat, Antonia M.; Braun, Joseph M.; Hauser, Russ

2017-01-01

Background: Personal care products (PCPs) are exposure sources to phthalates and parabens; however, their contribution to men’s exposure is understudied. Objectives: We examined the association between PCP use and urinary concentrations of phthalate metabolites and parabens in men. Methods: In a prospective cohort, at multiple study visits, men self-reported their use of 14 PCPs and provided a urine sample (2004–2015, Boston, MA). We measured urinary concentrations of 9 phthalate metabolites and methylparaben, propylparaben, and butylparaben. We estimated the covariate-adjusted percent change in urinary concentrations associated with PCP use using linear mixed and Tobit mixed regressions. We also estimated weights for each PCP in a weighted binary score regression and modeled the resulting composite weighted PCP use. Results: Four hundred men contributed 1,037 urine samples (mean of 3/man). The largest percent increase in monoethyl phthalate (MEP) was associated with use of cologne/perfume (83%, p-value<0.01) and deodorant (74%, p-value<0.01). In contrast, the largest percent increase for parabens was associated with the use of suntan/sunblock lotion (66–156%) and hand/body lotion (79–147%). Increases in MEP and parabens were generally greater with PCP use within 6 h of urine collection. A subset of 10 PCPs that were used within 6 h of urine collection contributed to at least 70% of the weighted score and predicted a 254–1,333% increase in MEP and parabens concentrations. Associations between PCP use and concentrations of the other phthalate metabolites were not statistically significant. Conclusions: We identified 10 PCPs of relevance and demonstrated that their use within 6 h of urine collection strongly predicted MEP and paraben urinary concentrations. https://doi.org/10.1289/EHP1374 PMID:28886595

Exposure to select phthalates and phenols through use of personal care products among Californian adults and their children.

PubMed

Philippat, Claire; Bennett, Deborah; Calafat, Antonia M; Picciotto, Irva Hertz

2015-07-01

Certain phenols and phthalates are used in many consumer products including personal care products (PCPs). We aimed to study the associations between the use of PCPs and urinary concentrations of biomarkers of select phenols and phthalates among Californian adults and their children. As an additional aim we compared phenols and phthalate metabolites concentrations measured in adults and children urine samples collected the same day. Our study relied on a subsample of 90 adult-child pairs participating in the Study of Use of Products and Exposure Related Behavior (SUPERB). Each adult and child provided one to two urine samples in which we measured concentrations of selected phenols and phthalate metabolites. We computed Spearman correlation coefficients to compare concentrations measured in adults and children urine samples collected the same day. We used adjusted linear and Tobit regression models to study the associations between the use of PCPs in the past 24h and biomarker concentrations. Benzophenone-3 and parabens concentrations were higher in adults compared to their children. Conversely children had higher mono-n-butyl phthalate and mono-isobutyl phthalate concentrations. No significant difference was observed for the other compounds. The total number of different PCPs used was positively associated with urinary concentrations of methyl, propyl and butyl parabens and the main metabolite of diethyl phthalate in adults. Among children, the use of a few specific products including liquid soap, hair care products and sunscreen was positively associated with urinary concentrations of some phenols or phthalate metabolites. These results strengthen the body of evidence suggesting that use of PCPs is an important source of exposure to parabens and diethyl phthalate in adults and provide data on exposure to selected phenols and phthalates through use of PCPs in children. Copyright © 2015 Elsevier Inc. All rights reserved.

Exposure to select phthalates and phenols through use of personal care products among Californian adults and their children

PubMed Central

Philippat, Claire; Bennett, Deborah; Calafat, Antonia M.; Picciotto, Irva Hertz

2016-01-01

Introduction Certain phenols and phthalates are used in many consumer products including personal care products (PCPs). Aims We aimed to study the associations between the use of PCPs and urinary concentrations of bio-markers of select phenols and phthalates among Californian adults and their children. As an additional aim we compared phenols and phthalate metabolites concentrations measured in adults and children urine samples collected the same day. Methods Our study relied on a subsample of 90 adult–child pairs participating in the Study of Use of Products and Exposure Related Behavior (SUPERB). Each adult and child provided one to two urine samples in which we measured concentrations of selected phenols and phthalate metabolites. We computed Spearman correlation coefficients to compare concentrations measured in adults and children urine samples collected the same day. We used adjusted linear and Tobit regression models to study the associations between the use of PCPs in the past 24 h and biomarker concentrations. Results Benzophenone-3 and parabens concentrations were higher in adults compared to their children. Conversely children had higher mono-n-butyl phthalate and mono-isobutyl phthalate concentrations. No significant difference was observed for the other compounds. The total number of different PCPs used was positively associated with urinary concentrations of methyl, propyl and butyl parabens and the main metabolite of diethyl phthalate in adults. Among children, the use of a few specific products including liquid soap, hair care products and sunscreen was positively associated with urinary concentrations of some phenols or phthalate metabolites. Discussion These results strengthen the body of evidence suggesting that use of PCPs is an important source of exposure to parabens and diethyl phthalate in adults and provide data on exposure to selected phenols and phthalates through use of PCPs in children. PMID:25929801

SMA-MAP: a plasma protein panel for spinal muscular atrophy.

PubMed

Kobayashi, Dione T; Shi, Jing; Stephen, Laurie; Ballard, Karri L; Dewey, Ruth; Mapes, James; Chung, Brett; McCarthy, Kathleen; Swoboda, Kathryn J; Crawford, Thomas O; Li, Rebecca; Plasterer, Thomas; Joyce, Cynthia; Chung, Wendy K; Kaufmann, Petra; Darras, Basil T; Finkel, Richard S; Sproule, Douglas M; Martens, William B; McDermott, Michael P; De Vivo, Darryl C; Walker, Michael G; Chen, Karen S

2013-01-01

Spinal Muscular Atrophy (SMA) presents challenges in (i) monitoring disease activity and predicting progression, (ii) designing trials that allow rapid assessment of candidate therapies, and (iii) understanding molecular causes and consequences of the disease. Validated biomarkers of SMA motor and non-motor function would offer utility in addressing these challenges. Our objectives were (i) to discover additional markers from the Biomarkers for SMA (BforSMA) study using an immunoassay platform, and (ii) to validate the putative biomarkers in an independent cohort of SMA patients collected from a multi-site natural history study (NHS). BforSMA study plasma samples (N = 129) were analyzed by immunoassay to identify new analytes correlating to SMA motor function. These immunoassays included the strongest candidate biomarkers identified previously by chromatography. We selected 35 biomarkers to validate in an independent cohort SMA type 1, 2, and 3 samples (N = 158) from an SMA NHS. The putative biomarkers were tested for association to multiple motor scales and to pulmonary function, neurophysiology, strength, and quality of life measures. We implemented a Tobit model to predict SMA motor function scores. 12 of the 35 putative SMA biomarkers were significantly associated (p<0.05) with motor function, with a 13(th) analyte being nearly significant. Several other analytes associated with non-motor SMA outcome measures. From these 35 biomarkers, 27 analytes were selected for inclusion in a commercial panel (SMA-MAP) for association with motor and other functional measures. Discovery and validation using independent cohorts yielded a set of SMA biomarkers significantly associated with motor function and other measures of SMA disease activity. A commercial SMA-MAP biomarker panel was generated for further testing in other SMA collections and interventional trials. Future work includes evaluating the panel in other neuromuscular diseases, for pharmacodynamic responsiveness to experimental SMA therapies, and for predicting functional changes over time in SMA patients.

Factor Analysis of Drawings: Application to College Student Models of the Greenhouse Effect

ERIC Educational Resources Information Center

Libarkin, Julie C.; Thomas, Stephen R.; Ording, Gabriel

2015-01-01

Exploratory factor analysis was used to identify models underlying drawings of the greenhouse effect made by over 200 entering university freshmen. Initial content analysis allowed deconstruction of drawings into salient features, with grouping of these features via factor analysis. A resulting 4-factor solution explains 62% of the data variance,…

Exploratory factor analysis of the 12-item Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being Scale in people newly diagnosed with advanced cancer.

PubMed

Bai, Mei; Dixon, Jane K

2014-01-01

The purpose of this study was to reexamine the factor pattern of the 12-item Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being Scale (FACIT-Sp-12) using exploratory factor analysis in people newly diagnosed with advanced cancer. Principal components analysis (PCA) and 3 common factor analysis methods were used to explore the factor pattern of the FACIT-Sp-12. Factorial validity was assessed in association with quality of life (QOL). Principal factor analysis (PFA), iterative PFA, and maximum likelihood suggested retrieving 3 factors: Peace, Meaning, and Faith. Both Peace and Meaning positively related to QOL, whereas only Peace uniquely contributed to QOL. This study supported the 3-factor model of the FACIT-Sp-12. Suggestions for revision of items and further validation of the identified factor pattern were provided.

Community factors to promote parents' quality of child-nurturing life.

PubMed

Aoyama, Megumi; Wei, Chang Nian; Chang-nian, Wei; Harada, Koichi; Ueda, Kimiyo; Takano, Miyuki; Ueda, Atsushi

2013-01-01

The purpose of this study was to clarify the role of community factors in parents' quality of child-nurturing life (QCNL). We developed a questionnaire to evaluate the degree of QCNL and determine the structural factors related to QCNL as community factors related to parents' QCNL derived from focus group interviews and the Delphi technique. The questionnaire also included the battery of the self-rating depression scale and Tsumori-Inage Infant's Developmental Test. Using the questionnaire, we then conducted a quantitative survey of parents whose children attended nursery schools in Kumamoto Prefecture. Factor analysis, calculation of the mean score and/or ratio to each item, Pearson's correlation coefficient, t test, multiple regression analysis, and covariance structure analysis were performed. The questionnaire we developed consisted of seven items with 75 elements, involving ten elements as community factors. Subjects included 699 parents (mean age 33.6 ± 5.4 years) and 965 children (age range 0-6 years). Factor analysis revealed that community factors consisted of five factors, such as "lifestyle rooted in the ground," "balance of housekeeping and work," "community network," "amenity," and "regeneration of life". These factors may be dominant in a rural area. Finally, we developed a structural model with "community factors," QCNL, QOL, and "child growth" by covariance structural analysis. The analysis revealed that community factors had a positive relation to parents' QCNL (r = 0.81, p < 0.001) and that parental SDS score had a negative relation to parents' QCNL (r = -0.59, p < 0.001). The analysis did show that community factors were positively related to the sound growth of children. The covariance structure analysis revealed that community factors were associated with parents' QCNL, SDS, and "child growth."

Analysis of Performance Factors for Accounting and Finance Related Business Courses in a Distance Education Environment

ERIC Educational Resources Information Center

Benligiray, Serdar; Onay, Ahmet

2017-01-01

The objective of this study is to explore business courses performance factors with a focus on accounting and finance. Course score interrelations are assumed to represent interpretable constructs of these factors. Factor analysis is proposed to identify the constructs that explain the correlations. Factor analysis results identify three…

The Infinitesimal Jackknife with Exploratory Factor Analysis

ERIC Educational Resources Information Center

Zhang, Guangjian; Preacher, Kristopher J.; Jennrich, Robert I.

2012-01-01

The infinitesimal jackknife, a nonparametric method for estimating standard errors, has been used to obtain standard error estimates in covariance structure analysis. In this article, we adapt it for obtaining standard errors for rotated factor loadings and factor correlations in exploratory factor analysis with sample correlation matrices. Both…

A Mapping from the Human Factors Analysis and Classification System (DOD-HFACS) to the Domains of Human Systems Integration (HSI)

DTIC Science & Technology

2009-11-01

Equation Chapter 1 Section 1 A MAPPING FROM THE HUMAN FACTORS ANALYSIS AND CLASSIFICATION SYSTEM (DOD...OMB control number. 1. REPORT DATE NOV 2009 2. REPORT TYPE 3. DATES COVERED 4. TITLE AND SUBTITLE A Mapping from the Human Factors Analysis ...7 The Human Factors Analysis and Classification System .................................................. 7 Mapping of DoD

A new technique for ordering asymmetrical three-dimensional data sets in ecology.

PubMed

Pavoine, Sandrine; Blondel, Jacques; Baguette, Michel; Chessel, Daniel

2007-02-01

The aim of this paper is to tackle the problem that arises from asymmetrical data cubes formed by two crossed factors fixed by the experimenter (factor A and factor B, e.g., sites and dates) and a factor which is not controlled for (the species). The entries of this cube are densities in species. We approach this kind of data by the comparison of patterns, that is to say by analyzing first the effect of factor B on the species-factor A pattern, and second the effect of factor A on the species-factor B pattern. The analysis of patterns instead of individual responses requires a correspondence analysis. We use a method we call Foucart's correspondence analysis to coordinate the correspondence analyses of several independent matrices of species x factor A (respectively B) type, corresponding to each modality of factor B (respectively A). Such coordination makes it possible to evaluate the effect of factor B (respectively A) on the species-factor A (respectively B) pattern. The results obtained by such a procedure are much more insightful than those resulting from a classical single correspondence analysis applied to the global matrix that is obtained by simply unrolling the data cube, juxtaposing for example the individual species x factor A matrices through modalities of factor B. This is because a single global correspondence analysis combines three effects of factors in a way that cannot be determined from factorial maps (factor A, factor B, and factor A x factor B interaction) whereas the applications of Foucart's correspondence analysis clearly discriminate two different issues. Using two data sets, we illustrate that this technique proves to be particularly powerful in the analyses of ecological convergence which include several distinct data sets and in the analyses of spatiotemporal variations of species distributions.

Inventory of File nam.t00z.awiphi00.tm00.grib2

Science.gov Websites

Factor [non-dim] 041 50 mb HGT analysis Geopotential Height [gpm] 042 50 mb TMP analysis Temperature [K /kg] 052 50 mb RIME analysis Rime Factor [non-dim] 053 75 mb HGT analysis Geopotential Height [gpm SNMR analysis Snow Mixing Ratio [kg/kg] 064 75 mb RIME analysis Rime Factor [non-dim] 065 100 mb HGT

Using BMDP and SPSS for a Q factor analysis.

PubMed

Tanner, B A; Koning, S M

1980-12-01

While Euclidean distances and Q factor analysis may sometimes be preferred to correlation coefficients and cluster analysis for developing a typology, commercially available software does not always facilitate their use. Commands are provided for using BMDP and SPSS in a Q factor analysis with Euclidean distances.

Text mining factor analysis (TFA) in green tea patent data

NASA Astrophysics Data System (ADS)

Rahmawati, Sela; Suprijadi, Jadi; Zulhanif

2017-03-01

Factor analysis has become one of the most widely used multivariate statistical procedures in applied research endeavors across a multitude of domains. There are two main types of analyses based on factor analysis: Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA). Both EFA and CFA aim to observed relationships among a group of indicators with a latent variable, but they differ fundamentally, a priori and restrictions made to the factor model. This method will be applied to patent data technology sector green tea to determine the development technology of green tea in the world. Patent analysis is useful in identifying the future technological trends in a specific field of technology. Database patent are obtained from agency European Patent Organization (EPO). In this paper, CFA model will be applied to the nominal data, which obtain from the presence absence matrix. While doing processing, analysis CFA for nominal data analysis was based on Tetrachoric matrix. Meanwhile, EFA model will be applied on a title from sector technology dominant. Title will be pre-processing first using text mining analysis.

Psychometric properties of Connor-Davidson Resilience Scale in a Spanish sample of entrepreneurs.

PubMed

Manzano-García, Guadalupe; Ayala Calvo, Juan Carlos

2013-01-01

The literature regarding entrepreneurship suggests that the resilience of entrepreneurs may help to explain entrepreneurial success, but there is no resilience measure widely accepted by researchers. This study analyzes the psychometric properties of the Connor and Davidson Resilience Scale (CD-RISC) in a sample of Spanish entrepreneurs. A telephone survey research method was used. The participants were entrepreneurs operating in the business services sector. Interviewers telephoned a total of 900 entrepreneurs of whom 783 produced usable questionnaires. The CD-RISC was used as data collection instrument. We used principal component analysis factor and confirmatory factor analysis to determine the factor structure of the CD-RISC. Confirmatory factor analysis failed to verify the original five-factor structure of the CD-RISC, whereas principal component analysis factor yielded a 3-factor structure of resilience (hardiness, resourcefulness and optimism). In this research, 47.48% of the total variance was accounted for by three factors, and the obtained factor structure was verified through confirmatory factor analysis. The CD-RISC has been shown to be a reliable and valid tool for measuring entrepreneurs' resilience.

Bootstrap Standard Error Estimates in Dynamic Factor Analysis

ERIC Educational Resources Information Center

Zhang, Guangjian; Browne, Michael W.

2010-01-01

Dynamic factor analysis summarizes changes in scores on a battery of manifest variables over repeated measurements in terms of a time series in a substantially smaller number of latent factors. Algebraic formulae for standard errors of parameter estimates are more difficult to obtain than in the usual intersubject factor analysis because of the…

Factor Analysis of the Aberrant Behavior Checklist in Individuals with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Brinkley, Jason; Nations, Laura; Abramson, Ruth K.; Hall, Alicia; Wright, Harry H.; Gabriels, Robin; Gilbert, John R.; Pericak-Vance, Margaret A. O.; Cuccaro, Michael L.

2007-01-01

Exploratory factor analysis (varimax and promax rotations) of the aberrant behavior checklist-community version (ABC) in 275 individuals with Autism spectrum disorder (ASD) identified four- and five-factor solutions which accounted for greater than 70% of the variance. Confirmatory factor analysis (Lisrel 8.7) revealed indices of moderate fit for…

How Factor Analysis Can Be Used in Classification.

ERIC Educational Resources Information Center

Harman, Harry H.

This is a methodological study that suggests a taxometric technique for objective classification of yeasts. It makes use of the minres method of factor analysis and groups strains of yeast according to their factor profiles. The similarities are judged in the higher-dimensional space determined by the factor analysis, but otherwise rely on the…

A Factor Analysis of Learning Data and Selected Ability Test Scores

ERIC Educational Resources Information Center

Jones, Dorothy L.

1976-01-01

A verbal concept-learning task permitting the externalizing and quantifying of learning behavior and 16 ability tests were administered to female graduate students. Data were analyzed by alpha factor analysis and incomplete image analysis. Six alpha factors and 12 image factors were extracted and orthogonally rotated. Four areas of cognitive…

Emotional Intelligence and Nurse Recruitment: Rasch and confirmatory factor analysis of the trait emotional intelligence questionnaire short form.

PubMed

Snowden, Austyn; Watson, Roger; Stenhouse, Rosie; Hale, Claire

2015-12-01

To examine the construct validity of the Trait Emotional Intelligence Questionnaire Short form. Emotional intelligence involves the identification and regulation of our own emotions and the emotions of others. It is therefore a potentially useful construct in the investigation of recruitment and retention in nursing and many questionnaires have been constructed to measure it. Secondary analysis of existing dataset of responses to Trait Emotional Intelligence Questionnaire Short form using concurrent application of Rasch analysis and confirmatory factor analysis. First year undergraduate nursing and computing students completed Trait Emotional Intelligence Questionnaire-Short Form in September 2013. Responses were analysed by synthesising results of Rasch analysis and confirmatory factor analysis. Participants (N = 938) completed Trait Emotional Intelligence Questionnaire Short form. Rasch analysis showed the majority of the Trait Emotional Intelligence Questionnaire-Short Form items made a unique contribution to the latent trait of emotional intelligence. Five items did not fit the model and differential item functioning (gender) accounted for this misfit. Confirmatory factor analysis revealed a four-factor structure consisting of: self-confidence, empathy, uncertainty and social connection. All five misfitting items from the Rasch analysis belonged to the 'social connection' factor. The concurrent use of Rasch and factor analysis allowed for novel interpretation of Trait Emotional Intelligence Questionnaire Short form. Much of the response variation in Trait Emotional Intelligence Questionnaire Short form can be accounted for by the social connection factor. Implications for practice are discussed. © 2015 John Wiley & Sons Ltd.

The Relation between Factor Score Estimates, Image Scores, and Principal Component Scores

ERIC Educational Resources Information Center

Velicer, Wayne F.

1976-01-01

Investigates the relation between factor score estimates, principal component scores, and image scores. The three methods compared are maximum likelihood factor analysis, principal component analysis, and a variant of rescaled image analysis. (RC)

Exploring the Factor Structure of Neurocognitive Measures in Older Individuals

PubMed Central

Santos, Nadine Correia; Costa, Patrício Soares; Amorim, Liliana; Moreira, Pedro Silva; Cunha, Pedro; Cotter, Jorge; Sousa, Nuno

2015-01-01

Here we focus on factor analysis from a best practices point of view, by investigating the factor structure of neuropsychological tests and using the results obtained to illustrate on choosing a reasonable solution. The sample (n=1051 individuals) was randomly divided into two groups: one for exploratory factor analysis (EFA) and principal component analysis (PCA), to investigate the number of factors underlying the neurocognitive variables; the second to test the “best fit” model via confirmatory factor analysis (CFA). For the exploratory step, three extraction (maximum likelihood, principal axis factoring and principal components) and two rotation (orthogonal and oblique) methods were used. The analysis methodology allowed exploring how different cognitive/psychological tests correlated/discriminated between dimensions, indicating that to capture latent structures in similar sample sizes and measures, with approximately normal data distribution, reflective models with oblimin rotation might prove the most adequate. PMID:25880732

Application of multivariate statistical techniques for differentiation of ripe banana flour based on the composition of elements.

PubMed

Alkarkhi, Abbas F M; Ramli, Saifullah Bin; Easa, Azhar Mat

2009-01-01

Major (sodium, potassium, calcium, magnesium) and minor elements (iron, copper, zinc, manganese) and one heavy metal (lead) of Cavendish banana flour and Dream banana flour were determined, and data were analyzed using multivariate statistical techniques of factor analysis and discriminant analysis. Factor analysis yielded four factors explaining more than 81% of the total variance: the first factor explained 28.73%, comprising magnesium, sodium, and iron; the second factor explained 21.47%, comprising only manganese and copper; the third factor explained 15.66%, comprising zinc and lead; while the fourth factor explained 15.50%, comprising potassium. Discriminant analysis showed that magnesium and sodium exhibited a strong contribution in discriminating the two types of banana flour, affording 100% correct assignation. This study presents the usefulness of multivariate statistical techniques for analysis and interpretation of complex mineral content data from banana flour of different varieties.

Biomotor structures in elite female handball players according to performance.

PubMed

Cavala, Marijana; Rogulj, Nenad; Srhoj, Vatromir; Srhoj, Ljerka; Katić, Ratko

2008-03-01

In order to identify biomotor structures in elite female handball players, factor structures of morphological characteristics and basic motor abilities, and of variables evaluating situation motor abilities of elite female handball players (n = 53) were determined first, followed by determination of differences and relations of the morphological, motor and specific motor space according to handball performance. Factor analysis of 16 morphological measures produced three morphological factors, i.e. factor of absolute voluminosity, i.e. mesoendomorphy, factor of longitudinal skeleton dimensionality, and factor of transverse hand dimensionality. Factor analysis of 15 motor variables yielded five basic motor dimensions, i.e. factor of agility, factor of throwing explosive strength, factor of running explosive strength (sprint), factor of jumping explosive strength and factor of movement frequency rate. Factor analysis of 5 situation motor variables produced two dimensions: factor of specific agility with explosiveness and factor of specific precision with ball manipulation. Analysis of variance yielded greatest differences relative to handball performance in the factor of specific agility and throwing strength, and the factor of basic motoricity that integrates the ability of coordination (agility) with upper extremity throwing explosiveness and lower extremity sprint (30-m sprint) and jumping (standing triple jump). Considering morphological factors, the factor of voluminosity, i.e. mesoendomorphy, which is defined by muscle mass rather than adipose tissue, was found to contribute significantly to the players'performance. Results of regression analysis indicated the handball performance to be predominantly determined by the general specific motor factor based on specific agility and explosiveness, and by the morphological factor based on body mass and volume, i.e. muscle mass. Concerning basic motor abilities, the factor of movement frequency rate, which is associated with the ability of ball manipulation, was observed to predict significantly the handball players' performance.

Bayesian Factor Analysis When Only a Sample Covariance Matrix Is Available

ERIC Educational Resources Information Center

Hayashi, Kentaro; Arav, Marina

2006-01-01

In traditional factor analysis, the variance-covariance matrix or the correlation matrix has often been a form of inputting data. In contrast, in Bayesian factor analysis, the entire data set is typically required to compute the posterior estimates, such as Bayes factor loadings and Bayes unique variances. We propose a simple method for computing…

Factor Retention in Exploratory Factor Analysis: A Comparison of Alternative Methods.

ERIC Educational Resources Information Center

Mumford, Karen R.; Ferron, John M.; Hines, Constance V.; Hogarty, Kristine Y.; Kromrey, Jeffery D.

This study compared the effectiveness of 10 methods of determining the number of factors to retain in exploratory common factor analysis. The 10 methods included the Kaiser rule and a modified Kaiser criterion, 3 variations of parallel analysis, 4 regression-based variations of the scree procedure, and the minimum average partial procedure. The…

What School Psychologists Need to Know about Factor Analysis

ERIC Educational Resources Information Center

McGill, Ryan J.; Dombrowski, Stefan C.

2017-01-01

Factor analysis is a versatile class of psychometric techniques used by researchers to provide insight into the psychological dimensions (factors) that may account for the relationships among variables in a given dataset. The primary goal of a factor analysis is to determine a more parsimonious set of variables (i.e., fewer than the number of…

Evaluation of Parallel Analysis Methods for Determining the Number of Factors

ERIC Educational Resources Information Center

Crawford, Aaron V.; Green, Samuel B.; Levy, Roy; Lo, Wen-Juo; Scott, Lietta; Svetina, Dubravka; Thompson, Marilyn S.

2010-01-01

Population and sample simulation approaches were used to compare the performance of parallel analysis using principal component analysis (PA-PCA) and parallel analysis using principal axis factoring (PA-PAF) to identify the number of underlying factors. Additionally, the accuracies of the mean eigenvalue and the 95th percentile eigenvalue criteria…

A Factor Analysis of Functional Independence and Functional Assessment Measure Scores Among Focal and Diffuse Brain Injury Patients: The Importance of Bifactor Models.

PubMed

Gunn, Sarah; Burgess, Gerald H; Maltby, John

2018-04-30

To explore the factor structure of the UK Functional Independence Measure and Functional Assessment Measure (FIM+FAM) among focal and diffuse acquired brain injury patients. Criterion standard. A National Health Service acute acquired brain injury inpatient rehabilitation hospital. Referred sample of N=447 adults admitted for inpatient treatment following an acquired brain injury significant enough to justify intensive inpatient neurorehabilitation INTERVENTION: Not applicable. Functional Independence Measure and Functional Assessment Measure. Exploratory factor analysis suggested a 2-factor structure to FIM+FAM scores, among both focal-proximate and diffuse-proximate acquired brain injury aetiologies. Confirmatory factor analysis suggested a 3-factor bifactor structure presented the best fit of the FIM+FAM score data across both aetiologies. However, across both analyses, a convergence was found towards a general factor, demonstrated by high correlations between factors in the exploratory factor analysis, and by a general factor explaining the majority of the variance in scores on confirmatory factor analysis. Our findings suggested that although factors describing specific functional domains can be derived from FIM+FAM item scores, there is a convergence towards a single factor describing overall functioning. This single factor informs the specific group factors (eg, motor, psychosocial, and communication function) after brain injury. Further research into the comparative value of the general and group factors as evaluative/prognostic measures is indicated. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Psychometric analysis of the Brisbane Practice Environment Measure (B-PEM).

PubMed

Flint, Anndrea; Farrugia, Charles; Courtney, Mary; Webster, Joan

2010-03-01

To undertake rigorous psychometric testing of the newly developed contemporary work environment measure (the Brisbane Practice Environment Measure [B-PEM]) using exploratory factor analysis and confirmatory factor analysis. Content validity of the 33-item measure was established by a panel of experts. Initial testing involved 195 nursing staff using principal component factor analysis with varimax rotation (orthogonal) and Cronbach's alpha coefficients. Confirmatory factor analysis was conducted using data from a further 983 nursing staff. Principal component factor analysis yielded a four-factor solution with eigenvalues greater than 1 that explained 52.53% of the variance. These factors were then verified using confirmatory factor analysis. Goodness-of-fit indices showed an acceptable fit overall with the full model, explaining 21% to 73% of the variance. Deletion of items took place throughout the evolution of the instrument, resulting in a 26-item, four-factor measure called the Brisbane Practice Environment Measure-Tested. The B-PEM has undergone rigorous psychometric testing, providing evidence of internal consistency and goodness-of-fit indices within acceptable ranges. The measure can be utilised as a subscale or total score reflective of a contemporary nursing work environment. An up-to-date instrument to measure practice environment may be useful for nursing leaders to monitor the workplace and to assist in identifying areas for improvement, facilitating greater job satisfaction and retention.

Likelihood-Based Confidence Intervals in Exploratory Factor Analysis

ERIC Educational Resources Information Center

Oort, Frans J.

2011-01-01

In exploratory or unrestricted factor analysis, all factor loadings are free to be estimated. In oblique solutions, the correlations between common factors are free to be estimated as well. The purpose of this article is to show how likelihood-based confidence intervals can be obtained for rotated factor loadings and factor correlations, by…

Comparisons of Exploratory and Confirmatory Factor Analysis.

ERIC Educational Resources Information Center

Daniel, Larry G.

Historically, most researchers conducting factor analysis have used exploratory methods. However, more recently, confirmatory factor analytic methods have been developed that can directly test theory either during factor rotation using "best fit" rotation methods or during factor extraction, as with the LISREL computer programs developed…

Strategic Analysis and Plan for Implementing Telemedicine at Fort Greely

DTIC Science & Technology

2003-03-01

Analysis The Situational Analysis tool assessed the environmental, market , and organizational factors involved in a Fort Greely telemedicine... Factors ): Medicaid reimbursement is now approved for Alaska regardless of method of healthcare delivery. Market Factors (Customers): The influx of...arrive are Active National Guardsmen and Fort Greely Telemedicine 50 their families. Market Factors (Services): Fairbanks Memorial Hospital (FMH) can

Toward Reflective Judgment in Exploratory Factor Analysis Decisions: Determining the Extraction Method and Number of Factors To Retain.

ERIC Educational Resources Information Center

Knight, Jennifer L.

This paper considers some decisions that must be made by the researcher conducting an exploratory factor analysis. The primary purpose is to aid the researcher in making informed decisions during the factor analysis instead of relying on defaults in statistical programs or traditions of previous researchers. Three decision areas are addressed.…

Factor Analysis of the Brazilian Version of UPPS Impulsive Behavior Scale.

PubMed

Sediyama, Cristina Y N; Moura, Ricardo; Garcia, Marina S; da Silva, Antonio G; Soraggi, Carolina; Neves, Fernando S; Albuquerque, Maicon R; Whiteside, Setephen P; Malloy-Diniz, Leandro F

2017-01-01

Objective: To examine the internal consistency and factor structure of the Brazilian adaptation of the UPPS Impulsive Behavior Scale. Methods: UPPS is a self-report scale composed by 40 items assessing four factors of impulsivity: (a) urgency, (b) lack of premeditation; (c) lack of perseverance; (d) sensation seeking. In the present study 384 participants (278 women and 106 men), who were recruited from schools, universities, leisure centers and workplaces fulfilled the UPPS scale. An exploratory factor analysis was performed by using Varimax factor rotation and Kaiser Normalization, and we also conducted two confirmatory analyses to test the independency of the UPPS components found in previous analysis. Results: Results showed a decrease in mean UPPS total scores with age and this analysis showed that the youngest participants (below 30 years) scored significantly higher than the other groups over 30 years. No difference in gender was found. Cronbach's alpha, results indicated satisfactory values for all subscales, with similar high values for the subscales and confirmatory factor analysis indexes also indicated a poor model fit. The results of two exploratory factor analysis were satisfactory. Conclusion: Our results showed that the Portuguese version has the same four-factor structure of the original and previous translations of the UPPS.

Using factor analysis to identify neuromuscular synergies during treadmill walking

NASA Technical Reports Server (NTRS)

Merkle, L. A.; Layne, C. S.; Bloomberg, J. J.; Zhang, J. J.

1998-01-01

Neuroscientists are often interested in grouping variables to facilitate understanding of a particular phenomenon. Factor analysis is a powerful statistical technique that groups variables into conceptually meaningful clusters, but remains underutilized by neuroscience researchers presumably due to its complicated concepts and procedures. This paper illustrates an application of factor analysis to identify coordinated patterns of whole-body muscle activation during treadmill walking. Ten male subjects walked on a treadmill (6.4 km/h) for 20 s during which surface electromyographic (EMG) activity was obtained from the left side sternocleidomastoid, neck extensors, erector spinae, and right side biceps femoris, rectus femoris, tibialis anterior, and medial gastrocnemius. Factor analysis revealed 65% of the variance of seven muscles sampled aligned with two orthogonal factors, labeled 'transition control' and 'loading'. These two factors describe coordinated patterns of muscular activity across body segments that would not be evident by evaluating individual muscle patterns. The results show that factor analysis can be effectively used to explore relationships among muscle patterns across all body segments to increase understanding of the complex coordination necessary for smooth and efficient locomotion. We encourage neuroscientists to consider using factor analysis to identify coordinated patterns of neuromuscular activation that would be obscured using more traditional EMG analyses.

Product competitiveness analysis for e-commerce platform of special agricultural products

NASA Astrophysics Data System (ADS)

Wan, Fucheng; Ma, Ning; Yang, Dongwei; Xiong, Zhangyuan

2017-09-01

On the basis of analyzing the influence factors of the product competitiveness of the e-commerce platform of the special agricultural products and the characteristics of the analytical methods for the competitiveness of the special agricultural products, the price, the sales volume, the postage included service, the store reputation, the popularity, etc. were selected in this paper as the dimensionality for analyzing the competitiveness of the agricultural products, and the principal component factor analysis was taken as the competitiveness analysis method. Specifically, the web crawler was adopted to capture the information of various special agricultural products in the e-commerce platform ---- chi.taobao.com. Then, the original data captured thereby were preprocessed and MYSQL database was adopted to establish the information library for the special agricultural products. Then, the principal component factor analysis method was adopted to establish the analysis model for the competitiveness of the special agricultural products, and SPSS was adopted in the principal component factor analysis process to obtain the competitiveness evaluation factor system (support degree factor, price factor, service factor and evaluation factor) of the special agricultural products. Then, the linear regression method was adopted to establish the competitiveness index equation of the special agricultural products for estimating the competitiveness of the special agricultural products.

An Evaluation of the Effects of Variable Sampling on Component, Image, and Factor Analysis.

ERIC Educational Resources Information Center

Velicer, Wayne F.; Fava, Joseph L.

1987-01-01

Principal component analysis, image component analysis, and maximum likelihood factor analysis were compared to assess the effects of variable sampling. Results with respect to degree of saturation and average number of variables per factor were clear and dramatic. Differential effects on boundary cases and nonconvergence problems were also found.…

A Comparison of Component and Factor Patterns: A Monte Carlo Approach.

ERIC Educational Resources Information Center

Velicer, Wayne F.; And Others

1982-01-01

Factor analysis, image analysis, and principal component analysis are compared with respect to the factor patterns they would produce under various conditions. The general conclusion that is reached is that the three methods produce results that are equivalent. (Author/JKS)

Inventory of File nam.t00z.awipak00.tm00.grib2

Science.gov Websites

Rime Factor [non-dim] 009 1 hybrid level HGT analysis Geopotential Height [gpm] 010 1 hybrid level TMP [kg/kg] 040 30 mb SNMR analysis Snow Mixing Ratio [kg/kg] 041 30 mb RIME analysis Rime Factor [non-dim Factor [non-dim] 054 75 mb HGT analysis Geopotential Height [gpm] 055 75 mb TMP analysis Temperature [K

On the Likelihood Ratio Test for the Number of Factors in Exploratory Factor Analysis

ERIC Educational Resources Information Center

Hayashi, Kentaro; Bentler, Peter M.; Yuan, Ke-Hai

2007-01-01

In the exploratory factor analysis, when the number of factors exceeds the true number of factors, the likelihood ratio test statistic no longer follows the chi-square distribution due to a problem of rank deficiency and nonidentifiability of model parameters. As a result, decisions regarding the number of factors may be incorrect. Several…

Scale-Free Nonparametric Factor Analysis: A User-Friendly Introduction with Concrete Heuristic Examples.

ERIC Educational Resources Information Center

Mittag, Kathleen Cage

Most researchers using factor analysis extract factors from a matrix of Pearson product-moment correlation coefficients. A method is presented for extracting factors in a non-parametric way, by extracting factors from a matrix of Spearman rho (rank correlation) coefficients. It is possible to factor analyze a matrix of association such that…

Assessing suicide risk among callers to crisis hotlines: a confirmatory factor analysis.

PubMed

Witte, Tracy K; Gould, Madelyn S; Munfakh, Jimmie Lou Harris; Kleinman, Marjorie; Joiner, Thomas E; Kalafat, John

2010-09-01

Our goal was to investigate the factor structure of a risk assessment tool utilized by suicide hotlines and to determine the predictive validity of the obtained factors in predicting subsequent suicidal behavior. We conducted an Exploratory Factor Analysis (EFA), an EFA in a Confirmatory Factor Analysis (EFA/CFA) framework, and a CFA on independent subsamples derived from a total sample of 1,085. Similar to previous studies, we found consistent evidence for a two-factor solution, with one factor representing a more pernicious form of suicide risk (i.e., Resolved Plans and Preparations; RPP) and one factor representing milder suicidal ideation (i.e., Suicidal Desire and Ideation; SDI). The RPP factor trended toward being more predictive of suicidal ideation at follow-up than the SDI factor. (c) 2010 Wiley Periodicals, Inc.

Bootstrap Confidence Intervals for Ordinary Least Squares Factor Loadings and Correlations in Exploratory Factor Analysis

ERIC Educational Resources Information Center

Zhang, Guangjian; Preacher, Kristopher J.; Luo, Shanhong

2010-01-01

This article is concerned with using the bootstrap to assign confidence intervals for rotated factor loadings and factor correlations in ordinary least squares exploratory factor analysis. Coverage performances of "SE"-based intervals, percentile intervals, bias-corrected percentile intervals, bias-corrected accelerated percentile…

Analysis of Factors Influencing Creative Personality of Elementary School Students

ERIC Educational Resources Information Center

Park, Jongman; Kim, Minkee; Jang, Shinho

2017-01-01

This quantitative research examined factors that affect elementary students' creativity and how those factors correlate. Aiming to identify significant factors that affect creativity and to clarify the relationship between these factors by path analysis, this research was designed to be a stepping stone for creativity enhancement studies. Data…

Confirmatory Factor Analysis of the Delirium Rating Scale Revised-98 (DRS-R98).

PubMed

Thurber, Steven; Kishi, Yasuhiro; Trzepacz, Paula T; Franco, Jose G; Meagher, David J; Lee, Yanghyun; Kim, Jeong-Lan; Furlanetto, Leticia M; Negreiros, Daniel; Huang, Ming-Chyi; Chen, Chun-Hsin; Kean, Jacob; Leonard, Maeve

2015-01-01

Principal components analysis applied to the Delirium Rating Scale-Revised-98 contributes to understanding the delirium construct. Using a multisite pooled international delirium database, the authors applied confirmatory factor analysis to Delirium Rating Scale-Revised-98 scores from 859 adult patients evaluated by delirium experts (delirium, N=516; nondelirium, N=343). Confirmatory factor analysis found all diagnostic features and core symptoms (cognitive, language, thought process, sleep-wake cycle, motor retardation), except motor agitation, loaded onto factor 1. Motor agitation loaded onto factor 2 with noncore symptoms (delusions, affective lability, and perceptual disturbances). Factor 1 loading supports delirium as a single construct, but when accompanied by psychosis, motor agitation's role may not be solely as a circadian activity indicator.

A dynamic factor model of the evaluation of the financial crisis in Turkey.

PubMed

Sezgin, F; Kinay, B

2010-01-01

Factor analysis has been widely used in economics and finance in situations where a relatively large number of variables are believed to be driven by few common causes of variation. Dynamic factor analysis (DFA) which is a combination of factor and time series analysis, involves autocorrelation matrices calculated from multivariate time series. Dynamic factor models were traditionally used to construct economic indicators, macroeconomic analysis, business cycles and forecasting. In recent years, dynamic factor models have become more popular in empirical macroeconomics. They have more advantages than other methods in various respects. Factor models can for instance cope with many variables without running into scarce degrees of freedom problems often faced in regression-based analysis. In this study, a model which determines the effect of the global crisis on Turkey is proposed. The main aim of the paper is to analyze how several macroeconomic quantities show an alteration before the evolution of the crisis and to decide if a crisis can be forecasted or not.

49 CFR Appendix D to Part 172 - Rail Risk Analysis Factors

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Rail Risk Analysis Factors D Appendix D to Part... REQUIREMENTS, AND SECURITY PLANS Pt. 172, App. D Appendix D to Part 172—Rail Risk Analysis Factors A. This... safety and security risk analyses required by § 172.820. The risk analysis to be performed may be...

49 CFR Appendix D to Part 172 - Rail Risk Analysis Factors

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Rail Risk Analysis Factors D Appendix D to Part... REQUIREMENTS, AND SECURITY PLANS Pt. 172, App. D Appendix D to Part 172—Rail Risk Analysis Factors A. This... safety and security risk analyses required by § 172.820. The risk analysis to be performed may be...

Critical Factors Analysis for Offshore Software Development Success by Structural Equation Modeling

NASA Astrophysics Data System (ADS)

Wada, Yoshihisa; Tsuji, Hiroshi

In order to analyze the success/failure factors in offshore software development service by the structural equation modeling, this paper proposes to follow two approaches together; domain knowledge based heuristic analysis and factor analysis based rational analysis. The former works for generating and verifying of hypothesis to find factors and causalities. The latter works for verifying factors introduced by theory to build the model without heuristics. Following the proposed combined approaches for the responses from skilled project managers of the questionnaire, this paper found that the vendor property has high causality for the success compared to software property and project property.

[Lake eutrophication modeling in considering climatic factors change: a review].

PubMed

Su, Jie-Qiong; Wang, Xuan; Yang, Zhi-Feng

2012-11-01

Climatic factors are considered as the key factors affecting the trophic status and its process in most lakes. Under the background of global climate change, to incorporate the variations of climatic factors into lake eutrophication models could provide solid technical support for the analysis of the trophic evolution trend of lake and the decision-making of lake environment management. This paper analyzed the effects of climatic factors such as air temperature, precipitation, sunlight, and atmosphere on lake eutrophication, and summarized the research results about the lake eutrophication modeling in considering in considering climatic factors change, including the modeling based on statistical analysis, ecological dynamic analysis, system analysis, and intelligent algorithm. The prospective approaches to improve the accuracy of lake eutrophication modeling with the consideration of climatic factors change were put forward, including 1) to strengthen the analysis of the mechanisms related to the effects of climatic factors change on lake trophic status, 2) to identify the appropriate simulation models to generate several scenarios under proper temporal and spatial scales and resolutions, and 3) to integrate the climatic factors change simulation, hydrodynamic model, ecological simulation, and intelligent algorithm into a general modeling system to achieve an accurate prediction of lake eutrophication under climatic change.

Three Factors Are Critical in Order to Synthesize Intelligible Noise-Vocoded Japanese Speech

PubMed Central

Kishida, Takuya; Nakajima, Yoshitaka; Ueda, Kazuo; Remijn, Gerard B.

2016-01-01

Factor analysis (principal component analysis followed by varimax rotation) had shown that 3 common factors appear across 20 critical-band power fluctuations derived from spoken sentences of eight different languages [Ueda et al. (2010). Fechner Day 2010, Padua]. The present study investigated the contributions of such power-fluctuation factors to speech intelligibility. The method of factor analysis was modified to obtain factors suitable for resynthesizing speech sounds as 20-critical-band noise-vocoded speech. The resynthesized speech sounds were used for an intelligibility test. The modification of factor analysis ensured that the resynthesized speech sounds were not accompanied by a steady background noise caused by the data reduction procedure. Spoken sentences of British English, Japanese, and Mandarin Chinese were subjected to this modified analysis. Confirming the earlier analysis, indeed 3–4 factors were common to these languages. The number of power-fluctuation factors needed to make noise-vocoded speech intelligible was then examined. Critical-band power fluctuations of the Japanese spoken sentences were resynthesized from the obtained factors, resulting in noise-vocoded-speech stimuli, and the intelligibility of these speech stimuli was tested by 12 native Japanese speakers. Japanese mora (syllable-like phonological unit) identification performances were measured when the number of factors was 1–9. Statistically significant improvement in intelligibility was observed when the number of factors was increased stepwise up to 6. The 12 listeners identified 92.1% of the morae correctly on average in the 6-factor condition. The intelligibility improved sharply when the number of factors changed from 2 to 3. In this step, the cumulative contribution ratio of factors improved only by 10.6%, from 37.3 to 47.9%, but the average mora identification leaped from 6.9 to 69.2%. The results indicated that, if the number of factors is 3 or more, elementary linguistic information is preserved in such noise-vocoded speech. PMID:27199790

Logistic regression analysis of factors associated with avascular necrosis of the femoral head following femoral neck fractures in middle-aged and elderly patients.

PubMed

Ai, Zi-Sheng; Gao, You-Shui; Sun, Yuan; Liu, Yue; Zhang, Chang-Qing; Jiang, Cheng-Hua

2013-03-01

Risk factors for femoral neck fracture-induced avascular necrosis of the femoral head have not been elucidated clearly in middle-aged and elderly patients. Moreover, the high incidence of screw removal in China and its effect on the fate of the involved femoral head require statistical methods to reflect their intrinsic relationship. Ninety-nine patients older than 45 years with femoral neck fracture were treated by internal fixation between May 1999 and April 2004. Descriptive analysis, interaction analysis between associated factors, single factor logistic regression, multivariate logistic regression, and detailed interaction analysis were employed to explore potential relationships among associated factors. Avascular necrosis of the femoral head was found in 15 cases (15.2 %). Age × the status of implants (removal vs. maintenance) and gender × the timing of reduction were interactive according to two-factor interactive analysis. Age, the displacement of fractures, the quality of reduction, and the status of implants were found to be significant factors in single factor logistic regression analysis. Age, age × the status of implants, and the quality of reduction were found to be significant factors in multivariate logistic regression analysis. In fine interaction analysis after multivariate logistic regression analysis, implant removal was the most important risk factor for avascular necrosis in 56-to-85-year-old patients, with a risk ratio of 26.00 (95 % CI = 3.076-219.747). The middle-aged and elderly have less incidence of avascular necrosis of the femoral head following femoral neck fractures treated by cannulated screws. The removal of cannulated screws can induce a significantly high incidence of avascular necrosis of the femoral head in elderly patients, while a high-quality reduction is helpful to reduce avascular necrosis.

A Factor Analysis of the BSRI and the PAQ.

ERIC Educational Resources Information Center

Edwards, Teresa A.; And Others

Factor analysis of the Bem Sex Role Inventory (BSRI) and the Personality Attributes Questionnaire (PAQ) was undertaken to study the independence of the masculine and feminine scales within each instrument. Both instruments were administered to undergraduate education majors. Analysis of primary first and second order factors of the BSRI indicated…

Cross-Validation of Levenson's Psychopathy Scale in a Sample of Federal Female Inmates

ERIC Educational Resources Information Center

Brinkley, Chad A.; Diamond, Pamela M.; Magaletta, Philip R.; Heigel, Caron P.

2008-01-01

Levenson, Kiehl, and Fitzpatrick's Self-Report Psychopathy Scale (LSRPS) is evaluated to determine the factor structure and concurrent validity of the instrument among 430 federal female inmates. Confirmatory factor analysis fails to validate the expected 2-factor structure. Subsequent exploratory factor analysis reveals a 3-factor structure…

Confirmatory Factor Analysis of the WISC-III with Child Psychiatric Inpatients.

ERIC Educational Resources Information Center

Tupa, David J.; Wright, Margaret O'Dougherty; Fristad, Mary A.

1997-01-01

Factor models of the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) for one, two, three, and four factors were tested using confirmatory factor analysis with a sample of 177 child psychiatric inpatients. The four-factor model proposed in the WISC-III manual provided the best fit to the data. (SLD)

Spectral compression algorithms for the analysis of very large multivariate images

DOEpatents

Keenan, Michael R.

2007-10-16

A method for spectrally compressing data sets enables the efficient analysis of very large multivariate images. The spectral compression algorithm uses a factored representation of the data that can be obtained from Principal Components Analysis or other factorization technique. Furthermore, a block algorithm can be used for performing common operations more efficiently. An image analysis can be performed on the factored representation of the data, using only the most significant factors. The spectral compression algorithm can be combined with a spatial compression algorithm to provide further computational efficiencies.

A replication of a factor analysis of motivations for trapping

USGS Publications Warehouse

Schroeder, Susan; Fulton, David C.

2015-01-01

Using a 2013 sample of Minnesota trappers, we employed confirmatory factor analysis to replicate an exploratory factor analysis of trapping motivations conducted by Daigle, Muth, Zwick, and Glass (1998).  We employed the same 25 items used by Daigle et al. and tested the same five-factor structure using a recent sample of Minnesota trappers. We also compared motivations in our sample to those reported by Daigle et el.

Factor Analysis of the Brazilian Version of UPPS Impulsive Behavior Scale

PubMed Central

Sediyama, Cristina Y. N.; Moura, Ricardo; Garcia, Marina S.; da Silva, Antonio G.; Soraggi, Carolina; Neves, Fernando S.; Albuquerque, Maicon R.; Whiteside, Setephen P.; Malloy-Diniz, Leandro F.

2017-01-01

Objective: To examine the internal consistency and factor structure of the Brazilian adaptation of the UPPS Impulsive Behavior Scale. Methods: UPPS is a self-report scale composed by 40 items assessing four factors of impulsivity: (a) urgency, (b) lack of premeditation; (c) lack of perseverance; (d) sensation seeking. In the present study 384 participants (278 women and 106 men), who were recruited from schools, universities, leisure centers and workplaces fulfilled the UPPS scale. An exploratory factor analysis was performed by using Varimax factor rotation and Kaiser Normalization, and we also conducted two confirmatory analyses to test the independency of the UPPS components found in previous analysis. Results: Results showed a decrease in mean UPPS total scores with age and this analysis showed that the youngest participants (below 30 years) scored significantly higher than the other groups over 30 years. No difference in gender was found. Cronbach’s alpha, results indicated satisfactory values for all subscales, with similar high values for the subscales and confirmatory factor analysis indexes also indicated a poor model fit. The results of two exploratory factor analysis were satisfactory. Conclusion: Our results showed that the Portuguese version has the same four-factor structure of the original and previous translations of the UPPS. PMID:28484414

Factors affecting job satisfaction in nurse faculty: a meta-analysis.

PubMed

Gormley, Denise K

2003-04-01

Evidence in the literature suggests job satisfaction can make a difference in keeping qualified workers on the job, but little research has been conducted focusing specifically on nursing faculty. Several studies have examined nurse faculty satisfaction in relationship to one or two influencing factors. These factors include professional autonomy, leader role expectations, organizational climate, perceived role conflict and role ambiguity, leadership behaviors, and organizational characteristics. This meta-analysis attempts to synthesize the various studies conducted on job satisfaction in nursing faculty and analyze which influencing factors have the greatest effect. The procedure used for this meta-analysis consisted of reviewing studies to identify factors influencing job satisfaction, research questions, sample size reported, instruments used for measurement of job satisfaction and influencing factors, and results of statistical analysis.

Application of factor analysis to the water quality in reservoirs

NASA Astrophysics Data System (ADS)

Silva, Eliana Costa e.; Lopes, Isabel Cristina; Correia, Aldina; Gonçalves, A. Manuela

2017-06-01

In this work we present a Factor Analysis of chemical and environmental variables of the water column and hydro-morphological features of several Portuguese reservoirs. The objective is to reduce the initial number of variables, keeping their common characteristics. Using the Factor Analysis, the environmental variables measured in the epilimnion and in the hypolimnion, together with the hydromorphological characteristics of the dams were reduced from 63 variables to only 13 factors, which explained a total of 83.348% of the variance in the original data. After performing rotation using the Varimax method, the relations between the factors and the original variables got clearer and more explainable, which provided a Factor Analysis model for these environmental variables using 13 varifactors: Water quality and distance to the source, Hypolimnion chemical composition, Sulfite-reducing bacteria and nutrients, Coliforms and faecal streptococci, Reservoir depth, Temperature, Location, among other factors.

Donor retention in health care in Iran: a factor analysis

PubMed Central

Aghababa, Sara; Nasiripour, Amir Ashkan; Maleki, Mohammadreza; Gohari, Mahmoodreza

2017-01-01

Background: Long-term financial support is essential for the survival of a charitable organization. Health charities need to identify the effective factors influencing donor retention. Methods: In the present study, the items of a questionnaire were derived from both literature review and semi-structured interviews related to donor retention. Using a purposive sampling, 300 academic and executive practitioners were selected. After the follow- up, a total of 243 usable questionnaires were prepared for factor analysis. The questionnaire was validated based on the face and content validity and reliability through Cronbach’s α-coefficient. Results: The results of exploratory factor analysis extracted 2 factors for retention: donor factor (variance = 33.841%; Cronbach’s α-coefficient = 90.2) and charity factor (variance = 29.038%; Cronbach’s α-coefficient = 82.8), respectively. Subsequently, confirmatory factor analysis was applied to support the overall reasonable fit. Conclusions: In this study, it was found that repeated monetary donations are supplied to the charitable organizations when both aspects of donor factor (retention factor and charity factor) for retention are taken into consideration. This model could provide a perspective for making sustainable donations and charitable giving PMID:28955663

Ultrasound-enhanced bioscouring of greige cotton: regression analysis of process factors

USDA-ARS?s Scientific Manuscript database

Process factors of enzyme concentration, time, power and frequency were investigated for ultrasound-enhanced bioscouring of greige cotton. A fractional factorial experimental design and subsequent regression analysis of the process factors were employed to determine the significance of each factor a...

Quantitative analysis of factors that affect oil pipeline network accident based on Bayesian networks: A case study in China

NASA Astrophysics Data System (ADS)

Zhang, Chao; Qin, Ting Xin; Huang, Shuai; Wu, Jian Song; Meng, Xin Yan

2018-06-01

Some factors can affect the consequences of oil pipeline accident and their effects should be analyzed to improve emergency preparation and emergency response. Although there are some qualitative analysis models of risk factors' effects, the quantitative analysis model still should be researched. In this study, we introduce a Bayesian network (BN) model of risk factors' effects analysis in an oil pipeline accident case that happened in China. The incident evolution diagram is built to identify the risk factors. And the BN model is built based on the deployment rule for factor nodes in BN and the expert knowledge by Dempster-Shafer evidence theory. Then the probabilities of incident consequences and risk factors' effects can be calculated. The most likely consequences given by this model are consilient with the case. Meanwhile, the quantitative estimations of risk factors' effects may provide a theoretical basis to take optimal risk treatment measures for oil pipeline management, which can be used in emergency preparation and emergency response.

The School Counseling Program Implementation Survey: Initial Instrument Development and Exploratory Factor Analysis

ERIC Educational Resources Information Center

Clemens, Elysia V.; Carey, John C.; Harrington, Karen M.

2010-01-01

This article details the initial development of the School Counseling Program Implementation Survey and psychometric results including reliability and factor structure. An exploratory factor analysis revealed a three-factor model that accounted for 54% of the variance of the intercorrelation matrix and a two-factor model that accounted for 47% of…

Affective Outcomes of Schooling: Full-Information Item Factor Analysis of a Student Questionnaire.

ERIC Educational Resources Information Center

Muraki, Eiji; Engelhard, George, Jr.

Recent developments in dichotomous factor analysis based on multidimensional item response models (Bock and Aitkin, 1981; Muthen, 1978) provide an effective method for exploring the dimensionality of questionnaire items. Implemented in the TESTFACT program, this "full information" item factor analysis accounts not only for the pairwise joint…

Item Factor Analysis: Current Approaches and Future Directions

ERIC Educational Resources Information Center

Wirth, R. J.; Edwards, Michael C.

2007-01-01

The rationale underlying factor analysis applies to continuous and categorical variables alike; however, the models and estimation methods for continuous (i.e., interval or ratio scale) data are not appropriate for item-level data that are categorical in nature. The authors provide a targeted review and synthesis of the item factor analysis (IFA)…

Spatial Dependence and Heterogeneity in Bayesian Factor Analysis: A Cross-National Investigation of Schwartz Values

ERIC Educational Resources Information Center

Stakhovych, Stanislav; Bijmolt, Tammo H. A.; Wedel, Michel

2012-01-01

In this article, we present a Bayesian spatial factor analysis model. We extend previous work on confirmatory factor analysis by including geographically distributed latent variables and accounting for heterogeneity and spatial autocorrelation. The simulation study shows excellent recovery of the model parameters and demonstrates the consequences…

Q-Type Factor Analysis of Healthy Aged Men.

ERIC Educational Resources Information Center

Kleban, Morton H.

Q-type factor analysis was used to re-analyze baseline data collected in 1957, on 47 men aged 65-91. Q-type analysis is the use of factor methods to study persons rather than tests. Although 550 variables were originally studied involving psychiatry, medicine, cerebral metabolism and chemistry, personality, audiometry, dichotic and diotic memory,…

Simulating the Effects of Common and Specific Abilities on Test Performance: An Evaluation of Factor Analysis

ERIC Educational Resources Information Center

McFarland, Dennis J.

2014-01-01

Purpose: Factor analysis is a useful technique to aid in organizing multivariate data characterizing speech, language, and auditory abilities. However, knowledge of the limitations of factor analysis is essential for proper interpretation of results. The present study used simulated test scores to illustrate some characteristics of factor…

On the stability analysis of approximate factorization methods for 3D Euler and Navier-Stokes equations

NASA Technical Reports Server (NTRS)

Demuren, A. O.; Ibraheem, S. O.

1993-01-01

The convergence characteristics of various approximate factorizations for the 3D Euler and Navier-Stokes equations are examined using the von-Neumann stability analysis method. Three upwind-difference based factorizations and several central-difference based factorizations are considered for the Euler equations. In the upwind factorizations both the flux-vector splitting methods of Steger and Warming and van Leer are considered. Analysis of the Navier-Stokes equations is performed only on the Beam and Warming central-difference scheme. The range of CFL numbers over which each factorization is stable is presented for one-, two-, and three-dimensional flow. Also presented for each factorization is the CFL number at which the maximum eigenvalue is minimized, for all Fourier components, as well as for the high frequency range only. The latter is useful for predicting the effectiveness of multigrid procedures with these schemes as smoothers. Further, local mode analysis is performed to test the suitability of using a uniform flow field in the stability analysis. Some inconsistencies in the results from previous analyses are resolved.

Measuring Prosocial Tendencies in Germany: Sources of Validity and Reliablity of the Revised Prosocial Tendency Measure

PubMed Central

Rodrigues, Johannes; Ulrich, Natalie; Mussel, Patrick; Carlo, Gustavo; Hewig, Johannes

2017-01-01

The prosocial tendencies measure (PTM; Carlo and Randall, 2002) is a widely used measurement for prosocial tendencies in English speaking participants. This instrument distinguishes between six different types of prosocial tendencies that partly share some common basis, but also can be opposed to each other. To examine these constructs in Germany, a study with 1067 participants was conducted. The study investigated the structure of this German version of the PTM-R via exploratory factor analysis, confirmatory factor analysis, correlations with similar constructs in subsamples as well as via measurement invariance test concerning the original English version. The German translation showed a similar factor structure to the English version in exploratory factor analysis and in confirmatory factor analysis. Measurement invariance was found between the English and German language versions of the PTM and support for the proposed six-factor structure (altruistic, anonymous, compliant, dire, emotional and public prosocial behavior) was also found in confirmatory factor analysis. Furthermore, the expected interrelations of these factors of prosocial behavior tendencies were obtained. Finally, correlations of the prosocial behavior tendencies with validating constructs and behaviors were found. Thus, the findings stress the importance of seeing prosocial behavior not as a single dimension construct, but as a factored construct which now can also be assessed in German speaking participants. PMID:29270144

Instruments measuring perceived racism/racial discrimination: review and critique of factor analytic techniques.

PubMed

Atkins, Rahshida

2014-01-01

Several compendiums of instruments that measure perceived racism and/or discrimination are present in the literature. Other works have reviewed the psychometric properties of these instruments in terms of validity and reliability and have indicated if the instrument was factor analyzed. However, little attention has been given to the quality of the factor analysis performed. The aim of this study was to evaluate the exploratory factor analyses done on instruments measuring perceived racism/racial discrimination using guidelines from experts in psychometric theory. The techniques used for factor analysis were reviewed and critiqued and the adequacy of reporting was evaluated. Internet search engines and four electronic abstract databases were used to identify 16 relevant instruments that met the inclusion/exclusion criteria. Principal component analysis was the most frequent method of extraction (81%). Sample sizes were adequate for factor analysis in 81 percent of studies. The majority of studies reported appropriate criteria for the acceptance of un-rotated factors (81%) and justified the rotation method (75%). Exactly 94 percent of studies reported partially acceptable criteria for the acceptance of rotated factors. The majority of articles (69%) reported adequate coefficient alphas for the resultant subscales. In 81 percent of the studies, the conceptualized dimensions were supported by factor analysis.

INSTRUMENTS MEASURING PERCEIVED RACISM/RACIAL DISCRIMINATION: REVIEW AND CRITIQUE OF FACTOR ANALYTIC TECHNIQUES

PubMed Central

Atkins, Rahshida

2015-01-01

Several compendiums of instruments that measure perceived racism and/or discrimination are present in the literature. Other works have reviewed the psychometric properties of these instruments in terms of validity and reliability and have indicated if the instrument was factor analyzed. However, little attention has been given to the quality of the factor analysis performed. The aim of this study was to evaluate the exploratory factor analyses done on instruments measuring perceived racism/racial discrimination using guidelines from experts in psychometric theory. The techniques used for factor analysis were reviewed and critiqued and the adequacy of reporting was evaluated. Internet search engines and four electronic abstract databases were used to identify 16 relevant instruments that met the inclusion/exclusion criteria. Principal component analysis was the most frequent method of extraction (81%). Sample sizes were adequate for factor analysis in 81 percent of studies. The majority of studies reported appropriate criteria for the acceptance of un-rotated factors (81%) and justified the rotation method (75%). Exactly 94 percent of studies reported partially acceptable criteria for the acceptance of rotated factors. The majority of articles (69%) reported adequate coefficient alphas for the resultant subscales. In 81 percent of the studies, the conceptualized dimensions were supported by factor analysis. PMID:25626225

Factor Analysis of Intern Effectiveness

ERIC Educational Resources Information Center

Womack, Sid T.; Hannah, Shellie Louise; Bell, Columbus David

2012-01-01

Four factors in teaching intern effectiveness, as measured by a Praxis III-similar instrument, were found among observational data of teaching interns during the 2010 spring semester. Those factors were lesson planning, teacher/student reflection, fairness & safe environment, and professionalism/efficacy. This factor analysis was as much of a…

Applying Cognitive Work Analysis to Time Critical Targeting Functionality

DTIC Science & Technology

2004-10-01

Cognitive Task Analysis , CTA, Cognitive Task Analysis , Human Factors, GUI, Graphical User Interface, Heuristic Evaluation... Cognitive Task Analysis MITRE Briefing January 2000 Dynamic Battle Management Functional Architecture 3-1 Section 3 Human Factors...clear distinction between Cognitive Work Analysis (CWA) and Cognitive Task Analysis (CTA), therefore this document will refer to these

Evaluating voice characteristics of first-year acting students in Israel: factor analysis.

PubMed

Amir, Ofer; Primov-Fever, Adi; Kushnir, Tami; Kandelshine-Waldman, Osnat; Wolf, Michael

2013-01-01

Acting students require diverse, high-quality, and high-intensity vocal performance from early stages of their training. Demanding vocal activities, before developing the appropriate vocal skills, put them in high risk for developing vocal problems. A retrospective analysis of voice characteristics of first-year acting students using several voice evaluation tools. A total of 79 first-year acting students (55 women and 24 men) were assigned into two study groups: laryngeal findings (LFs) and no laryngeal findings, based on stroboscopic findings. Their voice characteristics were evaluated using acoustic analysis, aerodynamic examination, perceptual scales, and self-report questionnaires. Results obtained from each set of measures were examined using a factor analysis approach. Significant differences between the two groups were found for a single fundamental frequency (F(0))-Regularity factor; a single Grade, Roughness, Breathiness, Asthenia, Strain perceptual factor; and the three self-evaluation factors. Gender differences were found for two acoustic analysis factors, which were based on F(0) and its derivatives, namely an aerodynamic factor that represents expiratory volume measurements and a single self-evaluation factor that represents the tendency to seek therapy. Approximately 50% of the first-year acting students had LFs. These students differed from their peers in the control group in a single acoustic analysis factor, as well as perceptual and self-report factors. No group differences, however, were found for the aerodynamic factors. Early laryngeal examination and voice evaluation of future professional voice users could provide a valuable individual baseline, to which later examinations could be compared, and assist in providing personally tailored treatment. Copyright © 2013 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Risky Business: Factor Analysis of Survey Data – Assessing the Probability of Incorrect Dimensionalisation

PubMed Central

van der Eijk, Cees; Rose, Jonathan

2015-01-01

This paper undertakes a systematic assessment of the extent to which factor analysis the correct number of latent dimensions (factors) when applied to ordered-categorical survey items (so-called Likert items). We simulate 2400 data sets of uni-dimensional Likert items that vary systematically over a range of conditions such as the underlying population distribution, the number of items, the level of random error, and characteristics of items and item-sets. Each of these datasets is factor analysed in a variety of ways that are frequently used in the extant literature, or that are recommended in current methodological texts. These include exploratory factor retention heuristics such as Kaiser’s criterion, Parallel Analysis and a non-graphical scree test, and (for exploratory and confirmatory analyses) evaluations of model fit. These analyses are conducted on the basis of Pearson and polychoric correlations. We find that, irrespective of the particular mode of analysis, factor analysis applied to ordered-categorical survey data very often leads to over-dimensionalisation. The magnitude of this risk depends on the specific way in which factor analysis is conducted, the number of items, the properties of the set of items, and the underlying population distribution. The paper concludes with a discussion of the consequences of over-dimensionalisation, and a brief mention of alternative modes of analysis that are much less prone to such problems. PMID:25789992

An Analysis of Factors that Influence Enlistment Decisions in the U.S. Army

DTIC Science & Technology

1998-03-01

NAVAL POSTGRADUATE SCHOOL Monterey, California CM THESIS AN ANALYSIS OF FACTORS THAT INFLUENCE ENLISTMENT DECISIONS IN THE U.S. ARMY by Young...TITLE AND SUBTITLE : AN ANALYSIS OF FACTORS THAT INFLUENCE ENLISTMENT DECISIONS IN THE U.S. ARMY 6. AUTHOR(S) Oh, Young Yeol 7...200 words) The purpose of this thesis is to analyze factors that influence decisions to enlist in the U.S. Army. This thesis uses 1997 New Recruit

Secondary School Burnout Scale (SSBS)

ERIC Educational Resources Information Center

Aypay, Ayse

2012-01-01

The purpose of this study is to develop "Secondary School Burnout Scale." Study group included 728 students out of 14 schools in four cities in Turkey. Both Exploratory Factor Analysis and Confirmatory Factor Analysis were conducted on the data. A seven-factor solution emerged. The seven factors explained 61% of the total variance. The…

Analyse Factorielle d'une Batterie de Tests de Comprehension Orale et Ecrite (Factor Analysis of a Battery of Tests of Listening and Reading Comprehension). Melanges Pedagogiques, 1971.

ERIC Educational Resources Information Center

Lonchamp, F.

This is a presentation of the results of a factor analysis of a battery of tests intended to measure listening and reading comprehension in English as a second language. The analysis sought to answer the following questions: (1) whether the factor analysis method yields results when applied to tests which are not specifically designed for this…

Confirmatory Factor Analysis of the Trinity Inventory of Precursors to Suicide (TIPS) and Its Relationship to Hopelessness and Depression

ERIC Educational Resources Information Center

Smyth, Caroline L.; MacLachlan, Malcolm

2005-01-01

Numerous existing measures assess attitudes toward suicide yet fail to account for contextual factors. The Trinity Inventory of Precursors to Suicide (TIPS) is presented as an alternative, with implications for the development of prevention programs. Having previously reported exploratory analysis of the TIPS; confirmatory factor analysis and…

Examining Evolving Performance on the Force Concept Inventory Using Factor Analysis

ERIC Educational Resources Information Center

Semak, M. R.; Dietz, R. D.; Pearson, R. H.; Willis, C. W

2017-01-01

The application of factor analysis to the "Force Concept Inventory" (FCI) has proven to be problematic. Some studies have suggested that factor analysis of test results serves as a helpful tool in assessing the recognition of Newtonian concepts by students. Other work has produced at best ambiguous results. For the FCI administered as a…

Prediction of quality attributes of chicken breast fillets by using Vis/NIR spectroscopy combined with factor analysis method

USDA-ARS?s Scientific Manuscript database

Visible/near-infrared (Vis/NIR) spectroscopy with wavelength range between 400 and 2500 nm combined with factor analysis method was tested to predict quality attributes of chicken breast fillets. Quality attributes, including color (L*, a*, b*), pH, and drip loss were analyzed using factor analysis ...

Factor Analysis Methods and Validity Evidence: A Systematic Review of Instrument Development across the Continuum of Medical Education

ERIC Educational Resources Information Center

Wetzel, Angela Payne

2011-01-01

Previous systematic reviews indicate a lack of reporting of reliability and validity evidence in subsets of the medical education literature. Psychology and general education reviews of factor analysis also indicate gaps between current and best practices; yet, a comprehensive review of exploratory factor analysis in instrument development across…

Dimensions of temperament: an analysis.

PubMed

Lorr, M; Stefic, E C

1976-01-01

The TDOT recast into a single stimulus format was administered to 150 college Ss. A factor analysis of the items followed by an analysis of item clusters that define each factor indicated the presence of 14 dimensions. Of the 10 bipolar scales of the TDOT, 3 were confirmed as independent dimensions, and 5 were confirmed in part or split into unipolar factors.

Assessing School Work Culture: A Higher-Order Analysis and Strategy.

ERIC Educational Resources Information Center

Johnson, William L.; Johnson, Annabel M.; Zimmerman, Kurt J.

This paper reviews a work culture productivity model and reports the development of a work culture instrument based on the culture productivity model. Higher order principal components analysis was used to assess work culture, and a third-order factor analysis shows how the first-order factors group into higher-order factors. The school work…

A Primer on Bootstrap Factor Analysis as Applied to Health Studies Research

ERIC Educational Resources Information Center

Lu, Wenhua; Miao, Jingang; McKyer, E. Lisako J.

2014-01-01

Objectives: To demonstrate how the bootstrap method could be conducted in exploratory factor analysis (EFA) with a syntax written in SPSS. Methods: The data obtained from the Texas Childhood Obesity Prevention Policy Evaluation project (T-COPPE project) were used for illustration. A 5-step procedure to conduct bootstrap factor analysis (BFA) was…

Exploratory Factor Analysis of a Force Concept Inventory Data Set

ERIC Educational Resources Information Center

Scott, Terry F.; Schumayer, Daniel; Gray, Andrew R.

2012-01-01

We perform a factor analysis on a "Force Concept Inventory" (FCI) data set collected from 2109 respondents. We address two questions: the appearance of conceptual coherence in student responses to the FCI and some consequences of this factor analysis on the teaching of Newtonian mechanics. We will highlight the apparent conflation of Newton's…

On the Extraction of Components and the Applicability of the Factor Model.

ERIC Educational Resources Information Center

Dziuban, Charles D.; Harris, Chester W.

A reanalysis of Shaycroft's matrix of intercorrelations of 10 test variables plus 4 random variables is discussed. Three different procedures were used in the reanalysis: (1) Image Component Analysis, (2) Uniqueness Rescaling Factor Analysis, and (3) Alpha Factor Analysis. The results of these analyses are presented in tables. It is concluded from…

A Markov Chain Monte Carlo Approach to Confirmatory Item Factor Analysis

ERIC Educational Resources Information Center

Edwards, Michael C.

2010-01-01

Item factor analysis has a rich tradition in both the structural equation modeling and item response theory frameworks. The goal of this paper is to demonstrate a novel combination of various Markov chain Monte Carlo (MCMC) estimation routines to estimate parameters of a wide variety of confirmatory item factor analysis models. Further, I show…

Developing Multidimensional Likert Scales Using Item Factor Analysis: The Case of Four-Point Items

ERIC Educational Resources Information Center

Asún, Rodrigo A.; Rdz-Navarro, Karina; Alvarado, Jesús M.

2016-01-01

This study compares the performance of two approaches in analysing four-point Likert rating scales with a factorial model: the classical factor analysis (FA) and the item factor analysis (IFA). For FA, maximum likelihood and weighted least squares estimations using Pearson correlation matrices among items are compared. For IFA, diagonally weighted…

Multiplication factor versus regression analysis in stature estimation from hand and foot dimensions.

PubMed

Krishan, Kewal; Kanchan, Tanuj; Sharma, Abhilasha

2012-05-01

Estimation of stature is an important parameter in identification of human remains in forensic examinations. The present study is aimed to compare the reliability and accuracy of stature estimation and to demonstrate the variability in estimated stature and actual stature using multiplication factor and regression analysis methods. The study is based on a sample of 246 subjects (123 males and 123 females) from North India aged between 17 and 20 years. Four anthropometric measurements; hand length, hand breadth, foot length and foot breadth taken on the left side in each subject were included in the study. Stature was measured using standard anthropometric techniques. Multiplication factors were calculated and linear regression models were derived for estimation of stature from hand and foot dimensions. Derived multiplication factors and regression formula were applied to the hand and foot measurements in the study sample. The estimated stature from the multiplication factors and regression analysis was compared with the actual stature to find the error in estimated stature. The results indicate that the range of error in estimation of stature from regression analysis method is less than that of multiplication factor method thus, confirming that the regression analysis method is better than multiplication factor analysis in stature estimation. Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Success Probability Analysis for Shuttle Based Microgravity Experiments

NASA Technical Reports Server (NTRS)

Liou, Ying-Hsin Andrew

1996-01-01

Presented in this report are the results of data analysis of shuttle-based microgravity flight experiments. Potential factors were identified in the previous grant period, and in this period 26 factors were selected for data analysis. In this project, the degree of success was developed and used as the performance measure. 293 of the 391 experiments in Lewis Research Center Microgravity Database were assigned degrees of success. The frequency analysis and the analysis of variance were conducted to determine the significance of the factors that effect the experiment success.

Assessing Suicide Risk Among Callers to Crisis Hotlines: A Confirmatory Factor Analysis

PubMed Central

Witte, Tracy K.; Gould, Madelyn S.; Munfakh, Jimmie Lou Harris; Kleinman, Marjorie; Joiner, Thomas E.; Kalafat, John

2012-01-01

Our goal was to investigate the factor structure of a risk assessment tool utilized by suicide hotlines and to determine the predictive validity of the obtained factors in predicting subsequent suicidal behavior. 1,085 suicidal callers to crisis hotlines were divided into three sub-samples, which allowed us to conduct an independent Exploratory Factor Analysis (EFA), EFA in a Confirmatory Factor Analysis (EFA/CFA) framework, and CFA. Similar to previous factor analytic studies (Beck et al., 1997; Holden & DeLisle, 2005; Joiner, Rudd, & Rajab, 1997; Witte et al., 2006), we found consistent evidence for a two-factor solution, with one factor representing a more pernicious form of suicide risk (i.e., Resolved Plans and Preparations) and one factor representing more mild suicidal ideation (i.e., Suicidal Desire and Ideation). Using structural equation modeling techniques, we found preliminary evidence that the Resolved Plans and Preparations factor trended toward being more predictive of suicidal ideation than the Suicidal Desire and Ideation factor. This factor analytic study is the first longitudinal study of the obtained factors. PMID:20578186

A decision model for selecting sustainable drinking water supply and greywater reuse systems for developing communities with a case study in Cimahi, Indonesia.

PubMed

Henriques, Justin J; Louis, Garrick E

2011-01-01

Capacity Factor Analysis is a decision support system for selection of appropriate technologies for municipal sanitation services in developing communities. Developing communities are those that lack the capability to provide adequate access to one or more essential services, such as water and sanitation, to their residents. This research developed two elements of Capacity Factor Analysis: a capacity factor based classification for technologies using requirements analysis, and a matching policy for choosing technology options. First, requirements analysis is used to develop a ranking for drinking water supply and greywater reuse technologies. Second, using the Capacity Factor Analysis approach, a matching policy is developed to guide decision makers in selecting the appropriate drinking water supply or greywater reuse technology option for their community. Finally, a scenario-based informal hypothesis test is developed to assist in qualitative model validation through case study. Capacity Factor Analysis is then applied in Cimahi Indonesia as a form of validation. The completed Capacity Factor Analysis model will allow developing communities to select drinking water supply and greywater reuse systems that are safe, affordable, able to be built and managed by the community using local resources, and are amenable to expansion as the community's management capacity increases. Copyright © 2010 Elsevier Ltd. All rights reserved.

The School Counselor Leadership Survey: Instrument Development and Exploratory Factor Analysis

ERIC Educational Resources Information Center

Young, Anita; Bryan, Julia

2015-01-01

This study examined the factor structure of the School Counselor Leadership Survey (SCLS). Survey development was a threefold process that resulted in a 39-item survey of 801 school counselors and school counselor supervisors. The exploratory factor analysis indicated a five-factor structure that revealed five key dimensions of school counselor…

A Confirmatory Factor Analysis of the Academic Motivation Scale with Black College Students

ERIC Educational Resources Information Center

Cokley, Kevin

2015-01-01

The factor structure of the Academic Motivation Scale (AMS) was examined with a sample of 578 Black college students. A confirmatory factor analysis of the AMS was conducted. Results indicated that the hypothesized seven-factor model did not fit the data. Implications for future research with the AMS are discussed.

Hierarchical Factoring Based On Image Analysis And Orthoblique Rotations.

PubMed

Stankov, L

1979-07-01

The procedure for hierarchical factoring suggested by Schmid and Leiman (1957) is applied within the framework of image analysis and orthoblique rotational procedures. It is shown that this approach necessarily leads to correlated higher order factors. Also, one can obtain a smaller number of factors than produced by typical hierarchical procedures.

The Factor Structure of the English Language Development Assessment: A Confirmatory Factor Analysis

ERIC Educational Resources Information Center

Kuriakose, Anju

2011-01-01

This study investigated the internal factor structure of the English language development Assessment (ELDA) using confirmatory factor analysis. ELDA is an English language proficiency test developed by a consortium of multiple states and is used to identify and reclassify English language learners in kindergarten to grade 12. Scores on item…

Factors Predictive of Mathematics Achievement in Kindergarten, First and Third Grades: An Opportunity-Propensity Analysis

ERIC Educational Resources Information Center

Byrnes, James P.; Wasik, Barbara A.

2009-01-01

A secondary analysis of the Early Childhood Longitudinal Study-Kindergarten Sample (N = 17,401) was conducted to determine the factors that are most strongly associated with math achievement during kindergarten, first grade, and third grade. Factors from the following three categories were considered: antecedent factors (e.g., family…

A Comparison of Distribution Free and Non-Distribution Free Factor Analysis Methods

ERIC Educational Resources Information Center

Ritter, Nicola L.

2012-01-01

Many researchers recognize that factor analysis can be conducted on both correlation matrices and variance-covariance matrices. Although most researchers extract factors from non-distribution free or parametric methods, researchers can also extract factors from distribution free or non-parametric methods. The nature of the data dictates the method…

Psychometric analysis of the new ADHD DSM-V derived symptoms.

PubMed

Ghanizadeh, Ahmad

2012-03-20

Following the agreements on the reformulating and revising of ADHD diagnostic criteria, recently, the proposed revision for ADHD added 4 new symptoms to the hyperactivity and Impulsivity aspect in DSM-V. This study investigates the psychometric properties of the proposed ADHD diagnostic criteria. ADHD diagnosis was made according to DSM-IV. The parents completed the screening test of ADHD checklist of Child Symptom Inventory-4 and the 4 items describing the new proposed symptoms in DSM-V. The confirmatory factor analysis of the ADHD DSM-V derived items supports the loading of two factors including inattentiveness and hyperactivity/impulsivity. There is a sufficient reliability for the items. However, confirmatory factor analysis showed that the three-factor model is better fitted than the two-factor one. Moreover, the results of the exploratory analysis raised some concerns about the factor loading of the four new items. The current results support the two-factor model of the DSM-V ADHD diagnostic criteria including inattentiveness and hyperactivity/impulsivity. However, the four new items can be considered as a third factor.

Sexual Harassment Retaliation Climate DEOCS 4.1 Construct Validity Summary

DTIC Science & Technology

2017-08-01

exploratory factor analysis, and bivariate correlations (sample 1) 2) To determine the factor structure of the remaining (final) questions via...statistics, reliability analysis, exploratory factor analysis, and bivariate correlations of the prospective Sexual Harassment Retaliation Climate...reported by the survey requester). For information regarding the composition of sample, refer to Table 1. Table 1. Sample 1 Demographics n

Frailty and Cognitive Function in Incident Hemodialysis Patients

PubMed Central

Tan, Jingwen; Salter, Megan L.; Gross, Alden; Meoni, Lucy A.; Jaar, Bernard G.; Kao, Wen-Hong Linda; Parekh, Rulan S.; Segev, Dorry L.; Sozio, Stephen M.

2015-01-01

Background and objectives Patients of all ages undergoing hemodialysis (HD) have a high prevalence of cognitive impairment and worse cognitive function than healthy controls, and those with dementia are at high risk of death. Frailty has been associated with poor cognitive function in older adults without kidney disease. We hypothesized that frailty might also be associated with poor cognitive function in adults of all ages undergoing HD. Design, setting, participants, & measurements At HD initiation, 324 adults enrolled (November 2008 to July 2012) in a longitudinal cohort study (Predictors of Arrhythmic and Cardiovascular Risk in ESRD) were classified into three groups (frail, intermediately frail, and nonfrail) based on the Fried frailty phenotype. Global cognitive function (3MS) and speed/attention (Trail Making Tests A and B [TMTA and TMTB, respectively]) were assessed at cohort entry and 1-year follow-up. Associations between frailty and cognitive function (at cohort entry and 1-year follow-up) were evaluated in adjusted (for sex, age, race, body mass index, education, depression and comorbidity at baseline) linear (3MS, TMTA) and Tobit (TMTB) regression models. Results At cohort entry, the mean age was 54.8 years (SD 13.3), 56.5% were men, and 72.8% were black. The prevalence of frailty and intermediate frailty were 34.0% and 37.7%, respectively. The mean 3MS was 89.8 (SD 7.6), TMTA was 55.4 (SD 29), and TMTB was 161 (SD 83). Frailty was independently associated with lower cognitive function at cohort entry for all three measures (3MS: −2.4 points; 95% confidence interval [95% CI], −4.2 to −0.5; P=0.01; TMTA: 12.1 seconds; 95% CI, 4.7 to 19.4; P<0.001; and TMTB: 33.2 seconds; 95% CI, 9.9 to 56.4; P=0.01; all tests for trend, P<0.001) and with worse 3MS at 1-year follow-up (−2.8 points; 95% CI, −5.4 to −0.2; P=0.03). Conclusions In adult incident HD patients, frailty is associated with worse cognitive function, particularly global cognitive function (3MS). PMID:26573615

Data Used in Analyses of Trends, and Nutrient and Suspended-Sediment Loads for Streams in the Southeastern United States, 1973-2005

USGS Publications Warehouse

Staub, Erik L.; Peak, Kelly L.; Tighe, Kirsten C.; Sadorf, Eric M.; Harned, Douglas A.

2010-01-01

Water-quality data from selected surface-water monitoring sites in the Southeastern United States were assessed for trends in concentrations of nutrients, suspended sediment, and major constituents and for in-stream nutrient and suspended-sediment loads for the period 1973-2005. The area of interest includes river basins draining into the southern Atlantic Ocean, the Gulf of Mexico, and the Tennessee River-drainage basins in Hydrologic Regions 03 (South Atlantic - Gulf) and 06 (Tennessee). This data assessment is related to studies of several major river basins as part of the U.S. Geological Survey National Water-Quality Assessment Program, which was designed to assess national water-quality trends during a common time period (1993-2004). Included in this report are data on which trend tests could be performed from 44 U.S. Geological Survey National Water Information System (NWIS) sampling sites. The constituents examined include major ions, nutrients, and suspended sediment; the physical properties examined include pH, specific conductance, dissolved oxygen, and streamflow. Also included are data that were tested for trends from an additional 290 sites from the U.S. Environmental Protection Agency Storage and Retrieval (STORET) database. The trend analyses of the STORET data were limited to total nitrogen and total phosphorus concentrations. Data from 48 U.S. Geological Survey NWIS sampling sites with sufficient water-quality and continuous streamflow data for estimating nutrient and sediment loads are included. The methods of data compilation and modification used prior to performing trend tests and load estimation are described. Results of the seasonal Kendall trend test and the Tobit trend test are given for the 334 monitoring sites, and in-stream load estimates are given for the 48 monitoring sites. Basin characteristics are provided, including regional landscape variables and agricultural nutrient sources (annual variations in cropping and fertilizer use). The data and results presented in this report are in tabular format and can be downloaded and used by environmental researchers and water managers, particularly in the Southeast.

Inferring biogeochemistry past: a millennial-scale multimodel assimilation of multiple paleoecological proxies.

NASA Astrophysics Data System (ADS)

Dietze, M.; Raiho, A.; Fer, I.; Dawson, A.; Heilman, K.; Hooten, M.; McLachlan, J. S.; Moore, D. J.; Paciorek, C. J.; Pederson, N.; Rollinson, C.; Tipton, J.

2017-12-01

The pre-industrial period serves as an essential baseline against which we judge anthropogenic impacts on the earth's systems. However, direct measurements of key biogeochemical processes, such as carbon, water, and nutrient cycling, are absent for this period and there is no direct way to link paleoecological proxies, such as pollen and tree rings, to these processes. Process-based terrestrial ecosystem models provide a way to make inferences about the past, but have large uncertainties and by themselves often fail to capture much of the observed variability. Here we investigate the ability to improve inferences about pre-industrial biogeochemical cycles through the formal assimilation of proxy data into multiple process-based models. A Tobit ensemble filter with explicit estimation of process error was run at five sites across the eastern US for three models (LINKAGES, ED2, LPJ-GUESS). In addition to process error, the ensemble accounted for parameter uncertainty, estimated through the assimilation of the TRY and BETY trait databases, and driver uncertainty, accommodated by probabilistically downscaling and debiasing CMIP5 GCM output then filtering based on paleoclimate reconstructions. The assimilation was informed by four PalEON data products, each of which includes an explicit Bayesian error estimate: (1) STEPPS forest composition estimated from fossil pollen; (2) REFAB aboveground biomass (AGB) estimated from fossil pollen; (3) tree ring AGB and woody net primary productivity (wNPP); and (4) public land survey composition, stem density, and AGB. By comparing ensemble runs with and without data assimilation we are able to assess the information contribution of the proxy data to constraining biogeochemical fluxes, which is driven by the combination of model uncertainty, data uncertainty, and the strength of correlation between observed and unobserved quantities in the model ensemble. To our knowledge this is the first attempt at multi-model data assimilation with terrestrial ecosystem models. Results from the data-model assimilation allow us to assess the consistency across models in post-assimilation inferences about indirectly inferred quantities, such as GPP, soil carbon, and the water budget.

Magnesium intake is inversely associated with coronary artery calcification: the Framingham Heart Study.

PubMed

Hruby, Adela; O'Donnell, Christopher J; Jacques, Paul F; Meigs, James B; Hoffmann, Udo; McKeown, Nicola M

2014-01-01

The aim of this study was to examine whether magnesium intake is associated with coronary artery calcification (CAC) and abdominal aortic calcification (AAC). Animal and cell studies suggest that magnesium may prevent calcification within atherosclerotic plaques underlying cardiovascular disease. Little is known about the association of magnesium intake and atherosclerotic calcification in humans. We examined cross-sectional associations of self-reported total (dietary and supplemental) magnesium intake estimated by food frequency questionnaire with CAC and AAC in participants of the Framingham Heart Study who were free of cardiovascular disease and underwent Multi-Detector Computed Tomography (MDCT) of the heart and abdomen (n = 2,695; age: 53 ± 11 years), using multivariate-adjusted Tobit regression. CAC and AAC were quantified using modified Agatston scores (AS). Models were adjusted for age, sex, body mass index, smoking status, systolic blood pressure, fasting insulin, total-to-high-density lipoprotein cholesterol ratio, use of hormone replacement therapy (women only), menopausal status (women only), treatment for hyperlipidemia, hypertension, cardiovascular disease prevention, or diabetes, as well as self-reported intake of calcium, vitamins D and K, saturated fat, fiber, alcohol, and energy. Secondary analyses included logistic regressions of CAC and AAC outcomes as cut-points (AS >0 and AS ≥90th percentile for age and sex), as well as sex-stratified analyses. In fully adjusted models, a 50-mg/day increment in self-reported total magnesium intake was associated with 22% lower CAC (p < 0.001) and 12% lower AAC (p = 0.07). Consistent with these observations, the odds of having any CAC were 58% lower (p trend: <0.001) and any AAC were 34% lower (p trend: 0.01), in those with the highest compared to those with the lowest magnesium intake. Stronger inverse associations were observed in women than in men. In community-dwelling participants free of cardiovascular disease, self-reported magnesium intake was inversely associated with arterial calcification, which may play a contributing role in magnesium's protective associations in stroke and fatal coronary heart disease. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Magnesium Intake Is Inversely Associated With Coronary Artery Calcification

PubMed Central

Hruby, Adela; O'Donnell, Christopher J.; Jacques, Paul F.; Meigs, James B.; Hoffmann, Udo; McKeown, Nicola M.

2014-01-01

OBJECTIVES The aim of this study was to examine whether magnesium intake is associated with coronary artery calcification (CAC) and abdominal aortic calcification (AAC). BACKGROUND Animal and cell studies suggest that magnesium may prevent calcification within atherosclerotic plaques underlying cardiovascular disease. Little is known about the association of magnesium intake and atherosclerotic calcification in humans. METHODS We examined cross-sectional associations of self-reported total (dietary and supplemental) magnesium intake estimated by food frequency questionnaire with CAC and AAC in participants of the Framingham Heart Study who were free of cardiovascular disease and underwent Multi-Detector Computed Tomography (MDCT) of the heart and abdomen (n = 2,695; age: 53 ± 11 years), using multivariate-adjusted Tobit regression. CAC and AAC were quantified using modified Agatston scores (AS). Models were adjusted for age, sex, body mass index, smoking status, systolic blood pressure, fasting insulin, total-to-high-density lipoprotein cholesterol ratio, use of hormone replacement therapy (women only), menopausal status (women only), treatment for hyperlipidemia, hypertension, cardiovascular disease prevention, or diabetes, as well as self-reported intake of calcium, vitamins D and K, saturated fat, fiber, alcohol, and energy. Secondary analyses included logistic regressions of CAC and AAC outcomes as cut-points (AS >0 and AS ≥90th percentile for age and sex), as well as sex-stratified analyses. RESULTS In fully adjusted models, a 50-mg/day increment in self-reported total magnesium intake was associated with 22% lower CAC (p < 0.001) and 12% lower AAC (p = 0.07). Consistent with these observations, the odds of having any CAC were 58% lower (p trend: <0.001) and any AAC were 34% lower (p trend: 0.01), in those with the highest compared to those with the lowest magnesium intake. Stronger inverse associations were observed in women than in men. CONCLUSIONS In community-dwelling participants free of cardiovascular disease, self-reported magnesium intake was inversely associated with arterial calcification, which may play a contributing role in magnesium's protective associations in stroke and fatal coronary heart disease. PMID:24290571

Depressive symptoms are associated with salivary shedding of Epstein-Barr virus in female adolescents: The role of sex differences.

PubMed

Ford, Jodi L; Stowe, Raymond P

2017-12-01

Adolescent females have a higher prevalence of depression in comparison to their male peers - a disparity that has been increasing over the past decade. Depression is of concern as it is associated with chronic disease and to immune dysregulation, which may be one mechanism linking depression to future pathology. This study examined the extent to which sex moderated the association between depressive symptoms and immune dysregulation during adolescence using Epstein-Barr virus (EBV) reactivation, a biomarker of cellular immune response, as a model. A representative community sample of 259 female and 279 male adolescents aged 11-17 years who were EBV IgG positive were examined. Trained interviewers collected the data during two home visits, one week apart. Depressive symptoms were measured at the first visit using the 9 item short-form of the Center for Epidemiologic Studies-Depression scale. EBV biomarkers were collected via saliva at the second visit and included a qualitative measure of EBV viral capsid antigen immunoglobulin G to assess prior EBV infection and a quantitative measure of EBV DNA to assess the number of viral copies shed in the saliva. In multivariable logistic regression analyses, increasing depressive symptoms were significantly associated with salivary shedding of EBV DNA for adolescent females only (logit=0.66, se=0.30, p<0.05), and the interaction between sex and depressive symptoms on salivary shedding of EBV DNA was statistically significant (logit=-1.19, se=0.42, p<0.01). Sensitivity analyses were conducted in which sex was examined as a moderator in the relationship between depressive symptoms and salivary EBV DNA quantitative copies via Tobit regression; results were consistent with the presented findings. Depressive symptoms are associated with EBV reactivation among EBV positive female adolescents, but not males. Future research is needed to examine EBV reactivation in female adolescents as a mechanism linking depression to future chronic disease and the role of sex hormones in explaining sex differences in the relationship between depressive symptoms and EBV reactivation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mapping health assessment questionnaire disability index (HAQ-DI) score, pain visual analog scale (VAS), and disease activity score in 28 joints (DAS28) onto the EuroQol-5D (EQ-5D) utility score with the KORean Observational study Network for Arthritis (KORONA) registry data.

PubMed

Kim, Hye-Lin; Kim, Dam; Jang, Eun Jin; Lee, Min-Young; Song, Hyun Jin; Park, Sun-Young; Cho, Soo-Kyung; Sung, Yoon-Kyoung; Choi, Chan-Bum; Won, Soyoung; Bang, So-Young; Cha, Hoon-Suk; Choe, Jung-Yoon; Chung, Won Tae; Hong, Seung-Jae; Jun, Jae-Bum; Kim, Jinseok; Kim, Seong-Kyu; Kim, Tae-Hwan; Kim, Tae-Jong; Koh, Eunmi; Lee, Hwajeong; Lee, Hye-Soon; Lee, Jisoo; Lee, Shin-Seok; Lee, Sung Won; Park, Sung-Hoon; Shim, Seung-Cheol; Yoo, Dae-Hyun; Yoon, Bo Young; Bae, Sang-Cheol; Lee, Eui-Kyung

2016-04-01

The aim of this study was to estimate the mapping model for EuroQol-5D (EQ-5D) utility values using the health assessment questionnaire disability index (HAQ-DI), pain visual analog scale (VAS), and disease activity score in 28 joints (DAS28) in a large, nationwide cohort of rheumatoid arthritis (RA) patients in Korea. The KORean Observational study Network for Arthritis (KORONA) registry data on 3557 patients with RA were used. Data were randomly divided into a modeling set (80 % of the data) and a validation set (20 % of the data). The ordinary least squares (OLS), Tobit, and two-part model methods were employed to construct a model to map to the EQ-5D index. Using a combination of HAQ-DI, pain VAS, and DAS28, four model versions were examined. To evaluate the predictive accuracy of the models, the root-mean-square error (RMSE) and mean absolute error (MAE) were calculated using the validation dataset. A model that included HAQ-DI, pain VAS, and DAS28 produced the highest adjusted R (2) as well as the lowest Akaike information criterion, RMSE, and MAE, regardless of the statistical methods used in modeling set. The mapping equation of the OLS method is given as EQ-5D = 0.95-0.21 × HAQ-DI-0.24 × pain VAS/100-0.01 × DAS28 (adjusted R (2) = 57.6 %, RMSE = 0.1654 and MAE = 0.1222). Also in the validation set, the RMSE and MAE were shown to be the smallest. The model with HAQ-DI, pain VAS, and DAS28 showed the best performance, and this mapping model enabled the estimation of an EQ-5D value for RA patients in whom utility values have not been measured.

A comprehensive probabilistic analysis model of oil pipelines network based on Bayesian network

NASA Astrophysics Data System (ADS)

Zhang, C.; Qin, T. X.; Jiang, B.; Huang, C.

2018-02-01

Oil pipelines network is one of the most important facilities of energy transportation. But oil pipelines network accident may result in serious disasters. Some analysis models for these accidents have been established mainly based on three methods, including event-tree, accident simulation and Bayesian network. Among these methods, Bayesian network is suitable for probabilistic analysis. But not all the important influencing factors are considered and the deployment rule of the factors has not been established. This paper proposed a probabilistic analysis model of oil pipelines network based on Bayesian network. Most of the important influencing factors, including the key environment condition and emergency response are considered in this model. Moreover, the paper also introduces a deployment rule for these factors. The model can be used in probabilistic analysis and sensitive analysis of oil pipelines network accident.

Global sensitivity analysis for urban water quality modelling: Terminology, convergence and comparison of different methods

NASA Astrophysics Data System (ADS)

Vanrolleghem, Peter A.; Mannina, Giorgio; Cosenza, Alida; Neumann, Marc B.

2015-03-01

Sensitivity analysis represents an important step in improving the understanding and use of environmental models. Indeed, by means of global sensitivity analysis (GSA), modellers may identify both important (factor prioritisation) and non-influential (factor fixing) model factors. No general rule has yet been defined for verifying the convergence of the GSA methods. In order to fill this gap this paper presents a convergence analysis of three widely used GSA methods (SRC, Extended FAST and Morris screening) for an urban drainage stormwater quality-quantity model. After the convergence was achieved the results of each method were compared. In particular, a discussion on peculiarities, applicability, and reliability of the three methods is presented. Moreover, a graphical Venn diagram based classification scheme and a precise terminology for better identifying important, interacting and non-influential factors for each method is proposed. In terms of convergence, it was shown that sensitivity indices related to factors of the quantity model achieve convergence faster. Results for the Morris screening method deviated considerably from the other methods. Factors related to the quality model require a much higher number of simulations than the number suggested in literature for achieving convergence with this method. In fact, the results have shown that the term "screening" is improperly used as the method may exclude important factors from further analysis. Moreover, for the presented application the convergence analysis shows more stable sensitivity coefficients for the Extended-FAST method compared to SRC and Morris screening. Substantial agreement in terms of factor fixing was found between the Morris screening and Extended FAST methods. In general, the water quality related factors exhibited more important interactions than factors related to water quantity. Furthermore, in contrast to water quantity model outputs, water quality model outputs were found to be characterised by high non-linearity.

Proposal for a recovery prediction method for patients affected by acute mediastinitis

PubMed Central

2012-01-01

Background An attempt to find a prediction method of death risk in patients affected by acute mediastinitis. There is not such a tool described in available literature for that serious disease. Methods The study comprised 44 consecutive cases of acute mediastinitis. General anamnesis and biochemical data were included. Factor analysis was used to extract the risk characteristic for the patients. The most valuable results were obtained for 8 parameters which were selected for further statistical analysis (all collected during few hours after admission). Three factors reached Eigenvalue >1. Clinical explanations of these combined statistical factors are: Factor1 - proteinic status (serum total protein, albumin, and hemoglobin level), Factor2 - inflammatory status (white blood cells, CRP, procalcitonin), and Factor3 - general risk (age, number of coexisting diseases). Threshold values of prediction factors were estimated by means of statistical analysis (factor analysis, Statgraphics Centurion XVI). Results The final prediction result for the patients is constructed as simultaneous evaluation of all factor scores. High probability of death should be predicted if factor 1 value decreases with simultaneous increase of factors 2 and 3. The diagnostic power of the proposed method was revealed to be high [sensitivity =90%, specificity =64%], for Factor1 [SNC = 87%, SPC = 79%]; for Factor2 [SNC = 87%, SPC = 50%] and for Factor3 [SNC = 73%, SPC = 71%]. Conclusion The proposed prediction method seems a useful emergency signal during acute mediastinitis control in affected patients. PMID:22574625

Independent Prognostic Factors for Acute Organophosphorus Pesticide Poisoning.

PubMed

Tang, Weidong; Ruan, Feng; Chen, Qi; Chen, Suping; Shao, Xuebo; Gao, Jianbo; Zhang, Mao

2016-07-01

Acute organophosphorus pesticide poisoning (AOPP) is becoming a significant problem and a potential cause of human mortality because of the abuse of organophosphate compounds. This study aims to determine the independent prognostic factors of AOPP by using multivariate logistic regression analysis. The clinical data for 71 subjects with AOPP admitted to our hospital were retrospectively analyzed. This information included the Acute Physiology and Chronic Health Evaluation II (APACHE II) scores, 6-h post-admission blood lactate levels, post-admission 6-h lactate clearance rates, admission blood cholinesterase levels, 6-h post-admission blood cholinesterase levels, cholinesterase activity, blood pH, and other factors. Univariate analysis and multivariate logistic regression analyses were conducted to identify all prognostic factors and independent prognostic factors, respectively. A receiver operating characteristic curve was plotted to analyze the testing power of independent prognostic factors. Twelve of 71 subjects died. Admission blood lactate levels, 6-h post-admission blood lactate levels, post-admission 6-h lactate clearance rates, blood pH, and APACHE II scores were identified as prognostic factors for AOPP according to the univariate analysis, whereas only 6-h post-admission blood lactate levels, post-admission 6-h lactate clearance rates, and blood pH were independent prognostic factors identified by multivariate logistic regression analysis. The receiver operating characteristic analysis suggested that post-admission 6-h lactate clearance rates were of moderate diagnostic value. High 6-h post-admission blood lactate levels, low blood pH, and low post-admission 6-h lactate clearance rates were independent prognostic factors identified by multivariate logistic regression analysis. Copyright © 2016 by Daedalus Enterprises.

Estimation of the behavior factor of existing RC-MRF buildings

NASA Astrophysics Data System (ADS)

Vona, Marco; Mastroberti, Monica

2018-01-01

In recent years, several research groups have studied a new generation of analysis methods for seismic response assessment of existing buildings. Nevertheless, many important developments are still needed in order to define more reliable and effective assessment procedures. Moreover, regarding existing buildings, it should be highlighted that due to the low knowledge level, the linear elastic analysis is the only analysis method allowed. The same codes (such as NTC2008, EC8) consider the linear dynamic analysis with behavior factor as the reference method for the evaluation of seismic demand. This type of analysis is based on a linear-elastic structural model subject to a design spectrum, obtained by reducing the elastic spectrum through a behavior factor. The behavior factor (reduction factor or q factor in some codes) is used to reduce the elastic spectrum ordinate or the forces obtained from a linear analysis in order to take into account the non-linear structural capacities. The behavior factors should be defined based on several parameters that influence the seismic nonlinear capacity, such as mechanical materials characteristics, structural system, irregularity and design procedures. In practical applications, there is still an evident lack of detailed rules and accurate behavior factor values adequate for existing buildings. In this work, some investigations of the seismic capacity of the main existing RC-MRF building types have been carried out. In order to make a correct evaluation of the seismic force demand, actual behavior factor values coherent with force based seismic safety assessment procedure have been proposed and compared with the values reported in the Italian seismic code, NTC08.

Exploratory factor analysis of borderline personality disorder criteria in hospitalized adolescents.

PubMed

Becker, Daniel F; McGlashan, Thomas H; Grilo, Carlos M

2006-01-01

The authors examined the factor structure of borderline personality disorder (BPD) in hospitalized adolescents and also sought to add to the theoretical and clinical understanding of any homogeneous components by determining whether they may be related to specific forms of Axis I pathology. Subjects were 123 adolescent inpatients, who were reliably assessed with structured diagnostic interviews for Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition Axes I and II disorders. Exploratory factor analysis identified BPD components, and logistic regression analyses tested whether these components were predictive of specific Axis I disorders. Factor analysis revealed a 4-factor solution that accounted for 67.0% of the variance. Factor 1 ("suicidal threats or gestures" and "emptiness or boredom") predicted depressive disorders and alcohol use disorders. Factor 2 ("affective instability," "uncontrolled anger," and "identity disturbance") predicted anxiety disorders and oppositional defiant disorder. Factor 3 ("unstable relationships" and "abandonment fears") predicted only anxiety disorders. Factor 4 ("impulsiveness" and "identity disturbance") predicted conduct disorder and substance use disorders. Exploratory factor analysis of BPD criteria in adolescent inpatients revealed 4 BPD factors that appear to differ from those reported for similar studies of adults. The factors represent components of self-negation, irritability, poorly modulated relationships, and impulsivity--each of which is associated with characteristic Axis I pathology. These findings shed light on the nature of BPD in adolescents and may also have implications for treatment.

Factor analysis of the Zung self-rating depression scale in a large sample of patients with major depressive disorder in primary care.

PubMed

Romera, Irene; Delgado-Cohen, Helena; Perez, Teresa; Caballero, Luis; Gilaberte, Immaculada

2008-01-14

The aim of this study was to examine the symptomatic dimensions of depression in a large sample of patients with major depressive disorder (MDD) in the primary care (PC) setting by means of a factor analysis of the Zung self-rating depression scale (ZSDS). A factor analysis was performed, based on the polychoric correlations matrix, between ZSDS items using promax oblique rotation in 1049 PC patients with a diagnosis of MDD (DSM-IV). A clinical interpretable four-factor solution consisting of a core depressive factor (I); a cognitive factor (II); an anxiety factor (III) and a somatic factor (IV) was extracted. These factors accounted for 36.9% of the variance on the ZSDS. The 4-factor structure was validated and high coefficients of congruence were obtained (0.98, 0.95, 0.92 and 0.87 for factors I, II, III and IV, respectively). The model seemed to fit the data well with fit indexes within recommended ranges (GFI = 0.9330, AGFI = 0.9112 and RMR = 0.0843). Our findings suggest that depressive symptoms in patients with MDD in the PC setting cluster into four dimensions: core depressive, cognitive, anxiety and somatic, by means of a factor analysis of the ZSDS. Further research is needed to identify possible diagnostic, therapeutic or prognostic implications of the different depressive symptomatic profiles.

Factor analysis of the Zung self-rating depression scale in a large sample of patients with major depressive disorder in primary care

PubMed Central

Romera, Irene; Delgado-Cohen, Helena; Perez, Teresa; Caballero, Luis; Gilaberte, Immaculada

2008-01-01

Background The aim of this study was to examine the symptomatic dimensions of depression in a large sample of patients with major depressive disorder (MDD) in the primary care (PC) setting by means of a factor analysis of the Zung self-rating depression scale (ZSDS). Methods A factor analysis was performed, based on the polychoric correlations matrix, between ZSDS items using promax oblique rotation in 1049 PC patients with a diagnosis of MDD (DSM-IV). Results A clinical interpretable four-factor solution consisting of a core depressive factor (I); a cognitive factor (II); an anxiety factor (III) and a somatic factor (IV) was extracted. These factors accounted for 36.9% of the variance on the ZSDS. The 4-factor structure was validated and high coefficients of congruence were obtained (0.98, 0.95, 0.92 and 0.87 for factors I, II, III and IV, respectively). The model seemed to fit the data well with fit indexes within recommended ranges (GFI = 0.9330, AGFI = 0.9112 and RMR = 0.0843). Conclusion Our findings suggest that depressive symptoms in patients with MDD in the PC setting cluster into four dimensions: core depressive, cognitive, anxiety and somatic, by means of a factor analysis of the ZSDS. Further research is needed to identify possible diagnostic, therapeutic or prognostic implications of the different depressive symptomatic profiles. PMID:18194524

Factor structure of the Japanese version of the Edinburgh Postnatal Depression Scale in the postpartum period.

PubMed

Kubota, Chika; Okada, Takashi; Aleksic, Branko; Nakamura, Yukako; Kunimoto, Shohko; Morikawa, Mako; Shiino, Tomoko; Tamaji, Ai; Ohoka, Harue; Banno, Naomi; Morita, Tokiko; Murase, Satomi; Goto, Setsuko; Kanai, Atsuko; Masuda, Tomoko; Ando, Masahiko; Ozaki, Norio

2014-01-01

The Edinburgh Postnatal Depression Scale (EPDS) is a widely used screening tool for postpartum depression (PPD). Although the reliability and validity of EPDS in Japanese has been confirmed and the prevalence of PPD is found to be about the same as Western countries, the factor structure of the Japanese version of EPDS has not been elucidated yet. 690 Japanese mothers completed all items of the EPDS at 1 month postpartum. We divided them randomly into two sample sets. The first sample set (n = 345) was used for exploratory factor analysis, and the second sample set was used (n = 345) for confirmatory factor analysis. The result of exploratory factor analysis indicated a three-factor model consisting of anxiety, depression and anhedonia. The results of confirmatory factor analysis suggested that the anxiety and anhedonia factors existed for EPDS in a sample of Japanese women at 1 month postpartum. The depression factor varies by the models of acceptable fit. We examined EPDS scores. As a result, "anxiety" and "anhedonia" exist for EPDS among postpartum women in Japan as already reported in Western countries. Cross-cultural research is needed for future research.

Factor analysis of serogroups botanica and aurisina of Leptospira biflexa.

PubMed

Cinco, M

1977-11-01

Factor analysis is performed on serovars of Botanica and Aurisina serogroup of Leptospira biflexa. The results show the arrangement of main factors serovar and serogroup specific, as well as the antigens common with serovars of heterologous serogroups.

Identifying Items to Assess Methodological Quality in Physical Therapy Trials: A Factor Analysis

PubMed Central

Cummings, Greta G.; Fuentes, Jorge; Saltaji, Humam; Ha, Christine; Chisholm, Annabritt; Pasichnyk, Dion; Rogers, Todd

2014-01-01

Background Numerous tools and individual items have been proposed to assess the methodological quality of randomized controlled trials (RCTs). The frequency of use of these items varies according to health area, which suggests a lack of agreement regarding their relevance to trial quality or risk of bias. Objective The objectives of this study were: (1) to identify the underlying component structure of items and (2) to determine relevant items to evaluate the quality and risk of bias of trials in physical therapy by using an exploratory factor analysis (EFA). Design A methodological research design was used, and an EFA was performed. Methods Randomized controlled trials used for this study were randomly selected from searches of the Cochrane Database of Systematic Reviews. Two reviewers used 45 items gathered from 7 different quality tools to assess the methodological quality of the RCTs. An exploratory factor analysis was conducted using the principal axis factoring (PAF) method followed by varimax rotation. Results Principal axis factoring identified 34 items loaded on 9 common factors: (1) selection bias; (2) performance and detection bias; (3) eligibility, intervention details, and description of outcome measures; (4) psychometric properties of the main outcome; (5) contamination and adherence to treatment; (6) attrition bias; (7) data analysis; (8) sample size; and (9) control and placebo adequacy. Limitation Because of the exploratory nature of the results, a confirmatory factor analysis is needed to validate this model. Conclusions To the authors' knowledge, this is the first factor analysis to explore the underlying component items used to evaluate the methodological quality or risk of bias of RCTs in physical therapy. The items and factors represent a starting point for evaluating the methodological quality and risk of bias in physical therapy trials. Empirical evidence of the association among these items with treatment effects and a confirmatory factor analysis of these results are needed to validate these items. PMID:24786942

Identifying items to assess methodological quality in physical therapy trials: a factor analysis.

PubMed

Armijo-Olivo, Susan; Cummings, Greta G; Fuentes, Jorge; Saltaji, Humam; Ha, Christine; Chisholm, Annabritt; Pasichnyk, Dion; Rogers, Todd

2014-09-01

Numerous tools and individual items have been proposed to assess the methodological quality of randomized controlled trials (RCTs). The frequency of use of these items varies according to health area, which suggests a lack of agreement regarding their relevance to trial quality or risk of bias. The objectives of this study were: (1) to identify the underlying component structure of items and (2) to determine relevant items to evaluate the quality and risk of bias of trials in physical therapy by using an exploratory factor analysis (EFA). A methodological research design was used, and an EFA was performed. Randomized controlled trials used for this study were randomly selected from searches of the Cochrane Database of Systematic Reviews. Two reviewers used 45 items gathered from 7 different quality tools to assess the methodological quality of the RCTs. An exploratory factor analysis was conducted using the principal axis factoring (PAF) method followed by varimax rotation. Principal axis factoring identified 34 items loaded on 9 common factors: (1) selection bias; (2) performance and detection bias; (3) eligibility, intervention details, and description of outcome measures; (4) psychometric properties of the main outcome; (5) contamination and adherence to treatment; (6) attrition bias; (7) data analysis; (8) sample size; and (9) control and placebo adequacy. Because of the exploratory nature of the results, a confirmatory factor analysis is needed to validate this model. To the authors' knowledge, this is the first factor analysis to explore the underlying component items used to evaluate the methodological quality or risk of bias of RCTs in physical therapy. The items and factors represent a starting point for evaluating the methodological quality and risk of bias in physical therapy trials. Empirical evidence of the association among these items with treatment effects and a confirmatory factor analysis of these results are needed to validate these items. © 2014 American Physical Therapy Association.

Factor analysis and multiple regression between topography and precipitation on Jeju Island, Korea

NASA Astrophysics Data System (ADS)

Um, Myoung-Jin; Yun, Hyeseon; Jeong, Chang-Sam; Heo, Jun-Haeng

2011-11-01

SummaryIn this study, new factors that influence precipitation were extracted from geographic variables using factor analysis, which allow for an accurate estimation of orographic precipitation. Correlation analysis was also used to examine the relationship between nine topographic variables from digital elevation models (DEMs) and the precipitation in Jeju Island. In addition, a spatial analysis was performed in order to verify the validity of the regression model. From the results of the correlation analysis, it was found that all of the topographic variables had a positive correlation with the precipitation. The relations between the variables also changed in accordance with a change in the precipitation duration. However, upon examining the correlation matrix, no significant relationship between the latitude and the aspect was found. According to the factor analysis, eight topographic variables (latitude being the exception) were found to have a direct influence on the precipitation. Three factors were then extracted from the eight topographic variables. By directly comparing the multiple regression model with the factors (model 1) to the multiple regression model with the topographic variables (model 3), it was found that model 1 did not violate the limits of statistical significance and multicollinearity. As such, model 1 was considered to be appropriate for estimating the precipitation when taking into account the topography. In the study of model 1, the multiple regression model using factor analysis was found to be the best method for estimating the orographic precipitation on Jeju Island.

Examining evolving performance on the Force Concept Inventory using factor analysis

NASA Astrophysics Data System (ADS)

Semak, M. R.; Dietz, R. D.; Pearson, R. H.; Willis, C. W.

2017-06-01

The application of factor analysis to the Force Concept Inventory (FCI) has proven to be problematic. Some studies have suggested that factor analysis of test results serves as a helpful tool in assessing the recognition of Newtonian concepts by students. Other work has produced at best ambiguous results. For the FCI administered as a pre- and post-test, we see factor analysis as a tool by which the changes in conceptual associations made by our students may be gauged given the evolution of their response patterns. This analysis allows us to identify and track conceptual linkages, affording us insight as to how our students have matured due to instruction. We report on our analysis of 427 pre- and post-tests. The factor models for the pre- and post-tests are explored and compared along with the methodology by which these models were fit to the data. The post-test factor pattern is more aligned with an expert's interpretation of the questions' content, as it allows for a more readily identifiable relationship between factors and physical concepts. We discuss this evolution in the context of approaching the characteristics of an expert with force concepts. Also, we find that certain test items do not significantly contribute to the pre- or post-test factor models and attempt explanations as to why this is so. This may suggest that such questions may not be effective in probing the conceptual understanding of our students.

Exploratory factor analysis in Rehabilitation Psychology: a content analysis.

PubMed

Roberson, Richard B; Elliott, Timothy R; Chang, Jessica E; Hill, Jessica N

2014-11-01

Our objective was to examine the use and quality of exploratory factor analysis (EFA) in articles published in Rehabilitation Psychology. Trained raters examined 66 separate exploratory factor analyses in 47 articles published between 1999 and April 2014. The raters recorded the aim of the EFAs, the distributional statistics, sample size, factor retention method(s), extraction and rotation method(s), and whether the pattern coefficients, structure coefficients, and the matrix of association were reported. The primary use of the EFAs was scale development, but the most widely used extraction and rotation method was principle component analysis, with varimax rotation. When determining how many factors to retain, multiple methods (e.g., scree plot, parallel analysis) were used most often. Many articles did not report enough information to allow for the duplication of their results. EFA relies on authors' choices (e.g., factor retention rules extraction, rotation methods), and few articles adhered to all of the best practices. The current findings are compared to other empirical investigations into the use of EFA in published research. Recommendations for improving EFA reporting practices in rehabilitation psychology research are provided.

Factor Structure of the Student-Teacher Relationship Scale for Norwegian School-Age Children Explored with Confirmatory Factor Analysis

ERIC Educational Resources Information Center

Drugli, May Britt; Hjemdal, Odin

2013-01-01

The validity of the Student-Teacher Relationship Scale (STRS) was examined in a national sample of 863 Norwegian schoolchildren in grades 1-7 (aged 6-13). The original factor structure of the STRS was tested by confirmatory factor analysis (CFA). The CFA results did not support the original three-factor structure of the STRS. Subsequent CFA of the…

Intrinsic disorder in transcription factors†

PubMed Central

Liu, Jiangang; Perumal, Narayanan B.; Oldfield, Christopher J.; Su, Eric W.; Uversky, Vladimir N.; Dunker, A. Keith

2008-01-01

Intrinsic disorder (ID) is highly abundant in eukaryotes, which reflect the greater need for disorder-associated signaling and transcriptional regulation in nucleated cells. Although several well-characterized examples of intrinsically disordered proteins in transcriptional regulation have been reported, no systematic analysis has been reported so far. To test for a general prevalence of intrinsic disorder in transcriptional regulation, we used the Predictor Of Natural Disorder Regions (PONDR) to analyze the abundance of intrinsic disorder in three transcription factor datasets and two control sets. This analysis revealed that from 94.13% to 82.63% of transcription factors posses extended regions of intrinsic disorder, relative to 54.51% and 18.64% of the proteins in two control datasets, which indicates the significant prevalence of intrinsic disorder in transcription factors. This propensity of transcription factors for intrinsic disorder was confirmed by cumulative distribution function analysis and charge-hydropathy plots. The amino acid composition analysis showed that all three transcription factor datasets were substantially depleted in order-promoting residues, and significantly enriched in disorder-promoting residues. Our analysis of the distribution of disorder within the transcription factor datasets revealed that: (a) The AT-hooks and basic regions of transcription factor DNA-binding domains are highly disordered; (b) The degree of disorder in transcription factor activation regions is much higher than that in DNA-binding domains; (c) The degree of disorder is significantly higher in eukaryotic transcription factors than in prokaryotic transcription factors; (d) The level of α-MoRFs (molecular recognition feature) prediction is much higher in transcription factors. Overall, our data reflected the fact that the eukaryotes with well-developed gene transcription machinery require transcription factor flexibility to be more efficient. PMID:16734424

Logistic Regression and Path Analysis Method to Analyze Factors influencing Students’ Achievement

NASA Astrophysics Data System (ADS)

Noeryanti, N.; Suryowati, K.; Setyawan, Y.; Aulia, R. R.

2018-04-01

Students' academic achievement cannot be separated from the influence of two factors namely internal and external factors. The first factors of the student (internal factors) consist of intelligence (X1), health (X2), interest (X3), and motivation of students (X4). The external factors consist of family environment (X5), school environment (X6), and society environment (X7). The objects of this research are eighth grade students of the school year 2016/2017 at SMPN 1 Jiwan Madiun sampled by using simple random sampling. Primary data are obtained by distributing questionnaires. The method used in this study is binary logistic regression analysis that aims to identify internal and external factors that affect student’s achievement and how the trends of them. Path Analysis was used to determine the factors that influence directly, indirectly or totally on student’s achievement. Based on the results of binary logistic regression, variables that affect student’s achievement are interest and motivation. And based on the results obtained by path analysis, factors that have a direct impact on student’s achievement are students’ interest (59%) and students’ motivation (27%). While the factors that have indirect influences on students’ achievement, are family environment (97%) and school environment (37).

Statistical analysis of microgravity experiment performance using the degrees of success scale

NASA Technical Reports Server (NTRS)

Upshaw, Bernadette; Liou, Ying-Hsin Andrew; Morilak, Daniel P.

1994-01-01

This paper describes an approach to identify factors that significantly influence microgravity experiment performance. Investigators developed the 'degrees of success' scale to provide a numerical representation of success. A degree of success was assigned to 293 microgravity experiments. Experiment information including the degree of success rankings and factors for analysis was compiled into a database. Through an analysis of variance, nine significant factors in microgravity experiment performance were identified. The frequencies of these factors are presented along with the average degree of success at each level. A preliminary discussion of the relationship between the significant factors and the degree of success is presented.

On the Factor Structure of a Reading Comprehension Test

ERIC Educational Resources Information Center

Salehi, Mohammad

2011-01-01

To investigate the construct validly of a section of a high stakes test, an exploratory factor analysis using principal components analysis was employed. The rotation used was varimax with the suppression level of 0.30. Eleven factors were extracted out of 35 reading comprehension items. The fact that these factors emerged speak to the construct…

Multilevel Confirmatory Factor Analysis of a Scale Measuring Interagency Collaboration of Children's Mental Health Agencies

ERIC Educational Resources Information Center

Dedrick, Robert F.; Greenbaum, Paul E.

2011-01-01

Multilevel confirmatory factor analysis was used to evaluate the factor structure underlying the 12-item, three-factor "Interagency Collaboration Activities Scale" (ICAS) at the informant level and at the agency level. Results from 378 professionals (104 administrators, 201 service providers, and 73 case managers) from 32 children's mental health…

Understanding Older Adults' Perceptions of Internet Use: An Exploratory Factor Analysis

ERIC Educational Resources Information Center

Zheng, Robert; Spears, Jeffrey; Luptak, Marilyn; Wilby, Frances

2015-01-01

The current study examined factors related to older adults' perceptions of Internet use. Three hundred ninety five older adults participated in the study. The factor analysis revealed four factors perceived by older adults as critical to their Internet use: social connection, self-efficacy, the need to seek financial information, and the need to…

A Note on Procrustean Rotation in Exploratory Factor Analysis: A Computer Intensive Approach to Goodness-of-Fit Evaluation.

ERIC Educational Resources Information Center

Raykov, Tenko; Little, Todd D.

1999-01-01

Describes a method for evaluating results of Procrustean rotation to a target factor pattern matrix in exploratory factor analysis. The approach, based on the bootstrap method, yields empirical approximations of the sampling distributions of: (1) differences between target elements and rotated factor pattern matrices; and (2) the overall…

Modification and Factor Analysis of the Grief Experience Inventory in Non-Death Loss/Bereavement Situations.

ERIC Educational Resources Information Center

Zinner, Ellen S.; And Others

1991-01-01

Administered Grief Experience Inventory (GEI) to 102 mothers of brain-injured adolescents and young adults across 3 years postinjury. Factor analysis of data was computed and compared to factors derived from original GEI General Reference Group (n=135). Found strikingly similar factor structures between modified nondeath form and original GEI.…

Exploratory and Confirmatory Factor Analyses of the WISC-IV with Gifted Students

ERIC Educational Resources Information Center

Rowe, Ellen W.; Dandridge, Jessica; Pawlush, Alexandra; Thompson, Dawna F.; Ferrier, David E.

2014-01-01

These 2 studies investigated the factor structure of the Wechsler Intelligence Scale for Children-4th edition (WISC-IV; Wechsler, 2003a) with exploratory factor analysis (EFA; Study 1) and confirmatory factor analysis (CFA; Study 2) among 2 independent samples of gifted students. The EFA sample consisted of 225 children who were referred for a…

FACTOR 9.2: A Comprehensive Program for Fitting Exploratory and Semiconfirmatory Factor Analysis and IRT Models

ERIC Educational Resources Information Center

Lorenzo-Seva, Urbano; Ferrando, Pere J.

2013-01-01

FACTOR 9.2 was developed for three reasons. First, exploratory factor analysis (FA) is still an active field of research although most recent developments have not been incorporated into available programs. Second, there is now renewed interest in semiconfirmatory (SC) solutions as suitable approaches to the complex structures are commonly found…

Confirmatory Analysis of Simultaneous, Sequential, and Achievement Factors on the K-ABC at 11 Age Levels Ranging from 2 1/2 to 12 1/2 years.

ERIC Educational Resources Information Center

Willson, Victor L.; And Others

1985-01-01

Presents results of confirmatory factor analysis of the Kaufman Assessment Battery for children which is based on the underlying theoretical model of sequential, simultaneous, and achievement factors. Found support for the two-factor, simultaneous and sequential processing model. (MCF)

Coping Patterns of African American Adolescents: A Confirmatory Factor Analysis and Cluster Analysis of the Children's Coping Strategies Checklist

ERIC Educational Resources Information Center

Gaylord-Harden, Noni K.; Gipson, Polly; Mance, GiShawn; Grant, Kathryn E.

2008-01-01

The current study examined patterns of coping strategies in a sample of 497 low-income urban African American adolescents (mean age = 12.61 years). Results of confirmatory factor analysis indicated that the 4-factor structure of the Children's Coping Strategies Checklist (T. S. Ayers, I. N. Sandler, S. G. West, & M. W. Roosa, 1996) was not…

Source apportionment of groundwater pollution around landfill site in Nagpur, India.

PubMed

Pujari, Paras R; Deshpande, Vijaya

2005-12-01

The present work attempts statistical analysis of groundwater quality near a Landfill site in Nagpur, India. The objective of the present work is to figure out the impact of different factors on the quality of groundwater in the study area. Statistical analysis of the data has been attempted by applying Factor Analysis concept. The analysis brings out the effect of five different factors governing the groundwater quality in the study area. Based on the contribution of the different parameters present in the extracted factors, the latter are linked to the geological setting, the leaching from the host rock, leachate of heavy metals from the landfill as well as the bacterial contamination from landfill site and other anthropogenic activities. The analysis brings out the vulnerability of the unconfined aquifer to contamination.

Assessing Management Support for Worksite Health Promotion: Psychometric Analysis of the Leading by Example (LBE) Instrument

PubMed Central

Della, Lindsay J.; DeJoy, David M.; Goetzel, Ron Z.; Ozminkowski, Ronald J.; Wilson, Mark G.

2009-01-01

Objective This paper describes the development of the Leading by Example (LBE) instrument. Methods Exploratory factor analysis was used to obtain an initial factor structure. Factor validity was evaluated using confirmatory factor analysis methods. Cronbach’s alpha and item-total correlations provided information on the reliability of the factor subscales. Results Four subscales were identified: business alignment with health promotion objectives; awareness of the health-productivity link; worksite support for health promotion; leadership support for health promotion. Factor by group comparisons revealed that the initial factor structure is effective in detecting differences in organizational support for health promotion across different employee groups Conclusions Management support for health promotion can be assessed using the LBE, a brief, self-report questionnaire. Researchers can use the LBE to diagnose, track, and evaluate worksite health promotion programs. PMID:18517097

Confirmatory factor analysis of the Child Oral Health Impact Profile (Korean version).

PubMed

Cho, Young Il; Lee, Soonmook; Patton, Lauren L; Kim, Hae-Young

2016-04-01

Empirical support for the factor structure of the Child Oral Health Impact Profile (COHIP) has not been fully established. The purposes of this study were to evaluate the factor structure of the Korean version of the COHIP (COHIP-K) empirically using confirmatory factor analysis (CFA) based on the theoretical framework and then to assess whether any of the factors in the structure could be grouped into a simpler single second-order factor. Data were collected through self-reported COHIP-K responses from a representative community sample of 2,236 Korean children, 8-15 yr of age. Because a large inter-factor correlation of 0.92 was estimated in the original five-factor structure, the two strongly correlated factors were combined into one factor, resulting in a four-factor structure. The revised four-factor model showed a reasonable fit with appropriate inter-factor correlations. Additionally, the second-order model with four sub-factors was reasonable with sufficient fit and showed equal fit to the revised four-factor model. A cross-validation procedure confirmed the appropriateness of the findings. Our analysis empirically supported a four-factor structure of COHIP-K, a summarized second-order model, and the use of an integrated summary COHIP score. © 2016 Eur J Oral Sci.

Analysis of the regulation of viral transcription.

PubMed

Gloss, Bernd; Kalantari, Mina; Bernard, Hans-Ulrich

2005-01-01

Despite the small genomes and number of genes of papillomaviruses, regulation of their transcription is very complex and governed by numerous transcription factors, cis-responsive elements, and epigenetic phenomena. This chapter describes the strategies of how one can approach a systematic analysis of these factors, elements, and mechanisms. From the numerous different techniques useful for studying transcription, we describe in detail three selected protocols of approaches that have been relevant in shaping our knowledge of human papillomavirus transcription. These are DNAse I protection ("footprinting") for location of transcription-factor binding sites, electrophoretic mobility shifts ("gelshifts") for analysis of bound transcription factors, and bisulfite sequencing for analysis of DNA methylation as a prerequisite for epigenetic transcriptional regulation.

[Factor Analysis: Principles to Evaluate Measurement Tools for Mental Health].

PubMed

Campo-Arias, Adalberto; Herazo, Edwin; Oviedo, Heidi Celina

2012-09-01

The validation of a measurement tool in mental health is a complex process that usually starts by estimating reliability, to later approach its validity. Factor analysis is a way to know the number of dimensions, domains or factors of a measuring tool, generally related to the construct validity of the scale. The analysis could be exploratory or confirmatory, and helps in the selection of the items with better performance. For an acceptable factor analysis, it is necessary to follow some steps and recommendations, conduct some statistical tests, and rely on a proper sample of participants. Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

[Quantitative surface analysis of Pt-Co, Cu-Au and Cu-Ag alloy films by XPS and AES].

PubMed

Li, Lian-Zhong; Zhuo, Shang-Jun; Shen, Ru-Xiang; Qian, Rong; Gao, Jie

2013-11-01

In order to improve the quantitative analysis accuracy of AES, We associated XPS with AES and studied the method to reduce the error of AES quantitative analysis, selected Pt-Co, Cu-Au and Cu-Ag binary alloy thin-films as the samples, used XPS to correct AES quantitative analysis results by changing the auger sensitivity factors to make their quantitative analysis results more similar. Then we verified the accuracy of the quantitative analysis of AES when using the revised sensitivity factors by other samples with different composition ratio, and the results showed that the corrected relative sensitivity factors can reduce the error in quantitative analysis of AES to less than 10%. Peak defining is difficult in the form of the integral spectrum of AES analysis since choosing the starting point and ending point when determining the characteristic auger peak intensity area with great uncertainty, and to make analysis easier, we also processed data in the form of the differential spectrum, made quantitative analysis on the basis of peak to peak height instead of peak area, corrected the relative sensitivity factors, and verified the accuracy of quantitative analysis by the other samples with different composition ratio. The result showed that the analytical error in quantitative analysis of AES reduced to less than 9%. It showed that the accuracy of AES quantitative analysis can be highly improved by the way of associating XPS with AES to correct the auger sensitivity factors since the matrix effects are taken into account. Good consistency was presented, proving the feasibility of this method.

Factor analysis of the Hamilton Depression Rating Scale in Parkinson's disease.

PubMed

Broen, M P G; Moonen, A J H; Kuijf, M L; Dujardin, K; Marsh, L; Richard, I H; Starkstein, S E; Martinez-Martin, P; Leentjens, A F G

2015-02-01

Several studies have validated the Hamilton Depression Rating Scale (HAMD) in patients with Parkinson's disease (PD), and reported adequate reliability and construct validity. However, the factorial validity of the HAMD has not yet been investigated. The aim of our analysis was to explore the factor structure of the HAMD in a large sample of PD patients. A principal component analysis of the 17-item HAMD was performed on data of 341 PD patients, available from a previous cross sectional study on anxiety. An eigenvalue ≥1 was used to determine the number of factors. Factor loadings ≥0.4 in combination with oblique rotations were used to identify which variables made up the factors. Kaiser-Meyer-Olkin measure (KMO), Cronbach's alpha, Bartlett's test, communality, percentage of non-redundant residuals and the component correlation matrix were computed to assess factor validity. KMO verified the sample's adequacy for factor analysis and Cronbach's alpha indicated a good internal consistency of the total scale. Six factors had eigenvalues ≥1 and together explained 59.19% of the variance. The number of items per factor varied from 1 to 6. Inter-item correlations within each component were low. There was a high percentage of non-redundant residuals and low communality. This analysis demonstrates that the factorial validity of the HAMD in PD is unsatisfactory. This implies that the scale is not appropriate for studying specific symptom domains of depression based on factorial structure in a PD population. Copyright © 2014 Elsevier Ltd. All rights reserved.

Modelling and analysis of FMS productivity variables by ISM, SEM and GTMA approach

NASA Astrophysics Data System (ADS)

Jain, Vineet; Raj, Tilak

2014-09-01

Productivity has often been cited as a key factor in a flexible manufacturing system (FMS) performance, and actions to increase it are said to improve profitability and the wage earning capacity of employees. Improving productivity is seen as a key issue for survival and success in the long term of a manufacturing system. The purpose of this paper is to make a model and analysis of the productivity variables of FMS. This study was performed by different approaches viz. interpretive structural modelling (ISM), structural equation modelling (SEM), graph theory and matrix approach (GTMA) and a cross-sectional survey within manufacturing firms in India. ISM has been used to develop a model of productivity variables, and then it has been analyzed. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) are powerful statistical techniques. CFA is carried by SEM. EFA is applied to extract the factors in FMS by the statistical package for social sciences (SPSS 20) software and confirming these factors by CFA through analysis of moment structures (AMOS 20) software. The twenty productivity variables are identified through literature and four factors extracted, which involves the productivity of FMS. The four factors are people, quality, machine and flexibility. SEM using AMOS 20 was used to perform the first order four-factor structures. GTMA is a multiple attribute decision making (MADM) methodology used to find intensity/quantification of productivity variables in an organization. The FMS productivity index has purposed to intensify the factors which affect FMS.

Asymmetric flow field flow fractionation with light scattering detection - an orthogonal sensitivity analysis.

PubMed

Galyean, Anne A; Filliben, James J; Holbrook, R David; Vreeland, Wyatt N; Weinberg, Howard S

2016-11-18

Asymmetric flow field flow fractionation (AF 4 ) has several instrumental factors that may have a direct effect on separation performance. A sensitivity analysis was applied to ascertain the relative importance of AF 4 primary instrument factor settings for the separation of a complex environmental sample. The analysis evaluated the impact of instrumental factors namely, cross flow, ramp time, focus flow, injection volume, and run buffer concentration on the multi-angle light scattering measurement of natural organic matter (NOM) molar mass (MM). A 2 (5-1) orthogonal fractional factorial design was used to minimize analysis time while preserving the accuracy and robustness in the determination of the main effects and interactions between any two instrumental factors. By assuming that separations resulting in smaller MM measurements would be more accurate, the analysis produced a ranked list of effects estimates for factors and interactions of factors based on their relative importance in minimizing the MM. The most important and statistically significant AF 4 instrumental factors were buffer concentration and cross flow. The least important was ramp time. A parallel 2 (5-2) orthogonal fractional factorial design was also employed on five environmental factors for synthetic natural water samples containing silver nanoparticles (NPs), namely: NP concentration, NP size, NOM concentration, specific conductance, and pH. None of the water quality characteristic effects or interactions were found to be significant in minimizing the measured MM; however, the interaction between NP concentration and NP size was an important effect when considering NOM recovery. This work presents a structured approach for the rigorous assessment of AF 4 instrument factors and optimal settings for the separation of complex samples utilizing efficient orthogonal factional factorial design and appropriate graphical analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

A systematic review of the relationship factor between women and health professionals within the multivariant analysis of maternal satisfaction.

PubMed

Macpherson, Ignacio; Roqué-Sánchez, María V; Legget Bn, Finola O; Fuertes, Ferran; Segarra, Ignacio

2016-10-01

personalised support provided to women by health professionals is one of the prime factors attaining women's satisfaction during pregnancy and childbirth. However the multifactorial nature of 'satisfaction' makes difficult to assess it. Statistical multivariate analysis may be an effective technique to obtain in depth quantitative evidence of the importance of this factor and its interaction with the other factors involved. This technique allows us to estimate the importance of overall satisfaction in its context and suggest actions for healthcare services. systematic review of studies that quantitatively measure the personal relationship between women and healthcare professionals (gynecologists, obstetricians, nurse, midwifes, etc.) regarding maternity care satisfaction. The literature search focused on studies carried out between 1970 and 2014 that used multivariate analyses and included the woman-caregiver relationship as a factor of their analysis. twenty-four studies which applied various multivariate analysis tools to different periods of maternity care (antenatal, perinatal, post partum) were selected. The studies included discrete scale scores and questionnaires from women with low-risk pregnancies. The "personal relationship" factor appeared under various names: care received, personalised treatment, professional support, amongst others. The most common multivariate techniques used to assess the percentage of variance explained and the odds ratio of each factor were principal component analysis and logistic regression. the data, variables and factor analysis suggest that continuous, personalised care provided by the usual midwife and delivered within a family or a specialised setting, generates the highest level of satisfaction. In addition, these factors foster the woman's psychological and physiological recovery, often surpassing clinical action (e.g. medicalization and hospital organization) and/or physiological determinants (e.g. pain, pathologies, etc.). Copyright © 2016 Elsevier Ltd. All rights reserved.

Associated factors of radiation pneumonitis induced by precise radiotherapy in 186 elderly patients with esophageal cancer.

PubMed

Cui, Zhen; Tian, Ye; He, Bin; Li, Hongwei; Li, Duojie; Liu, Jingjing; Cai, Hanfei; Lou, Jianjun; Jiang, Hao; Shen, Xueming; Peng, Kaigui

2015-01-01

Radiation pneumonitis is one of the most severe complications of esophageal cancer. To explore the factors correlated to radiation pneumonitis induced by precise radiotherapy for elderly patients with esophageal cancer. The retrospective analysis was used to collect clinical data from 186 elderly patients with esophageal cancer. The incidence of radiation pneumonitis was observed, followed by statistical analysis through ANVON or multiple regression analysis. 27 in 186 cases of esophageal cancer suffered from radiation pneumonitis, with incidence of 14.52%. The single factor analysis showed that, Karnofsky performance status (KPS) score, chronic obstructive pulmonary disease, concurrent chemoradiotherapy, gross tumor volume (GTV) dose, lung V20, mean lung dose (MLD) and planning target volume (PTV) were associated with radiation pneumonitis. The logistic regression analysis indicated that, concurrent chemoradiotherapy, GTV dose, lung V20 and PTV were the independent factors of radiation pneumonitis. The concurrent chemoradiotherapy, GTV dose, lung V20, MLD and PTV are the major risk factors of radiation pneumonitis for elderly patients with esophageal cancer.

Exploratory Factor Analysis of the Beck Anxiety Inventory and the Beck Depression Inventory-II in a Psychiatric Outpatient Population

PubMed Central

2018-01-01

Background To further understand the relationship between anxiety and depression, this study examined the factor structure of the combined items from two validated measures for anxiety and depression. Methods The participants were 406 patients with mixed psychiatric diagnoses including anxiety and depressive disorders from a psychiatric outpatient unit at a university-affiliated medical center. Responses of the Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI)-II, and Symptom Checklist-90-Revised (SCL-90-R) were analyzed. We conducted an exploratory factor analysis of 42 items from the BAI and BDI-II. Correlational analyses were performed between subscale scores of the SCL-90-R and factors derived from the factor analysis. Scores of individual items of the BAI and BDI-II were also compared between groups of anxiety disorder (n = 185) and depressive disorder (n = 123). Results Exploratory factor analysis revealed the following five factors explaining 56.2% of the total variance: somatic anxiety (factor 1), cognitive depression (factor 2), somatic depression (factor 3), subjective anxiety (factor 4), and autonomic anxiety (factor 5). The depression group had significantly higher scores for 12 items on the BDI while the anxiety group demonstrated higher scores for six items on the BAI. Conclusion Our results suggest that anxiety and depressive symptoms as measured by the BAI and BDI-II can be empirically differentiated and that particularly items of the cognitive domain in depression and those of physical domain in anxiety are noteworthy. PMID:29651821

Factors Influencing the Organizational Stress among Teachers Working in Higher Education Sector in Kerala: An Empirical Analysis

ERIC Educational Resources Information Center

Areekkuzhiyil, Santhosh

2014-01-01

The study aims to explore the various factors that influence the organizational stress of teachers working in higher education sector in the state of Kerala. The data required for the study has been conveniently collected from 200 teachers working in higher education sector. Exploratory factor analysis revealed nine factors, which significantly…

The Construct Validity of Scores on the Ways of Coping Questionnaire: Confirmatory Analysis of Alternative Factor Structures.

ERIC Educational Resources Information Center

Edwards, Jeffrey R.; O'Neill, Regina M.

1998-01-01

Confirmatory factor analysis was used to evaluate alternative factor structures, based on previous exploratory factor analyses and coping dimensions derived from the theory of R. Lazarus, for the Ways of Coping Questionnaire (S. Folkman and R. Lazarus, 1988). Results from responses of 654 college graduates provide little support for the factor…

The Columbia Impairment Scale: Factor Analysis Using a Community Mental Health Sample

ERIC Educational Resources Information Center

Singer, Jonathan B.; Eack, Shaun M.; Greeno, Catherine M.

2011-01-01

Objective: The objective of this study was to test the factor structure of the parent version of the Columbia Impairment Scale (CIS) in a sample of mothers who brought their children for community mental health (CMH) services (n = 280). Method: Confirmatory factor analysis (CFA) was used to test the fit of the hypothesized four-factor structure…

Exploratory factor analysis of the Clinical Learning Environment, Supervision and Nurse Teacher Scale (CLES+T).

PubMed

Watson, Paul Barry; Seaton, Philippa; Sims, Deborah; Jamieson, Isabel; Mountier, Jane; Whittle, Rose; Saarikoski, Mikko

2014-01-01

The Clinical Learning Environment, Supervision and Nurse Teacher (CLES+T) scale measures student nurses' perceptions of clinical learning environments. This study evaluates the construct validity and internal reliability of the CLES+T in hospital settings in New Zealand. Comparisons are made between New Zealand and Finnish data. The CLES+T scale was completed by 416 Bachelor of Nursing students following hospital clinical placements between October 2008 and December 2009. Construct validity and internal reliability were assessed using exploratory factor analysis and Cronbach's alpha. Exploratory factor analysis supports 4 factors. Cronbach's alpha ranged from .82 to .93. All items except 1 loaded on the same factors found in unpublished Finnish data. The first factor combined 2 previous components from the published Finnish component analysis and was renamed: connecting with, and learning in, communities of clinical practice. The remaining 3 factors (Nurse teacher, Supervisory relationship, and Leadership style of the manager) corresponded to previous components and their conceptualizations. The CLES+T has good internal reliability and a consistent factor structure across samples. The consistency across international samples supports faculties and hospitals using the CLES+T to benchmark the quality of clinical learning environments provided to students.

A factor analysis of the SSQ (Speech, Spatial, and Qualities of Hearing Scale).

PubMed

Akeroyd, Michael A; Guy, Fiona H; Harrison, Dawn L; Suller, Sharon L

2014-02-01

The speech, spatial, and qualities of hearing questionnaire (SSQ) is a self-report test of auditory disability. The 49 items ask how well a listener would do in many complex listening situations illustrative of real life. The scores on the items are often combined into the three main sections or into 10 pragmatic subscales. We report here a factor analysis of the SSQ that we conducted to further investigate its statistical properties and to determine its structure. Statistical factor analysis of questionnaire data, using parallel analysis to determine the number of factors to retain, oblique rotation of factors, and a bootstrap method to estimate the confidence intervals. 1220 people who have attended MRC IHR over the last decade. We found three clear factors, essentially corresponding to the three main sections of the SSQ. They are termed "speech understanding", "spatial perception", and "clarity, separation, and identification". Thirty-five of the SSQ questions were included in the three factors. There was partial evidence for a fourth factor, "effort and concentration", representing two more questions. These results aid in the interpretation and application of the SSQ and indicate potential methods for generating average scores.

Multivariate analysis of fears in dental phobic patients according to a reduced FSS-II scale.

PubMed

Hakeberg, M; Gustafsson, J E; Berggren, U; Carlsson, S G

1995-10-01

This study analyzed and assessed dimensions of a questionnaire developed to measure general fears and phobias. A previous factor analysis among 109 dental phobics had revealed a five-factor structure with 22 items and an explained total variance of 54%. The present study analyzed the same material using a multivariate statistical procedure (LISREL) to reveal structural latent variables. The LISREL analysis, based on the correlation matrix, yielded a chi-square of 216.6 with 195 degrees of freedom (P = 0.138) and showed a model with seven latent variables. One was a general fear factor correlated to all 22 items. The other six factors concerned "Illness & Death" (5 items), "Failures & Embarrassment" (5 items), "Social situations" (5 items), "Physical injuries" (4 items), "Animals & Natural phenomena" (4 items). One item (opposite sex) was included in both "Failures & Embarrassment" and "Social situations". The last factor, "Social interaction", combined all the items in "Failures & Embarrassment" and "Social situations" (9 items). In conclusion, this multivariate statistical analysis (LISREL) revealed and confirmed a factor structure similar to our previous study, but added two important dimensions not shown with a traditional factor analysis. This reduced FSS-II version measures general fears and phobias and may be used on a routine clinical basis as well as in dental phobia research.

The Dispositions for Culturally Responsive Pedagogy Scale

ERIC Educational Resources Information Center

Whitaker, Manya C.; Valtierra, Kristina Marie

2018-01-01

Purpose: The purpose of this study is to develop and validate the dispositions for culturally responsive pedagogy scale (DCRPS). Design/methodology/approach: Scale development consisted of a six-step process including item development, expert review, exploratory factor analysis, factor interpretation, confirmatory factor analysis and convergent…

Human Factors Analysis of Pipeline Monitoring and Control Operations: Final Technical Report

DOT National Transportation Integrated Search

2008-11-26

The purpose of the Human Factors Analysis of Pipeline Monitoring and Control Operations project was to develop procedures that could be used by liquid pipeline operators to assess and manage the human factors risks in their control rooms that may adv...

To Identify the Important Soil Properties Affecting Dinoseb Adsorption with Statistical Analysis

PubMed Central

Guan, Yiqing; Wei, Jianhui; Zhang, Danrong; Zu, Mingjuan; Zhang, Liru

2013-01-01

Investigating the influences of soil characteristic factors on dinoseb adsorption parameter with different statistical methods would be valuable to explicitly figure out the extent of these influences. The correlation coefficients and the direct, indirect effects of soil characteristic factors on dinoseb adsorption parameter were analyzed through bivariate correlation analysis, and path analysis. With stepwise regression analysis the factors which had little influence on the adsorption parameter were excluded. Results indicate that pH and CEC had moderate relationship and lower direct effect on dinoseb adsorption parameter due to the multicollinearity with other soil factors, and organic carbon and clay contents were found to be the most significant soil factors which affect the dinoseb adsorption process. A regression is thereby set up to explore the relationship between the dinoseb adsorption parameter and the two soil factors: the soil organic carbon and clay contents. A 92% of the variation of dinoseb sorption coefficient could be attributed to the variation of the soil organic carbon and clay contents. PMID:23737715

A study and meta-analysis of lay attributions of cures for overcoming specific psychological problems.

PubMed

Furnham, A; Hayward, R

1997-09-01

Lay beliefs about the importance of 24 different contributors to overcoming 4 disorders that constitute primarily cognitive deficits were studied. A meta-analysis of previous programmatic studies in the area was performed so that 22 different psychological problems could be compared. In the present study, 107 participants completed a questionnaire indicating how effective 24 factors were in overcoming 4 specific problems: dyslexia, fear of flying, amnesia, and learning difficulties. Factor analysis revealed almost identical clusters (inner control, social consequences, understanding, receiving help, and fate) for each problem. The perceived relevance of those factors differed significantly between problems. Some individual difference factors (sex and religion) were found to predict certain factor attributions for specific disorders. A meta-analysis of the 5 studies in this series yielded a 6-factor structure comparable to those of the individual studies and provided results indicating the benefits and limitations of this kind of investigation. The clinical relevance of studying attributions for cure is considered.

Potential barriers to the application of multi-factor portfolio analysis in public hospitals: evidence from a pilot study in the Netherlands.

PubMed

Pavlova, Milena; Tsiachristas, Apostolos; Vermaeten, Gerhard; Groot, Wim

2009-01-01

Portfolio analysis is a business management tool that can assist health care managers to develop new organizational strategies. The application of portfolio analysis to US hospital settings has been frequently reported. In Europe however, the application of this technique has received little attention, especially concerning public hospitals. Therefore, this paper examines the peculiarities of portfolio analysis and its applicability to the strategic management of European public hospitals. The analysis is based on a pilot application of a multi-factor portfolio analysis in a Dutch university hospital. The nature of portfolio analysis and the steps in a multi-factor portfolio analysis are reviewed along with the characteristics of the research setting. Based on these data, a multi-factor portfolio model is developed and operationalized. The portfolio model is applied in a pilot investigation to analyze the market attractiveness and hospital strengths with regard to the provision of three orthopedic services: knee surgery, hip surgery, and arthroscopy. The pilot portfolio analysis is discussed to draw conclusions about potential barriers to the overall adoption of portfolio analysis in the management of a public hospital. Copyright (c) 2008 John Wiley & Sons, Ltd.

Factor structure of DSM-IV criteria for obsessive compulsive personality disorder in patients with binge eating disorder.

PubMed

Grilo, C M

2004-01-01

To examine the factor structure of DSM-IV criteria for obsessive compulsive personality disorder (OCPD) in patients with binge eating disorder (BED). Two hundred and eleven consecutive out-patients with axis I diagnoses of BED were reliably assessed with semi-structured diagnostic interviews. The eight criteria for the OCPD diagnosis were examined with reliability and correlational analyses. Exploratory factor analysis was performed to identify potential components. Cronbach's coefficient alpha for the OCPD criteria was 0.77. Principal components factor analysis with varimax rotation revealed a three-factor solution (rigidity, perfectionism, and miserliness), which accounted for 65% of variance. The DSM-IV criteria for OCPD showed good internal consistency. Exploratory factor analysis, however, revealed three components that may reflect distinct interpersonal, intrapersonal (cognitive), and behavioral features.

Comparison Virtual Landing Gear Drop Test for Commuter Aircraft Utilize MSC ADAMS And Solidworks Motion Analysis

NASA Astrophysics Data System (ADS)

Hidayat, Dony; Istiyanto, Jos; Agus Sumarsono, Danardono

2018-04-01

Loads at main landing gear while touchdown impact is function of aircraft weight and ground reaction load factor. In regulation states ground reaction load factor at Vsink = 3.05 m/s is below 3. Contact/impact force from simulation using MSC ADAMS is 94680 N, while using Solidworks Motion Analysis is 97691 N. The difference between MSC ADAMS and Solidworks Motion Analysis is 3.08%. The ground reaction load factor in MSC ADAMS is 2.78 while in Solidworks Motion Analysis is 2.87.

Testing all six person-oriented principles in dynamic factor analysis.

PubMed

Molenaar, Peter C M

2010-05-01

All six person-oriented principles identified by Sterba and Bauer's Keynote Article can be tested by means of dynamic factor analysis in its current form. In particular, it is shown how complex interactions and interindividual differences/intraindividual change can be tested in this way. In addition, the necessity to use single-subject methods in the analysis of developmental processes is emphasized, and attention is drawn to the possibility to optimally treat developmental psychopathology by means of new computational techniques that can be integrated with dynamic factor analysis.

A Bootstrap Generalization of Modified Parallel Analysis for IRT Dimensionality Assessment

ERIC Educational Resources Information Center

Finch, Holmes; Monahan, Patrick

2008-01-01

This article introduces a bootstrap generalization to the Modified Parallel Analysis (MPA) method of test dimensionality assessment using factor analysis. This methodology, based on the use of Marginal Maximum Likelihood nonlinear factor analysis, provides for the calculation of a test statistic based on a parametric bootstrap using the MPA…

A Study of Algorithms for Covariance Structure Analysis with Specific Comparisons Using Factor Analysis.

ERIC Educational Resources Information Center

Lee, S. Y.; Jennrich, R. I.

1979-01-01

A variety of algorithms for analyzing covariance structures are considered. Additionally, two methods of estimation, maximum likelihood, and weighted least squares are considered. Comparisons are made between these algorithms and factor analysis. (Author/JKS)

Measuring Filial Piety in the 21st Century: Development, Factor Structure, and Reliability of the 10-Item Contemporary Filial Piety Scale.

PubMed

Lum, Terry Y S; Yan, Elsie C W; Ho, Andy H Y; Shum, Michelle H Y; Wong, Gloria H Y; Lau, Mandy M Y; Wang, Junfang

2016-11-01

The experience and practice of filial piety have evolved in modern Chinese societies, and existing measures fail to capture these important changes. Based on a conceptual analysis on current literature, 42 items were initially compiled to form a Contemporary Filial Piety Scale (CFPS), and 1,080 individuals from a representative sample in Hong Kong were surveyed. Principal component analysis generated a 16-item three-factor model: Pragmatic Obligations (Factor 1; 10 items), Compassionate Reverence (Factor 2; 4 items), and Family Continuity (Factor 3; 2 items). Confirmatory factor analysis revealed strong factor loadings for Factors 1 and 2, while removing Factor 3 and conceptually duplicated items increased total variance explained from 58.02% to 60.09% and internal consistency from .84 to .88. A final 10-item two-factor structure model was adopted with a goodness of fit of 0.95. The CFPS-10 is a data-driven, simple, and efficient instrument with strong psychometric properties for assessing contemporary filial piety. © The Author(s) 2015.

Acoustic fill factors for a 120 inch diameter fairing

NASA Technical Reports Server (NTRS)

Lee, Y. Albert

1992-01-01

Data from the acoustic test of a 120-inch diameter payload fairing were collected and an analysis of acoustic fill factors were performed. Correction factors for obtaining a weighted spatial average of the interior sound pressure level (SPL) were derived based on this database and a normalized 200-inch diameter fairing database. The weighted fill factors were determined and compared with statistical energy analysis (VAPEPS code) derived fill factors. The comparison is found to be reasonable.

Can pain and function be distinguished in the Oxford Hip Score in a meaningful way? : an exploratory and confirmatory factor analysis.

PubMed

Harris, K K; Price, A J; Beard, D J; Fitzpatrick, R; Jenkinson, C; Dawson, J

2014-11-01

The objective of this study was to explore dimensionality of the Oxford Hip Score (OHS) and examine whether self-reported pain and functioning can be distinguished in the form of subscales. This was a secondary data analysis of the UK NHS hospital episode statistics/patient-reported outcome measures dataset containing pre-operative OHS scores on 97 487 patients who were undergoing hip replacement surgery. The proposed number of factors to extract depended on the method of extraction employed. Velicer's Minimum Average Partial test and the Parallel Analysis suggested one factor, the Cattell's scree test and Kaiser-over-1 rule suggested two factors. Exploratory factor analysis demonstrated that the two-factor OHS had most of the items saliently loading either of the two factors. These factors were named 'Pain' and 'Function' and their respective subscales were created. There was some cross-loading of items: 8 (pain on standing up from a chair) and 11 (pain during work). These items were assigned to the 'Pain' subscale. The final 'Pain' subscale consisted of items 1, 8, 9, 10, 11 and 12. The 'Function' subscale consisted of items 2, 3, 4, 5, 6 and 7, with the recommended scoring of the subscales being from 0 (worst) to 100 (best). Cronbach's alpha was 0.855 for the 'Pain' subscale and 0.861 for the 'Function' subscale. A confirmatory factor analysis demonstrated that the two-factor model of the OHS had a better fit. However, none of the one-factor or two-factor models was rejected. Factor analyses demonstrated that, in addition to current usage as a single summary scale, separate information on pain and self-reported function can be extracted from the OHS in a meaningful way in the form of subscales. Cite this article: Bone Joint Res 2014;3:305-9. ©2014 The British Editorial Society of Bone & Joint Surgery.

The Counseling Competencies Scale: Validation and Refinement

ERIC Educational Resources Information Center

Lambie, Glenn W.; Mullen, Patrick R.; Swank, Jacqueline M.; Blount, Ashley

2018-01-01

Supervisors evaluated counselors-in-training at multiple points during their practicum experience using the Counseling Competencies Scale (CCS; N = 1,070). The CCS evaluations were randomly split to conduct exploratory factor analysis and confirmatory factor analysis, resulting in a 2-factor model (61.5% of the variance explained).

Development and Psychometric Evaluation of the Interpersonal Sexual Objectification Scale

ERIC Educational Resources Information Center

Kozee, Holly B.; Tylka, Tracy L.; Augustus-Horvath, Casey L.; Denchik, Angela

2007-01-01

This study reports on the development and psychometric evaluation of the Interpersonal Sexual Objectification Scale (ISOS). Data from 576 college women were collected in three studies. Exploratory factor analysis uncovered two factors: Body Evaluation and Unwanted Explicit Sexual Advances; confirmatory factor analysis supported this factor…

40 CFR 1042.245 - Deterioration factors.

Code of Federal Regulations, 2014 CFR

2014-07-01

... to meet the Tier 1 and Tier 2 emission standards would qualify as established technology. We must... deterioration factors for Category 1 and Category 2 engines, either with an engineering analysis, with pre... deterioration factors for an engine family with established technology based on engineering analysis instead of...

40 CFR 1042.245 - Deterioration factors.

Code of Federal Regulations, 2012 CFR

2012-07-01

... to meet the Tier 1 and Tier 2 emission standards would qualify as established technology. We must... deterioration factors for Category 1 and Category 2 engines, either with an engineering analysis, with pre... deterioration factors for an engine family with established technology based on engineering analysis instead of...

40 CFR 1042.245 - Deterioration factors.

Code of Federal Regulations, 2010 CFR

2010-07-01

... to meet the Tier 1 and Tier 2 emission standards would qualify as established technology. We must... deterioration factors for Category 1 and Category 2 engines, either with an engineering analysis, with pre... deterioration factors for an engine family with established technology based on engineering analysis instead of...

40 CFR 1042.245 - Deterioration factors.

Code of Federal Regulations, 2011 CFR

2011-07-01

... to meet the Tier 1 and Tier 2 emission standards would qualify as established technology. We must... deterioration factors for Category 1 and Category 2 engines, either with an engineering analysis, with pre... deterioration factors for an engine family with established technology based on engineering analysis instead of...

40 CFR 1042.245 - Deterioration factors.

Code of Federal Regulations, 2013 CFR

2013-07-01

... to meet the Tier 1 and Tier 2 emission standards would qualify as established technology. We must... deterioration factors for Category 1 and Category 2 engines, either with an engineering analysis, with pre... deterioration factors for an engine family with established technology based on engineering analysis instead of...

Bayesian Exploratory Factor Analysis

PubMed Central

Conti, Gabriella; Frühwirth-Schnatter, Sylvia; Heckman, James J.; Piatek, Rémi

2014-01-01

This paper develops and applies a Bayesian approach to Exploratory Factor Analysis that improves on ad hoc classical approaches. Our framework relies on dedicated factor models and simultaneously determines the number of factors, the allocation of each measurement to a unique factor, and the corresponding factor loadings. Classical identification criteria are applied and integrated into our Bayesian procedure to generate models that are stable and clearly interpretable. A Monte Carlo study confirms the validity of the approach. The method is used to produce interpretable low dimensional aggregates from a high dimensional set of psychological measurements. PMID:25431517

Evaluation of breast cancer using intravoxel incoherent motion (IVIM) histogram analysis: comparison with malignant status, histological subtype, and molecular prognostic factors.

PubMed

Cho, Gene Young; Moy, Linda; Kim, Sungheon G; Baete, Steven H; Moccaldi, Melanie; Babb, James S; Sodickson, Daniel K; Sigmund, Eric E

2016-08-01

To examine heterogeneous breast cancer through intravoxel incoherent motion (IVIM) histogram analysis. This HIPAA-compliant, IRB-approved retrospective study included 62 patients (age 48.44 ± 11.14 years, 50 malignant lesions and 12 benign) who underwent contrast-enhanced 3 T breast MRI and diffusion-weighted imaging. Apparent diffusion coefficient (ADC) and IVIM biomarkers of tissue diffusivity (Dt), perfusion fraction (fp), and pseudo-diffusivity (Dp) were calculated using voxel-based analysis for the whole lesion volume. Histogram analysis was performed to quantify tumour heterogeneity. Comparisons were made using Mann-Whitney tests between benign/malignant status, histological subtype, and molecular prognostic factor status while Spearman's rank correlation was used to characterize the association between imaging biomarkers and prognostic factor expression. The average values of the ADC and IVIM biomarkers, Dt and fp, showed significant differences between benign and malignant lesions. Additional significant differences were found in the histogram parameters among tumour subtypes and molecular prognostic factor status. IVIM histogram metrics, particularly fp and Dp, showed significant correlation with hormonal factor expression. Advanced diffusion imaging biomarkers show relationships with molecular prognostic factors and breast cancer malignancy. This analysis reveals novel diagnostic metrics that may explain some of the observed variability in treatment response among breast cancer patients. • Novel IVIM biomarkers characterize heterogeneous breast cancer. • Histogram analysis enables quantification of tumour heterogeneity. • IVIM biomarkers show relationships with breast cancer malignancy and molecular prognostic factors.

Frequencies and Flutter Speed Estimation for Damaged Aircraft Wing Using Scaled Equivalent Plate Analysis

NASA Technical Reports Server (NTRS)

Krishnamurthy, Thiagarajan

2010-01-01

Equivalent plate analysis is often used to replace the computationally expensive finite element analysis in initial design stages or in conceptual design of aircraft wing structures. The equivalent plate model can also be used to design a wind tunnel model to match the stiffness characteristics of the wing box of a full-scale aircraft wing model while satisfying strength-based requirements An equivalent plate analysis technique is presented to predict the static and dynamic response of an aircraft wing with or without damage. First, a geometric scale factor and a dynamic pressure scale factor are defined to relate the stiffness, load and deformation of the equivalent plate to the aircraft wing. A procedure using an optimization technique is presented to create scaled equivalent plate models from the full scale aircraft wing using geometric and dynamic pressure scale factors. The scaled models are constructed by matching the stiffness of the scaled equivalent plate with the scaled aircraft wing stiffness. It is demonstrated that the scaled equivalent plate model can be used to predict the deformation of the aircraft wing accurately. Once the full equivalent plate geometry is obtained, any other scaled equivalent plate geometry can be obtained using the geometric scale factor. Next, an average frequency scale factor is defined as the average ratio of the frequencies of the aircraft wing to the frequencies of the full-scaled equivalent plate. The average frequency scale factor combined with the geometric scale factor is used to predict the frequency response of the aircraft wing from the scaled equivalent plate analysis. A procedure is outlined to estimate the frequency response and the flutter speed of an aircraft wing from the equivalent plate analysis using the frequency scale factor and geometric scale factor. The equivalent plate analysis is demonstrated using an aircraft wing without damage and another with damage. Both of the problems show that the scaled equivalent plate analysis can be successfully used to predict the frequencies and flutter speed of a typical aircraft wing.

Implementation of MCA Method for Identification of Factors for Conceptual Cost Estimation of Residential Buildings

NASA Astrophysics Data System (ADS)

Juszczyk, Michał; Leśniak, Agnieszka; Zima, Krzysztof

2013-06-01

Conceptual cost estimation is important for construction projects. Either underestimation or overestimation of building raising cost may lead to failure of a project. In the paper authors present application of a multicriteria comparative analysis (MCA) in order to select factors influencing residential building raising cost. The aim of the analysis is to indicate key factors useful in conceptual cost estimation in the early design stage. Key factors are being investigated on basis of the elementary information about the function, form and structure of the building, and primary assumptions of technological and organizational solutions applied in construction process. The mentioned factors are considered as variables of the model which aim is to make possible conceptual cost estimation fast and with satisfying accuracy. The whole analysis included three steps: preliminary research, choice of a set of potential variables and reduction of this set to select the final set of variables. Multicriteria comparative analysis is applied in problem solution. Performed analysis allowed to select group of factors, defined well enough at the conceptual stage of the design process, to be used as a describing variables of the model.

Bayesian Factor Analysis as a Variable Selection Problem: Alternative Priors and Consequences

PubMed Central

Lu, Zhao-Hua; Chow, Sy-Miin; Loken, Eric

2016-01-01

Factor analysis is a popular statistical technique for multivariate data analysis. Developments in the structural equation modeling framework have enabled the use of hybrid confirmatory/exploratory approaches in which factor loading structures can be explored relatively flexibly within a confirmatory factor analysis (CFA) framework. Recently, a Bayesian structural equation modeling (BSEM) approach (Muthén & Asparouhov, 2012) has been proposed as a way to explore the presence of cross-loadings in CFA models. We show that the issue of determining factor loading patterns may be formulated as a Bayesian variable selection problem in which Muthén and Asparouhov’s approach can be regarded as a BSEM approach with ridge regression prior (BSEM-RP). We propose another Bayesian approach, denoted herein as the Bayesian structural equation modeling with spike and slab prior (BSEM-SSP), which serves as a one-stage alternative to the BSEM-RP. We review the theoretical advantages and disadvantages of both approaches and compare their empirical performance relative to two modification indices-based approaches and exploratory factor analysis with target rotation. A teacher stress scale data set (Byrne, 2012; Pettegrew & Wolf, 1982) is used to demonstrate our approach. PMID:27314566

Developing a Basic Scale for Workers' Psychological Burden from the Perspective of Occupational Safety and Health.

PubMed

Kim, Kyung Woo; Lim, Ho Chan; Park, Jae Hee; Park, Sang Gyu; Park, Ye Jin; Cho, Hm Hak

2018-06-01

Organizations are pursing complex and diverse aims to generate higher profits. Many workers experience high work intensity such as workload and work pressure in this organizational environment. Especially, psychological burden is a commonly used term in workplace of Republic of Korea. This study focused on defining the psychological burden from the perspective of occupational safety and health and tried to develop a scale for psychological burden. The 48 preliminary questionnaire items for psychological burden were prepared by a focus group interview with 16 workers through the Copenhagen Psychosocial Questionnaire II and Mindful Awareness Attention Scale. The preliminary items were surveyed with 572 workers, and exploratory factor analysis, confirmatory factor analysis, and correlation analysis were conducted for a new scale. As a result of the exploratory factor analysis, five factors were extracted: organizational activity, human error, safety and health workload, work attitude, and negative self-management. These factors had significant correlations and reliability, and the stability of the model for validity was confirmed using confirmatory factor analysis. The developed scale for psychological burden can measure workers' psychological burden in relation to safety and health. Despite some limitations, this study has applicability in the workplace, given the relatively small-sized questionnaire.

Predictors of postoperative outcomes of cubital tunnel syndrome treatments using multiple logistic regression analysis.

PubMed

Suzuki, Taku; Iwamoto, Takuji; Shizu, Kanae; Suzuki, Katsuji; Yamada, Harumoto; Sato, Kazuki

2017-05-01

This retrospective study was designed to investigate prognostic factors for postoperative outcomes for cubital tunnel syndrome (CubTS) using multiple logistic regression analysis with a large number of patients. Eighty-three patients with CubTS who underwent surgeries were enrolled. The following potential prognostic factors for disease severity were selected according to previous reports: sex, age, type of surgery, disease duration, body mass index, cervical lesion, presence of diabetes mellitus, Workers' Compensation status, preoperative severity, and preoperative electrodiagnostic testing. Postoperative severity of disease was assessed 2 years after surgery by Messina's criteria which is an outcome measure specifically for CubTS. Bivariate analysis was performed to select candidate prognostic factors for multiple linear regression analyses. Multiple logistic regression analysis was conducted to identify the association between postoperative severity and selected prognostic factors. Both bivariate and multiple linear regression analysis revealed only preoperative severity as an independent risk factor for poor prognosis, while other factors did not show any significant association. Although conflicting results exist regarding prognosis of CubTS, this study supports evidence from previous studies and concludes early surgical intervention portends the most favorable prognosis. Copyright © 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

How Do Executive Functions Fit with the Cattell-Horn-Carroll Model? Some Evidence from a Joint Factor Analysis of the Delis-Kaplan Executive Function System and the Woodcock-Johnson III Tests of Cognitive Abilities

ERIC Educational Resources Information Center

Floyd, Randy G.; Bergeron, Renee; Hamilton, Gloria; Parra, Gilbert R.

2010-01-01

This study investigated the relations among executive functions and cognitive abilities through a joint exploratory factor analysis and joint confirmatory factor analysis of 25 test scores from the Delis-Kaplan Executive Function System and the Woodcock-Johnson III Tests of Cognitive Abilities. Participants were 100 children and adolescents…

A human factors methodology for real-time support applications

NASA Technical Reports Server (NTRS)

Murphy, E. D.; Vanbalen, P. M.; Mitchell, C. M.

1983-01-01

A general approach to the human factors (HF) analysis of new or existing projects at NASA/Goddard is delineated. Because the methodology evolved from HF evaluations of the Mission Planning Terminal (MPT) and the Earth Radiation Budget Satellite Mission Operations Room (ERBS MOR), it is directed specifically to the HF analysis of real-time support applications. Major topics included for discussion are the process of establishing a working relationship between the Human Factors Group (HFG) and the project, orientation of HF analysts to the project, human factors analysis and review, and coordination with major cycles of system development. Sub-topics include specific areas for analysis and appropriate HF tools. Management support functions are outlined. References provide a guide to sources of further information.

Applying a Danish Version of the Learning Transfer System Inventory and Testing It for Different Types of Education

ERIC Educational Resources Information Center

Soerensen, Peter; Stegeager, Nikolaj; Bates, Reid

2017-01-01

The purpose of this study was to answer two research questions. First, will an exploratory factor analysis of a Danish version of the Learning Transfer System Inventory (LTSI) result in a factor structure which is consistent with the original American LTSI factor structure? Second, does the mean score in the factor analysis vary in a statistically…

Factor Structure of Coping: Two Studies of Mothers with High Levels of Life Stress

ERIC Educational Resources Information Center

Eisengart, Sheri P.; Singer, Lynn T.; Kirchner, H. Lester; Min, Meeyoung Oh; Fulton, Sarah; Short, Elizabeth J.; Minnes, Sonia

2006-01-01

Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used to investigate the factor structure of coping in mothers with high levels of life stress. In Study 1, EFA of the Coping Orientation to Problems Experienced (C. S. Carver, M. F. Scheier, & J. K. Weintraub, 1989) in a sample of mothers of full-term or very low…

Assessing Stress in Cancer Patients: A Second-Order Factor Analysis Model for the Perceived Stress Scale

ERIC Educational Resources Information Center

Golden-Kreutz, Deanna M.; Browne, Michael W.; Frierson, Georita M.; Andersen, Barbara L.

2004-01-01

Using the Perceived Stress Scale (PSS), perceptions of global stress were assessed in 111women following breast cancer surgery and at 12 and 24 months later. This is the first study to factor analyze the PSS. The PSS data were factor analyzed each time using exploratory factor analysis with oblique direct quartimin rotation. Goodness-of-fit…

Assessing Social Competence and Behavior Problems in a Sample of Italian Preschoolers Using the Social Competence and Behavior Evaluation Scale

ERIC Educational Resources Information Center

Sette, Stefania; Baumgartner, Emma; MacKinnon, David P.

2015-01-01

Research Findings: The main goals of this study were to examine the factor validity of the Social Competence and Behavior Evaluation (SCBE-30) scale using exploratory factor analysis and confirmatory factor analysis and to test factor invariance across gender in a sample of Italian preschool-age children (241 boys, 252 girls). The concurrent…

Factor analysis of some socio-economic and demographic variables for Bangladesh.

PubMed

Islam, S M

1986-01-01

The author carries out an exploratory factor analysis of some socioeconomic and demographic variables for Bangladesh using the classical or common factor approach with the varimax rotation method. The socioeconomic and demographic indicators used in this study include literacy, rate of growth, female employment, economic development, urbanization, population density, childlessness, sex ratio, proportion of women ever married, and fertility. The 18 administrative districts of Bangladesh constitute the unit of analysis. 3 common factors--modernization, fertility, and social progress--are identified in this study to explain the correlations among the set of selected socioeconomic and demographic variables.

Identifying the hydrochemical characteristics of rivers and groundwater by multivariate statistical analysis in the Sanjiang Plain, China

NASA Astrophysics Data System (ADS)

Cao, Yingjie; Tang, Changyuan; Song, Xianfang; Liu, Changming; Zhang, Yinghua

2016-06-01

Two multivariate statistical technologies, factor analysis (FA) and discriminant analysis (DA), are applied to study the river and groundwater hydrochemistry and its controlling processes in the Sanjiang Plain of the northeast China. Factor analysis identifies five factors which account for 79.65 % of the total variance in the dataset. Four factors bearing specific meanings as the river and groundwater hydrochemistry controlling processes are divided into two groups, the "natural hydrochemistry evolution" group and the "pollution" group. The "natural hydrochemistry evolution" group includes the salinity factor (factor 1) caused by rock weathering and the residence time factor (factor 2) reflecting the groundwater traveling time. The "pollution" group represents the groundwater quality deterioration due to geogenic pollution caused by elevated Fe and Mn (factor 3) and elevated nitrate (NO3 -) introduced by human activities such as agriculture exploitations (factor 5). The hydrochemical difference and hydraulic connection among rivers (surface water, SW), shallow groundwater (SG) and deep groundwater (DG) group are evaluated by the factor scores obtained from FA and DA (Fisher's method). It is showed that the river water is characterized as low salinity and slight pollution, and the shallow groundwater has the highest salinity and severe pollution. The SW is well separated from SG and DG by Fisher's discriminant function, but the SG and DG can not be well separated showing their hydrochemical similarities, and emphasize hydraulic connections between SG and DG.

Bem Sex Role Inventory Validation in the International Mobility in Aging Study.

PubMed

Ahmed, Tamer; Vafaei, Afshin; Belanger, Emmanuelle; Phillips, Susan P; Zunzunegui, Maria-Victoria

2016-09-01

This study investigated the measurement structure of the Bem Sex Role Inventory (BSRI) with different factor analysis methods. Most previous studies on validity applied exploratory factor analysis (EFA) to examine the BSRI. We aimed to assess the psychometric properties and construct validity of the 12-item short-form BSRI in a sample administered to 1,995 older adults from wave 1 of the International Mobility in Aging Study (IMIAS). We used Cronbach's alpha to assess internal consistency reliability and confirmatory factor analysis (CFA) to assess psychometric properties. EFA revealed a three-factor model, further confirmed by CFA and compared with the original two-factor structure model. Results revealed that a two-factor solution (instrumentality-expressiveness) has satisfactory construct validity and superior fit to data compared to the three-factor solution. The two-factor solution confirms expected gender differences in older adults. The 12-item BSRI provides a brief, psychometrically sound, and reliable instrument in international samples of older adults.

Connectivism in Postsecondary Online Courses: An Exploratory Factor Analysis

ERIC Educational Resources Information Center

Hogg, Nanette; Lomicky, Carol S.

2012-01-01

This study explores 465 postsecondary students' experiences in online classes through the lens of connectivism. Downes' 4 properties of connectivism (diversity, autonomy, interactivity, and openness) were used as the study design. An exploratory factor analysis was performed. This study found a 4-factor solution. Subjects indicated that autonomy…

Confirmatory Factor Analysis of the Cancer Locus of Control Scale.

ERIC Educational Resources Information Center

Henderson, Jessica W.; Donatelle, Rebecca J.; Acock, Alan C.

2002-01-01

Conducted a confirmatory factor analysis of the Cancer Locus of Control scale (M. Watson and others, 1990), administered to 543 women with a history of breast cancer. Results support a three-factor model of the scale and support use of the scale to assess control dimensions. (SLD)

Establishing Evidence for Internal Structure Using Exploratory Factor Analysis

ERIC Educational Resources Information Center

Watson, Joshua C.

2017-01-01

Exploratory factor analysis (EFA) is a data reduction technique used to condense data into smaller sets of summary variables by identifying underlying factors potentially accounting for patterns of collinearity among said variables. Using an illustrative example, the 5 general steps of EFA are described with best practices for decision making…

A Study of Item Bias for Attitudinal Measurement Using Maximum Likelihood Factor Analysis.

ERIC Educational Resources Information Center

Mayberry, Paul W.

A technique for detecting item bias that is responsive to attitudinal measurement considerations is a maximum likelihood factor analysis procedure comparing multivariate factor structures across various subpopulations, often referred to as SIFASP. The SIFASP technique allows for factorial model comparisons in the testing of various hypotheses…

The Mediating Effects of Generative Cognition on Imagination Stimulation

ERIC Educational Resources Information Center

Hsu, Yuling; Liang, Chaoyun; Chang, Chi-Cheng

2014-01-01

This study, based in Taiwan, aims to explore what psychological factors influence imagination stimulation of education major students, and what the relationship is between these factors and imagination. Both principal component analysis and confirmatory factor analysis were employed to determine the most appropriate structure of the developed…

33 CFR Appendix A to Part 279 - Sample Resource Use Objectives

Code of Federal Regulations, 2010 CFR

2010-07-01

... boating. (Discussion) The analysis of regional and site specific factors indicates that this project with...) The analysis of regional and site factors indicate that this project with its small water surface and... factors indicate that this project with its outstanding scenic qualities and its location, is suitable for...

Authoritarianism Revisited: Evidence for an Aggression Factor.

ERIC Educational Resources Information Center

Raden, David

1981-01-01

Performed a principal components factor analysis on scores of 245 undergraduates to a short version of the F Scale and measures of prejudice, attitude toward welfare, toleration of political deviance, punitiveness toward criminals, and support of the Vietnam War. Analysis produced two factors: authoritarian aggression and attitude toward welfare.…

The Concerns about Counseling Racial Minority Clients Scale

ERIC Educational Resources Information Center

Wei, Meifen; Chao, Ruth Chu-Lien; Tsai, Pei-Chun; Botello-Zamarron, Raquel

2012-01-01

The purpose of this study was to develop and validate the Concerns about Counseling Racial Minority Clients (CCRMC) scale among counselor trainees. Sample 1 was used for an exploratory factor analysis and confirmatory factor analysis. Four factors were identified, Managing Cultural Differences ([alpha] = 0.82), Offending or Hurting Clients…

Establishing Factor Validity Using Variable Reduction in Confirmatory Factor Analysis.

ERIC Educational Resources Information Center

Hofmann, Rich

1995-01-01

Using a 21-statement attitude-type instrument, an iterative procedure for improving confirmatory model fit is demonstrated within the context of the EQS program of P. M. Bentler and maximum likelihood factor analysis. Each iteration systematically eliminates the poorest fitting statement as identified by a variable fit index. (SLD)

Scale Development: Perceived Barriers to Public Use of School Recreational Facilities

ERIC Educational Resources Information Center

Spengler, John O.; Ko, Yong Jae; Connaughton, Daniel P.

2012-01-01

Objectives: To test an original scale assessing perceived barriers among school administrators to allowing community use of school recreational facilities outside of regular school hours. Methods: Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Results: Using EFA and CFA, we found that a model including factors of…

Determinants of Standard Errors of MLEs in Confirmatory Factor Analysis

ERIC Educational Resources Information Center

Yuan, Ke-Hai; Cheng, Ying; Zhang, Wei

2010-01-01

This paper studies changes of standard errors (SE) of the normal-distribution-based maximum likelihood estimates (MLE) for confirmatory factor models as model parameters vary. Using logical analysis, simplified formulas and numerical verification, monotonic relationships between SEs and factor loadings as well as unique variances are found.…

Reporting Practices in Confirmatory Factor Analysis: An Overview and Some Recommendations

ERIC Educational Resources Information Center

Jackson, Dennis L.; Gillaspy, J. Arthur, Jr.; Purc-Stephenson, Rebecca

2009-01-01

Reporting practices in 194 confirmatory factor analysis studies (1,409 factor models) published in American Psychological Association journals from 1998 to 2006 were reviewed and compared with established reporting guidelines. Three research questions were addressed: (a) how do actual reporting practices compare with published guidelines? (b) how…

Gender differences associated with enrollment in the Texas Academy of Mathematics and Science

NASA Astrophysics Data System (ADS)

Burns, Robert Thomas

This study sought to determine if different factors had influenced females and males to select engineering/science-related studies at the Texas Academy of Mathematics and Science (TAMS). The data were collected in the fall semester in 1997 at TAMS located on the University of North Texas campus from a survey of factors reported in the literature that had influenced students to enroll in engineering/science-related curriculum. Of the 380 TAMS students enrolled fall semester, 303 or 85% participated in the study. Those who participated included 135 or 45% females and 168 or 55% males. A dichotomous discriminant function analysis to identify relationships between the criterion variable (gender) and the predictor variable (factors) was used. The analysis of variance (ANOVA) was used to identify any significant predictor (factor) when the criterion was gender. Analysis of the data indicated no difference between females and males concerning factors that influenced them to enroll in TAMS. Neither discriminant function analysis nor the regression analysis using weighted least squares could significantly establish any relationship that could predict a student to be female or male with respect to factors that influenced them to enroll in TAMS. The factors were ranked utilizing the Thurstone equal appearing intervals scale for both females and males. Both females and males in TAMS ranked extrinsic interest including job opportunity, salary, and promotion, as the most important factor. The least important factor for both females and males was family encouragement. The findings indicate that TAMS students based their enrollment decision on factors independent of those suggested in the literature as applying to males and females. This may have resulted from the fact that these students are a unique population biased toward valuing a math/science curriculum.

Factors that influence career choice in primary care among medical students starting social service in Honduras.

PubMed

Puertas, E Benjamín; Rivera, Tamara Y

2016-11-01

To 1) describe patterns of specialty choice; 2) investigate relationships between career selection and selected demographic indicators; and 3) identify salary perception, factors that influence career choice in primary care, and factors that influence desired location of future medical practice. The study used a mixed-methods approach that included a cross-sectional questionnaire survey applied to 234 last-year medical students in Honduras (September 2014), and semi-structured interviews with eight key informants (October 2014). Statistical analysis included chi-square and factor analysis. An alpha level of 0.05 was used to determine significance. In the qualitative analysis, several codes were associated with each other, and five major themes emerged. Primary care careers were the preferred choice for 8.1% of students, who preferred urban settings for future practice location. The perceived salary of specialties other than primary care was significantly higher than those of general practitioners, family practitioners, and pediatricians (P < 0.001). Participants considered "making a difference," income, teaching, prestige, and challenging work the most important factors influencing career choice. Practice in ambulatory settings was significantly associated with a preference for primary care specialties (P = < 0.05). Logistic regression analysis found that factors related to patient-based care were statistically significant for selecting primary care (P = 0.006). The qualitative analysis further endorsed the survey findings, identifying additional factors that influence career choice (future work option; availability of residency positions; and social factors, including violence). Rationales behind preference of a specialty appeared to be based on a combination of ambition and prestige, and on personal and altruistic considerations. Most factors that influence primary care career choice are similar to those found in the literature. There are several factors distinctive to medical students in Honduras-most of them barriers to primary care career choice.

Factor structure of the Halstead-Reitan Neuropsychological Battery for children: a brief report supplement.

PubMed

Ross, Sylvia An; Allen, Daniel N; Goldstein, Gerald

2014-01-01

The Halstead-Reitan Neuropsychological Battery (HRNB) is the first factor-analyzed neuropsychological battery and consists of three batteries for young children, older children, and adults. Halstead's original factor analysis extracted four factors from the adult version of the battery, which were the basis for his theory of biological intelligence. These factors were called Central Integrative Field, Abstraction, Power, and Directional. Since this original analysis, Reitan's additions to the battery, and the development of the child versions of the test, this factor-analytic research continued. An introduction and the adult literature are reviewed in Ross, Allen, and Goldstein ( in press ). In this supplemental article, factor-analytic studies of the HRNB with children are reviewed. It is concluded that factor analysis of the HRNB or Reitan-Indiana Neuropsychological Battery with children does not replicate the extensiveness of the adult literature, although there is some evidence that when the traditional battery for older children is used, the factor structure is similar to what is found in adult studies. Reitan's changes to the battery appear to have added factors including language and sensory-perceptual factors. When other tests and scoring methods are used in addition to the core battery, differing solutions are produced.

Analysis of factors that influencing the interest of Bali State Polytechnic’s students in entrepreneurship

NASA Astrophysics Data System (ADS)

Ayuni, N. W. D.; Sari, I. G. A. M. K. K.

2018-01-01

The high rate of unemployment results the economic growth to be hampered. To solve this situation, the government try to change the students’ mindset from becoming a job seeker to become a job creator or entrepreneur. One real action that usually been held in Bali State Polytechnic is Student Entrepreneurial Program. The purpose of this research is to identify and analyze the factors that influence the interest of Bali State Polytechnic’s Students in entrepreneurship, especially in the Entrepreneurial Student Program. Method used in this research is Factor Analysis including Bartlett Test, Kaiser-Mayer Olkin (KMO), Measure of Sampling Adequacy (MSA), factor extraction using Principal Component Analysis (PCA), factor selection using eigen value and scree plot, and factor rotation using orthogonal rotation varimax. Result shows that there are four factors that influencing the interest of Bali State Polytechnic’s Students in Entrepreneurship which are Contextual Factor (including Entrepreneurship Training, Academic Support, Perceived Confidence, and Economic Challenge), Self Efficacy Factor (including Leadership, Mental Maturity, Relation with Entrepreneur, and Authority), Subjective Norm Factor (including Support of Important Relative, Support of Friends, and Family Role), and Attitude Factor (including Self Realization).

Factor analysis of the Zarit Burden Interview in family caregivers of patients with amyotrophic lateral sclerosis.

PubMed

Oh, Juyeon; Kim, Jung A

2018-02-01

The Zarit Burden Interview has been used in many studies to assess caregiver burden in family caregivers of patients with amyotrophic lateral sclerosis, but the factor structure of the Zarit Burden Interview in the caregivers of amyotrophic lateral sclerosis patients is unknown. The aim of this study was to explore the factor structure of the Zarit Burden Interview in family caregivers of amyotrophic lateral sclerosis patients using exploratory factor analysis. The exploratory factor analysis was performed using generalized least squares with oblique rotation in a sample of 202 family caregivers. Three factors had an eigenvalue greater than 1 and accounted for 60.33% of the total variance. The three factors were named as follows: (factor 1) "Social restrictions" (items 2, 3, and 10-15); (factor 2) "Self-criticism" (items 20-21); and (factor 3) "Anger and frustration" (items 1, 4-6, 9, and 16-19). The correlation between factors 1 and 3 was much higher (r = 0.79) than that between factors 1 and 2 (r = 0.14) or factors 2 and 3 (r = 0.15). The findings of this study enriched our understanding of several meaningful dimensions of the caregiving burden in caregivers of an amyotrophic lateral sclerosis population and provided opportunities for future intervention.

The effects of common risk factors on stock returns: A detrended cross-correlation analysis

NASA Astrophysics Data System (ADS)

Ruan, Qingsong; Yang, Bingchan

2017-10-01

In this paper, we investigate the cross-correlations between Fama and French three factors and the return of American industries on the basis of cross-correlation statistic test and multifractal detrended cross-correlation analysis (MF-DCCA). Qualitatively, we find that the return series of Fama and French three factors and American industries were overall significantly cross-correlated based on the analysis of a statistic. Quantitatively, we find that the cross-correlations between three factors and the return of American industries were strongly multifractal, and applying MF-DCCA we also investigate the cross-correlation of industry returns and residuals. We find that there exists multifractality of industry returns and residuals. The result of correlation coefficients we can verify that there exist other factors which influence the industry returns except Fama three factors.

Methods for Improving Information from ’Undesigned’ Human Factors Experiments.

DTIC Science & Technology

Human factors engineering, Information processing, Regression analysis , Experimental design, Least squares method, Analysis of variance, Correlation techniques, Matrices(Mathematics), Multiple disciplines, Mathematical prediction

Exploratory factor analysis of self-reported symptoms in a large, population-based military cohort

PubMed Central

2010-01-01

Background US military engagements have consistently raised concern over the array of health outcomes experienced by service members postdeployment. Exploratory factor analysis has been used in studies of 1991 Gulf War-related illnesses, and may increase understanding of symptoms and health outcomes associated with current military conflicts in Iraq and Afghanistan. The objective of this study was to use exploratory factor analysis to describe the correlations among numerous physical and psychological symptoms in terms of a smaller number of unobserved variables or factors. Methods The Millennium Cohort Study collects extensive self-reported health data from a large, population-based military cohort, providing a unique opportunity to investigate the interrelationships of numerous physical and psychological symptoms among US military personnel. This study used data from the Millennium Cohort Study, a large, population-based military cohort. Exploratory factor analysis was used to examine the covariance structure of symptoms reported by approximately 50,000 cohort members during 2004-2006. Analyses incorporated 89 symptoms, including responses to several validated instruments embedded in the questionnaire. Techniques accommodated the categorical and sometimes incomplete nature of the survey data. Results A 14-factor model accounted for 60 percent of the total variance in symptoms data and included factors related to several physical, psychological, and behavioral constructs. A notable finding was that many factors appeared to load in accordance with symptom co-location within the survey instrument, highlighting the difficulty in disassociating the effects of question content, location, and response format on factor structure. Conclusions This study demonstrates the potential strengths and weaknesses of exploratory factor analysis to heighten understanding of the complex associations among symptoms. Further research is needed to investigate the relationship between factor analytic results and survey structure, as well as to assess the relationship between factor scores and key exposure variables. PMID:20950474

Physics Metacognition Inventory Part II: Confirmatory factor analysis and Rasch analysis

NASA Astrophysics Data System (ADS)

Taasoobshirazi, Gita; Bailey, MarLynn; Farley, John

2015-11-01

The Physics Metacognition Inventory was developed to measure physics students' metacognition for problem solving. In one of our earlier studies, an exploratory factor analysis provided evidence of preliminary construct validity, revealing six components of students' metacognition when solving physics problems including knowledge of cognition, planning, monitoring, evaluation, debugging, and information management. The college students' scores on the inventory were found to be reliable and related to students' physics motivation and physics grade. However, the results of the exploratory factor analysis indicated that the questionnaire could be revised to improve its construct validity. The goal of this study was to revise the questionnaire and establish its construct validity through a confirmatory factor analysis. In addition, a Rasch analysis was applied to the data to better understand the psychometric properties of the inventory and to further evaluate the construct validity. Results indicated that the final, revised inventory is a valid, reliable, and efficient tool for assessing student metacognition for physics problem solving.

Entrance and exit region friction factor models for annular seal analysis. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Elrod, David Alan

1988-01-01

The Mach number definition and boundary conditions in Nelson's nominally-centered, annular gas seal analysis are revised. A method is described for determining the wall shear stress characteristics of an annular gas seal experimentally. Two friction factor models are developed for annular seal analysis; one model is based on flat-plate flow theory; the other uses empirical entrance and exit region friction factors. The friction factor predictions of the models are compared to experimental results. Each friction model is used in an annular gas seal analysis. The seal characteristics predicted by the two seal analyses are compared to experimental results and to the predictions of Nelson's analysis. The comparisons are for smooth-rotor seals with smooth and honeycomb stators. The comparisons show that the analysis which uses empirical entrance and exit region shear stress models predicts the static and stability characteristics of annular gas seals better than the other analyses. The analyses predict direct stiffness poorly.

Design and Analysis of Subscale and Full-Scale Buckling-Critical Cylinders for Launch Vehicle Technology Development

NASA Technical Reports Server (NTRS)

Hilburger, Mark W.; Lovejoy, Andrew E.; Thornburgh, Robert P.; Rankin, Charles

2012-01-01

NASA s Shell Buckling Knockdown Factor (SBKF) project has the goal of developing new analysis-based shell buckling design factors (knockdown factors) and design and analysis technologies for launch vehicle structures. Preliminary design studies indicate that implementation of these new knockdown factors can enable significant reductions in mass and mass-growth in these vehicles. However, in order to validate any new analysis-based design data or methods, a series of carefully designed and executed structural tests are required at both the subscale and full-scale levels. This paper describes the design and analysis of three different orthogrid-stiffeNed metallic cylindrical-shell test articles. Two of the test articles are 8-ft-diameter, 6-ft-long test articles, and one test article is a 27.5-ft-diameter, 20-ft-long Space Shuttle External Tank-derived test article.

Factors that Affect Poverty Areas in North Sumatera Using Discriminant Analysis

NASA Astrophysics Data System (ADS)

Nasution, D. H.; Bangun, P.; Sitepu, H. R.

2018-04-01

In Indonesia, especially North Sumatera, the problem of poverty is one of the fundamental problems that become the focus of government both central and local government. Although the poverty rate decreased but the fact is there are many people who are poor. Poverty happens covers several aspects such as education, health, demographics, and also structural and cultural. This research will discuss about several factors such as population density, Unemployment Rate, GDP per capita ADHK, ADHB GDP per capita, economic growth and life expectancy that affect poverty in Indonesia. To determine the factors that most influence and differentiate the level of poverty of the Regency/City North Sumatra used discriminant analysis method. Discriminant analysis is one multivariate analysis technique are used to classify the data into a group based on the dependent variable and independent variable. Using discriminant analysis, it is evident that the factor affecting poverty is Unemployment Rate.

Cement Leakage in Percutaneous Vertebral Augmentation for Osteoporotic Vertebral Compression Fractures: Analysis of Risk Factors.

PubMed

Xie, Weixing; Jin, Daxiang; Ma, Hui; Ding, Jinyong; Xu, Jixi; Zhang, Shuncong; Liang, De

2016-05-01

The risk factors for cement leakage were retrospectively reviewed in 192 patients who underwent percutaneous vertebral augmentation (PVA). To discuss the factors related to the cement leakage in PVA procedure for the treatment of osteoporotic vertebral compression fractures. PVA is widely applied for the treatment of osteoporotic vertebral fractures. Cement leakage is a major complication of this procedure. The risk factors for cement leakage were controversial. A retrospective review of 192 patients who underwent PVA was conducted. The following data were recorded: age, sex, bone density, number of fractured vertebrae before surgery, number of treated vertebrae, severity of the treated vertebrae, operative approach, volume of injected bone cement, preoperative vertebral compression ratio, preoperative local kyphosis angle, intraosseous clefts, preoperative vertebral cortical bone defect, and ratio and type of cement leakage. To study the correlation between each factor and cement leakage ratio, bivariate regression analysis was employed to perform univariate analysis, whereas multivariate linear regression analysis was employed to perform multivariate analysis. The study included 192 patients (282 treated vertebrae), and cement leakage occurred in 100 vertebrae (35.46%). The vertebrae with preoperative cortical bone defects generally exhibited higher cement leakage ratio, and the leakage is typically type C. Vertebrae with intact cortical bones before the procedure tend to experience type S leakage. Univariate analysis showed that patient age, bone density, number of fractured vertebrae before surgery, and vertebral cortical bone were associated with cement leakage ratio (P<0.05). Multivariate analysis showed that the main factors influencing bone cement leakage are bone density and vertebral cortical bone defect, with standardized partial regression coefficients of -0.085 and 0.144, respectively. High bone density and vertebral cortical bone defect are independent risk factors associated with bone cement leakage.

Anthropometric data reduction using confirmatory factor analysis.

PubMed

Rohani, Jafri Mohd; Olusegun, Akanbi Gabriel; Rani, Mat Rebi Abdul

2014-01-01

The unavailability of anthropometric data especially in developing countries has remained a limiting factor towards the design of learning facilities with sufficient ergonomic consideration. Attempts to use anthropometric data from developed countries have led to provision of school facilities unfit for the users. The purpose of this paper is to use factor analysis to investigate the suitability of the collected anthropometric data as a database for school design in Nigerian tertiary institutions. Anthropometric data were collected from 288 male students in a Federal Polytechnic in North-West of Nigeria. Their age is between 18-25 years. Nine vertical anthropometric dimensions related to heights were collected using the conventional traditional equipment. Exploratory factor analysis was used to categorize the variables into a model consisting of two factors. Thereafter, confirmatory factor analysis was used to investigate the fit of the data to the proposed model. A just identified model, made of two factors, each with three variables was developed. The variables within the model accounted for 81% of the total variation of the entire data. The model was found to demonstrate adequate validity and reliability. Various measuring indices were used to verify that the model fits the data properly. The final model reveals that stature height and eye height sitting were the most stable variables for designs that have to do with standing and sitting construct. The study has shown the application of factor analysis in anthropometric data analysis. The study highlighted the relevance of these statistical tools to investigate variability among anthropometric data involving diverse population, which has not been widely used for analyzing previous anthropometric data. The collected data is therefore suitable for use while designing for Nigerian students.

A single factor underlies the metabolic syndrome: a confirmatory factor analysis.

PubMed

Pladevall, Manel; Singal, Bonita; Williams, L Keoki; Brotons, Carlos; Guyer, Heidi; Sadurni, Josep; Falces, Carles; Serrano-Rios, Manuel; Gabriel, Rafael; Shaw, Jonathan E; Zimmet, Paul Z; Haffner, Steven

2006-01-01

Confirmatory factor analysis (CFA) was used to test the hypothesis that the components of the metabolic syndrome are manifestations of a single common factor. Three different datasets were used to test and validate the model. The Spanish and Mauritian studies included 207 men and 203 women and 1,411 men and 1,650 women, respectively. A third analytical dataset including 847 men was obtained from a previously published CFA of a U.S. population. The one-factor model included the metabolic syndrome core components (central obesity, insulin resistance, blood pressure, and lipid measurements). We also tested an expanded one-factor model that included uric acid and leptin levels. Finally, we used CFA to compare the goodness of fit of one-factor models with the fit of two previously published four-factor models. The simplest one-factor model showed the best goodness-of-fit indexes (comparative fit index 1, root mean-square error of approximation 0.00). Comparisons of one-factor with four-factor models in the three datasets favored the one-factor model structure. The selection of variables to represent the different metabolic syndrome components and model specification explained why previous exploratory and confirmatory factor analysis, respectively, failed to identify a single factor for the metabolic syndrome. These analyses support the current clinical definition of the metabolic syndrome, as well as the existence of a single factor that links all of the core components.

Common factor analysis versus principal component analysis: choice for symptom cluster research.

PubMed

Kim, Hee-Ju

2008-03-01

The purpose of this paper is to examine differences between two factor analytical methods and their relevance for symptom cluster research: common factor analysis (CFA) versus principal component analysis (PCA). Literature was critically reviewed to elucidate the differences between CFA and PCA. A secondary analysis (N = 84) was utilized to show the actual result differences from the two methods. CFA analyzes only the reliable common variance of data, while PCA analyzes all the variance of data. An underlying hypothetical process or construct is involved in CFA but not in PCA. PCA tends to increase factor loadings especially in a study with a small number of variables and/or low estimated communality. Thus, PCA is not appropriate for examining the structure of data. If the study purpose is to explain correlations among variables and to examine the structure of the data (this is usual for most cases in symptom cluster research), CFA provides a more accurate result. If the purpose of a study is to summarize data with a smaller number of variables, PCA is the choice. PCA can also be used as an initial step in CFA because it provides information regarding the maximum number and nature of factors. In using factor analysis for symptom cluster research, several issues need to be considered, including subjectivity of solution, sample size, symptom selection, and level of measure.

Hand function evaluation: a factor analysis study.

PubMed

Jarus, T; Poremba, R

1993-05-01

The purpose of this study was to investigate hand function evaluations. Factor analysis with varimax rotation was used to assess the fundamental characteristics of the items included in the Jebsen Hand Function Test and the Smith Hand Function Evaluation. The study sample consisted of 144 subjects without disabilities and 22 subjects with Colles fracture. Results suggest a four factor solution: Factor I--pinch movement; Factor II--grasp; Factor III--target accuracy; and Factor IV--activities of daily living. These categories differentiated the subjects without Colles fracture from the subjects with Colles fracture. A hand function evaluation consisting of these four factors would be useful. Such an evaluation that can be used for current clinical purposes is provided.

Factor Structure and Item Level Psychometrics of the Social Problem Solving Inventory Revised-Short Form in Traumatic Brain Injury

PubMed Central

Li, Chih-Ying; Waid-Ebbs, Julia; Velozo, Craig A.; Heaton, Shelley C.

2016-01-01

Primary Objective Social problem solving deficits characterize individuals with traumatic brain injury (TBI). Poor social problem solving interferes with daily functioning and productive lifestyles. Therefore, it is of vital importance to use the appropriate instrument to identify deficits in social problem solving for individuals with TBI. This study investigates factor structure and item-level psychometrics of the Social Problem Solving Inventory-Revised Short Form (SPSI-R:S), for adults with moderate and severe TBI. Research Design Secondary analysis of 90 adults with moderate and severe TBI who completed the SPSI-R:S. Methods and Procedures An exploratory factor analysis (EFA), principal components analysis (PCA) and Rasch analysis examined the factor structure and item-level psychometrics of the SPSI-R:S. Main Outcomes and Results The EFA showed three dominant factors, with positively worded items represented as the most definite factor. The other two factors are negative problem solving orientation and skills; and negative problem solving emotion. Rasch analyses confirmed the three factors are each unidimensional constructs. Conclusions The total score interpretability of the SPSI-R:S may be challenging due to the multidimensional structure of the total measure. Instead, we propose using three separate SPSI-R:S subscores to measure social problem solving for the TBI population. PMID:26052731

Morphometric assessment of the red stripe weevils, Rhynchophorus vulneratus (Coleoptera: Curculionidae) from several localities in Malaysia

NASA Astrophysics Data System (ADS)

Sazali, Siti Nurlydia; Hazmi, Izfa Riza; Rahim, Faszly; Abang, Fatimah; Jemain, Abdul Aziz

2018-04-01

The recognition of intraspecific variation could enhance knowledge and understanding on the population divergence that might be resulted from different geographical areas. To study the possible effect derived from different locations, a morphometric study of the red stripe weevils, Rhynchophorus vulneratus from different localities in Malaysia was conducted using field and voucher specimens. A total of twenty-three morphological characters were examined from 108 individuals of R. vulneratus representing population of Kota Samarahan, Mukah and central of Peninsular Malaysia. The data were subjected to univariate one-way single factor analysis of variance (ANOVA) and analysed in factor analysis using SPSS version 22.0 software. Univariate ANOVA showed that all tested variables were significantly different (p<0.05) except for mesocoxal distance (MSD), meanwhile from the factor analysis, the first three factors with eigenvalues greater than 1.0 were successfully extracted, resulting in a high variation of 82.687%. For factor 1, 39.213% of total variation was recorded, factor 2 accounted for 34.096% and factor 3 contributing to 9.377%, respectively. The mixed plotting among the twenty-three morphological characters suggests a strong correlation among the parameters examined and further statistical analysis should be conducted to include environmental factors such as habitat types, food availability and predation effect.

Factor structure and item level psychometrics of the Social Problem Solving Inventory-Revised: Short Form in traumatic brain injury.

PubMed

Li, Chih-Ying; Waid-Ebbs, Julia; Velozo, Craig A; Heaton, Shelley C

2016-01-01

Social problem-solving deficits characterise individuals with traumatic brain injury (TBI), and poor social problem solving interferes with daily functioning and productive lifestyles. Therefore, it is of vital importance to use the appropriate instrument to identify deficits in social problem solving for individuals with TBI. This study investigates factor structure and item-level psychometrics of the Social Problem Solving Inventory-Revised: Short Form (SPSI-R:S), for adults with moderate and severe TBI. Secondary analysis of 90 adults with moderate and severe TBI who completed the SPSI-R:S was performed. An exploratory factor analysis (EFA), principal components analysis (PCA) and Rasch analysis examined the factor structure and item-level psychometrics of the SPSI-R:S. The EFA showed three dominant factors, with positively worded items represented as the most definite factor. The other two factors are negative problem-solving orientation and skills; and negative problem-solving emotion. Rasch analyses confirmed the three factors are each unidimensional constructs. It was concluded that the total score interpretability of the SPSI-R:S may be challenging due to the multidimensional structure of the total measure. Instead, we propose using three separate SPSI-R:S subscores to measure social problem solving for the TBI population.

A factor analysis of the SSQ (Speech, Spatial, and Qualities of Hearing Scale)

PubMed Central

2014-01-01

Objective The speech, spatial, and qualities of hearing questionnaire (SSQ) is a self-report test of auditory disability. The 49 items ask how well a listener would do in many complex listening situations illustrative of real life. The scores on the items are often combined into the three main sections or into 10 pragmatic subscales. We report here a factor analysis of the SSQ that we conducted to further investigate its statistical properties and to determine its structure. Design Statistical factor analysis of questionnaire data, using parallel analysis to determine the number of factors to retain, oblique rotation of factors, and a bootstrap method to estimate the confidence intervals. Study sample 1220 people who have attended MRC IHR over the last decade. Results We found three clear factors, essentially corresponding to the three main sections of the SSQ. They are termed “speech understanding”, “spatial perception”, and “clarity, separation, and identification”. Thirty-five of the SSQ questions were included in the three factors. There was partial evidence for a fourth factor, “effort and concentration”, representing two more questions. Conclusions These results aid in the interpretation and application of the SSQ and indicate potential methods for generating average scores. PMID:24417459

Psychometric analysis of the leadership environment scale (LENS): Outcome from the Oregon research initiative on the organisation of nursing (ORION).

PubMed

Ross, Amy M; Ilic, Kelley; Kiyoshi-Teo, Hiroko; Lee, Christopher S

2017-12-26

The purpose of this study was to establish the psychometric properties of the new 16-item leadership environment scale. The leadership environment scale was based on complexity science concepts relevant to complex adaptive health care systems. A workforce survey of direct-care nurses was conducted (n = 1,443) in Oregon. Confirmatory factor analysis, exploratory factor analysis, concordant validity test and reliability tests were conducted to establish the structure and internal consistency of the leadership environment scale. Confirmatory factor analysis indices approached acceptable thresholds of fit with a single factor solution. Exploratory factor analysis showed improved fit with a two-factor model solution; the factors were labelled 'influencing relationships' and 'interdependent system supports'. Moderate to strong convergent validity was observed between the leadership environment scale/subscales and both the nursing workforce index and the safety organising scale. Reliability of the leadership environment scale and subscales was strong, with all alphas ≥.85. The leadership environment scale is structurally sound and reliable. Nursing management can employ adaptive complexity leadership attributes, measure their influence on the leadership environment, subsequently modify system supports and relationships and improve the quality of health care systems. The leadership environment scale is an innovative fit to complex adaptive systems and how nurses act as leaders within these systems. © 2017 John Wiley & Sons Ltd.

Determinants of job stress in chemical process industry: A factor analysis approach.

PubMed

Menon, Balagopal G; Praveensal, C J; Madhu, G

2015-01-01

Job stress is one of the active research domains in industrial safety research. The job stress can result in accidents and health related issues in workers in chemical process industries. Hence it is important to measure the level of job stress in workers so as to mitigate the same to avoid the worker's safety related problems in the industries. The objective of this study is to determine the job stress factors in the chemical process industry in Kerala state, India. This study also aims to propose a comprehensive model and an instrument framework for measuring job stress levels in the chemical process industries in Kerala, India. The data is collected through a questionnaire survey conducted in chemical process industries in Kerala. The collected data out of 1197 surveys is subjected to principal component and confirmatory factor analysis to develop the job stress factor structure. The factor analysis revealed 8 factors that influence the job stress in process industries. It is also found that the job stress in employees is most influenced by role ambiguity and the least by work environment. The study has developed an instrument framework towards measuring job stress utilizing exploratory factor analysis and structural equation modeling.

Factors Influencing Cecal Intubation Time during Retrograde Approach Single-Balloon Enteroscopy

PubMed Central

Chen, Peng-Jen; Shih, Yu-Lueng; Huang, Hsin-Hung; Hsieh, Tsai-Yuan

2014-01-01

Background and Aim. The predisposing factors for prolonged cecal intubation time (CIT) during colonoscopy have been well identified. However, the factors influencing CIT during retrograde SBE have not been addressed. The aim of this study was to determine the factors influencing CIT during retrograde SBE. Methods. We investigated patients who underwent retrograde SBE at a medical center from January 2011 to March 2014. The medical charts and SBE reports were reviewed. The patients' characteristics and procedure-associated data were recorded. These data were analyzed with univariate analysis as well as multivariate logistic regression analysis to identify the possible predisposing factors. Results. We enrolled 66 patients into this study. The median CIT was 17.4 minutes. With univariate analysis, there was no statistical difference in age, sex, BMI, or history of abdominal surgery, except for bowel preparation (P = 0.021). Multivariate logistic regression analysis showed that inadequate bowel preparation (odds ratio 30.2, 95% confidence interval 4.63–196.54; P < 0.001) was the independent predisposing factors for prolonged CIT during retrograde SBE. Conclusions. For experienced endoscopist, inadequate bowel preparation was the independent predisposing factor for prolonged CIT during retrograde SBE. PMID:25505904

Population-Based Questionnaire Survey on Health Effects of Aircraft Noise on Residents Living around U.S. Airfields in the RYUKYUS—PART II: AN Analysis of the Discriminant Score and the Factor Score

NASA Astrophysics Data System (ADS)

HIRAMATSU, K.; MATSUI, T.; MIYAKITA, T.; ITO, A.; TOKUYAMA, T.; OSADA, Y.; YAMAMOTO, T.

2002-02-01

Discriminant function values of psychosomatics and neurosis are calculated using the 12 scale scores of the Todai Health Index, a general health questionnaire, obtained in the survey done around the Kadena and Futenma U.S. airfields in Okinawa, Japan. The total number of answers available for the analysis is 6301. Factor analysis is applied to the 12 scale scores by means of the principal factor method, and Oblimin rotation is done because the factors extracted are considered likely to correlate with each other to a greater or lesser extent. The logistic regression analysis is made with the independent variables of discriminant function (DF) values and factor scores and with the dependent variables of Ldn, age (six levels), sex, occupation (four categories) and the interaction of age and sex. Results indicate that the odds ratio of the DF values regarding psychosomatic disorder and of the score of somatic factor have clear dose-response relationship. The odds ratios of the DF value of neurosis and of the score of the mental factor increase in the area where noise exposure is very intense.

Confirmatory factor analysis of the Child Health Questionnaire-Parent Form 50 in a predominantly minority sample.

PubMed

Hepner, Kimberly A; Sechrest, Lee

2002-12-01

The Child Health Questionnaire-Parent Form 50 (CHQ-PF50; Landgraf JM et al., The CHQ User's Manual. Boston, MA: The Health Institute, New England Medical Centre, 1996) appears to be a useful method of assessing children's health. The CHQ-PF50 is designed to measure general functional status and well-being and is available in several versions to suit the needs of the health researcher. Several publications have reported favorably on the psychometric properties of the CHQ. Landgraf et al. reported the results of an exploratory factor analysis at the scale level that provided evidence for a two-factor structure representing physical and psychosocial dimensions of health. In order to cross-validate and extend these results, a confirmatory factor analysis was conducted with an independent sample of generally healthy, predominantly minority children. Results of the analysis indicate that a two-factor model provides a good fit to the data, confirming previous exploratory analyses with this questionnaire. One additional method factor seems likely because of the substantial similarity of three of the scales, but that does not affect the substantive two-factor interpretation overall.

Measuring attitudes towards suicide: Preliminary evaluation of an attitude towards suicide scale.

PubMed

Cwik, Jan Christopher; Till, Benedikt; Bieda, Angela; Blackwell, Simon E; Walter, Carolin; Teismann, Tobias

2017-01-01

Our study aimed to validate a previously published scale assessing attitudes towards suicide. Factor structure, convergent and discriminant validity, and predictive validity were investigated. Adult German participants (N=503; mean age=24.74years; age range=18-67years) anonymously completed a set of questionnaires. An exploratory factor analysis was conducted, and incongruous items were deleted. Subsequently, scale properties of the reduced scale and its construct validity were analyzed. A confirmatory factor analysis was then conducted in an independent sample (N=266; mean age=28.77years; age range=18-88years) to further confirm the factor structure of the questionnaire. Parallel analysis indicated a three-factor solution, which was also supported by confirmatory factor analysis: right to commit suicide, interpersonal gesture and resilience. The subscales demonstrated acceptable construct and discriminant validity. Cronbach's α for the subscales ranged from 0.67 to 0.83, explaining 49.70% of the total variance. Positive attitudes towards suicide proved to be predictive of suicide risk status, providing preliminary evidence for the utility of the scale. Future studies aiming to reproduce the factor structure in a more heterogeneous sample are warranted. Copyright © 2016 Elsevier Inc. All rights reserved.

Understanding clinician attitudes towards implementation of guided self-help cognitive behaviour therapy for those who hear distressing voices: using factor analysis to test normalisation process theory.

PubMed

Hazell, Cassie M; Strauss, Clara; Hayward, Mark; Cavanagh, Kate

2017-07-24

The Normalisation Process Theory (NPT) has been used to understand the implementation of physical health care interventions. The current study aims to apply the NPT model to a secondary mental health context, and test the model using exploratory factor analysis. This study will consider the implementation of a brief cognitive behaviour therapy for psychosis (CBTp) intervention. Mental health clinicians were asked to complete a NPT-based questionnaire on the implementation of a brief CBTp intervention. All clinicians had experience of either working with the target client group or were able to deliver psychological therapies. In total, 201 clinicians completed the questionnaire. The results of the exploratory factor analysis found partial support for the NPT model, as three of the NPT factors were extracted: (1) coherence, (2) cognitive participation, and (3) reflexive monitoring. We did not find support for the fourth NPT factor (collective action). All scales showed strong internal consistency. Secondary analysis of these factors showed clinicians to generally support the implementation of the brief CBTp intervention. This study provides strong evidence for the validity of the three NPT factors extracted. Further research is needed to determine whether participants' level of seniority moderates factor extraction, whether this factor structure can be generalised to other healthcare settings, and whether pre-implementation attitudes predict actual implementation outcomes.

Construction and validation of a questionnaire on the knowledge of healthy habits and risk factors for cardiovascular disease in schoolchildren.

PubMed

Cecchetto, Fátima H; Pellanda, Lucia C

2014-01-01

To develop and analyze the reliability and validity of a questionnaire on the knowledge of healthy habits and risk factors for cardiovascular disease (CARDIOKID) to be used in schoolchildren. The study included 145 children aged 7 to 11 years. The measured factors were the knowledge of healthy habits and risk factors for cardiovascular disease. Cronbach's alpha and intra-class correlation coefficient (ICC) were used to verify reliability, and exploratory factor analysis was used to assess the validity of the questionnaire. The sample consisted of 60% females and 40% males. In factorial analysis, the Kaiser-Meyer-Olkin (KMO) test result was measures of sampling adequacy (MSA)=0.81 and Bartlett's test of sphericity was X(2)=(66)=458.64 (p<0.001). In the factorial analysis with varimax rotation, two dimensions were defined. The "healthy habits" dimension was composed of five factors (ICC=0.87 and α=0.93) and the "cardiovascular risk factors" dimension was composed of seven factors (ICC=0.83 and α=0.91). In the individual factor analysis, Cronbach's alphas were between 0.93 and 0.91. Total variance was 46.87%. There were no significant differences between test and retest applications. The questionnaire presented satisfactory validity and reliability (internal consistency and reproducibility), allowing for its use in children. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Dimension of Typus melancholicus on Kasahara's Inventory for the Melancholic Type Personality.

PubMed

Ueki, Hirofumi; Holzapfel, Christian; Sakado, Kaoru; Washino, Kaei; Inoue, Masato; Ogawa, Naoshi

2004-01-01

Traditionally, Typus melancholicus (TM) was considered, a priori, to represent unidimensionality. Recent studies have suggested that TM is not a personality trait, but rather a constellation of personality traits. The purpose of this study was to examine whether TM on Kasahara's Inventory for the Melancholic Type Personality (KIMTP), considered to represent one of the valid TM questionnaires, is comprised of personality dimensions, and if so, which dimension is essential for distinguishing depressive subjects from control subjects. To clarify the dimensionality of TM scores on KIMTP, factor analysis of the TM scores was conducted using principal factor analysis followed by varimax rotation. Comparisons were then made between endogenous depressive patients (n = 38), nonendogenous depressive patients (n = 20), and healthy volunteers (n = 81) for total KIMTP score and factor scores using analysis of covariance, adjusting for sex and age. Factor analysis of KIMTP revealed 2 distinct clusters of items, i.e. 'harmony in personal relationships' (factor 1) and 'social norms' (factor 2). Endogenous and nonendogenous depressive patients showed significantly higher KIMTP total and factor 1 scores than did control subjects. However, no significant differences were observed for KIMTP total score and scores of individual factors between endogenous and nonendogenous depressive patients. The present results indicate that TM on KIMTP represents a constellation of personality traits, and that the factor 'harmony in personal relationship' possesses the essential meaning for assessing TM. Copyright 2004 S. Karger AG, Basel

[Development and validation of the Korean patient safety culture scale for nursing homes].

PubMed

Yoon, Sook Hee; Kim, Byungsoo; Kim, Se Young

2013-06-01

The purpose of this study was to develop a tool to evaluate patient safety culture in nursing homes and to test its validity and reliability. A preliminary tool was developed through interviews with focus group, content validity tests, and a pilot study. A nationwide survey was conducted from February to April, 2011, using self-report questionnaires. Participants were 982 employees in nursing homes. Data were analyzed using Cronbach's alpha, item analysis, factor analysis, and multitrait/multi-Item analysis. From the results of the analysis, 27 final items were selected from 49 items on the preliminary tool. Items with low correlation with total scale were excluded. The 4 factors sorted by factor analysis contributed 63.4% of the variance in the total scale. The factors were labeled as leadership, organizational system, working attitude, management practice. Cronbach's alpha for internal consistency was .95 and the range for the 4 factors was from .86 to .93. The results of this study indicate that the Korean Patient Safety Culture Scale has reliability and validity and is suitable for evaluation of patient safety culture in Korean nursing homes.

MULTIVARIATE ANALYSIS OF DRINKING BEHAVIOUR IN A RURAL POPULATION

PubMed Central

Mathrubootham, N.; Bashyam, V.S.P.; Shahjahan

1997-01-01

This study was carried out to find out the drinking pattern in a rural population, using multivariate techniques. 386 current users identified in a community were assessed with regard to their drinking behaviours using a structured interview. For purposes of the study the questions were condensed into 46 meaningful variables. In bivariate analysis, 14 variables including dependent variables such as dependence, MAST & CAGE (measuring alcoholic status), Q.F. Index and troubled drinking were found to be significant. Taking these variables and other multivariate techniques too such as ANOVA, correlation, regression analysis and factor analysis were done using both SPSS PC + and HCL magnum mainframe computer with FOCUS package and UNIX systems. Results revealed that number of factors such as drinking style, duration of drinking, pattern of abuse, Q.F. Index and various problems influenced drinking and some of them set up a vicious circle. Factor analysis revealed mainly 3 factors, abuse, dependence and social drinking factors. Dependence could be divided into low/moderate dependence. The implications and practical applications of these tests are also discussed. PMID:21584077

[Developing Perceived Competence Scale (PCS) for Adolescents].

PubMed

Özer, Arif; Gençtanirim Kurt, Dilek; Kizildağ, Seval; Demırtaş Zorbaz, Selen; Arici Şahın, Fatma; Acar, Tülin; Ergene, Tuncay

2016-01-01

In this study, Perceived Competence Scale was developed to measure high school students' perceived competence. Scale development process was verified on three different samples. Participants of the research are some high school students in 2011-2012 academic terms from Ankara. Participants' numbers are incorporated in exploratory factor analysis, confirmatory factor analysis and test-retest reliability respectively, as follows: 372, 668 and 75. Internal consistency coefficients (Cronbach's and stratified α) are calculated separately for each group. For data analysis Factor 8.02 and LISREL 8.70 package programs were used. According to results of the analyses, internal consistency coefficients (α) are .90 - .93 for academic competence, .82 - .86 for social competence in the samples that exploratory and confirmatory factor analysis performed. For the whole scale internal consistency coefficient (stratified α) is calculated as .91. As a result of test-retest reliability, adjusted correlation coefficients (r) are .94 for social competence and .90 for academic competence. In addition, to fit indexes and regression weights obtained from factor analysis, findings related convergent and discriminant validity, indicating that competence can be addressed in two dimensions which are academic (16 items) and social (14 items).

Identification of Scoliosis Research Society-22r Health-Related Quality of Life questionnaire domains using factor analysis methodology.

PubMed

Lai, Sue-Min; Asher, Marc A; Burton, Douglas C; Carlson, Brandon B

2010-05-20

Cross-sectional mail questionnaire. Examination of the underlying construct validity of the Scoliosis Research Society-22r (SRS-22r) Health-Related Quality of Life (HRQoL) Questionnaire using factor analysis. The original SRS-24 HRQoL questionnaire has undergone a series of modifications in an effort to further improve its psychometric properties and validate its use in patients from 10 years of age until well into adulthood. The SRS-22r questionnaire is the result of this effort. To date, the underlying construct validity of the original English version has not been analyzed by factor analysis. A questionnaire including all questions on the SRS-24, -23, -22, and -22r questionnaires (49 total questions) was mailed to a consecutive series of 235 patients who had received primary posterior or anterior instrumentation and arthrodesis. Domain structure of the SRS-22r questions was analyzed using iterated principal factor analysis with orthogonal rotation. One hundred twenty-one (51%) of the patients, age 23.34 +/- 4.52 years (range, 14.16-34.57 years), returned the questionnaire at 8.63 +/- 4.00 years (range, 2.32-15.94 years) following surgery. Factor analysis using all 22 questions resulted in 3 factors with many shared items because of significant collinearity of the satisfaction/dissatisfaction with management questions with the others. After 18 iterations, factor analysis using the 20 nonmanagement questions revealed 4 factors that explained 98% of the variance. These factors parallel the assigned domains of the SRS-22r questionnaire. Three questions (2 self-image and 1 function) were identified that had high loading in 2 factors. However, internal consistency was best when 2 of the questions (1 self-image and 1 function) were retained in their assigned SRS-22r domains and the third decreased self-image internal consistency by only 0.01%. The internal consistencies (Cronbach alpha) of the assigned SRS-22r nonmanagement domains were excellent or very good: function 0.83, pain 0.87, self-image 0.80, and mental health 0.90. For the management domain it was good: 0.73. Factor analysis of the SRS-22r HRQoL confirms placement of the 20 nonmanagement domain questions in the assigned 4 domains, all with excellent or very good internal consistency.

Measuring the effects of socioeconomic factors on mental health among migrants in urban China: a multiple indicators multiple causes model.

PubMed

Guan, Ming

2017-01-01

Since 1978, rural-urban migrants mainly contribute Chinese urbanization. The purpose of this paper is to examine the effects of socioeconomic factors on mental health of them. Their mental health was measured by 12-item general health questionnaire (GHQ-12). The study sample comprised 5925 migrants obtained from the 2009 rural-to-urban migrants survey (RUMiC). The relationships among the instruments were assessed by the correlation analysis. The one-factor (overall items), two-factor (positive vs. negative items), and model conducted by principal component analysis were tested in the confirmatory factor analysis (CFA). On the basis of three CFA models, the three multiple indicators multiple causes (MIMIC) models with age, gender, marriage, ethnicity, and employment were constructed to investigate the concurrent associations between socioeconomic factors and GHQ-12. Of the sample, only 1.94% were of ethnic origin and mean age was 31.63 (SD = ±10.43) years. The one-factor, two-factor, and three-factor structure (i.e. semi-positive/negative/independent usefulness) had good model fits in the CFA analysis and gave order (i.e. 2 factor>3 factor>1 factor), which suggests that the three models can be used to assess psychological symptoms of migrants in urban China. All MIMIC models had acceptable fit and gave order (i.e. one-dimensional model>two-dimensional model>three-dimensional model). There were weak associations of socioeconomic factors with mental health among migrants in urban China. Policy discussion suggested that improvement of socioeconomic status of rural-urban migrants and mental health systems in urban China should be highlighted and strengthened.

Robust Bayesian Factor Analysis

ERIC Educational Resources Information Center

Hayashi, Kentaro; Yuan, Ke-Hai

2003-01-01

Bayesian factor analysis (BFA) assumes the normal distribution of the current sample conditional on the parameters. Practical data in social and behavioral sciences typically have significant skewness and kurtosis. If the normality assumption is not attainable, the posterior analysis will be inaccurate, although the BFA depends less on the current…

Human error analysis of commercial aviation accidents using the human factors analysis and classification system (HFACS)

DOT National Transportation Integrated Search

2001-02-01

The Human Factors Analysis and Classification System (HFACS) is a general human error framework : originally developed and tested within the U.S. military as a tool for investigating and analyzing the human : causes of aviation accidents. Based upon ...

A human factors analysis of fatal and serious injury accidents in Alaska, 2004-2009.

DOT National Transportation Integrated Search

2011-12-01

"This report summarizes the analysis of 97 general aviation accidents in Alaska that resulted in a fatality or serious : injury to one or more aircraft occupants for the years 2004-2009. The accidents were analyzed using the Human : Factors Analysis ...

Confirmatory Factor Analysis of the Behavior Rating Inventory of Executive Function-Adult Version in Healthy Adults and Application to Attention-Deficit/Hyperactivity Disorder

PubMed Central

Roth, Robert M.; Lance, Charles E.; Isquith, Peter K.; Fischer, Adina S.; Giancola, Peter R.

2013-01-01

The Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A) is a questionnaire measure designed to assess executive functioning in everyday life. Analysis of data from the BRIEF-A standardization sample yielded a two-factor solution (labeled Behavioral Regulation and Metacognition). The present investigation employed confirmatory factor analysis (CFA) to evaluate four alternative models of the factor structure of the BRIEF-A self-report form in a sample of 524 healthy young adults. Results indicated that a three-factor model best fits the data: a Metacognition factor, a Behavioral Regulation factor consisting of the Inhibit and Self-Monitor scales, and an Emotional Regulation factor composed of the Emotional Control and Shift scales. The three factors contributed 14%, 19%, and 24% of unique variance to the model, respectively, and a second-order general factor accounted for 41% of variance overall. This three-factor solution is consistent with recent CFAs of the Parent report form of the BRIEF. Furthermore, although the Behavioral Regulation factor score in the two-factor model did not differ between adults with attention-deficit/hyperactivity disorder and a matched healthy comparison group, greater impairment on the Behavioral Regulation factor but not the Emotional Regulation factor was found using the three-factor model. Together, these findings support the multidimensional nature of executive function and the clinical relevance of a three-factor model of the BRIEF-A. PMID:23676185

Exploratory factor analysis of signalment and conformational measurements in Thoroughbred horses with and without recurrent laryngeal neuropathy.

PubMed

McGivney, C L; Gough, K F; McGivney, B A; Farries, G; Hill, E W; Katz, L M

2018-06-23

Conflicting results have been reported for risk factors for recurrent laryngeal neuropathy (RLN) based on resting endoscopic evaluation and comparison of single conformation traits, with many traits correlated to one another. To simplify identification of signalment and conformation traits (i.e. variables) associated with RLN cases and controls diagnosed with exercising overground endoscopy (OGE) using exploratory factor analysis (EFA). Prospective cohort. Pearson's rank correlation was used to establish significance and association between variables collected from n = 188 Thoroughbreds from one stable by observers blinded to OGE results. Exploratory factor analysis was conducted on 9 variables for cases and controls; common elements between variables developed a factor, with variables grouped into 3 factors for cases and controls, respectively. Correlation (loading) between each variable and factor was calculated to rank relationships between variables and cases/controls, with factors retrospectively named based on their underlying correlations with variables. Numerous inter-correlations were present between variables. Most strongly correlated in cases were wither height with body weight (r = 0.70) and ventral neck length (r = 0.68) and in controls body weight with rostral neck circumference (r = 0.58). Wither height (r = 0.61) significantly loaded the top-ranked factor for cases ('height RLN '), explaining 25% of conformational variance. Ventral neck length (r = 0.69) and age (r = 0.57) significantly loaded the second-ranked factor for cases ('neck length RLN '), explaining 16% of conformational variance. Rostral neck circumference (r = 0.86) and body weight (r = 0.6) significantly loaded the top-ranked factor for controls ('body size CON '), explaining 19% of the variance. Wither height (r = 0.84) significantly loaded the second-ranked factor for controls ('height CON '), explaining 13% of the variance. Horses had not reached skeletal maturity. Exploratory factor analysis allowed weightings to be determined for each variable. Wither height was the predominant conformational feature associated with RLN. Exploratory factor analysis confirms aggregated conformational differences exist between RLN cases and controls, suitable for future evaluations. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Determination of apparent coupling factors for adhesive bonded acrylic plates using SEAL approach

NASA Astrophysics Data System (ADS)

Pankaj, Achuthan. C.; Shivaprasad, M. V.; Murigendrappa, S. M.

2018-04-01

Apparent coupling loss factors (CLF) and velocity responses has been computed for two lap joined adhesive bonded plates using finite element and experimental statistical energy analysis like approach. A finite element model of the plates has been created using ANSYS software. The statistical energy parameters have been computed using the velocity responses obtained from a harmonic forced excitation analysis. Experiments have been carried out for two different cases of adhesive bonded joints and the results have been compared with the apparent coupling factors and velocity responses obtained from finite element analysis. The results obtained from the studies signify the importance of modeling of adhesive bonded joints in computation of the apparent coupling factors and its further use in computation of energies and velocity responses using statistical energy analysis like approach.

Examining the Dimensionality of ADHD Symptomatology in Young Adults Using Factor Analysis and Outcome Prediction

ERIC Educational Resources Information Center

McKee, Tara E.

2012-01-01

Objective: Current diagnostic criteria specify that ADHD involves difficulties with inattention and/or hyperactivity/impulsivity. Researchers using factor analysis have consistently found support for an inattention factor in both children and adults. Findings have been mixed regarding whether hyperactivity and impulsivity reflect one or two…

Derived Basic Ability Factors: A Factor Analysis Replication Study.

ERIC Educational Resources Information Center

Lee, Mickey, M.; Lee, Lynda Newby

The purpose of this study was to replicate the study conducted by Potter, Sagraves, and McDonald to determine whether their recommended analysis could separate criterion variables into similar factors that were stable from year to year and from school to school. The replication samples consisted of all students attending Louisiana State University…

An Analysis of Factors That Affect the Educational Performance of Agricultural Students

ERIC Educational Resources Information Center

Greenway, Gina

2012-01-01

Many factors contribute to student achievement. This study focuses on three areas: how students learn, how student personality type affects performance, and how course format affects performance outcomes. The analysis sought to improve understanding of the direction and magnitude with which each of these factors impacts student success. Improved…

Obesity as a risk factor for developing functional limitation among older adults: A conditional inference tree analysis

USDA-ARS?s Scientific Manuscript database

Objective: To examine the risk factors of developing functional decline and make probabilistic predictions by using a tree-based method that allows higher order polynomials and interactions of the risk factors. Methods: The conditional inference tree analysis, a data mining approach, was used to con...

Confirmatory Factor Analysis of the Elementary School Success Profile for Teachers

ERIC Educational Resources Information Center

Webber, Kristina C.; Rizo, Cynthia F.; Bowen, Natasha K.

2012-01-01

Objectives: This study examines the factor structure and scale quality of data collected with the online Elementary School Success Profile (ESSP) for Teachers from a sample of teachers of 1,145 third through fifth graders. Methods: Confirmatory factor analysis (CFA) using Mplus and weighted least squares means and variances adjusted (WLSMV)…

Factors of Spatial Visualization: An Analysis of the PSVT:R

ERIC Educational Resources Information Center

Ernst, Jeremy V.; Willams, Thomas O.; Clark, Aaron C.; Kelly, Daniel P.

2017-01-01

The Purdue Spatial Visualization Test: Visualization of Rotations (PVST:R) is among the most commonly used measurement instruments to assess spatial ability among engineering students. Previous analysis that explores the factor structure of the PSVT:R indicates a single-factor measure of the instrument. With this as a basis, this research seeks to…

15 CFR 400.34 - Examiner's review-application for production authority.

Code of Federal Regulations, 2013 CFR

2013-01-01

...—application for production authority. (a) The examiner shall conduct a review taking into account the factors... warranted; (4) Developing information and evidence necessary for analysis of the threshold factors and the economic factors enumerated in § 400.27; and (5) Conducting an analysis to include: (i) An evaluation of...

An Empirical Analysis of Factors Affecting Honors Program Completion Rates

ERIC Educational Resources Information Center

Savage, Hallie; Raehsler, Rod D.; Fiedor, Joseph

2014-01-01

One of the most important issues in any educational environment is identifying factors that promote academic success. A plethora of research on such factors exists across most academic fields, involving a wide range of student demographics, and the definition of student success varies across the range of studies published. The analysis in this…

Structural Analysis of Correlated Factors: Lessons from the Verbal-Performance Dichotomy of the Wechsler Scales.

ERIC Educational Resources Information Center

Macmann, Gregg M.; Barnett, David W.

1994-01-01

Describes exploratory and confirmatory analyses of verbal-performance procedures to illustrate concepts and procedures for analysis of correlated factors. Argues that, based on convergent and discriminant validity criteria, factors should have higher correlations with variables that they purport to measure than with other variables. Discusses…

The Psychometric Properties of the School Engagement Measure in Adolescents in Singapore

ERIC Educational Resources Information Center

Yusof, Noradlin; Ang, Rebecca P.; Oei, Tian Po S.

2017-01-01

This study examined the psychometric properties of the school engagement measure (SEM) in Singapore. The sample consisted of 1,027 students from a multi-ethnic Singapore adolescent community. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) confirmed that the two-factor solution, namely, (a) Emotional and (b) Cognitive…

Measuring Adjustment to College: Construct Validity of the Student Adaptation to College Questionnaire

ERIC Educational Resources Information Center

Feldt, Ronald C.; Graham, Melody; Dew, Dennis

2011-01-01

This study employed confirmatory factor analysis to examine the quality of fit of two measurement models of the Student Adaptation to College Questionnaire (N = 305). Following the observation of poor fit, exploratory factor analysis was used. Results indicated six factors that account for the variance in Student Adaptation to College…