A random spatial sampling method in a rural developing nation
Michelle C. Kondo; Kent D.W. Bream; Frances K. Barg; Charles C. Branas
2014-01-01
Nonrandom sampling of populations in developing nations has limitations and can inaccurately estimate health phenomena, especially among hard-to-reach populations such as rural residents. However, random sampling of rural populations in developing nations can be challenged by incomplete enumeration of the base population. We describe a stratified random sampling method...
Report for Colorado: Background & Visuals, Math 2005. The Nation's Report Card
ERIC Educational Resources Information Center
Sandoval, Pam A.
2005-01-01
The National Assessment of Educational Progress (NAEP) 2005 assessment was administered to a stratified random sample of fourth-, eighth-, and twelfth-graders at the national level and to a stratified random sample of fourth- and eighth-graders at the state level. The Mathematics Framework for NAEP was revised in 1996 and again in 2005. The new…
THE SELECTION OF A NATIONAL RANDOM SAMPLE OF TEACHERS FOR EXPERIMENTAL CURRICULUM EVALUATION.
ERIC Educational Resources Information Center
WELCH, WAYNE W.; AND OTHERS
MEMBERS OF THE EVALUATION SECTION OF HARVARD PROJECT PHYSICS, DESCRIBING WHAT IS SAID TO BE THE FIRST ATTEMPT TO SELECT A NATIONAL RANDOM SAMPLE OF (HIGH SCHOOL PHYSICS) TEACHERS, LIST THE STEPS AS (1) PURCHASE OF A LIST OF PHYSICS TEACHERS FROM THE NATIONAL SCIENCE TEACHERS ASSOCIATION (MOST COMPLETE AVAILABLE), (2) SELECTION OF 136 NAMES BY A…
ERIC Educational Resources Information Center
Felce, David; Perry, Jonathan
2004-01-01
Background: The aims were to: (i) explore the association between age and size of setting and staffing per resident; and (ii) report resident and setting characteristics, and indicators of service process and resident activity for a national random sample of staffed housing provision. Methods: Sixty settings were selected randomly from those…
Reweighting of the primary sampling units in the National Automotive Sampling System
DOT National Transportation Integrated Search
1997-09-01
The original design of hte National Automotive Sampling System - formerly the National Accident Sampling System - called for 75 PSUs randomly selected from PSUs which were grouped into various strata across the U.S. The implementation of the PSU samp...
Describing Typical Capstone Course Experiences from a National Random Sample
ERIC Educational Resources Information Center
Grahe, Jon E.; Hauhart, Robert C.
2013-01-01
The pedagogical value of capstones has been regularly discussed within psychology. This study presents results from an examination of a national random sample of department webpages and an online survey that characterized the typical capstone course in terms of classroom activities and course administration. The department webpages provide an…
What Are Probability Surveys used by the National Aquatic Resource Surveys?
The National Aquatic Resource Surveys (NARS) use probability-survey designs to assess the condition of the nation’s waters. In probability surveys (also known as sample-surveys or statistical surveys), sampling sites are selected randomly.
ERIC Educational Resources Information Center
Price, James H.; Thompson, Amy; Khubchandani, Jagdish; Dake, Joseph; Payton, Erica; Teeple, Karen
2014-01-01
Objective: To assess the perceptions and practices of a national sample of college and university presidents regarding their support for concealed handguns being carried on college campuses. Participants: The sample for this study consisted of a national random sample of 900 college or university presidents. Methods: In the spring of 2013, a…
Exploratory and Confirmatory Analysis of the Trauma Practices Questionnaire
ERIC Educational Resources Information Center
Craig, Carlton D.; Sprang, Ginny
2009-01-01
Objective: The present study provides psychometric data for the Trauma Practices Questionnaire (TPQ). Method: A nationally randomized sample of 2,400 surveys was sent to self-identified trauma treatment specialists, and 711 (29.6%) were returned. Results: An exploratory factor analysis (N = 319) conducted on a randomly split sample (RSS) revealed…
1977 Survey of the American Professoriate. Technical Report.
ERIC Educational Resources Information Center
Ladd, Everett Carll, Jr.; And Others
The development and data validation of the 1977 Ladd-Lipset national survey of the American professoriate are described. The respondents were selected from a random sample of colleges and universities and from a random sample of individual faculty members from the universities. The 158 institutions in the 1977 survey were selected from 2,406…
Reaching a Representative Sample of College Students: A Comparative Analysis
ERIC Educational Resources Information Center
Giovenco, Daniel P.; Gundersen, Daniel A.; Delnevo, Cristine D.
2016-01-01
Objective: To explore the feasibility of a random-digit dial (RDD) cellular phone survey in order to reach a national and representative sample of college students. Methods: Demographic distributions from the 2011 National Young Adult Health Survey (NYAHS) were benchmarked against enrollment numbers from the Integrated Postsecondary Education…
ERIC Educational Resources Information Center
Hayford, Samuel K.; Ocansey, Frederick
2017-01-01
This study reports part of a national survey on sources of information, education and communication materials on HIV/AIDS available to students with visual impairments in residential, segregated, and integrated schools in Ghana. A multi-staged stratified random sampling procedure and a purposive and simple random sampling approach, where…
ERIC Educational Resources Information Center
Johnson, Matthew S.; Jenkins, Frank
2005-01-01
Large-scale educational assessments such as the National Assessment of Educational Progress (NAEP) sample examinees to whom an exam will be administered. In most situations the sampling design is not a simple random sample and must be accounted for in the estimating model. After reviewing the current operational estimation procedure for NAEP, this…
ERIC Educational Resources Information Center
Wang, Shudong; Wang, Ning; Hoadley, David
This study examined the comparability of scores on the National Nurses Aides Assessment Program (NNAAP) test across language and administration condition groups for calibration and validation samples that were randomly drawn from the same population. A sample of 20,568 candidate responses to 1 test form was used. This examination is given in…
L'Engle, Kelly; Sefa, Eunice; Adimazoya, Edward Akolgo; Yartey, Emmanuel; Lenzi, Rachel; Tarpo, Cindy; Heward-Mills, Nii Lante; Lew, Katherine; Ampeh, Yvonne
2018-01-01
Generating a nationally representative sample in low and middle income countries typically requires resource-intensive household level sampling with door-to-door data collection. High mobile phone penetration rates in developing countries provide new opportunities for alternative sampling and data collection methods, but there is limited information about response rates and sample biases in coverage and nonresponse using these methods. We utilized data from an interactive voice response, random-digit dial, national mobile phone survey in Ghana to calculate standardized response rates and assess representativeness of the obtained sample. The survey methodology was piloted in two rounds of data collection. The final survey included 18 demographic, media exposure, and health behavior questions. Call outcomes and response rates were calculated according to the American Association of Public Opinion Research guidelines. Sample characteristics, productivity, and costs per interview were calculated. Representativeness was assessed by comparing data to the Ghana Demographic and Health Survey and the National Population and Housing Census. The survey was fielded during a 27-day period in February-March 2017. There were 9,469 completed interviews and 3,547 partial interviews. Response, cooperation, refusal, and contact rates were 31%, 81%, 7%, and 39% respectively. Twenty-three calls were dialed to produce an eligible contact: nonresponse was substantial due to the automated calling system and dialing of many unassigned or non-working numbers. Younger, urban, better educated, and male respondents were overrepresented in the sample. The innovative mobile phone data collection methodology yielded a large sample in a relatively short period. Response rates were comparable to other surveys, although substantial coverage bias resulted from fewer women, rural, and older residents completing the mobile phone survey in comparison to household surveys. Random digit dialing of mobile phones offers promise for future data collection in Ghana and may be suitable for other developing countries.
Sefa, Eunice; Adimazoya, Edward Akolgo; Yartey, Emmanuel; Lenzi, Rachel; Tarpo, Cindy; Heward-Mills, Nii Lante; Lew, Katherine; Ampeh, Yvonne
2018-01-01
Introduction Generating a nationally representative sample in low and middle income countries typically requires resource-intensive household level sampling with door-to-door data collection. High mobile phone penetration rates in developing countries provide new opportunities for alternative sampling and data collection methods, but there is limited information about response rates and sample biases in coverage and nonresponse using these methods. We utilized data from an interactive voice response, random-digit dial, national mobile phone survey in Ghana to calculate standardized response rates and assess representativeness of the obtained sample. Materials and methods The survey methodology was piloted in two rounds of data collection. The final survey included 18 demographic, media exposure, and health behavior questions. Call outcomes and response rates were calculated according to the American Association of Public Opinion Research guidelines. Sample characteristics, productivity, and costs per interview were calculated. Representativeness was assessed by comparing data to the Ghana Demographic and Health Survey and the National Population and Housing Census. Results The survey was fielded during a 27-day period in February-March 2017. There were 9,469 completed interviews and 3,547 partial interviews. Response, cooperation, refusal, and contact rates were 31%, 81%, 7%, and 39% respectively. Twenty-three calls were dialed to produce an eligible contact: nonresponse was substantial due to the automated calling system and dialing of many unassigned or non-working numbers. Younger, urban, better educated, and male respondents were overrepresented in the sample. Conclusions The innovative mobile phone data collection methodology yielded a large sample in a relatively short period. Response rates were comparable to other surveys, although substantial coverage bias resulted from fewer women, rural, and older residents completing the mobile phone survey in comparison to household surveys. Random digit dialing of mobile phones offers promise for future data collection in Ghana and may be suitable for other developing countries. PMID:29351349
Lacey, John H.; Kelley-Baker, Tara; Voas, Robert B.; Romano, Eduardo; Furr-Holden, C. Debra; Torres, Pedro; Berning, Amy
2013-01-01
This article describes the methodology used in the 2007 U.S. National Roadside Survey to estimate the prevalence of alcohol- and drug-impaired driving and alcohol- and drug-involved driving. This study involved randomly stopping drivers at 300 locations across the 48 continental U.S. states at sites selected through a stratified random sampling procedure. Data were collected during a 2-hour Friday daytime session at 60 locations and during 2-hour nighttime weekend periods at 240 locations. Both self-report and biological measures were taken. Biological measures included breath alcohol measurements from 9,413 respondents, oral fluid samples from 7,719 respondents, and blood samples from 3,276 respondents. PMID:21997324
Li, Xiao-Zhou; Li, Song-Sui; Zhuang, Jun-Ping; Chan, Sze-Chun
2015-09-01
A semiconductor laser with distributed feedback from a fiber Bragg grating (FBG) is investigated for random bit generation (RBG). The feedback perturbs the laser to emit chaotically with the intensity being sampled periodically. The samples are then converted into random bits by a simple postprocessing of self-differencing and selecting bits. Unlike a conventional mirror that provides localized feedback, the FBG provides distributed feedback which effectively suppresses the information of the round-trip feedback delay time. Randomness is ensured even when the sampling period is commensurate with the feedback delay between the laser and the grating. Consequently, in RBG, the FBG feedback enables continuous tuning of the output bit rate, reduces the minimum sampling period, and increases the number of bits selected per sample. RBG is experimentally investigated at a sampling period continuously tunable from over 16 ns down to 50 ps, while the feedback delay is fixed at 7.7 ns. By selecting 5 least-significant bits per sample, output bit rates from 0.3 to 100 Gbps are achieved with randomness examined by the National Institute of Standards and Technology test suite.
Importance of the National Career Development Guidelines to School Counselors.
ERIC Educational Resources Information Center
Freeman, Brenda
1994-01-01
Surveyed opinions of national random sample of school counselors (n=1,510) toward importance of elementary, junior high/middle, and high school competencies in National Career Development Guidelines. Results indicated that school counselors considered the career development competencies in the guidelines to be "important" to "very important"…
Findings from the 2013 NZCER Primary and Intermediate Schools National Survey
ERIC Educational Resources Information Center
New Zealand Council for Educational Research, 2014
2014-01-01
The New Zealand Council for Educational Research (NZCER) primary and intermediate schools national survey was carried out in July-August 2013. NZCER questioned principals, teachers and trustees at a representative sample of schools, and sought the views of a random sample of 1 in 4 parents in 36 of these schools. In all, the survey gathered data…
The Danish National Health Survey 2010. Study design and respondent characteristics.
Christensen, Anne Illemann; Ekholm, Ola; Glümer, Charlotte; Andreasen, Anne Helms; Hvidberg, Michael Falk; Kristensen, Peter Lund; Larsen, Finn Breinholt; Ortiz, Britta; Juel, Knud
2012-06-01
In 2010 the five Danish regions and the National Institute of Public Health at the University of Southern Denmark conducted a national representative health survey among the adult population in Denmark. This paper describes the study design and the sample and study population as well as the content of the questionnaire. The survey was based on five regional stratified random samples and one national random sample. The samples were mutually exclusive. A total of 298,550 individuals (16 years or older) were invited to participate. Information was collected using a mixed mode approach (paper and web questionnaires). A questionnaire with a minimum of 52 core questions was used in all six subsamples. Calibrated weights were computed in order to take account of the complex survey design and reduce non-response bias. In all, 177,639 individuals completed the questionnaire (59.5%). The response rate varied from 52.3% in the Capital Region of Denmark sample to 65.5% in the North Denmark Region sample. The response rate was particularly low among young men, unmarried people and among individuals with a different ethnic background than Danish. The survey was a result of extensive national cooperation across sectors, which makes it unique in its field of application, e.g. health surveillance, planning and prioritizing public health initiatives and research. However, the low response rate in some subgroups of the study population can pose problems in generalizing data, and efforts to increase the response rate will be important in the forthcoming surveys.
ERIC Educational Resources Information Center
Rosch, David M.; Coers, Natalie
2013-01-01
Given the importance of leadership development within the various agricultural professions, a national sample (n = 461) of students with agriculture-related majors from 55 colleges was compared to a similarly-sized random peer group from the same institutions. The data were analyzed to compare the agricultural student sample to their peers with…
Mitigating budget constraints on visitation volume surveys: the case of U.S. National forests
Ashley E. Askew; Donald B.K. English; Stanley J. Zarnoch; Neelam C. Poudyal; J.M. Bowker
2014-01-01
Stratified random sampling (SRS) provides a scientifically based estimate of a population comprising mutually exclusive, homogenous subgroups. In the National Visitor Use Monitoring (NVUM) program, SRS is used to estimate recreation visitation and visitor characteristics across activities on National forests. However, with rising costs and declining budgets, carrying...
Designing a national soil erosion monitoring network for England and Wales
NASA Astrophysics Data System (ADS)
Lark, Murray; Rawlins, Barry; Anderson, Karen; Evans, Martin; Farrow, Luke; Glendell, Miriam; James, Mike; Rickson, Jane; Quine, Timothy; Quinton, John; Brazier, Richard
2014-05-01
Although soil erosion is recognised as a significant threat to sustainable land use and may be a priority for action in any forthcoming EU Soil Framework Directive, those responsible for setting national policy with respect to erosion are constrained by a lack of robust, representative, data at large spatial scales. This reflects the process-orientated nature of much soil erosion research. Recognising this limitation, The UK Department for Environment, Food and Rural Affairs (Defra) established a project to pilot a cost-effective framework for monitoring of soil erosion in England and Wales (E&W). The pilot will compare different soil erosion monitoring methods at a site scale and provide statistical information for the final design of the full national monitoring network that will: provide unbiased estimates of the spatial mean of soil erosion rate across E&W (tonnes ha-1 yr-1) for each of three land-use classes - arable and horticultural grassland upland and semi-natural habitats quantify the uncertainty of these estimates with confidence intervals. Probability (design-based) sampling provides most efficient unbiased estimates of spatial means. In this study, a 16 hectare area (a square of 400 x 400 m) positioned at the centre of a 1-km grid cell, selected at random from mapped land use across E&W, provided the sampling support for measurement of erosion rates, with at least 94% of the support area corresponding to the target land use classes. Very small or zero erosion rates likely to be encountered at many sites reduce the sampling efficiency and make it difficult to compare different methods of soil erosion monitoring. Therefore, to increase the proportion of samples with larger erosion rates without biasing our estimates, we increased the inclusion probability density in areas where the erosion rate is likely to be large by using stratified random sampling. First, each sampling domain (land use class in E&W) was divided into strata; e.g. two sub-domains within which, respectively, small or no erosion rates, and moderate or larger erosion rates are expected. Each stratum was then sampled independently and at random. The sample density need not be equal in the two strata, but is known and is accounted for in the estimation of the mean and its standard error. To divide the domains into strata we used information on slope angle, previous interpretation of erosion susceptibility of the soil associations that correspond to the soil map of E&W at 1:250 000 (Soil Survey of England and Wales, 1983), and visual interpretation of evidence of erosion from aerial photography. While each domain could be stratified on the basis of the first two criteria, air photo interpretation across the whole country was not feasible. For this reason we used a two-phase random sampling for stratification (TPRS) design (de Gruijter et al., 2006). First, we formed an initial random sample of 1-km grid cells from the target domain. Second, each cell was then allocated to a stratum on the basis of the three criteria. A subset of the selected cells from each stratum were then selected for field survey at random, with a specified sampling density for each stratum so as to increase the proportion of cells where moderate or larger erosion rates were expected. Once measurements of erosion have been made, an estimate of the spatial mean of the erosion rate over the target domain, its standard error and associated uncertainty can be calculated by an expression which accounts for the estimated proportions of the two strata within the initial random sample. de Gruijter, J.J., Brus, D.J., Biekens, M.F.P. & Knotters, M. 2006. Sampling for Natural Resource Monitoring. Springer, Berlin. Soil Survey of England and Wales. 1983 National Soil Map NATMAP Vector 1:250,000. National Soil Research Institute, Cranfield University.
National occupant protection use survey : controlled intersection detailed study
DOT National Transportation Integrated Search
1997-02-01
In late 1994, NHTSA conducted the first National Occupant Protection Use Survey : (NOPUS). Shoulder belt use was observed at a random sample of sites across the : country for drivers and right-front passengers of cars and light trucks. In one : porti...
Teplin, Linda A; McClelland, Gary M; Abram, Karen M; Weiner, Dana A
2005-08-01
Since deinstitutionalization, most persons with severe mental illness (SMI) now live in the community, where they are at great risk for crime victimization. To determine the prevalence and incidence of crime victimization among persons with SMI by sex, race/ethnicity, and age, and to compare rates with general population data (the National Crime Victimization Survey), controlling for income and demographic differences between the samples. Epidemiologic study of persons in treatment. Independent master's-level clinical research interviewers administered the National Crime Victimization Survey to randomly selected patients sampled from 16 randomly selected mental health agencies. Sixteen agencies providing outpatient, day, and residential treatment to persons with SMI in Chicago, Ill. Randomly selected, stratified sample of 936 patients aged 18 or older (483 men, 453 women) who were African American (n = 329), non-Hispanic white (n = 321), Hispanic (n = 270), or other race/ethnicity (n = 22). The comparison group comprised 32 449 participants in the National Crime Victimization Survey. National Crime Victimization Survey, developed by the Bureau of Justice Statistics. More than one quarter of persons with SMI had been victims of a violent crime in the past year, a rate more than 11 times higher than the general population rates even after controlling for demographic differences between the 2 samples (P<.001). The annual incidence of violent crime in the SMI sample (168.2 incidents per 1000 persons) is more than 4 times higher than the general population rates (39.9 incidents per 1000 persons) (P<.001). Depending on the type of violent crime (rape/sexual assault, robbery, assault, and their subcategories), prevalence was 6 to 23 times greater among persons with SMI than among the general population. Crime victimization is a major public health problem among persons with SMI who are treated in the community. We recommend directions for future research, propose modifications in public policy, and suggest how the mental health system can respond to reduce victimization and its consequences.
Effects of Client Violence on Social Work Students: A National Study
ERIC Educational Resources Information Center
Criss, Pam
2010-01-01
This study uses a work stress theoretical framework to examine the effects of direct and indirect client violence on a randomly selected national sample of MSW and BSW social work students from the National Association of Social Workers (N=595). Client violence variables were analyzed in relationship to fear of future violence and occupational…
Urban and Suburban Residents' Perceptions of Farmers and Agriculture.
ERIC Educational Resources Information Center
Molnar, Joseph J.; Duffy, Patricia A.
Attitudes about farming and government agricultural policies differed among residential categories ranging from urban to rural. A mail survey gathered 3,232 completed questionnaires from a national random sample of 9,250 households. Statistical weighting made respondent categories representative of national proportions. Although respondents…
American Healthy Homes Survey: A National Study of Residential Pesticides Measured from Floor Wipes.
The U.S. Department of Housing and Urban Development in collaboration with the United States Environmental Protection Agency conducted a survey measuring lead, allergens, and insecticides in a randomly selected nationally representative sample of resodential homes. Multistage sa...
Legleye, S; Bohet, A; Razafindratsima, N; Bajos, N; Moreau, C
2014-08-01
Healthcare professionals play a critical role in women's choice of contraceptive methods. However, national surveys on sexual and reproductive health (SRH) among physicians are rare and present low participation rates. We conducted a randomized trial to test for the effectiveness of three interventions to improve survey participation of private physicians delivering reproductive health services in France. The study comprised a national random sample of 500 general practitioners and 500 gynecologists working in private offices. All received a postal invitation to participate either by completing a paper, phone or online questionnaire. Physicians were randomly assigned to six groups to test for the effect of three interventions: a non-monetary incentive in the form of a scientific book, telephone contact, and the possibility of completing the questionnaire by phone. Overall, 362 questionnaires were collected (26 online, 2 by phone) and 58 physicians were ineligible. The completion rate increased from 26.7% in physicians who received no intervention to 42.7% in those who received the book and a phone call. The phone call increased the completion rate by 11% percentage points (P=0.01), while the book had no significant effect. Results from multivariate logistic regressions also indicate that gynecologists (OR=1.6) and female physicians (OR=1.5) were more likely to participate than others. The results suggest that phone calls substantially increase participation of physicians in sexual and reproductive health surveys but have little impact on sampling distortion. Differentials in response rates by physicians' characteristics should be considered in future SRH studies among physicians. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
1973 U.S. national roadside breathtesting survey : procedures and results
DOT National Transportation Integrated Search
1974-10-01
Author's abstract: This first U.S. national roadside breathtesting survey was conducted at 185 roadside locations in 18 states. Random samples of 3,698 motorists were stopped between 10PM and 3AM on eight weekends in the fall of 1973. From these driv...
D. Erran Seaman
1997-01-01
We monitored the threatened Northern Spotted Owl (Strix occidentalis caurina) in Olympic National Park from 1992 through 1996. We used a stratified random sampling scheme to survey 35 plots totaling 236 km?, approximately 10 percent of the forested area of the park.
ERIC Educational Resources Information Center
Li, Tiandong
2012-01-01
In large-scale assessments, such as the National Assessment of Educational Progress (NAEP), plausible values based on Multiple Imputations (MI) have been used to estimate population characteristics for latent constructs under complex sample designs. Mislevy (1991) derived a closed-form analytic solution for a fixed-effect model in creating…
Crime Victimization in Adults With Severe Mental Illness
Teplin, Linda A.; McClelland, Gary M.; Abram, Karen M.; Weiner, Dana A.
2006-01-01
Context Since deinstitutionalization, most persons with severe mental illness (SMI) now live in the community, where they are at great risk for crime victimization. Objectives To determine the prevalence and incidence of crime victimization among persons with SMI by sex, race/ethnicity, and age, and to compare rates with general population data (the National Crime Victimization Survey), controlling for income and demographic differences between the samples. Design Epidemiologic study of persons in treatment. Independent master’s-level clinical research interviewers administered the National Crime Victimization Survey to randomly selected patients sampled from 16 randomly selected mental health agencies. Setting Sixteen agencies providing outpatient, day, and residential treatment to persons with SMI in Chicago, Ill. Participants Randomly selected, stratified sample of 936 patients aged 18 or older (483 men, 453 women) who were African American (n = 329), non-Hispanic white (n = 321), Hispanic (n = 270), or other race/ethnicity (n = 22). The comparison group comprised 32449 participants in the National Crime Victimization Survey. Main Outcome Measure National Crime Victimization Survey, developed by the Bureau of Justice Statistics. Results More than one quarter of persons with SMI had been victims of a violent crime in the past year, a rate more than 11 times higher than the general population rates even after controlling for demographic differences between the 2 samples (P<.001). The annual incidence of violent crime in the SMI sample (168.2 incidents per 1000 persons) is more than 4 times higher than the general population rates (39.9 incidents per 1000 persons) (P<.001). Depending on the type of violent crime (rape/sexual assault, robbery, assault, and their subcategories), prevalence was 6 to 23 times greater among persons with SMI than among the general population. Conclusions Crime victimization is a major public health problem among persons with SMI who are treated in the community. We recommend directions for future research, propose modifications in public policy, and suggest how the mental health system can respond to reduce victimization and its consequences. PMID:16061769
ERIC Educational Resources Information Center
General Accounting Office, Washington, DC. Div. of Human Resources.
A national study of effective schools programs provides information on the extent and characteristics of these programs in the nation's school districts and schools. A questionnaire was mailed to a random sample of 1,685 school district superintendents. Findings are representative of the approximately 16,000 local school districts in the nation.…
Kelly, Heath; Riddell, Michaela A; Gidding, Heather F; Nolan, Terry; Gilbert, Gwendolyn L
2002-08-19
We compared estimates of the age-specific population immunity to measles, mumps, rubella, hepatitis B and varicella zoster viruses in Victorian school children obtained by a national sero-survey, using a convenience sample of residual sera from diagnostic laboratories throughout Australia, with those from a three-stage random cluster survey. When grouped according to school age (primary or secondary school) there was no significant difference in the estimates of immunity to measles, mumps, hepatitis B or varicella. Compared with the convenience sample, the random cluster survey estimated higher immunity to rubella in samples from both primary (98.7% versus 93.6%, P = 0.002) and secondary school students (98.4% versus 93.2%, P = 0.03). Despite some limitations, this study suggests that the collection of a convenience sample of sera from diagnostic laboratories is an appropriate sampling strategy to provide population immunity data that will inform Australia's current and future immunisation policies. Copyright 2002 Elsevier Science Ltd.
Campus HIV Prevention Strategies: Planning for Success.
ERIC Educational Resources Information Center
Hoban, Mary T.; Ottenritter, Nan W.; Gascoigne, Jan L.; Kerr, Dianne L.
This document presents the results of the National College Health Risk Behavior Survey (NCHRBS) conducted by the U.S. Centers for Disease Control (CDC) that pertain to HIV transmission. These results include sexual assault, alcohol and other drug use, and sexual behaviors. The survey was administered to a nationally representative random sample of…
A National Study of Work-Family Balance and Job Satisfaction among Agriculture Teachers
ERIC Educational Resources Information Center
Sorensen, Tyson J.; McKim, Aaron J.; Velez, Jonathan J.
2016-01-01
This national study sought to extend previous research on the work-family balance (WFB) ability of secondary school agriculture teachers. We utilized data from a simple random sample of agriculture teachers to explore the relationships between work and family characteristics, WFB ability, and job satisfaction. Work role characteristics of interest…
A Confirmatory Factor Analysis of the Professional Opinion Scale
ERIC Educational Resources Information Center
Greeno, Elizabeth J.; Hughes, Anne K.; Hayward, R. Anna; Parker, Karen L.
2007-01-01
The Professional Opinion Scale (POS) was developed to measure social work values orientation. Objective: A confirmatory factor analysis was performed on the POS. Method: This cross-sectional study used a mailed survey design with a national random (simple) sample of members of the National Association of Social Workers. Results: The study…
Epidemiology of Attention Problems among Turkish Children and Adolescents: A National Study
ERIC Educational Resources Information Center
Erol, Nese; Simsek, Zeynep; Oner, Ozgur; Munir, Kerim
2008-01-01
Objective: To evaluate the epidemiology of attention problems using parent, teacher, and youth informants among a nationally representative Turkish sample. Method: The children and adolescents, 4 to 18 years old, were selected from a random household survey. Attention problems derived from the Child Behavior Checklist (CBCL) (N = 4,488), Teacher…
Jerry J. Vaske; Maureen P. Donnelly; Daniel R. Williams; Sandra Jonker
2001-01-01
Using the cognitive hierarchy as the theoretical foundation, this article examines the predictive influence of individuals' demographic characteristics on environmental value orientations and normative beliefs about national forest management. Data for this investigation were obtained from a random sample of Colorado residents (n = 960). As predicted by theory, a...
Enrolled Nurses: A Study for the UKCC.
ERIC Educational Resources Information Center
Seccombe, I.; Smith, G.; Buchan, J.; Ball, J.
Selected issues of concern to second-level enrolled (registered) nurses in the United Kingdom were examined through national surveys of two groups: (1) a random sample of 21,762 of the 115,459 nurses holding second-level registration in the United Kingdom, and (2) 700 employers who, included nurse executive directors in all National Health Service…
ERIC Educational Resources Information Center
Wang, Shudong; Wang, Ning; Hoadley, David
2007-01-01
This study used confirmatory factor analysis (CFA) to examine the comparability of the National Nurse Aide Assessment Program (NNAAP[TM]) test scores across language and administration condition groups for calibration and validation samples that were randomly drawn from the same population. Fit statistics supported both the calibration and…
Catholic High Schools and Their Finances. 1986.
ERIC Educational Resources Information Center
Augenstein, John J.
This report is based on a randomly selected and stratified sample of 208 United States Catholic high schools. The sample was stratified by governance (diocesan, parochial/interparochial, and private); five categories of enrollment; and six regions. Data are compared with an earlier study, "The Catholic High School: A National Portrait" and show…
[Prevalence and risk factors of bronchial asthma among Li nationality in Hainan province].
Ding, Yi-peng; Yao, Hong-xia; Tang, Xiao-lan; He, Hai-wu; Shi, Hui-fang; Lin, Li; Li, Min; Chen, Shan; Chen, Jing; Wang, Hai-jiao
2011-02-01
To study the risk factors of bronchial asthma of Li nationality in Hainan. A total of 13 050 subjects of Li nationality were selected by random unequal ratio stratified cluster sampling method from southern, central and western part of Hainan and investigated with Hainan Epidemiological Asthma Survey Questionnaire of Li Nationality. There were 441 cases of bronchial asthma, and 1296 cases of control that were sampled by random number table method. The logistic regression method was used to analyze risk factors. The asthma prevalence of Li nationality in Hainan was 3.38%(441/13 050). The main risk factors of asthma were family asthma (OR = 4.323, 95%CI = 3.259 - 5.735), hypersensitiveness (OR = 7.775, 95%CI = 5.686 - 10.632), smoking (OR = 1.494, 95%CI = 1.174 - 1.902), cooking fuels and living environment. Cold air change (OR = 1.604, 95%CI = 1.286 - 2.001) and respirable dust or irritant gas (OR = 2.123, 95%CI = 1.702 - 2.648) were the important incentives. The main risk factors of asthma among Li nationality were family asthma, hypersensitiveness, smoking, cooking fuels by means of fuel oil, hay or wood, living environment by means of couch grass room and human-livestock mix live, cold air change, respirable dust or irritant gas.
A management-oriented classification of pinyon-juniper woodlands of the Great Basin
Neil E. West; Robin J. Tausch; Paul T. Tueller
1998-01-01
A hierarchical framework for the classification of Great Basin pinyon-juniper woodlands was based on a systematic sample of 426 stands from a random selection of 66 of the 110 mountain ranges in the region. That is, mountain ranges were randomly selected, but stands were systematically located on mountain ranges. The National Hierarchical Framework of Ecological Units...
MediaQuotient[TM]: National Survey of Family Media Habits, Knowledge, and Attitudes.
ERIC Educational Resources Information Center
Gentile, Douglas A.; Walsh, David A.
This study examined family media habits, including the use of television, movies, videos, computer and video games, the Internet, music, and print media. The study was conducted by mail with telephone follow-ups, surveying a national random sample of 527 parents of 2- to 17-year-olds who completed MediaQuotient questionnaires. Findings were…
Suicide in the Army National Guard: An Empirical Inquiry
ERIC Educational Resources Information Center
Griffith, James
2012-01-01
Since 2004, suicides in the U.S. military have risen, most notably in the Army National Guard (ARNG). Data used in this study were obtained for suicides occurring from 2007 to 2010 and for a random sample of nonsuicides from the general ARNG population. Of the military-related variables considered, a few showed relationships to suicide. Rather,…
ERIC Educational Resources Information Center
McDermott, Paul A.; Watkins, Marley W.; Rovine, Michael J.; Rikoon, Samuel H.
2013-01-01
This article reports the development and evidence for validity and application of the Adjustment Scales for Early Transition in Schooling (ASETS). Based on primary analyses of data from the Head Start Impact Study, a nationally representative sample (N = 3077) of randomly selected children from low-income households is configured to inform…
National Study of Emotional and Perceptional Changes Since September 11
ERIC Educational Resources Information Center
Seo, Dong-Chul; Torabi, Mohammad R.
2004-01-01
This study examined emotional and perceptional changes American people had experienced 10 to 12 months after the September 11 (9-11) terrorist attacks. A nationally representative sample of 807 U.S. adults ages 18 or older was interviewed using random-digit dialing that included unpublished numbers and new listings. The results indicated that 5 to…
ERIC Educational Resources Information Center
Osunde, A. U.; Omoruyi, F. E. O.
2004-01-01
This study evaluated the manpower-training program for teaching personnel in mid-western Nigeria by the National Teachers' Institute. Overall, 240 participants involved in the training program who were randomly selected from the area constituted the sample for the study. A questionnaire designed by the authors was the major instrument used for…
Baseline Survey of Sun Protection Policies and Practices in Primary School Settings in New Zealand
ERIC Educational Resources Information Center
Reeder, A. I.; Jopson, J. A.; Gray, A.
2009-01-01
The SunSmart Schools Accreditation Programme (SSAP) was launched as a national programme in October 2005 to help reduce the risk of excessive child exposure to ultraviolet radiation. As part of the need for evaluation, this paper reports the findings of a national survey of a randomly selected sample of approximately 12% of New Zealand primary…
Analytical Study of E-Learning Resources in National Open University of Nigeria
ERIC Educational Resources Information Center
Ajegbomogun, Fredrick Olatunji; Okunlaya, Rifqah Olufunmilayo Afolake; Alawiye, Mariam Kehinde
2017-01-01
This paper analyses e-learning resources in the National Open University of Nigeria (NOUN) using Abeokuta study center. Survey research method was adopted for this study. A questionnaire was designed and used to collect data for this study. A sample of 150 respondents was randomly selected from the final year students in the six schools of the…
Head Start FACES 2000: A Whole-Child Perspective on Program Performance. Fourth Progress Report.
ERIC Educational Resources Information Center
Zill, Nicholas; Resnick, Gary; Kim, Kwang; O'Donnell, Kevin; Sorongon, Alberto; McKey, Ruth Hubbell; Pai-Samant, Shefali; Clark, Cheryl; O'Brien, Robert; D'Elio, Mary Ann
In 1997, Head Start launched the Family and Child Experiences Survey (FACES), a study of a national random sample of Head Start programs, designed to describe characteristics, experiences, and outcomes for children and families served by Head Start. In 2000, FACES began data collection on a new national cohort of 2,800 children and their families…
Hawkins, Alesia Oscea; Danielson, Carla Kmett; de Arellano, Michael A; Hanson, Rochelle F; Ruggiero, Kenneth J; Smith, Daniel W; Saunders, Benjamin E; Kilpatrick, Dean G
2010-08-01
Limited research has examined whether similar patterns in injurious spanking and other forms of child physical abuse (CPA) exist across specific ethnic/racial groups. The authors examined and compared differences in the lifetime prevalence of injurious spanking and CPA in two national samples of adolescents across ethnic/racial groups and over time. Participants were 4,023 youth (12-17 years) and 3,614 youth (12-17 years) who participated in the 1995 National Survey of Adolescents (NSA) and 2005 National Survey of Adolescents-Replication (NSA-R), respectively. Adolescents, who were identified through random digit dial procedures, completed a telephone interview assessment. Results indicated significant ethnic/racial variation across groups in reports of injurious spanking in the NSA and the NSA-R samples; however, significant differences were not observed within groups between the two samples over time. Ethnic/racial differences also were found between groups in reports of CPA in the NSA-R sample. Limitations and future directions of this research are discussed.
School Readiness in Children Living in Non-Parental Care: Impacts of Head Start
ERIC Educational Resources Information Center
Lipscomb, Shannon T.; Pratt, Megan E.; Schmitt, Sara A.; Pears, Katherine C.; Kim, Hyoun K.
2013-01-01
The current study examines the effects of Head Start on the development of school readiness outcomes for children living in non-parental care. Data were obtained from the Head Start Impact Study, a randomized controlled trial of Head Start conducted with a nationally representative sample of Head Start programs and families. The sample included…
Use of Nutritional Information in Canada: National Trends between 2004 and 2008
ERIC Educational Resources Information Center
Goodman, Samantha; Hammond, David; Pillo-Blocka, Francy; Glanville, Theresa; Jenkins, Richard
2011-01-01
Objective: To examine longitudinal trends in use of nutrition information among Canadians. Design: Population-based telephone and Internet surveys. Setting and Participants: Representative samples of Canadian adults recruited with random-digit dialing sampling in 2004 (n = 2,405) and 2006 (n = 2,014) and an online commercial panel in 2008 (n =…
[Design of the National Surveillance of Nutritional Indicators (MONIN), Peru 2007-2010].
Campos-Sánchez, Miguel; Ricaldi-Sueldo, Rita; Miranda-Cuadros, Marianella
2011-06-01
To describe the design and methods of the national surveillance of nutritional indicators (MONIN) 2007-2010, carried out by INS/CENAN. MONIN was designed as a continuous (repeated cross-sectional) survey, with stratified multi-stage random sampling, considering the universe as all under five children and pregnant women residing in Peru, divided into 5 geographical strata and 6 trimesters (randomly permuted weeks, about 78% of the time between November 19, 2007 and April 2, 2010). The total sample was 3,827 children in 361 completed clusters. The dropout rate was 8.4% in clusters, 1.8% in houses, and 13.2% in households. Dropout was also 4.2, 13.3, 21.2, 55% and 29% in anthropometry, hemoglobin, food intake, retinol and ioduria measurements, respectively. The MONIN design is feasible and useful for the estimation of indicators of childhood malnutrition.
Billington, D. Rex; Hsu, Patricia Hsien-Chuan; Feng, Xuan Joanna; Medvedev, Oleg N.; Kersten, Paula; Landon, Jason; Siegert, Richard J.
2016-01-01
The World Health Organisation Quality of Life (WHOQOL) questionnaires are widely used around the world and can claim strong cross-cultural validity due to their development in collaboration with international field centres. To enhance conceptual equivalence of quality of life across cultures, optional national items are often developed for use alongside the core instrument. The present study outlines the development of national items for the New Zealand WHOQOL-BREF. Focus groups with members of the community as well as health experts discussed what constitutes quality of life in their opinion. Based on themes extracted of aspects not contained in the existing WHOQOL instrument, 46 candidate items were generated and subsequently rated for their importance by a random sample of 585 individuals from the general population. Applying importance criteria reduced these items to 24, which were then sent to another large random sample (n = 808) to be rated alongside the existing WHOQOL-BREF. A final set of five items met the criteria for national items. Confirmatory factor analysis identified four national items as belonging to the psychological domain of quality of life, and one item to the social domain. Rasch analysis validated these results and generated ordinal-to-interval conversion algorithms to allow use of parametric statistics for domain scores with and without national items. PMID:27812203
Temte, Jonathan L; Anderson, Anna Lisa
2004-01-01
Early detection of bioterrorism requires assessment of diagnoses assigned to cases of rare diseases with which clinicians have little experience. In this study, we evaluated the process of defining the differential diagnosis for inhalational anthrax using electronic communication within a practice-based research network (PBRN) and compared the results with those obtained from a nationwide random sample of family physicians with a mailed instrument. We distributed survey instruments by e-mail to 55 physician members of the Wisconsin Research Network (WReN), a regional PBRN. The instruments consisted of 3 case vignettes randomly drawn from a set describing 11 patients with inhalational anthrax, 2 with influenza A, and 1 with Legionella pneumonia. Physicians provided their most likely nonanthrax diagnosis, along with their responses to 4 yes-or-no management questions for each case. Physicians who had not responded at 1 week received a second e-mail with the survey instrument. The comparison group consisted of the nationwide sample of physicians who completed mailed survey instruments. Primary outcome measures were response rate, median response time, and frequencies of diagnostic categories assigned to cases of inhalational anthrax. The PBRN response rate compared favorably with that of the national sample (47.3% vs 37.0%; P = not significant). The median response time for the PBRN was significantly shorter than that for the national sample (2 vs 28 days; P < .001). No significant differences were found between the PBRN and the Midwest subset of the national sample in the frequencies of major diagnostic categories or in case management. Electronic means of creating differential diagnoses for rare infectious diseases of national significance is feasible within PBRNs. Information is much more rapidly acquired and is consistent with that obtained by conventional methods.
The public's preparedness: self-reliance, flashbulb memories, and conservative values.
Greenberg, Michael R; Dyen, Susannah; Elliott, Stacey
2013-06-01
We surveyed how many US residents engaged in 6 preparedness activities and measured the relationship between engagement and personal experience in hazard events, flashbulb memories of major events, self-reliance, and other indicators of a conservative philosophy. We used random digit dialing for national landline (75%) and cell phone (25%) surveys of 1930 US residents from July 6, 2011, to September 9, 2011; 1080 of the sample lived near 6 US Department of Energy nuclear waste management facilities and 850 were a national random sample. The median respondent engaged in 3 of the 6 activities; those who disproportionately engaged in 4 or more had experienced a hazard event, had distressing and strong flashbulb memories of major hazard events, and had strong feelings about the need for greater self-reliance. The results for the national and US Department of Energy site-specific surveys were almost identical. A cadre of US residents are disproportionately engaged in disaster preparedness, and they typically have stronger negative memories of past disasters and tend to be self-reliant. How their efforts can or should be integrated into local preparedness efforts is unclear.
General aviation pilot and aircraft activity survey
DOT National Transportation Integrated Search
1983-12-01
This report provides a summary and analysis of the data collected : in the 1981 General Aviation Pilot and Aircraft Activity Survey. : The survey was conducted at a random sample of airports across the : nation throughout the months of July, August, ...
General aviation pilot and aircraft activity survey.
DOT National Transportation Integrated Search
1983-12-01
This report provides a summary and analysis of the data collected : in the 1981 General Aviation Pilot and Aircraft Activity Survey. : The survey was conducted at a random sample of airports across the : nation throughout the months of July, August, ...
JoAnn M. Hanowski; Gerald J. Niemi
1995-01-01
We established bird monitoring programs in two regions of Minnesota: the Chippewa National Forest and the Superior National Forest. The experimental design defined forest cover types as strata in which samples of forest stands were randomly selected. Subsamples (3 point counts) were placed in each stand to maximize field effort and to assess within-stand and between-...
ERIC Educational Resources Information Center
Mulvaney, C. A.; Watson, M. C.; Smith, S.; Coupland, C.; Kendrick, D.
2014-01-01
Objective: To determine the prevalence of home safety practices and use of safety equipment by disadvantaged families participating in a national home safety equipment scheme in England. Design: Cross-sectional postal survey sent to a random sample of 1,000 families. Setting: England, United Kingdom. Results: Half the families (51%) returned a…
The Needs of Tribal Men and the Social Service Providers on or Near the Nez Perce Indian Nation.
ERIC Educational Resources Information Center
High Eagle, Gordon; And Others
This report results from an action research project of the Nee Mee Poom Ha Hum (Men's Coalition), investigating the needs of tribal men in the Nez Perce Indian Nation, as part of planning to improve men's development. Research was directed toward interviewing a stratified random sample of tribal men and interviewing the directors and employees of…
ERIC Educational Resources Information Center
Beran, Tanya N.; Lupart, Judy
2009-01-01
The relationship between school achievement and peer harassment was examined using individual and peer characteristics as mediating factors. The sample consisted of adolescents age 12-15 years (n = 4,111) drawn from the Canadian National Longitudinal Survey of Children and Youth, which is a stratified random sample of 22,831 households in Canada.…
ERIC Educational Resources Information Center
Andrade, Naleen N.; Hishinuma, Earl S.; McDermott, John F., Jr.; Johnson, Ronald C.; Goebert, Deborah A.; Makini, George K., Jr.; Nahulu, Linda B.; Yuen, Noelle Y. C.; McArdle, John J.; Bell, Cathy K.; Carlton, Barry S.; Miyamoto, Robin H.; Nishimura, Stephanie T.; Else, Iwalani R. N.; Guerrero, Anthony P. S.; Darmal, Arsalan; Yates, Alayne; Waldron, Jane A.
2006-01-01
Objectives: The prevalence rates of disorders among a community-based sample of Hawaiian youths were determined and compared to previously published epidemiological studies. Method: Using a two-phase design, 7,317 adolescents were surveyed (60% participation rate), from which 619 were selected in a modified random sample during the 1992-1993 to…
General aviation pilot and aircraft activity survey
DOT National Transportation Integrated Search
1979-12-01
This report provides a summary and analysis of the data collected : 1n the 1978 General Aviation Pilot and Aircraft Activity Survey. The : survey Has conducted at a random sample of airports across the nation : and Puerto Rico, throughout the months ...
General aviation pilot and aircraft activity survey.
DOT National Transportation Integrated Search
1985-09-01
This report provides a summary and analysis of the data collected in the 1984 General Aviation Pilot and Aircraft Activity Survey. The survey was conducted at a random sample of airports across the nation throughout the months of July, August, and Se...
Dong, Qi; Elliott, Michael R; Raghunathan, Trivellore E
2014-06-01
Outside of the survey sampling literature, samples are often assumed to be generated by a simple random sampling process that produces independent and identically distributed (IID) samples. Many statistical methods are developed largely in this IID world. Application of these methods to data from complex sample surveys without making allowance for the survey design features can lead to erroneous inferences. Hence, much time and effort have been devoted to develop the statistical methods to analyze complex survey data and account for the sample design. This issue is particularly important when generating synthetic populations using finite population Bayesian inference, as is often done in missing data or disclosure risk settings, or when combining data from multiple surveys. By extending previous work in finite population Bayesian bootstrap literature, we propose a method to generate synthetic populations from a posterior predictive distribution in a fashion inverts the complex sampling design features and generates simple random samples from a superpopulation point of view, making adjustment on the complex data so that they can be analyzed as simple random samples. We consider a simulation study with a stratified, clustered unequal-probability of selection sample design, and use the proposed nonparametric method to generate synthetic populations for the 2006 National Health Interview Survey (NHIS), and the Medical Expenditure Panel Survey (MEPS), which are stratified, clustered unequal-probability of selection sample designs.
Dong, Qi; Elliott, Michael R.; Raghunathan, Trivellore E.
2017-01-01
Outside of the survey sampling literature, samples are often assumed to be generated by a simple random sampling process that produces independent and identically distributed (IID) samples. Many statistical methods are developed largely in this IID world. Application of these methods to data from complex sample surveys without making allowance for the survey design features can lead to erroneous inferences. Hence, much time and effort have been devoted to develop the statistical methods to analyze complex survey data and account for the sample design. This issue is particularly important when generating synthetic populations using finite population Bayesian inference, as is often done in missing data or disclosure risk settings, or when combining data from multiple surveys. By extending previous work in finite population Bayesian bootstrap literature, we propose a method to generate synthetic populations from a posterior predictive distribution in a fashion inverts the complex sampling design features and generates simple random samples from a superpopulation point of view, making adjustment on the complex data so that they can be analyzed as simple random samples. We consider a simulation study with a stratified, clustered unequal-probability of selection sample design, and use the proposed nonparametric method to generate synthetic populations for the 2006 National Health Interview Survey (NHIS), and the Medical Expenditure Panel Survey (MEPS), which are stratified, clustered unequal-probability of selection sample designs. PMID:29200608
NASA Astrophysics Data System (ADS)
Deng, Chengbin; Wu, Changshan
2013-12-01
Urban impervious surface information is essential for urban and environmental applications at the regional/national scales. As a popular image processing technique, spectral mixture analysis (SMA) has rarely been applied to coarse-resolution imagery due to the difficulty of deriving endmember spectra using traditional endmember selection methods, particularly within heterogeneous urban environments. To address this problem, we derived endmember signatures through a least squares solution (LSS) technique with known abundances of sample pixels, and integrated these endmember signatures into SMA for mapping large-scale impervious surface fraction. In addition, with the same sample set, we carried out objective comparative analyses among SMA (i.e. fully constrained and unconstrained SMA) and machine learning (i.e. Cubist regression tree and Random Forests) techniques. Analysis of results suggests three major conclusions. First, with the extrapolated endmember spectra from stratified random training samples, the SMA approaches performed relatively well, as indicated by small MAE values. Second, Random Forests yields more reliable results than Cubist regression tree, and its accuracy is improved with increased sample sizes. Finally, comparative analyses suggest a tentative guide for selecting an optimal approach for large-scale fractional imperviousness estimation: unconstrained SMA might be a favorable option with a small number of samples, while Random Forests might be preferred if a large number of samples are available.
Vallée, Julie; Souris, Marc; Fournet, Florence; Bochaton, Audrey; Mobillion, Virginie; Peyronnie, Karine; Salem, Gérard
2007-01-01
Background Geographical objectives and probabilistic methods are difficult to reconcile in a unique health survey. Probabilistic methods focus on individuals to provide estimates of a variable's prevalence with a certain precision, while geographical approaches emphasise the selection of specific areas to study interactions between spatial characteristics and health outcomes. A sample selected from a small number of specific areas creates statistical challenges: the observations are not independent at the local level, and this results in poor statistical validity at the global level. Therefore, it is difficult to construct a sample that is appropriate for both geographical and probability methods. Methods We used a two-stage selection procedure with a first non-random stage of selection of clusters. Instead of randomly selecting clusters, we deliberately chose a group of clusters, which as a whole would contain all the variation in health measures in the population. As there was no health information available before the survey, we selected a priori determinants that can influence the spatial homogeneity of the health characteristics. This method yields a distribution of variables in the sample that closely resembles that in the overall population, something that cannot be guaranteed with randomly-selected clusters, especially if the number of selected clusters is small. In this way, we were able to survey specific areas while minimising design effects and maximising statistical precision. Application We applied this strategy in a health survey carried out in Vientiane, Lao People's Democratic Republic. We selected well-known health determinants with unequal spatial distribution within the city: nationality and literacy. We deliberately selected a combination of clusters whose distribution of nationality and literacy is similar to the distribution in the general population. Conclusion This paper describes the conceptual reasoning behind the construction of the survey sample and shows that it can be advantageous to choose clusters using reasoned hypotheses, based on both probability and geographical approaches, in contrast to a conventional, random cluster selection strategy. PMID:17543100
Vallée, Julie; Souris, Marc; Fournet, Florence; Bochaton, Audrey; Mobillion, Virginie; Peyronnie, Karine; Salem, Gérard
2007-06-01
Geographical objectives and probabilistic methods are difficult to reconcile in a unique health survey. Probabilistic methods focus on individuals to provide estimates of a variable's prevalence with a certain precision, while geographical approaches emphasise the selection of specific areas to study interactions between spatial characteristics and health outcomes. A sample selected from a small number of specific areas creates statistical challenges: the observations are not independent at the local level, and this results in poor statistical validity at the global level. Therefore, it is difficult to construct a sample that is appropriate for both geographical and probability methods. We used a two-stage selection procedure with a first non-random stage of selection of clusters. Instead of randomly selecting clusters, we deliberately chose a group of clusters, which as a whole would contain all the variation in health measures in the population. As there was no health information available before the survey, we selected a priori determinants that can influence the spatial homogeneity of the health characteristics. This method yields a distribution of variables in the sample that closely resembles that in the overall population, something that cannot be guaranteed with randomly-selected clusters, especially if the number of selected clusters is small. In this way, we were able to survey specific areas while minimising design effects and maximising statistical precision. We applied this strategy in a health survey carried out in Vientiane, Lao People's Democratic Republic. We selected well-known health determinants with unequal spatial distribution within the city: nationality and literacy. We deliberately selected a combination of clusters whose distribution of nationality and literacy is similar to the distribution in the general population. This paper describes the conceptual reasoning behind the construction of the survey sample and shows that it can be advantageous to choose clusters using reasoned hypotheses, based on both probability and geographical approaches, in contrast to a conventional, random cluster selection strategy.
de Jong, Martijn G; Pieters, Rik; Stremersch, Stefan
2012-09-01
Answers to sensitive questions are prone to social desirability bias. If not properly addressed, the validity of the research can be suspect. This article presents multigroup item randomized response theory (MIRRT) to measure self-reported sensitive topics across cultures. The method was specifically developed to reduce social desirability bias by making an a priori change in the design of the survey. The change involves the use of a randomization device (e.g., a die) that preserves participants' privacy at the item level. In cases where multiple items measure a higher level theoretical construct, the researcher could still make inferences at the individual level. The method can correct for under- and overreporting, even if both occur in a sample of individuals or across nations. We present and illustrate MIRRT in a nontechnical manner, provide WinBugs software code so that researchers can directly implement it, and present 2 cross-national studies in which it was applied. The first study compared nonstudent samples from 2 countries (total n = 927) on permissive sexual attitudes and risky sexual behavior and related these to individual-level characteristics such as the Big Five personality traits. The second study compared nonstudent samples from 17 countries (total n = 6,195) on risky sexual behavior and related these to individual-level characteristics, such as gender and age, and to country-level characteristics, such as sex ratio.
Using maximum entropy modeling for optimal selection of sampling sites for monitoring networks
Stohlgren, Thomas J.; Kumar, Sunil; Barnett, David T.; Evangelista, Paul H.
2011-01-01
Environmental monitoring programs must efficiently describe state shifts. We propose using maximum entropy modeling to select dissimilar sampling sites to capture environmental variability at low cost, and demonstrate a specific application: sample site selection for the Central Plains domain (453,490 km2) of the National Ecological Observatory Network (NEON). We relied on four environmental factors: mean annual temperature and precipitation, elevation, and vegetation type. A “sample site” was defined as a 20 km × 20 km area (equal to NEON’s airborne observation platform [AOP] footprint), within which each 1 km2 cell was evaluated for each environmental factor. After each model run, the most environmentally dissimilar site was selected from all potential sample sites. The iterative selection of eight sites captured approximately 80% of the environmental envelope of the domain, an improvement over stratified random sampling and simple random designs for sample site selection. This approach can be widely used for cost-efficient selection of survey and monitoring sites.
General Aviation Pilot and Aircraft Activity Survey : 1978
DOT National Transportation Integrated Search
1979-12-01
This report provides a summary and analysis of the data collected in the 1978 General Aviation Pilot and Aircraft Activity Survey. The survey was conducted at a random sample of airports across the nation and Puerto Rico, throughout the months of Jul...
1998 motor vehicle occupant safety survey. Volume 1, methodology report
DOT National Transportation Integrated Search
2000-03-01
This is the Methodology Report for the 1998 Motor Vehicle Occupant Safety Survey. The survey is conducted on a biennial basis (initiated in 1994), and is administered by telephone to a randomly selected national sample. Two questionnaires are used, e...
Design and operation of the National Survey of Children with Special Health Care Needs, 2009-2010.
Bramlett, Matthew D; Blumberg, Stephen J; Ormson, A Elizabeth; George, Jacquelyn M; Williams, Kim L; Frasier, Alicia M; Skalland, Benjamin J; Santos, Kathleen B; Vsetecka, Danielle M; Morrison, Heather M; Pedlow, Steven; Wang, Fang
2014-11-01
This report presents the development, plan, and operation of the 2009-2010 National Survey of Children with Special Health Care Needs, a module of the State and Local Area Integrated Telephone Survey. The survey is conducted by the Centers for Disease Control and Prevention's National Center for Health Statistics. This survey was designed to produce national and state-specific prevalence estimates of children with special health care needs (CSHCN), to describe the types of services that they need and use, and to assess aspects of the system of care for CSHCN. A random-digit-dial sample of households with children under age 18 years was constructed for each of the 50 states and the District of Columbia. The sampling frame consisted of landline phone numbers and cellular(cell) phone numbers of households that reported a cell-phone-only or cell-phone-mainly status. Children in identified households were screened for special health care needs. If CSHCN were identified in the household, a detailed interview was conducted for one randomly selected child with special health care needs. Respondents were parents or guardians who knew about the children's health and health care. A total of 196,159 household screening interviews were completed from July 2009 through March 2011, resulting in 40,242 completed special-needs interviews, including 2,991 from cell-phone interviews. The weighted overall response rate was 43.7% for the landline sample, 15.2% for the cell-phone sample, and 25.5% overall. All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.
Watanabe, Kazuhiro; Tabuchi, Takahiro; Kawakami, Norito
2017-03-01
This cross-sectional multilevel study aimed to investigate the relationship between improvement of the work environment and work-related stress in a nationally representative sample in Japan. The study was based on a national survey that randomly sampled 1745 worksites and 17,500 nested employees. The survey asked the worksites whether improvements of the work environment were conducted; and it asked the employees to report the number of work-related stresses they experienced. Multilevel multinominal logistic and linear regression analyses were conducted. Improvement of the work environment was not significantly associated with any level of work-related stress. Among men, it was significantly and negatively associated with the severe level of work-related stress. The association was not significant among women. Improvements to work environments may be associated with reduced work-related stress among men nationwide in Japan.
Susukida, Ryoko; Crum, Rosa M; Stuart, Elizabeth A; Ebnesajjad, Cyrus; Mojtabai, Ramin
2016-07-01
To compare the characteristics of individuals participating in randomized controlled trials (RCTs) of treatments of substance use disorder (SUD) with individuals receiving treatment in usual care settings, and to provide a summary quantitative measure of differences between characteristics of these two groups of individuals using propensity score methods. Design Analyses using data from RCT samples from the National Institute of Drug Abuse Clinical Trials Network (CTN) and target populations of patients drawn from the Treatment Episodes Data Set-Admissions (TEDS-A). Settings Multiple clinical trial sites and nation-wide usual SUD treatment settings in the United States. A total of 3592 individuals from 10 CTN samples and 1 602 226 individuals selected from TEDS-A between 2001 and 2009. Measurements The propensity scores for enrolling in the RCTs were computed based on the following nine observable characteristics: sex, race/ethnicity, age, education, employment status, marital status, admission to treatment through criminal justice, intravenous drug use and the number of prior treatments. Findings The proportion of those with ≥ 12 years of education and the proportion of those who had full-time jobs were significantly higher among RCT samples than among target populations (in seven and nine trials, respectively, at P < 0.001). The pooled difference in the mean propensity scores between the RCTs and the target population was 1.54 standard deviations and was statistically significant at P < 0.001. In the United States, individuals recruited into randomized controlled trials of substance use disorder treatments appear to be very different from individuals receiving treatment in usual care settings. Notably, RCT participants tend to have more years of education and a greater likelihood of full-time work compared with people receiving care in usual care settings. © 2016 Society for the Study of Addiction.
The Public’s Preparedness: Self-Reliance, Flashbulb Memories, and Conservative Values
Dyen, Susannah; Elliott, Stacey
2013-01-01
Objectives. We surveyed how many US residents engaged in 6 preparedness activities and measured the relationship between engagement and personal experience in hazard events, flashbulb memories of major events, self-reliance, and other indicators of a conservative philosophy. Methods. We used random digit dialing for national landline (75%) and cell phone (25%) surveys of 1930 US residents from July 6, 2011, to September 9, 2011; 1080 of the sample lived near 6 US Department of Energy nuclear waste management facilities and 850 were a national random sample. Results. The median respondent engaged in 3 of the 6 activities; those who disproportionately engaged in 4 or more had experienced a hazard event, had distressing and strong flashbulb memories of major hazard events, and had strong feelings about the need for greater self-reliance. The results for the national and US Department of Energy site–specific surveys were almost identical. Conclusions. A cadre of US residents are disproportionately engaged in disaster preparedness, and they typically have stronger negative memories of past disasters and tend to be self-reliant. How their efforts can or should be integrated into local preparedness efforts is unclear. PMID:23597367
ERIC Educational Resources Information Center
Kaiser Foundation, Oakland, CA.
In the midst of a growing national debate about the role of television as a de facto "sex educator" for young people today, this survey asked parents nationwide in the fall of 1996 about their views on kids and television. A random sample of 853 parents and children ages 6 to 15 were surveyed by telephone (the data reported here focus on…
Computers in Public Education Study.
ERIC Educational Resources Information Center
HBJ Enterprises, Highland Park, NJ.
This survey conducted for the National Institute of Education reports the use of computers in U.S. public schools in the areas of instructional computing, student accounting, management of educational resources, research, guidance, testing, and library applications. From a stratified random sample of 1800 schools in varying geographic areas and…
Why Students Are Hostile to Free Enterprise
ERIC Educational Resources Information Center
Kilpatrick, James L.
1975-01-01
A Gallup study is described, which was commissioned by Oklahoma State Christian College regarding the philosophical orientation of college students generally (liberal or conservative). The author presents selected findings and concludes that students in the national random sample are ignorant of industrial life and generally hostile toward the…
American Healthy Homes Survey: A National Study of Residential Phthalates Measured from Floor Wipes
The United States Environmental Protection Agency (U.S. EPA), in collaboration with the U.S. Department of Housing and Urban Development (HUD), conducted a survey measuring phthalates in randomly selected residential homes throughout the U.S. Multistage sampling with clustering w...
Who Recommends Long-Term Care Matters
ERIC Educational Resources Information Center
Kane, Robert L.; Bershadsky, Boris; Bershadsky, Julie
2006-01-01
Purpose: Making good consumer decisions requires having good information. This study compared long-term-care recommendations among various types of health professionals. Design and Methods: We gave randomly varied scenarios to a convenience national sample of 211 professionals from varying disciplines and work locations. For each scenario, we…
White, V; Tan, N; Wakefield, M; Hill, D
2003-09-01
To examine adolescents' awareness of and response to an adult focused anti-smoking advertising campaign. Data were obtained from two cross sectional surveys of adolescents. The first study, a national evaluation study, involved a telephone survey of a randomly selected sample of 400 14-17 year olds across Australia in 1998. The second study involved a survey of 3714 students aged 12-17 years, randomly selected from a probability sample of secondary schools in the Australian State of Victoria. In both surveys, adolescents answered questions on their awareness of the advertising campaign and actions taken in response to the campaign. Adolescents in the national evaluation study also answered questions assessing knowledge of health effects of smoking, impact of the campaign on adolescents, and relevance of the campaign for adolescents and other groups. Responses for smokers and nonsmokers were examined. Among the national evaluation sample, 85% of adolescent smokers thought the campaign was relevant to them. Fifty three per cent indicated that the campaign had led some teenagers to at least try to quit and 85% thought it made smoking seem less cool and desirable. Among students who were established smokers the campaign generated quitting activity, with 27% cutting down the number of cigarettes they smoked and 26% having thought about quitting. Results indicate that adolescents were very aware of this adult focused anti-smoking campaign and thought it relevant to them. The findings suggest that a graphic health effects cessation focused campaign may have been successful in promoting anti-smoking attitudes among adolescents.
Jun, Jae Kwan; Kim, Mi Jin; Choi, Kui Son; Suh, Mina; Jung, Kyu-Won
2012-01-01
Mammographic breast density is a known risk factor for breast cancer. To conduct a survey to estimate the distribution of mammographic breast density in Korean women, appropriate sampling strategies for representative and efficient sampling design were evaluated through simulation. Using the target population from the National Cancer Screening Programme (NCSP) for breast cancer in 2009, we verified the distribution estimate by repeating the simulation 1,000 times using stratified random sampling to investigate the distribution of breast density of 1,340,362 women. According to the simulation results, using a sampling design stratifying the nation into three groups (metropolitan, urban, and rural), with a total sample size of 4,000, we estimated the distribution of breast density in Korean women at a level of 0.01% tolerance. Based on the results of our study, a nationwide survey for estimating the distribution of mammographic breast density among Korean women can be conducted efficiently.
Efficacy of abstinence promotion media messages: findings from an online randomized trial.
Evans, W Douglas; Davis, Kevin C; Ashley, Olivia Silber; Blitstein, Jonathan; Koo, Helen; Zhang, Yun
2009-10-01
We conducted an online randomized experiment to evaluate the efficacy of messages from the Parents Speak Up National Campaign (PSUNC) to promote parent-child communication about sex. We randomly assigned a national sample of 1,969 mothers and fathers to treatment (PSUNC exposure) and control (no exposure) conditions. Mothers were further randomized into treatment and booster (additional messages) conditions to evaluate dose-response effects. Participants were surveyed at baseline, 4 weeks postexposure, and 6 months postexposure. We used multivariable logistic regression procedures in our analysis. Treatment fathers were more likely than control fathers to initiate conversations about sex at 4 weeks, and treatment fathers and mothers were more likely than controls at 6 months to recommend that their children wait to have sex. Treatment fathers and mothers were far more likely than controls to use the campaign Web site. There was a dose-response effect for mothers' Web site use. Using new media methods, this study shows that PSUNC messages are efficacious in promoting parent-child communication about sex and abstinence. Future research should evaluate mechanisms and effectiveness in natural settings.
Ng, Ding-Quan; Liu, Shu-Wei; Lin, Yi-Pin
2018-09-15
In this study, a sampling campaign with a total of nine sampling events investigating lead in drinking water was conducted at 7 sampling locations in an old building with lead pipes in service in part of the building on the National Taiwan University campus. This study aims to assess the effectiveness of four different sampling methods, namely first draw sampling, sequential sampling, random daytime sampling and flush sampling, in lead contamination detection. In 3 out of the 7 sampling locations without lead pipe, lead could not be detected (<1.1 μg/L) in most samples regardless of the sampling methods. On the other hand, in the 4 sampling locations where lead pipes still existed, total lead concentrations >10 μg/L were consistently observed in 3 locations using any of the four sampling methods while the remaining location was identified to be contaminated using sequential sampling. High lead levels were consistently measured by the four sampling methods in the 3 locations in which particulate lead was either predominant or comparable to soluble lead. Compared to first draw and random daytime samplings, although flush sampling had a high tendency to reduce total lead in samples in lead-contaminated sites, the extent of lead reduction was location-dependent and not dependent on flush durations between 5 and 10 min. Overall, first draw sampling and random daytime sampling were reliable and effective in determining lead contamination in this study. Flush sampling could reveal the contamination if the extent is severe but tends to underestimate lead exposure risk. Copyright © 2018 Elsevier B.V. All rights reserved.
College Counselors' Perceptions and Practices regarding Anticipatory Guidance on Firearms
ERIC Educational Resources Information Center
Price, James; Mrdjenovich, Adam J.; Thompson, Amy; Dake, Joseph A.
2009-01-01
Objectives: This study assessed college counselors' anticipatory guidance on firearms for student clients. Participants: The membership of the Association for University and College Counseling Center Directors was used to identify a national random sample of counseling centers (n = 361). One counselor from each center was selected to survey.…
School Nurses' Experiences with Medication Administration
ERIC Educational Resources Information Center
Kelly, Michael W.; McCarthy, Ann Marie; Mordhorst, Matthew J.
2003-01-01
This article reports school nurses' experiences with medication administration through qualitative analyses of a written survey and focus groups. From a random sample of 1,000 members of the National Association of School Nurses, 649 (64.9%) school nurses completed the survey. The quantitative data from the survey were presented previously.…
Beliefs and Attitudes of Secondary Agriculture Teachers about Global Agriculture Issues
ERIC Educational Resources Information Center
Hurst, Sara D.; Roberts, T. Grady; Harder, Amy
2015-01-01
The purpose of this study was to explore the beliefs and attitudes of secondary agriculture teachers regarding global agricultural issues. A randomized national sample of 417 teachers were surveyed using a modified version of the International Agricultural Awareness and Understanding Survey (Wingenbach, Boyd, Lindner, Dick, Arispe, & Haba,…
Drug and Alcohol Use by Canadian University Athletes: A National Survey.
ERIC Educational Resources Information Center
Spence, John C.; Gauvin, Lise
1996-01-01
Using a stratified random sampling procedure, 754 student athletes were surveyed regarding drug and alcohol use in eight different sports from eight universities across Canada. Provides statistics of substances athletes reported using, including pain medications, weight loss products, anabolic steroids, smokeless tobacco products, alcohol,…
Students with Disabilities and Higher Education
ERIC Educational Resources Information Center
Singh, Delar K.
2005-01-01
This paper reports the findings of a national survey that collected data describing the selected facilities and services of 137 randomly selected institutions of higher learning. The survey was sent to the Directors of services for disabled students of the sample institutions. The findings indicate that only 7% of the institutions of higher…
Job Satisfaction of High School Journalism Educators.
ERIC Educational Resources Information Center
Dvorak, Jack; Phillips, Kay D.
Four research questions are posed to explore the job satisfaction of high school journalism educators. A national random sample of 669 respondents shows that journalism educators are generally satisfied with their jobs--more so than teachers in other disciplines. Multiple regression analysis using Herzberg's motivation-hygiene theory as a…
Metrication -- A Construction Point of View
ERIC Educational Resources Information Center
Stein, Joseph
1974-01-01
Random sampling of construction executives revealed a surprising lack of awareness concerning the proposed 10-year metric conversion recommendation made by the National Bureau of Standards in 1971. Explains attitudes on the desirability of conversion to the metric system and prognoses on the impact of conversion. (A paper presented at Building…
ERIC Educational Resources Information Center
Balkin, Richard S.; Schlosser, Lewis Z.; Levitt, Dana Heller
2009-01-01
In this article, the authors present the results from a national study investigating the relationships between religious identity, sexism, homophobia, and multicultural competence. Participants were 111 randomly sampled counseling professionals and graduate students. The results indicated a relationship between religious identity and various…
Consumer Perceptions of the Media and Their Advertising Content.
ERIC Educational Resources Information Center
Larkin, Ernest F.
To determine consumer preference regarding four forms of mass communication, an 18-item questionnaire was devised that asked individuals where they sought information on national and world affairs, local events, entertainment, and shopping (advertising). Results from the 108 respondents in the random sample indicated the following: newspapers…
School Counselors' Perceptions of Biracial Students' Functioning
ERIC Educational Resources Information Center
Kindaichi, Mai Margaret
2010-01-01
The number of biracial school-aged youth has continued to increase dramatically (Jones & Smith, 2001), and has drawn timely attention to the extent to which practicing school counselors address biracial youths' concerns in a culturally competent manner. This study examined the perceptions of a nationally-based random sample of 203 White school…
ERIC Educational Resources Information Center
White, Susan; Tesfaye, Casey Langer
2014-01-01
In this report, the authors share their analysis of the data from over 3,500 high schools in the U.S. beginning with an examination of the availability of physics in U.S. high schools. The schools in their sample are a nationally-representative random sample of the almost 25,000 high schools in forty-nine of the fifty states. Table 1 shows the…
Longitudinal analysis of bioaccumulative contaminants in freshwater fishes
Sun, Jielun; Kim, Y.; Schmitt, C.J.
2003-01-01
The National Contaminant Biomonitoring Program (NCBP) was initiated in 1967 as a component of the National Pesticide Monitoring program. It consists of periodic collection of freshwater fish and other samples and the analysis of the concentrations of persistent environmental contaminants in these samples. For the analysis, the common approach has been to apply the mixed two-way ANOVA model to combined data. A main disadvantage of this method is that it cannot give a detailed temporal trend of the concentrations since the data are grouped. In this paper, we present an alternative approach that performs a longitudinal analysis of the information using random effects models. In the new approach, no grouping is needed and the data are treated as samples from continuous stochastic processes, which seems more appropriate than ANOVA for the problem.
Lindquist, Lisa K; Love, Holly C; Elbogen, Eric B
2017-01-01
This study randomly sampled post-9/11 military veterans and reports on causes, predictors, and frequency of traumatic brain injury (TBI) (N=1,388). A total of 17.3% met criteria for TBI during military service, with about one-half reporting multiple head injuries, which were related to higher rates of posttraumatic stress disorder, depression, back pain, and suicidal ideation. The most common mechanisms of TBI included blasts (33.1%), objects hitting head (31.7%), and fall (13.5%). TBI was associated with enlisted rank, male gender, high combat exposure, and sustaining TBI prior to military service. Clinical and research efforts in veterans should consider TBI mechanism, effects of cumulative TBI, and screening for premilitary TBI.
Donovan, John E.; Chung, Tammy
2015-01-01
Objective: Most studies of adolescent drinking focus on single alcohol use behaviors (e.g., high-volume drinking, drunkenness) and ignore the patterning of adolescents’ involvement across multiple alcohol behaviors. The present latent class analyses (LCAs) examined a procedure for empirically determining multiple cut points on the alcohol use behaviors in order to establish a typology of adolescent alcohol involvement. Method: LCA was carried out on six alcohol use behavior indicators collected from 6,504 7th through 12th graders who participated in Wave I of the National Longitudinal Study of Adolescent Health (AddHealth). To move beyond dichotomous indicators, a “progressive elaboration” strategy was used, starting with six dichotomous indicators and then evaluating a series of models testing additional cut points on the ordinal indicators at progressively higher points for one indicator at a time. Analyses were performed on one random half-sample, and confirmatory LCAs were performed on the second random half-sample and in the Wave II data. Results: The final model consisted of four latent classes (never or non–current drinkers, low-intake drinkers, non–problem drinkers, and problem drinkers). Confirmatory LCAs in the second random half-sample from Wave I and in Wave II support this four-class solution. The means on the four latent classes were also generally ordered on an array of measures reflecting psychosocial risk for problem behavior. Conclusions: These analyses suggest that there may be four different classes or types of alcohol involvement among adolescents, and, more importantly, they illustrate the utility of the progressive elaboration strategy for moving beyond dichotomous indicators in latent class models. PMID:25978828
2012-01-01
Background With the current focus on personalized medicine, patient/subject level inference is often of key interest in translational research. As a result, random effects models (REM) are becoming popular for patient level inference. However, for very large data sets that are characterized by large sample size, it can be difficult to fit REM using commonly available statistical software such as SAS since they require inordinate amounts of computer time and memory allocations beyond what are available preventing model convergence. For example, in a retrospective cohort study of over 800,000 Veterans with type 2 diabetes with longitudinal data over 5 years, fitting REM via generalized linear mixed modeling using currently available standard procedures in SAS (e.g. PROC GLIMMIX) was very difficult and same problems exist in Stata’s gllamm or R’s lme packages. Thus, this study proposes and assesses the performance of a meta regression approach and makes comparison with methods based on sampling of the full data. Data We use both simulated and real data from a national cohort of Veterans with type 2 diabetes (n=890,394) which was created by linking multiple patient and administrative files resulting in a cohort with longitudinal data collected over 5 years. Methods and results The outcome of interest was mean annual HbA1c measured over a 5 years period. Using this outcome, we compared parameter estimates from the proposed random effects meta regression (REMR) with estimates based on simple random sampling and VISN (Veterans Integrated Service Networks) based stratified sampling of the full data. Our results indicate that REMR provides parameter estimates that are less likely to be biased with tighter confidence intervals when the VISN level estimates are homogenous. Conclusion When the interest is to fit REM in repeated measures data with very large sample size, REMR can be used as a good alternative. It leads to reasonable inference for both Gaussian and non-Gaussian responses if parameter estimates are homogeneous across VISNs. PMID:23095325
ERIC Educational Resources Information Center
Bowling, Ann; Gabriel, Zahava
2004-01-01
This paper is based on the results of a national survey of the quality of life of 999 randomly sampled people aged 65 and over, living at home in Britain. The survey was semi-structured, and a sample of survey respondents was followed up and interviewed in-depth in order to explore their perceptions of quality of life in full. Comparisons are made…
ERIC Educational Resources Information Center
Sibthorp, Jim; Furman, Nate; Paisley, Karen; Gookin, John; Schumann, Scott
2011-01-01
Transfer of learning from adventure programs remains of critical interest to adventure education professionals. Although some research has investigated what transfers, notably less has focused on mechanisms that might influence transfer. This paper explores the mechanisms of transfer reported by a stratified random sample of National Outdoor…
Framework for Disciplinary Writing in Science Grades 6-12: A National Survey
ERIC Educational Resources Information Center
Drew, Sally Valentino; Olinghouse, Natalie G.; Faggella-Luby, Michael; Welsh, Megan E.
2017-01-01
This study investigated the current state of writing instruction in science classes (Grades 6-12). A random sample of certified science teachers from the United States (N = 287) was electronically surveyed. Participants reported on their purposes for teaching writing, the writing assignments most often given to students, use of evidence-based…
Job Demand in the Cosmetology Industry.
ERIC Educational Resources Information Center
Rudner, Lawrence M.; Deutermann, William V., Jr.
In order to determine job demand in the cosmetology industry, a survey was made of a nationally representative stratified random sample of 1,454 beauty salons, barber shops, and unisex salons in July 1991. Salon owners were asked about 1990 and their plans for the future. Survey results were supplemented with information about the industry…
ERIC Educational Resources Information Center
Sorensen, Tyson J.; McKim, Aaron J.; Velez, Jonathan J.
2016-01-01
Using data from a random sample of secondary school agriculture teachers in the United States, this study explored the work-family conflict and turnover intentions of agriculture teachers. Additionally, this study sought to determine the relationship between work-family conflict and turnover intentions among agriculture teachers. Work-family…
Psychiatrists' Perceptions and Practices in Treating Patients' Obesity
ERIC Educational Resources Information Center
Lichwala-Zyla, Christine; Price, James H.; Dake, Joseph A.; Jordan, Timothy; Price, Joy Ann
2009-01-01
Objective: This study identified psychiatrists' perceptions and practices regarding advising and treating obese patients. Methods: Questionnaires were mailed to a national random sample of 500 members of APA. A three-wave mailing was used to maximize the return rate. The questionnaire contained items on weight control based on the Stages of Change…
MPA and CPM Curriculum: An Analysis of the Views of Public Administrators.
ERIC Educational Resources Information Center
Rose, Bruce J.
Views of state public administrators about management education and training needs were investigated, as were administrator views concerning short-term management development workshops. Data was drawn from responses to questionnaires mailed to 5,980 state administrators who were selected from a national survey and from random samples using lists…
How Do Primary Grade Teachers Teach Handwriting? A National Survey
ERIC Educational Resources Information Center
Graham, Steve; Harris, Karen R.; Mason, Linda; Fink-Chorzempa, Barbara; Moran, Susan; Saddler, Bruce
2008-01-01
A random sample of primary grade teachers from across the United States was surveyed about their instructional practices in handwriting. Nine out of every ten teachers indicated that they taught handwriting, averaging 70 minutes of instruction per week. Only 12% of teachers, however, indicated that the education courses taken in college adequately…
Sexual Health Among Male College Students in the United States and the Netherlands
ERIC Educational Resources Information Center
Dodge, Brian; Sandfort, Theo G. M.; Yarber, William L.; de Wit, John
2005-01-01
Objectives: To assess differences in sexual health behaviors, outcomes, and potential sociocultural determinants among male college students in the United States and the Netherlands. Methods: Survey data were collected from random samples of students from both national cultures. Results: American men were more likely to report inadequate…
Adolescent Pregnancy in an Urban Environment: Issues, Programs, and Evaluation.
ERIC Educational Resources Information Center
Hardy, Janet B.; Zabin, Laurie Schwab
An in-depth discussion of national and local statistics regarding teenage and adolescent pregnancy and the developmental issues involved opens this analysis. Problems and adverse consequences of adolescent pregnancy in an urban setting are explored using a city-wide random sample of adolescent births. A model pregnancy and parenting program and…
TAFE Teachers: Facing the Challenge.
ERIC Educational Resources Information Center
Kronemann, Michaela
Nearly 1,000 technical and further education (TAFE) teachers in Australia responded to a national survey to determine the impact of funding cuts, constant changes, and restructuring on their work and family life. More than 2,000 questionnaires were sent to a random sample of education union members, approximately 1,700 women and 300 men. In…
Perceptions of Elementary School Children's Parents Regarding Sexuality Education
ERIC Educational Resources Information Center
Fisher, Christine M.; Telljohann, Susan K.; Price, James H.; Dake, Joseph A.; Glassman, Tavis
2015-01-01
This study examined the preferences of parents of elementary school-aged children regarding when sexuality topics should be discussed in school and at home. The survey was mailed to a national random sample of parents of elementary school age children. Overall, 92% of parents believed that sexuality education should be taught in schools.…
Conflict in the Workplace: Social Workers as Victims and Perpetrators
ERIC Educational Resources Information Center
Ringstad, Robin
2005-01-01
Conflict and violence in the workplace have emerged as a real but inadequately explored concern in the social work profession. The present study surveyed a national random sample of 1,029 NASW members about their experiences with client violence and with physical and psychological assault in relationship to practice setting, age, gender, and…
Legal Implications for Teacher Selection as Defined by the ADA and the ADEA.
ERIC Educational Resources Information Center
Young, I. Phillip; Prince, Arthur L.
1999-01-01
Hypothetical teacher candidates were created, some of whom were depicted as having an acknowledged disability, others having no acknowledged disability and all varied with respect to chronological age. A national random sample of public school principals evaluated the teacher candidates as if screening for a vacant position within their school…
Classroom Connectivity and Algebra 1 Achievement: A Three-Year Longitudinal Study
ERIC Educational Resources Information Center
Irving, Karen E.; Pape, Stephen J.; Owens, Douglas T.; Abrahamson, Louis; Silver, David; Sanalan, Vehbi A.
2016-01-01
Findings from three years of a longitudinal randomized control trial involving a national U.S. sample of Algebra 1 teachers and students are reported. The study examines the effects of a connected classroom technology (CCT) professional development and classroom intervention on student achievement when compared to classroom instruction with…
Student Teaching in the United States. Executive Summary
ERIC Educational Resources Information Center
National Council on Teacher Quality, 2011
2011-01-01
In an effort to understand what makes a student teaching experience strong, the National Council on Teacher Quality (NCTQ) has undertaken this comprehensive review. Over a period of two years, NCTQ researchers examined the student teaching programs of a stratified random sample of 134 higher education institutions across the United States, with at…
ERIC Educational Resources Information Center
Pascarella, Christina Bechle
2012-01-01
This study examined play therapy training across the nation among school psychology, social work, and school counseling graduate training programs. It also compared current training to previous training among school psychology and school counseling programs. A random sample of trainers was selected from lists of graduate programs provided by…
Deaf College Students' Attitudes toward Racial/Ethnic Diversity, Campus Climate, and Role Models
ERIC Educational Resources Information Center
Parasnis, Ila; Samar, Vincent J.; Fischer, Susan D.
2005-01-01
Deaf college Students attitudes toward a variety of issues related to racial/ethnic diversity were surveyed by contacting all racial/ethnic minority deaf students and a random sample of Caucasian deaf students attending the National Technical Institute for the Deaf (NTID), Rochester Institute of Technology; 38% completed the survey. Although…
The Prevalence and Correlates of Depression among College Students
ERIC Educational Resources Information Center
Lindsey, Billie J.; Fabiano, Patricia; Stark, Chris
2009-01-01
This study examined depression among a random sample of students (N = 618) enrolled in a medium size university in the Pacific Northwest who responded to the American College Health Association's National College Health Assessment. The results indicated that one in four students experienced depression in the past year and men were as likely as…
School Web Sites: Are They Accessible to All?
ERIC Educational Resources Information Center
Wells, Julie A.; Barron, Ann E.
2006-01-01
In 2002, the National Center for Educational Statistics reported that 99% of public schools had Internet access and 86% of those schools had a web site or web page (Kleiner & Lewis, 2003). This study examined accessibility issues on elementary school homepages. Using a random sample of elementary school web sites, the researchers documented…
ERIC Educational Resources Information Center
Bon, Susan C.
2009-01-01
In this experimental study, a national random sample of high school principals (stratified by gender) were asked to evaluate hypothetical applicants whose resumes varied by religion (Jewish, Catholic, nondenominational) and gender (male, female) for employment as assistant principals. Results reveal that male principals rate all applicants higher…
USDA-ARS?s Scientific Manuscript database
To identify the factors associated with anemia and to document the severity of micronutrient deficiencies, malaria and inflammation, a nationally representative cross-sectional survey was conducted. A three-stage sampling procedure was used to randomly select children <5 years of age and adult women...
Faculty Preparedness to Build Cultural Inclusiveness
ERIC Educational Resources Information Center
Samuels, Dena Renee
2010-01-01
Faculty members play a significant role in retaining diverse students, faculty, and staff on a college campus based on how culturally inclusive their behavior is. This research elucidates the development of a faculty inclusiveness survey, and tests it on a national random sample of 637 faculty members to determine how prepared they are to build…
Sleep Complaints in the Adult Brazilian Population: A National Survey Based on Screening Questions
Bittencourt, Lia Rita A.; Santos-Silva, Rogerio; Taddei, Jose A.; Andersen, Monica L.; de Mello, Marco T.; Tufik, Sergio
2009-01-01
Study Objectives: The aim of the current survey was to investigate the prevalence of sleep complaints in a randomized cluster sample of the Brazilian population. Methods: A 3-stage cluster sampling technique was utilized to randomly select Brazilian subjects older than 16 years, of both genders and all socioeconomic classes. The final sample of 2,110 subjects from 150 different cities was enough to estimate prevalence in the Brazilian population with a sampling error of ± 2%. Questions about sleep complaints were administered face-to-face by Instituto Datafolha interviewers on March 26 and 27, 2008. Data were expanded using a weighted variable. Results: Of all interviewed subjects, 63% reported at least one sleep related complaint. Sleep complaint prevalence increased with age and was similar among inhabitants of different Brazilian regions, as well as between metropolitan areas and smaller cities. Insomnia and nightmares were significantly more prevalent in women (40% and 25%, respectively), and snoring was more prevalent in men (35%). For sleep complaints with frequencies greater than 3 times per week, we found the following prevalence: 61% for snoring, 35% for insomnia, 17% for nightmares, 53% for leg kicking, and 37% for breathing pauses. Conclusions: Because sleep disorders are affect a high proportion of the population and are known to be correlated with decreased well-being and productivity, more detailed national surveys are necessary to provide relevant information to develop approaches to prevention and treatment. Citation: Bittencourt LRA; Santos-Silva R; Taddei JA; Andersen ML; de Mello MT; Tufik S. Sleep complaints in the adult brazilian population: a national survey based on screening questions. J Clin Sleep Med 2009;5(5):459-463. PMID:19961032
Kopp, Blaine S.; Nielsen, Martha; Glisic, Dejan; Neckles, Hilary A.
2009-01-01
This report documents results of pilot tests of a protocol for monitoring estuarine nutrient enrichment for the Vital Signs Monitoring Program of the National Park Service Northeast Coastal and Barrier Network. Data collected from four parks during protocol development in 2003-06 are presented: Gateway National Recreation Area, Colonial National Historic Park, Fire Island National Seashore, and Assateague Island National Seashore. The monitoring approach incorporates several spatial and temporal designs to address questions at a hierarchy of scales. Indicators of estuarine response to nutrient enrichment were sampled using a probability design within park estuaries during a late-summer index period. Monitoring variables consisted of dissolved-oxygen concentration, chlorophyll a concentration, water temperature, salinity, attenuation of downwelling photosynthetically available radiation (PAR), and turbidity. The statistical sampling design allowed the condition of unsampled locations to be inferred from the distribution of data from a set of randomly positioned "probability" stations. A subset of sampling stations was sampled repeatedly during the index period, and stations were not rerandomized in subsequent years. These "trend stations" allowed us to examine temporal variability within the index period, and to improve the sensitivity of the monitoring protocol to detecting change through time. Additionally, one index site in each park was equipped for continuous monitoring throughout the index period. Thus, the protocol includes elements of probabilistic and targeted spatial sampling, and the temporal intensity ranges from snapshot assessments to continuous monitoring.
Beliefs about the causes of obesity in a national sample of 4th year medical students.
Phelan, Sean M; Burgess, Diana J; Burke, Sara E; Przedworski, Julia M; Dovidio, John F; Hardeman, Rachel; Morris, Megan; van Ryn, Michelle
2015-11-01
Physician knowledge of the complex contributors to obesity varies. We do not know whether today's medical students are graduating with deep understanding of the causes of obesity. Our objective was to assess beliefs about causes of obesity in a national sample of 4th year medical students. We randomly selected 2000 4th year students from a random sample of 50 U.S. medical schools and asked them to rate the importance of several factors as causes of obesity. Of those invited, 1244 (62%) responded. We conducted latent class analysis to identify groups with similar response patterns. Most students demonstrated knowledge that obesity has multiple contributors. Students fell into 1 of 4 classes: (1) more likely to endorse all contributors (28%), (2) more likely to endorse physiological contributors (27%), (3) more likely to endorse behavioral or social contributors (24%), and (4) unlikely to endorse contributors outside of overeating and physical activity (22%). Though students were generally aware of multiple causes, there were 4 distinct patterns of beliefs, with implications for patient care. Targeted interventions may help to improve depth of knowledge about the causes of obesity and lead to more effective care for obese patients. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Terry, Ana L; Cogswell, Mary E; Wang, Chia-Yih; Chen, Te-Ching; Loria, Catherine M; Wright, Jacqueline D; Zhang, Xinli; Lacher, David A; Merritt, Robert K; Bowman, Barbara A
2016-01-01
Background: Twenty-four–hour urine sodium excretion is recommended for monitoring population sodium intake. Because of concerns about participation and completion, sodium excretion has not been collected previously in US nationally representative surveys. Objective: We assessed the feasibility of implementing 24-h urine collections as part of a nationally representative survey. Design: We selected a random half sample of nonpregnant US adults aged 20–69 y in 3 geographic locations of the 2013 NHANES. Participants received explicit instructions, started and ended the urine collection in a urine study mobile examination center, and answered questions about their collection. Among those with a complete 24-h urine collection, a random one-half were asked to collect a second 24-h urine sample. Sodium, potassium, chloride, and creatinine excretion were analyzed. Results: The final NHANES examination response rate for adults aged 20–69 y in these 3 study locations was 71%. Of those examined (n = 476), 282 (59%) were randomly selected to participate in the 24-h urine collection. Of these, 212 persons [75% of those selected for 24-h urine collection; 53% (equal to 71% × 75% of those selected for the NHANES)] collected a complete initial 24-h specimen and 92 persons (85% of 108 selected) collected a second complete 24-h urine sample. More men than women completed an initial collection (P = 0.04); otherwise, completion did not vary by sociodemographic characteristics, body mass index, education, or employment status for either collection. Mean 24-h urine volume and sodium excretion were 1964 ± 1228 mL and 3657 ± 2003 mg, respectively, for the first 24-h urine sample, and 2048 ± 1288 mL and 3773 ± 1891 mg, respectively, for the second collection. Conclusion: Given the 53% final component response rate and 75% completion rate, 24-h urine collections were deemed feasible and implemented in the NHANES 2014 on a subsample of adults aged 20–69 y to assess population sodium intake. This study was registered at clinicaltrials.gov as NCT02723682. PMID:27413136
Ahmadani, Muhammad Yakoob; Hakeem, Rubina; Fawwad, Asher; Basit, Abdul; Shera, A Samad
2008-06-01
To assess insulin levels and their association with metabolic risk factors (family history of diabetes, abnormal glucose tolerance, hypertension, overweight and android obesity) among a representative group of Pakistan. The study data was taken from the database of a population-based survey conducted in Sindh Province, Pakistan, in 1994 to assess the prevalence of diabetes mellitus and impaired glucose tolerance (IGT). Through stratified random sampling; oral glucose tolerance tests were performed in 967 adults; every fifth sample was estimated for fasting and random (2-hour post-75 gm glucose load) insulin levels. The total number of metabolic risk factors was counted for each subject, and their association with insulin levels studied. Of the 130 subjects, 56.1% were females and 95.4% were Sindhi. The mean age of males and females was 43.84 and 40.61 years, respectively. Family history for diabetes and frequency of overweight had significant positive associations with both fasting and random insulin levels (P < 0.05). Association between hypertension and insulin levels was significant only for random insulin levels, and between android obesity, abnormal glucose tolerance, or male gender and insulin levels only for fasting insulin levels (P < 0.05). Metabolic risk factors had significant positive associations with both fasting (r = 0.351 P = 0.000) as well as random insulin levels (r = 0.364 P = 0.000). This paper provides baseline pioneering information applicable to the Pakistani population. Furthermore, the observations made in this study about differences in association of fasting or random insulin levels with various metabolic risk factors highlight the possibility of using either of them for risk assessment. This finding needs to be assessed in a larger and nationally representative sample.
Depression Screening Patterns for Women in Rural Health Clinics
ERIC Educational Resources Information Center
Tudiver, Fred; Edwards, Joellen Beckett; Pfortmiller, Deborah T.
2010-01-01
Context: Rates and types of screening for depression in rural primary care practices are unknown. Purpose: To identify rates of depression screening among rural women in a sample of rural health clinics (RHCs). Methods: A chart review of 759 women's charts in 19 randomly selected RHCs across the nation. Data were collected from charts of female…
Populus tremuloides mortality near the southwestern edge of its range
Thomas J. Zegler; Margaret M. Moore; Mary L. Fairweather; Kathryn B. Ireland; Peter Z. Fule
2012-01-01
Mortality and crown dieback of quaking aspen (Populus tremuloides) were extensive on the Williams Ranger District, Kaibab National Forest in northern Arizona. We collected data from a random sample of 48 aspen sites to determine the relationship of predisposing site and stand factors and contributing agents to ramet mortality. Mortality of overstory (P10.1 cm DBH)...
ERIC Educational Resources Information Center
Sorensen, Tyson J.; McKim, Aaron J.; Velez, Jonathan J.
2017-01-01
Data from a random sample of secondary school agriculture teachers in the United States were utilized to explore work characteristics and their relationship to work-family conflict, specifically how the work role interfered with the family role. Nine workplace characteristics (i.e., salary, work hours per work week, weekend work hours, years of…
Parental Influence on Academic Achievement among the Primary School Students in Trinidad
ERIC Educational Resources Information Center
Johnson, Emmanuel Janagan; Descartes, Christine H.
2017-01-01
The present study examined the level of parental influence on academic achievement in primary school students who prepare for the National-level test at standard five (grade 6), Secondary Entrance Examinations in Trinidad. A sample of 128 students studying standard five from primary schools was randomly selected. The data were analysed using SPSS.…
ERIC Educational Resources Information Center
Westervelt, Miriam O.; Llewellyn, Lynn G.
This report analyzes the attitudes, beliefs and behaviors of a random national sample of 3,087 fifth and sixth grade students from 15,787 respondents to a Wildlife Survey distributed in "Weekly Reader" periodicals. The questionnaire examined the prevalence of four basic orientations toward wildlife (humanistic, moralistic, naturalistic,…
Acculturation Stress, Drinking, and Intimate Partner Violence among Hispanic Couples in the U.S
ERIC Educational Resources Information Center
Caetano, Raul; Ramisetty-Mikler, Suhasini; Caetano Vaeth, Patrice A.; Harris, T. Robert
2007-01-01
This article examines the cross-sectional association between acculturation, acculturation stress, drinking, and intimate partner violence (IPV) among Hispanic couples in the U.S. The data being analyzed come from a multi-cluster random household sample of couples interviewed as part of the second wave of a 5-year national longitudinal study. The…
A Classroom Observational Study of Qatar's Independent Schools: Instruction and School Reform
ERIC Educational Resources Information Center
Palmer, Douglas J.; Sadiq, Hissa M.; Lynch, Patricia; Parker, Dawn; Viruru, Radhika; Knight, Stephanie; Waxman, Hersh; Alford, Beverly; Brown, Danielle Bairrington; Rollins, Kayla; Stillisano, Jacqueline; Abu-Tineh, Abdullah M. Hamdan; Nasser, Ramzi; Allen, Nancy; Al-Binali, Hessa; Ellili, Maha; Al-Kateeb, Haithem; Al-Kubaisi, Huda
2016-01-01
Qatar initiated a K-12 national educational reform in 2001. However, there is limited information on the instructional practices of the teachers in the reform schools. This project was an observational study of classrooms with a stratified random sample of the first six cohorts of reform schools. Specifically, 156 classrooms were observed in 29…
A Nationwide Epidemiologic Modeling Study of LD: Risk, Protection, and Unintended Impact
ERIC Educational Resources Information Center
McDermott, Paul A.; Goldberg, Michelle M.; Watkins, Marley W.; Stanley, Jeanne L.; Glutting, Joseph J.
2006-01-01
Through multiple logistic regression modeling, this article explores the relative importance of risk and protective factors associated with learning disabilities (LD). A representative national sample of 6- to 17-year-old students (N = 1,268) was drawn by random stratification and classified by the presence versus absence of LD in reading,…
Characteristics and Clinical Practices of Marriage and Family Therapists: A National Survey
ERIC Educational Resources Information Center
Northey, William F., Jr.
2002-01-01
This report presents data from a telephone survey of a randomly selected sample of 292 marriage and family therapists (MFTs) who were Clinical Members of the American Association for Marriage and Family Therapy. The study, designed to better understand the current state of the field of MFT, provides descriptive data on the demographic…
ERIC Educational Resources Information Center
VanDeusen, Karen M.; Way, Ineke
2006-01-01
This study examined vicarious trauma effects in male and female clinicians who treat sexual abuse survivors (n = 111) and sexual offenders (n = 272). The national survey was conducted using a random sample of clinical members of two professional organizations. Analyses tested the relationships between demographic variables, maltreatment history,…
Highlights of the national evaluation of the Forest Stewardship Planning Program
R.J. Moulton; J.D. Esseks
2001-01-01
In 1998 and 1999, a nationwide random sample of 1238 nonindustrial private (NIPF) landowners with approved multiple resource Forest Stewardship Plans were interviewed to determine if this program is meeting its Congressional mandate of promoting sustainable management of forest resources on NIPF ownerships. It was found that two-thirds of program participants had never...
ERIC Educational Resources Information Center
Coaston, Susannah C.
2013-01-01
The purpose of this study was to explore experience of burnout in Counselor Education faculty. A national sample of Counselor Educators were randomly selected to participate anonymously in the online study. Participants completed the Maslach Burnout Inventory-General Survey (MBI-GS) which measures the three dimensions of burnout: exhaustion,…
Third and Fourth Grade Teacher's Classroom Practices in Writing: A National Survey
ERIC Educational Resources Information Center
Brindle, Mary; Graham, Steve; Harris, Karen R.; Hebert, Michael
2016-01-01
A random sample of teachers in grades 3 and 4 (N = 157) from across the United States were surveyed about their use of evidence-based writing practices, preparation to teach writing, and beliefs about writing. Teachers' beliefs included their efficacy to teach writing, their orientations to teach writing, their attitude about teaching writing, and…
ERIC Educational Resources Information Center
Kelly, Bridget; Margolis, Marjorie; McCormack, Lauren; LeBaron, Patricia A.; Chowdhury, Dhuly
2017-01-01
The literature on factors that influence participation in qualitative research is lacking. We conducted an experiment with a nationally representative sample to test the impact of different incentive types and amounts on willingness to participate in a hypothetical qualitative interview. We randomized participants from an online panel to one of…
Women Students at Coeducational and Women's Colleges: How Do Their Experiences Compare?
ERIC Educational Resources Information Center
Kinzie, Jillian L.; Thomas, Auden D.; Palmer, Megan M.; Umbach, Paul D.; Kuh, George D.
2007-01-01
This study compared the experiences of women attending women's colleges with those of women attending coeducational institutions. Analyses of data from the National Survey of Student Engagement (NSSE) from random samples of female first-year and senior students from 26 women's colleges and 264 other four-year institutions were conducted. Women at…
On the importance of incorporating sampling weights in ...
Occupancy models are used extensively to assess wildlife-habitat associations and to predict species distributions across large geographic regions. Occupancy models were developed as a tool to properly account for imperfect detection of a species. Current guidelines on survey design requirements for occupancy models focus on the number of sample units and the pattern of revisits to a sample unit within a season. We focus on the sampling design or how the sample units are selected in geographic space (e.g., stratified, simple random, unequal probability, etc). In a probability design, each sample unit has a sample weight which quantifies the number of sample units it represents in the finite (oftentimes areal) sampling frame. We demonstrate the importance of including sampling weights in occupancy model estimation when the design is not a simple random sample or equal probability design. We assume a finite areal sampling frame as proposed for a national bat monitoring program. We compare several unequal and equal probability designs and varying sampling intensity within a simulation study. We found the traditional single season occupancy model produced biased estimates of occupancy and lower confidence interval coverage rates compared to occupancy models that accounted for the sampling design. We also discuss how our findings inform the analyses proposed for the nascent North American Bat Monitoring Program and other collaborative synthesis efforts that propose h
Contaminants in fish tissue from US lakes and reservoirs: a national probabilistic study.
Stahl, Leanne L; Snyder, Blaine D; Olsen, Anthony R; Pitt, Jennifer L
2009-03-01
An unequal probability design was used to develop national estimates for 268 persistent, bioaccumulative, and toxic chemicals in fish tissue from lakes and reservoirs of the conterminous United States (excluding the Laurentian Great Lakes and Great Salt Lake). Predator (fillet) and bottom-dweller (whole body) composites were collected from 500 lakes selected randomly from the target population of 147,343 lakes in the lower 48 states. Each of these composite types comprised nationally representative samples whose results were extrapolated to the sampled population of an estimated 76,559 lakes for predators and 46,190 lakes for bottom dwellers. Mercury and PCBs were detected in all fish samples. Dioxins and furans were detected in 81% and 99% of predator and bottom-dweller samples, respectively. Cumulative frequency distributions showed that mercury concentrations exceeded the EPA 300 ppb mercury fish tissue criterion at nearly half of the lakes in the sampled population. Total PCB concentrations exceeded a 12 ppb human health risk-based consumption limit at nearly 17% of lakes, and dioxins and furans exceeded a 0.15 ppt (toxic equivalent or TEQ) risk-based threshold at nearly 8% of lakes in the sampled population. In contrast, 43 target chemicals were not detected in any samples. No detections were reported for nine organophosphate pesticides, one PCB congener, 16 polycyclic aromatic hydrocarbons, or 17 other semivolatile organic chemicals.
Yang, Z Janet; McComas, Katherine A; Gay, Geri K; Leonard, John P; Dannenberg, Andrew J; Dillon, Hildy
2012-01-01
This study extends a risk information seeking and processing model to explore the relative effect of cognitive processing strategies, positive and negative emotions, and normative beliefs on individuals' decision making about potential health risks. Most previous research based on this theoretical framework has examined environmental risks. Applying this risk communication model to study health decision making presents an opportunity to explore theoretical boundaries of the model, while also bringing this research to bear on a pressing medical issue: low enrollment in clinical trials. Comparative analysis of data gathered from 2 telephone surveys of a representative national sample (n = 500) and a random sample of cancer patients (n = 411) indicated that emotions played a more substantive role in cancer patients' decisions to enroll in a potential trial, whereas cognitive processing strategies and normative beliefs had greater influences on the decisions of respondents from the national sample.
Vitiello, Benedetto; Shader, Richard I; Parker, Corette B; Ritz, Louise; Harlan, William; Greenblatt, David J; Gadde, Kishore M; Krishnan, K Ranga R; Davidson, Jonathan R T
2005-06-01
A previously reported clinical trial of Hypericum perforatum (St John's wort) in depression did not demonstrate efficacy. We assessed treatment adherence by measuring plasma hyperforin and evaluated the possible impact of adherence on study results. Outpatients with major depression (N = 340) were randomized to an 8-week trial of H. perforatum (900-1500 mg/d), sertraline (50-100 mg/d) as active comparator, or placebo. Plasma was available from 292 patients (86% of randomized). Samples from the placebo and H. perforatum groups were assayed for hyperforin, and samples from the sertraline group for sertraline/N-desmethyl-sertraline. Of the 104 patients randomized to placebo, 18 (17%) had detectable plasma hyperforin. Of the 97 patients randomized to H. perforatum, 17 (17%) had no detectable plasma hyperforin. All the assayed sertraline patients (N = 91) had plasma sertraline/N-desmethyl-sertraline. The clinical trial conclusions remained unchanged when only patients with plasma assay consistent with random assignment were included in the analyses. One of every 6 patients assigned to placebo had plasma hyperforin, and 1 of every 6 patients assigned to H. perforatum had no detectable plasma hyperforin. The finding underscores the difficulty of enforcing treatment adherence in clinical trials of preparations that are readily available in the community.
Pathological video-game use among youth ages 8 to 18: a national study.
Gentile, Douglas
2009-05-01
Researchers have studied whether some youth are "addicted" to video games, but previous studies have been based on regional convenience samples. Using a national sample, this study gathered information about video-gaming habits and parental involvement in gaming, to determine the percentage of youth who meet clinical-style criteria for pathological gaming. A Harris poll surveyed a randomly selected sample of 1,178 American youth ages 8 to 18. About 8% of video-game players in this sample exhibited pathological patterns of play. Several indicators documented convergent and divergent validity of the results: Pathological gamers spent twice as much time playing as nonpathological gamers and received poorer grades in school; pathological gaming also showed comorbidity with attention problems. Pathological status significantly predicted poorer school performance even after controlling for sex, age, and weekly amount of video-game play. These results confirm that pathological gaming can be measured reliably, that the construct demonstrates validity, and that it is not simply isomorphic with a high amount of play.
Delzer, Gregory C.; Ivahnenko, Tamara
2003-01-01
The large-scale use of the gasoline oxygenate methyl tert-butyl ether (MTBE), and its high solubility, low soil adsorption, and low biodegradability, has resulted in its detection in ground water and surface water in many places throughout the United States. Studies by numerous researchers, as well as many State and local environmental agencies, have discovered high levels of MTBE in soils and ground water at leaking underground gasoline-storage-tank sites and frequent occurrence of low to intermediate levels of MTBE in reservoirs used for both public water supply and recreational boating.In response to these findings, the American Water Works Association Research Foundation sponsored an investigation of MTBE and other volatile organic compounds (VOCs) in the Nation?s sources of drinking water. The goal of the investigation was to provide additional information on the frequency of occurrence, concentration, and temporal variability of MTBE and other VOCs in source water used by community water systems (CWSs). The investigation was completed in two stages: (1) reviews of available literature and (2) the collection of new data. Two surveys were associated with the collection of new data. The first, termed the Random Survey, employed a statistically stratified design for sampling source water from 954 randomly selected CWSs. The second, which is the focus of this report, is termed the Focused Survey, which included samples collected from 134 CWS source waters, including ground water, reservoirs, lakes, rivers, and streams, that were suspected or known to contain MTBE. The general intent of the Focused Survey was to compare results with the Random Survey and provide an improved understanding of the occurrence, concentration, temporal variability, and anthropogenic factors associated with frequently detected VOCs. Each sample collected was analyzed for 66 VOCs, including MTBE and three other ether gasoline oxygenates (hereafter termed gasoline oxygenates). As part of the Focused Survey, 451 source-water samples and 744 field quality-control (QC) samples were collected from 78 ground-water, 39 reservoir and (or) lake, and 17 river and (or) stream source waters at fixed intervals for a period of 1 year.Using a common assessment level of 0.2 ?g/L (micrograms per liter) (2.0 ?g/L for methyl ethyl ketone), 37 of the 66 VOCs analyzed were detected in both surveys. However, VOCs, especially MTBE and other gasoline oxygenates, were detected more frequently in the Focused Survey than in the Random Survey. MTBE was detected in 55.5 percent of the CWSs sampled in the Focused Survey and in 8.7 percent of those sampled in the Random Survey. Little difference in occurrence, however, was observed for trihalomethanes (THMs), which were detected in 16.4 and 14.8 percent of Focused Survey and The large-scale use of the gasoline oxygenate methyl tert-butyl ether (MTBE), and its high solubility, low soil adsorption, and low biodegradability, has resulted in its detection in ground water and surface water in many places throughout the United States. Studies by numerous researchers, as well as many State and local environmental agencies, have discovered high levels of MTBE in soils and ground water at leaking underground gasoline-storage-tank sites and frequent occurrence of low to intermediate levels of MTBE in reservoirs used for both public water supply and recreational boating.In response to these findings, the American Water Works Association Research Foundation sponsored an investigation of MTBE and other volatile organic compounds (VOCs) in the Nation?s sources of drinking water. The goal of the investigation was to provide additional information on the frequency of occurrence, concentration, and temporal variability of MTBE and other VOCs in source water used by community water systems (CWSs). The investigation was completed in two stages: (1) reviews of available literature and (2) the collection of new data. Two surveys wer
Depression among Couples in the United States in the Context of Intimate Partner Violence
ERIC Educational Resources Information Center
Vaeth, Patrice A. C.; Ramisetty-Mikler, Suhasini; Caetano, Raul
2010-01-01
This paper examines the relationship between intimate partner violence and depression. A multicluster random household sample of U.S. couples was interviewed as part of a five-year national longitudinal study (response rate = 72%). Depression was assessed with the CES-D. The multivariate analyses for men showed that the odds of depression did not…
High School Teachers Use of Writing to Support Students' Learning: A National Survey
ERIC Educational Resources Information Center
Gillespie, Amy; Graham, Steve; Kiuhara, Sharlene; Hebert, Michael
2014-01-01
A random sample of language arts, social studies, science, and math high school teachers from across the United States were surveyed about their use of writing to support student learning. Four out of every five teachers reported they used writing to support student learning, applying on average 24 different writing activities across the school…
ERIC Educational Resources Information Center
Hinnerich, Bjorn Tyrefors; Höglin, Erik; Johannesson, Magnus
2015-01-01
We rigorously test for discrimination against students with foreign backgrounds in high school grading in Sweden. We analyse a random sample of national tests in the Swedish language graded both non-blindly by the student's own teacher and blindly without any identifying information. The increase in the test score due to non-blind grading is…
ERIC Educational Resources Information Center
Adams, Russell; Kalliny, Morris; Saran, Anshu; de los Santos, Gilberto
2005-01-01
Increasing shifts in population proportions have led to an increasing demand on education institutions to recruit Hispanics. A random and stratified national sample was used to answer the following questions: (1) What are the psychographic typologies that are likely to identify Hispanic students by their desire to pursue or not to pursue graduate…
ERIC Educational Resources Information Center
Aggarwal, Vishal R.; Joughin, Amy; Zakrzewska, Joanna; Appelbe, Priscilla; Tickle, Martin
2012-01-01
Aim: To explore the diagnosis, treatment and referral patterns of chronic oro-facial pain patients by generalist primary care dentists (GDPs) in the UK. Methods: A cross-sectional survey was conducted using a non-stratified random sample of 500 GDPs who were selected from the General Dental Council register. A self-complete postal questionnaire…
Effects of Two Modes of Exercise Training on Physical Fitness of 10 Year-Old Children
ERIC Educational Resources Information Center
Ribeiro, Ligia G. dos Santos Chaves; Portal, Maria de Nazare Dias; da Silva, Joao Bittencourt; Saraiva, Alan; da Cruz Monte, Gerson, Jr.; Dantas, Estelio H. M.
2010-01-01
Study aim: To compare two exercise training modes on the physical fitness of 10 year-old children. Material and methods: A sample of 60 schoolboys aged 10 years were randomly divided into 3 groups: Traditional (TG), trained according to the Brazilian national curricular parameters, Maturational (MG), in which the degree of difficulty of the…
Addressing Inadequacies of the Observation Survey of Early Literacy Achievement
ERIC Educational Resources Information Center
D'Agostino, Jerome V.; Rodgers, Emily; Mauck, Susan
2018-01-01
The authors used nationally based, random sample data from three different years (2009-2010, 2011-2012, and 2014-2015) for nearly 20,000 first-grade students (n = 9,760, 3,657, and 3,121, respectively) to examine long-reported inadequacies of a commonly used early literacy assessment tool, the Observation Survey of Early Literacy Achievement…
Assessing change in large-scale forest area by visually interpreting Landsat images
Jerry D. Greer; Frederick P. Weber; Raymond L. Czaplewski
2000-01-01
As part of the Forest Resources Assessment 1990, the Food and Agriculture Organization of the United Nations visually interpreted a stratified random sample of 117 Landsat scenes to estimate global status and change in tropical forest area. Images from 1980 and 1990 were interpreted by a group of widely experienced technical people in many different tropical countries...
Wisconsin Youth Risk Behavior Survey. Executive Summary and Report.
ERIC Educational Resources Information Center
Sloan, Matt
The 1999 Wisconsin Youth Risk Behavior Survey (YRBS) was conducted as part of a national survey effort by the U.S. Centers for Disease Control and Prevention. A stratified random sample of classrooms in all public schools with ninth through twelfth grades was taken. The YRBS was administered to 1,336 students in 46 public schools in Wisconsin in…
Exploring the Possibility and Potential for Pay for Performance in America's Public Schools
ERIC Educational Resources Information Center
Ellerson, Noelle M.
2009-01-01
In response to a growing dialogue at the local, state and national levels around the idea of restructuring teacher pay to include performance measures, the American Association of School Administrators surveyed a randomly selected sample of its members to gauge their feedback and interest in pay-for-performance programs. AASA launched this survey…
Foodservice trends in the elderly nutrition program.
Balsam, A L; Rogers, B L
1989-01-01
The foodservice delivery aspects of the federally-funded Elderly Nutrition Program (ENP) were examined via an original survey instrument sent to a random sample of nutrition projects nationally. In comparison to a similar survey conducted a decade ago, projects were more apt to rely on a combination of foodservice mechanisms including caterer contracts, on-site preparation, and use of central kitchens.
Paying for College: Trends in Student Financial Aid at Independent Colleges and Universities.
ERIC Educational Resources Information Center
Thrift, Julianne Still; Toppe, Christopher M.
Sources of funds for students at private colleges are assessed, along with major changes in student financial aid during 1979-1984, based on the Student Aid Recipient Data Bank of the National Institute of Independent Colleges and Universities. A random sample of actual student financial aid records was examined in order to show how aid is…
The Effect of Observing Parental Violence on Gender-Role Attitudes.
ERIC Educational Resources Information Center
Ulbrich, Patricia; Huber, Joan
Results of a study to determine the effect of observing parental violence on attitudes about women's roles and the use of violence against women are reported. A national random sample of 1,092 women and 910 men were interviewed by telephone. Participants responded to questions such as: Did your father ever hit your mother? Did your mother ever hit…
The Missing Link: Workplace Education in Small Business.
ERIC Educational Resources Information Center
BCEL Newsletter for the Business & Literacy Communities, 1992
1992-01-01
A study sought to determine how and why small businesses invest or do not invest in basic skills instruction for their workers. Data were gathered through a national mail and telephone survey of a random sampling of 11,000 small (50 or fewer employees) and medium-sized (51-400 employees) firms, a targeted mail survey of 4,317 manufacturers, a…
A Study on Primary School Teacher Burnout Levels: The Northern Cyprus Case
ERIC Educational Resources Information Center
Ozan, Mukadder Boydak
2009-01-01
The study population included the 1482 teachers who were working at the 98 schools affiliated to the Ministry of National Education and Culture in Lefkosa, Girne, Gazimagusa and Guzelyurt during the 2007-2008 academic year. The sample comprised 196 teachers from 14 of these schools which were selected randomly. Data was collected by using the (1)…
ERIC Educational Resources Information Center
Sweeney, Sophia Jean
2010-01-01
A researcher-developed questionnaire regarding the importance and developmental appropriateness of 12 specific elements of the nature of science (Alshamrani, 2008) for early elementary (kindergarten through fourth grade [K-4]) science instruction was mailed to a random sample of U.S. K-4 teachers. At least half (N = 377) of the respondents…
ERIC Educational Resources Information Center
Rosenberg, Sarah; Silva, Elena
2012-01-01
Over the past decade, teachers have seen changes in both their conditions of employment--from pay to retirement benefits--and their practice. Far too often, these policies have been made by people who talk "about" teachers, rather than talking "to" them. Last fall, Education Sector surveyed a nationally representative random sample of more than…
Haggard, Megan C; Kang, Linda L; Rowatt, Wade C; Shen, Megan Johnson
2015-01-01
The connection between religiousness and volunteering for the community can be explained through two distinct features of religion. First, religious organizations are social groups that encourage members to help others through planned opportunities. Second, helping others is regarded as an important value for members in religious organizations to uphold. We examined the relationship between religiousness and self-reported community volunteering in two independent national random surveys of American adults (i.e., the 2005 and 2007 waves of the Baylor Religion Survey). In both waves, frequency of religious service attendance was associated with an increase in likelihood that individuals would volunteer, whether through their religious organization or not, whereas frequency of reading sacred texts outside of religious services was associated with an increase in likelihood of volunteering only for or through their religious organization. The role of religion in community volunteering is discussed in light of these findings.
Le Maréchal, M; Collange, F; Fressard, L; Peretti-Watel, P; Sebbah, R; Mikol, F; Agamaliyev, E; Gautier, A; Pulcini, C; Verger, P
2015-10-01
France is currently facing a vaccine-hesitancy crisis. We conducted a questionnaire-based telephone interview with a large sample of general practitioners (GPs) as they play a crucial role in the vaccination process. Our main objectives were to study the GPs' vaccination behaviors when it comes to their own vaccination and that of their relatives, and the vaccine recommendations made to their patients. We also aimed to understand their opinion related to the severity of vaccine-preventable diseases and to assess their trust in various sources of information. Finally, we enquired about their opinion in terms of vaccination-related tools that could help them in their daily practice. The article aimed to present the design of this panel and survey. Four samples of GPs (one national and three regional) were selected among all the French GPs (metropolitan France) using random sampling. Five cross-sectional surveys should be conducted with that panel. The mean targeted sample size is 2350 GPs for each survey. The survey dedicated to vaccination was conducted by telephone or on the Internet. GPs were included in the survey between December 2013 and February 2014. The national sample included 1582 GPs (response rate: 46%) and the three regional samples included 1297 GPs (response rate: 44%). The survey dedicated to vaccination was conducted between April and July 2014; the national sample response rate was 92% (1582/1712). The results of the first wave of surveys, conducted on a large sample of French GPs, provide important information to guide the French vaccination policy. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
The Prevalence of Four Types of Childhood Maltreatment in Denmark
Christoffersen, Mogens N; Armour, Cherie; Lasgaard, Mathias; Andersen, Tonny E; Elklit, Ask
2013-01-01
Objectives: To estimate the prevalence of four types of childhood maltreatment in Denmark while taking into considerations how each of the types of maltreatment vary as a function of gender or child-protection status. Methods: Data were collected from a Danish national study conducted by The Danish National Centre for Social Research in 2008 and 2009. The study used a stratified random probability sample of young people aged 24 years. A sample of 4718 young adults were randomly selected by Statistics Denmark using the total birth cohort of all children born in 1984. The response rate was 63% leaving a total effective sample size of 2980. A structured residential or telephone interview enquired about a range of respondents maltreatment experiences. Results: Maltreatment is experienced by a significant proportion of Danish children. The reported prevalence rates were; physical neglect (3.0%), emotional abuse (5.2%), physical abuse (5.4%) and sexual abuse (3.4%). All trauma types were experienced by a greater percentage of females compared to males with the exception of physical abuse and all trauma types were experienced by a greater percentage of children given child-protection status. Conclusions: Female children and children who are given child protection status are those most at risk for experiencing maltreatment in Denmark. However, variability in prevalence rates of maltreatment across studies is problematic. Methodological variations and variation in abuse definitions may be partly attributable. PMID:24155769
Karoly, Paul; Ruehlman, Linda S.
2005-01-01
A heterogeneous national sample of adults (mean age = 40 years) employed in management positions was contacted by random digit dialing procedures and interviewed about current pain experience, work-goal cognitions, and psychological status (depression and anxiety). In accord with predictions, persistent pain experience was differentially related to the construal of work-related goals. Specifically, individuals with both persistent and episodic pain (relative to those with no pain) reported lower levels of goal-centered value, self-efficacy, and positive arousal and heightened perceptions of goal-based self-criticism, negative arousal, and conflict between work and nonwork goals. Furthermore, regression analyses revealed that goal cognition accounted for unique variance in depression and anxiety over and above the contribution of pain chronicity. PMID:8891717
Westen, Drew; Shedler, Jonathan; Bradley, Bekh; DeFife, Jared A.
2013-01-01
Objective The authors describe a system for diagnosing personality pathology that is empirically derived, clinically relevant, and practical for day-to-day use. Method A random national sample of psychiatrists and clinical psychologists (N=1,201) described a randomly selected current patient with any degree of personality dysfunction (from minimal to severe) using the descriptors in the Shedler-Westen Assessment Procedure–II and completed additional research forms. Results The authors applied factor analysis to identify naturally occurring diagnostic groupings within the patient sample. The analysis yielded 10 clinically coherent personality diagnoses organized into three higher-order clusters: internalizing, externalizing, and borderline-dysregulated. The authors selected the most highly rated descriptors to construct a diagnostic prototype for each personality syndrome. In a second, independent sample, research interviewers and patients’ treating clinicians were able to diagnose the personality syndromes with high agreement and minimal comorbidity among diagnoses. Conclusions The empirically derived personality prototypes described here provide a framework for personality diagnosis that is both empirically based and clinically relevant. PMID:22193534
Humphreys, Keith; Blodgett, Janet C.; Wagner, Todd H.
2014-01-01
Background Observational studies of Alcoholics Anonymous’ (AA) effectiveness are vulnerable to self-selection bias because individuals choose whether or not to attend AA. The present study therefore employed an innovative statistical technique to derive a selection bias-free estimate of AA’s impact. Methods Six datasets from 5 National Institutes of Health-funded randomized trials (one with two independent parallel arms) of AA facilitation interventions were analyzed using instrumental variables models. Alcohol dependent individuals in one of the datasets (n = 774) were analyzed separately from the rest of sample (n = 1582 individuals pooled from 5 datasets) because of heterogeneity in sample parameters. Randomization itself was used as the instrumental variable. Results Randomization was a good instrument in both samples, effectively predicting increased AA attendance that could not be attributed to self-selection. In five of the six data sets, which were pooled for analysis, increased AA attendance that was attributable to randomization (i.e., free of self-selection bias) was effective at increasing days of abstinence at 3-month (B = .38, p = .001) and 15-month (B = 0.42, p = .04) follow-up. However, in the remaining dataset, in which pre-existing AA attendance was much higher, further increases in AA involvement caused by the randomly assigned facilitation intervention did not affect drinking outcome. Conclusions For most individuals seeking help for alcohol problems, increasing AA attendance leads to short and long term decreases in alcohol consumption that cannot be attributed to self-selection. However, for populations with high pre-existing AA involvement, further increases in AA attendance may have little impact. PMID:25421504
Humphreys, Keith; Blodgett, Janet C; Wagner, Todd H
2014-11-01
Observational studies of Alcoholics Anonymous' (AA) effectiveness are vulnerable to self-selection bias because individuals choose whether or not to attend AA. The present study, therefore, employed an innovative statistical technique to derive a selection bias-free estimate of AA's impact. Six data sets from 5 National Institutes of Health-funded randomized trials (1 with 2 independent parallel arms) of AA facilitation interventions were analyzed using instrumental variables models. Alcohol-dependent individuals in one of the data sets (n = 774) were analyzed separately from the rest of sample (n = 1,582 individuals pooled from 5 data sets) because of heterogeneity in sample parameters. Randomization itself was used as the instrumental variable. Randomization was a good instrument in both samples, effectively predicting increased AA attendance that could not be attributed to self-selection. In 5 of the 6 data sets, which were pooled for analysis, increased AA attendance that was attributable to randomization (i.e., free of self-selection bias) was effective at increasing days of abstinence at 3-month (B = 0.38, p = 0.001) and 15-month (B = 0.42, p = 0.04) follow-up. However, in the remaining data set, in which preexisting AA attendance was much higher, further increases in AA involvement caused by the randomly assigned facilitation intervention did not affect drinking outcome. For most individuals seeking help for alcohol problems, increasing AA attendance leads to short- and long-term decreases in alcohol consumption that cannot be attributed to self-selection. However, for populations with high preexisting AA involvement, further increases in AA attendance may have little impact. Copyright © 2014 by the Research Society on Alcoholism.
Attitudes towards smoking restrictions and tobacco advertisement bans in Georgia.
Bakhturidze, George D; Mittelmark, Maurice B; Aarø, Leif E; Peikrishvili, Nana T
2013-11-25
This study aims to provide data on a public level of support for restricting smoking in public places and banning tobacco advertisements. A nationally representative multistage sampling design, with sampling strata defined by region (sampling quotas proportional to size) and substrata defined by urban/rural and mountainous/lowland settlement, within which census enumeration districts were randomly sampled, within which households were randomly sampled, within which a randomly selected respondent was interviewed. The country of Georgia, population 4.7 million, located in the Caucasus region of Eurasia. One household member aged between 13 and 70 was selected as interviewee. In households with more than one age-eligible person, selection was carried out at random. Of 1588 persons selected, 14 refused to participate and interviews were conducted with 915 women and 659 men. Respondents were interviewed about their level of agreement with eight possible smoking restrictions/bans, used to calculate a single dichotomous (agree/do not agree) opinion indicator. The level of agreement with restrictions was analysed in bivariate and multivariate analyses by age, gender, education, income and tobacco use status. Overall, 84.9% of respondents indicated support for smoking restrictions and tobacco advertisement bans. In all demographic segments, including tobacco users, the majority of respondents indicated agreement with restrictions, ranging from a low of 51% in the 13-25 age group to a high of 98% in the 56-70 age group. Logistic regression with all demographic variables entered showed that agreement with restrictions was higher with age, and was significantly higher among never smokers as compared to daily smokers. Georgian public opinion is normatively supportive of more stringent tobacco-control measures in the form of smoking restrictions and tobacco advertisement bans.
Fazeli Dehkordy, Soudabeh; Hall, Kelli S; Dalton, Vanessa K; Carlos, Ruth C
2016-10-01
Research has not adequately examined the potential negative effects of perceiving routine discrimination on general healthcare utilization or health status, especially among reproductive-aged women. We sought to evaluate the association between everyday discrimination, health service use, and perceived health among a national sample of women in the United States. Data were drawn from the Women's Healthcare Experiences and Preferences survey, a randomly selected, national probability sample of 1078 U.S. women aged 18-55 years. We examined associations between everyday discrimination (via a standardized scale) on frequency of health service utilization and perceived general health status using chi-square and multivariable logistic regression modeling. Compared with women who reported healthcare visits every 3 years or less (reference group), each one-point increase in discrimination score was associated with higher odds of having healthcare visits annually or more often (odds ratio [OR] = 1.36, confidence interval [95% CI] = 1.01-1.83). Additionally, each one-point increase in discrimination score was significantly associated with lower odds of having excellent/very good perceived health (OR = 0.65; 95% CI = 0.54-0.80). Perceived discrimination was associated with increased exposure to the healthcare setting among this national sample of women. Perceived discrimination was also inversely associated with excellent/very good perceived health status.
[Observation on gene polymorphism of Rh blood group in Chinese Han nationality].
Lan, Jiong-Cai; Wang, Cong-Rong; Wei, Ya-Ming; Zhou, Hua-You; Cao, Qiong; Zhang, Yin-Ze; Jiang, KuReXi; Wu, Da-Lin; Liu, Zhong
2003-12-01
To observe the gene polymorphism of Rh blood group in unrelated random individuals and families for Chinese Han nationality, polymerase chain reaction-sequence specific primer (PCR-SSP) was used to amplify the Rh C/E gene, RhD gene, exons, intron 2 and 10, insert and Rh Box in 160 blood samples of RhD positive unrelated individuals and 71 samples of RhD negative unrelated individuals and 7 samples of families whose probands were RhD-negative. The results showed that RhD genes of RhD-negative individuals with C antigens were polymorphism, three forms were found for D exon including intact, partial deletion and complete deletion exons. Insert fragments and Rh Box were found in most cases of families whose probands were RhD-negative and its inheritance accorded with the Mendel's Law, and it did not affect the expression of RhD gene. "Normal" RhD exon 4 amplifying product was not found in all of the samples. It was concluded that gene structure of the RhD-negative in Chinese was polymorphism, intact, partial deletion and complete deletion exons were found in the individuals with C antigen and probably existed specific D (nf) Ce haplotype. The function of insert was uncertain. The Rh gene sequences of Chinese Han nationality are different from those of Caucasian and the Rh gene library based on Han nationality should be established.
Abdel Rahman, Mohamed F.; Hashad, Ingy M.; Abdel-Maksoud, Sahar M.; Farag, Nabil M.; Abou-Aisha, Khaled
2012-01-01
Aim: The aim of this study was to detect endothelial nitric oxide synthase (eNOS) Glu298Asp gene variants in a random sample of the Egyptian population, compare it with those from other populations, and attempt to correlate these variants with serum levels of nitric oxide (NO). The association of eNOS genotypes or serum NO levels with the incidence of acute myocardial infarction (AMI) was also examined. Methods: One hundred one unrelated healthy subjects and 104 unrelated AMI patients were recruited randomly from the 57357 Hospital and intensive care units of El Demerdash Hospital and National Heart Institute, Cairo, Egypt. eNOS genotypes were determined by polymerase chain reaction–restriction fragment length polymorphism. Serum NO was determined spectrophotometrically. Results: The genotype distribution of eNOS Glu298Asp polymorphism determined for our sample was 58.42% GG (wild type), 33.66% GT, and 7.92% TT genotypes while allele frequencies were 75.25% and 24.75% for G and T alleles, respectively. No significant association between serum NO and specific eNOS genotype could be detected. No significant correlation between eNOS genotype distribution or allele frequencies and the incidence of AMI was observed. Conclusion: The present study demonstrated the predominance of the homozygous genotype GG over the heterozygous GT and homozygous TT in random samples of Egyptian population. It also showed the lack of association between eNOS genotypes and mean serum levels of NO, as well as the incidence of AMI. PMID:22731641
Hahs-Vaughn, Debbie L; McWayne, Christine M; Bulotsky-Shearer, Rebecca J; Wen, Xiaoli; Faria, Ann-Marie
2011-06-01
Complex survey data are collected by means other than simple random samples. This creates two analytical issues: nonindependence and unequal selection probability. Failing to address these issues results in underestimated standard errors and biased parameter estimates. Using data from the nationally representative Head Start Family and Child Experiences Survey (FACES; 1997 and 2000 cohorts), three diverse multilevel models are presented that illustrate differences in results depending on addressing or ignoring the complex sampling issues. Limitations of using complex survey data are reported, along with recommendations for reporting complex sample results. © The Author(s) 2011
NASA Technical Reports Server (NTRS)
Strahler, A. H.; Woodcock, C. E.; Logan, T. L.
1983-01-01
A timber inventory of the Eldorado National Forest, located in east-central California, provides an example of the use of a Geographic Information System (GIS) to stratify large areas of land for sampling and the collection of statistical data. The raster-based GIS format of the VICAR/IBIS software system allows simple and rapid tabulation of areas, and facilitates the selection of random locations for ground sampling. Algorithms that simplify the complex spatial pattern of raster-based information, and convert raster format data to strings of coordinate vectors, provide a link to conventional vector-based geographic information systems.
Slater, Michael D; Long, Marilee; Ford, Valerie L
2006-11-01
The present study seeks to establish the extent to which media coverage acknowledges alcohol's contribution to violent crime as well as to motor vehicle injuries and other injury incidents. The study content-analyzes a unique sample, closely approximating national representativeness, of local and national television news, local newspapers, and national magazines randomly sampled during a 2-year period. Alcohol's role in violent crime and, to a lesser extent, in motor vehicle and other injury incidents is underreported relative to available estimates regarding alcohol-attributable fractions. Relative frequency of various news frames for coverage of alcohol and illegal drugs and differences in coverage of alcohol and illegal drugs as a function of the type of story and news medium are described. The underreporting in the United States of alcohol's contribution to serious and fatal injury from these causes may reduce public perceptions of alcohol-related risks, potentially influencing behavior, including public support of alcohol-control policies. This provides an opportunity for media-advocacy approaches to improve public health content of news coverage.
Lv, Shan; Zhang, Yi; Liu, He-Xiang; Hu, Ling; Yang, Kun; Steinmann, Peter; Chen, Zhao; Wang, Li-Ying; Utzinger, Jürg; Zhou, Xiao-Nong
2009-01-01
Background Eosinophilic meningitis (angiostrongyliasis) caused by Angiostrongylus cantonensis is emerging in mainland China. However, the distribution of A. cantonensis and its intermediate host snails, and the role of two invasive snail species in the emergence of angiostrongyliasis, are not well understood. Methodology/Principal Findings A national survey pertaining to A. cantonensis was carried out using a grid sampling approach (spatial resolution: 40×40 km). One village per grid cell was randomly selected from a 5% random sample of grid cells located in areas where the presence of the intermediate host snail Pomacea canaliculata had been predicted based on a degree-day model. Potential intermediate hosts of A. cantonensis were collected in the field, restaurants, markets and snail farms, and examined for infection. The infection prevalence among intermediate host snails was estimated, and the prevalence of A. cantonensis within P. canaliculata was displayed on a map, and predicted for non-sampled locations. It was confirmed that P. canaliculata and Achatina fulica were the predominant intermediate hosts of A. cantonensis in China, and these snails were found to be well established in 11 and six provinces, respectively. Infected snails of either species were found in seven provinces, closely matching the endemic area of A. cantonensis. Infected snails were also found in markets and restaurants. Two clusters of A. cantonensis–infected P. canaliculata were predicted in Fujian and Guangxi provinces. Conclusions/Significance The first national survey in China revealed a wide distribution of A. cantonensis and two invasive snail species, indicating that a considerable number of people are at risk of angiostrongyliasis. Health education, rigorous food inspection and surveillance are all needed to prevent recurrent angiostrongyliasis outbreaks. PMID:19190771
Ben-Zur, Hasida; Gilbar, Ora
2011-10-01
Resilience and distress in Israeli society were assessed at three points in time: before and after the Israeli disengagement from Gaza, and after the second Lebanese war. A random sample of 366 Israelis was assessed for nation-related anxiety and hostility, personal resources and post-traumatic symptoms. The lowest levels of anxiety were observed at the second time point, after the disengagement. Respondents with high-resilience profiles showed lower levels of post-traumatic symptoms and higher levels of personal resources. The findings underscore Israelis' resilience and the importance of personal resources in ongoing nationally stressful situations.
ERIC Educational Resources Information Center
McRoy, James J.
The content of essays written by randomly selected samples of 1500 U.S. and 500 British secondary students on the topic "What have I learned about Adolf Hitler?" were partitioned into theme-related assertions and analyzed. An experimental group of 150 9th- and 11th-grade male students who had studied the Holocaust also contributed papers…
ERIC Educational Resources Information Center
Ng, Daniel; Supaporn, Potibut
A study investigated the trend of current U.S. television commercial informativeness by comparing the results with Alan Resnik and Bruce Stern's previous benchmark study conducted in 1977. A systematic random sampling procedure was used to select viewing dates and times of commercials from the three national networks. Ultimately, a total of 550…
ERIC Educational Resources Information Center
Burke, Eilish; McCarron, Mary; Carroll, Rachael; McGlinchey, Eimear; McCallion, Philip
2014-01-01
The Intellectual Disability Supplement to The Irish Longitudinal Study on Ageing is a national longitudinal study on the aging of people with an intellectual disability (ID) using a randomly selected sample of people with ID over the age of 40. In total, 367 people with an ID completed the aging perception self-report only section. Over 57% of…
Dennis E. Ferguson; John C. Byrne
2016-01-01
The response of 28 shrub species to wildfire burn severity was assessed for 8 wildfires on 6 national forests in the northern Rocky Mountains, USA. Stratified random sampling was used to choose 224 stands based on burn severity, habitat type series, slope steepness, stand height, and stand density, which resulted in 896 plots measured at approximately 2-year intervals...
ERIC Educational Resources Information Center
Ray, Amber B.; Graham, Steve; Houston, Julia D.; Harris, Karen R.
2016-01-01
A random sample of middle school teachers (grades 6-9) from across the United States was surveyed about their use of writing to support students' learning. The selection process was stratified so there were an equal number of English language arts, social studies, and science teachers. More than one-half of the teachers reported applying 15 or…
ERIC Educational Resources Information Center
Wayne, Julie Holliday; Musisca, Nicholas; Fleeson, William
2004-01-01
Using a national, random sample (N=2130), we investigated the relationship between each of the Big Five personality traits and conflict and facilitation between work and family roles. Extraversion was related to greater facilitation between roles but was not related to conflict, whereas neuroticism was related to greater conflict but only weakly…
ERIC Educational Resources Information Center
Mu'min, Ridgely A.; And Others
There are few racial or urban/rural differences in public attitudes toward agriculture and government agricultural policies. The Farming in American Life Study, a collaborative effort by 14 land grant institutions in the South and Midwest, gathered 3,239 completed questionnaires from a national stratified random sample for a completion rate of 46…
ERIC Educational Resources Information Center
Bruce, Willa
This study empirically examined the quality of work life and job satisfaction of municipal clerks employed in cities in the United States. Questionnaires were sent to a random sample of 10 percent of the membership in the United States of the International Institute of Municipal Clerks. Results of factor analysis produced 12 distinct dimensions of…
ERIC Educational Resources Information Center
Edwards, Jane U.; Magel, Rhonda
2007-01-01
Background: The Youth Risk Behavior Survey (YRBS) was used by a city school district (approximately 11,000 students) in the upper Midwest to monitor trends for nutrition and physical activity (PA) behaviors both within and between years and to compare with national 2003 data. Methods: Independent random samples were obtained in 1999 (387 middle…
Do Children Who Bully Their Peers Also Play Violent Video Games? A Canadian National Study
ERIC Educational Resources Information Center
Dittrick, Crystal J.; Beran, Tanya N.; Mishna, Faye; Hetherington, Ross; Shariff, Shaheen
2013-01-01
The study examined whether children who bully others are likely to prefer playing video games that are rated high in maturity and violence. A stratified random sample of Canadian children ages 10 to 17 years from the provinces of Canada was obtained. Parents (n = 397) and their children (n = 492) completed an online survey of children's bullying…
Henry V. Bastian
2001-01-01
Vegetation and fuel loading plots were monitored and sampled in wilderness areas treated with prescribed fire. Changes in ponderosa pine (Pinus ponderosa) forest structure tree species and fuel loading are presented. Plots were randomly stratified and established in burn units in 1995. Preliminary analysis of nine plots 2 years after burning show litter was reduced 54....
ERIC Educational Resources Information Center
Young, I. Phillip
2005-01-01
This study addresses the screening decisions for a national random sample of high school principals as viewed from the attraction-similarity theory of interpersonal perceptions. Independent variables are the sex of principals, sex of applicants, and the type of focal positions sought by hypothetical job applicants (teacher or counselor). Dependent…
ERIC Educational Resources Information Center
Zugazaga, Carole B.; Surette, Raymond B.; Mendez, Monica; Otto, Charles W.
2006-01-01
This exploratory study describes social workers' perceptions of the depiction of the social work profession found in the news and entertainment media. A random sample of 665 MSW social workers who were members of the Florida Chapter of the National Association of Social Workers were surveyed regarding how they felt the profession was depicted in…
ERIC Educational Resources Information Center
National Science Foundation, Washington, DC. Div. of Science Resources Studies.
This report is based upon the National Science Foundation (NSF) 1975 Quick Response Survey which consisted of a stratified random sample of l,297 departments in 294 institutions (including 67 medical schools) granting a Ph.D. in science or engineering. Variables investigated were: (1) area of science, (2) full-time enrollment number, (3) part-time…
ERIC Educational Resources Information Center
Steele, Ric G.; Wu, Yelena P.; Cushing, Christopher C.; Jensen, Chad D.
2013-01-01
The goal of the current study was to assess the efficacy and acceptability of a web-based tutorial (Child Health Matters, CHM) designed to improve school nurses' communications with families about pediatric weight-related health issues. Using a randomized wait-list control design, a nationally representative sample of school nurses was assigned to…
Abdulaziz, Kasim; Brehaut, Jamie; Taljaard, Monica; Émond, Marcel; Sirois, Marie-Josée; Lee, Jacques S; Wilding, Laura; Perry, Jeffrey J
2015-01-01
Objectives Physicians are a commonly targeted group in health research surveys, but their response rates are often relatively low. The goal of this paper was to evaluate the effect of unconditional incentives in the form of a coffee card on physician postal survey response rates. Design Following 13 key informant interviews and eight cognitive interviews a survey questionnaire was developed. Participants A random sample of 534 physicians, stratified by physician group (geriatricians, family physicians, emergency physicians) was selected from a national medical directory. Setting Using computer generated random numbers; half of the physicians in each stratum were allocated to receive a coffee card to a popular national coffee chain together with the first survey mailout. Interventions The intervention was a $10 Tim Hortons gift card given to half of the physicians who were randomly allocated to receive the incentive. Results 265 (57.0%) physicians completed the survey. The response rate was significantly higher in the group allocated to receive the incentive (62.7% vs 51.3% in the control group; p=0.01). Conclusions Our results indicate that an unconditional incentive in the form of a coffee gift card can substantially improve physician response rates. Future research can look at the effect of varying amounts of cash on the gift cards on response rates. PMID:25694460
DOE Office of Scientific and Technical Information (OSTI.GOV)
Long, E.R.; Sloane, G.M.; Carr, R.S.
1997-10-01
The toxicity of sediments in Pensacola, Choctawhatcheee, St. Andrew and Apalachicola Bays was determined as part of bioeffects assessments performed by NOAA`s National Status and Trends Program. The objectives of the survey were to determine: (1) the spatial patterns in toxicity throughout each bay, (2) the spatial extent of toxicity throughout and among the bays, (3) the severity of degree of toxicity, and (4) the relationships between chemical contamination and toxicity. The survey was conducted over two years: Pensacola Bay and St. Andrew Bay were sampled in 1993; and Choctawhatchee Bay, Apalachicola Bay and Bayou Chico (a sub-basin of Pensacolamore » Bay) were sampled during 1994. Surficial sediment samples were collected from 123 randomly-chosen locations throughout the five areas. Multiple toxicity tests were conducted on all samples, and chemical analyses were performed on 102 of the 123 samples. Toxicological tests were conducted to determine survival, reproductive success, morphological development, metabolic activity, and genotoxicity; all bays showed toxicity in at least some of the samples.« less
Study Design Rigor in Animal-Experimental Research Published in Anesthesia Journals.
Hoerauf, Janine M; Moss, Angela F; Fernandez-Bustamante, Ana; Bartels, Karsten
2018-01-01
Lack of reproducibility of preclinical studies has been identified as an impediment for translation of basic mechanistic research into effective clinical therapies. Indeed, the National Institutes of Health has revised its grant application process to require more rigorous study design, including sample size calculations, blinding procedures, and randomization steps. We hypothesized that the reporting of such metrics of study design rigor has increased over time for animal-experimental research published in anesthesia journals. PubMed was searched for animal-experimental studies published in 2005, 2010, and 2015 in primarily English-language anesthesia journals. A total of 1466 publications were graded on the performance of sample size estimation, randomization, and blinding. Cochran-Armitage test was used to assess linear trends over time for the primary outcome of whether or not a metric was reported. Interrater agreement for each of the 3 metrics (power, randomization, and blinding) was assessed using the weighted κ coefficient in a 10% random sample of articles rerated by a second investigator blinded to the ratings of the first investigator. A total of 1466 manuscripts were analyzed. Reporting for all 3 metrics of experimental design rigor increased over time (2005 to 2010 to 2015): for power analysis, from 5% (27/516), to 12% (59/485), to 17% (77/465); for randomization, from 41% (213/516), to 50% (243/485), to 54% (253/465); and for blinding, from 26% (135/516), to 38% (186/485), to 47% (217/465). The weighted κ coefficients and 98.3% confidence interval indicate almost perfect agreement between the 2 raters beyond that which occurs by chance alone (power, 0.93 [0.85, 1.0], randomization, 0.91 [0.85, 0.98], and blinding, 0.90 [0.84, 0.96]). Our hypothesis that reported metrics of rigor in animal-experimental studies in anesthesia journals have increased during the past decade was confirmed. More consistent reporting, or explicit justification for absence, of sample size calculations, blinding techniques, and randomization procedures could better enable readers to evaluate potential sources of bias in animal-experimental research manuscripts. Future studies should assess whether such steps lead to improved translation of animal-experimental anesthesia research into successful clinical trials.
Measles deaths in Nepal: estimating the national case-fatality ratio.
Joshi, Anand B; Luman, Elizabeth T; Nandy, Robin; Subedi, Bal K; Liyanage, Jayantha B L; Wierzba, Thomas F
2009-06-01
To estimate the case-fatality ratio (CFR) for measles in Nepal, determine the role of risk factors, such as political instability, for measles mortality, and compare the use of a nationally representative sample of outbreaks versus routine surveillance or a localized study to establish the national CFR (nCFR). This was a retrospective study of measles cases and deaths in Nepal. Through two-stage random sampling, we selected 37 districts with selection probability proportional to the number of districts in each region, and then randomly selected within each district one outbreak among all those that had occurred between 1 March and 1 September 2004. Cases were identified by interviewing a member of each and every household and tracing contacts. Bivariate analyses were performed to assess the risk factors for a high CFR and determine the time from rash onset until death. Each factor's contribution to the CFR was determined through multivariate logistic regression. From the number of measles cases and deaths found in the study we calculated the total number of measles cases and deaths for all of Nepal during the study period and in 2004. We identified 4657 measles cases and 64 deaths in the study period and area. This yielded a total of about 82 000 cases and 900 deaths for all outbreaks in 2004 and a national CFR of 1.1% (95% confidence interval, CI: 0.5-2.3). CFR ranged from 0.1% in the eastern region to 3.4% in the mid-western region and was highest in politically insecure areas, in the Ganges plains and among cases < 5 years of age. Vitamin A treatment and measles immunization were protective. Most deaths occurred during the first week of illness. To our knowledge, this is the first CFR study based on a nationally representative sample of measles outbreaks. Routine surveillance and studies of a single outbreak may not yield an accurate nCFR. Increased fatalities associated with political insecurity are a challenge for health-care service delivery. The short period from disease onset to death and reduced mortality from treatment with vitamin A suggest the need for rapid, field-based treatment early in the outbreak.
Goldzweig, Caroline Lubick; Parkerton, Patricia H; Washington, Donna L; Lanto, Andrew B; Yano, Elizabeth M
2004-04-01
Despite the importance of early cancer detection, variation in screening rates among physicians is high. Insights into factors influencing variation can guide efforts to decrease variation and increase screening rates. To explore the association of primary care practice features and a facility's quality orientation with breast and cervical cancer screening rates. Cross-sectional study of screening rates among 144 Department of Veterans Affairs (VA) medical centers and for a national sample of women. We linked practice structure and quality improvement characteristics of individual VA medical centers from 2 national surveys (1 to primary care directors and 1 to a stratified random sample of employees) to breast and cervical cancer screening rates determined from a review of random medical records. We conducted bivariate analyses and multivariate logistic regression of primary care practice and facility features on cancer screening rates, above and below the median. While the national screening rates were high for breast (87%) and cervical cancer (90%), higher screening rates were more likely when primary care providers were consistently notified of specialty visits and when staff perceived a greater organizational commitment to quality and anticipated rewards and recognition for better performance. Organization and quality orientation of the primary care practice and its facility can enhance breast and cervical cancer screening rates. Internal recognition of quality performance and an overall commitment to quality improvement may foster improved prevention performance, with impact varying by clinical service.
Nitzan-Kaluski, Dorit; Chinich, Ayelet; Ifrah, Anneke; Merom, Dafna; Green, Manfred S
2003-01-01
To determine the prevalence and correlates of osteoporosis among middle-aged and elderly Jewish and Arab women in Israel. A cross-sectional study on a random sample of Israeli women, carried out through telephone interviews. Questions included physician-diagnosed osteoporosis, demographic and lifestyle variables, medical conditions, and present and past use of estrogen-containing medications. Body mass index (BMI) was calculated from reported height and weight. A national population-based survey conducted from March through August 1998. A national random sample of 888 women aged 45-74. The overall prevalence of self-reported osteoporosis was estimated at 13.7%. The rates increased abruptly from about 5.8% at ages 45-59 to 19.6% at ages 60-64, and reached 27.7% at ages 70-74. Between ages 45-59, the rates were higher among Arab women, whereas in the older group they were higher among Jewish women. There was a marked increase following menopause. After adjustment for potential confounders, at ages 45-59, osteoporosis was positively associated with menopause and BMI, whereas at ages 60-74, it was positively associated with age and family history of osteoporosis, and negatively associated with BMI. The prevalence of physician-diagnosed osteoporosis in Israel among women aged 45-74 is estimated to be 13.7%, which is similar to that for the United States. The association of osteoporosis with risk factors is age-dependent, and in particular, age-BMI interaction on osteoporosis requires further investigation.
Randomized trials published in some Chinese journals: how many are randomized?
Wu, Taixiang; Li, Youping; Bian, Zhaoxiang; Liu, Guanjian; Moher, David
2009-07-02
The approximately 1100 medical journals now active in China are publishing a rapidly increasing number of research reports, including many studies identified by their authors as randomized controlled trials. It has been noticed that these reports mostly present positive results, and their quality and authenticity have consequently been called into question. We investigated the adequacy of randomization of clinical trials published in recent years in China to determine how many of them met acceptable standards for allocating participants to treatment groups. The China National Knowledge Infrastructure electronic database was searched for reports of randomized controlled trials on 20 common diseases published from January 1994 to June 2005. From this sample, a subset of trials that appeared to have used randomization methods was selected. Twenty-one investigators trained in the relevant knowledge, communication skills and quality control issues interviewed the original authors of these trials about the participant randomization methods and related quality-control features of their trials. From an initial sample of 37,313 articles identified in the China National Knowledge Infrastructure database, we found 3137 apparent randomized controlled trials. Of these, 1452 were studies of conventional medicine (published in 411 journals) and 1685 were studies of traditional Chinese medicine (published in 352 journals). Interviews with the authors of 2235 of these reports revealed that only 207 studies adhered to accepted methodology for randomization and could on those grounds be deemed authentic randomized controlled trials (6.8%, 95% confidence interval 5.9-7.7). There was no statistically significant difference in the rate of authenticity between randomized controlled trials of traditional interventions and those of conventional interventions. Randomized controlled trials conducted at hospitals affiliated to medical universities were more likely to be authentic than trials conducted at level 3 and level 2 hospitals (relative risk 1.58, 95% confidence interval 1.18-2.13, and relative risk 14.42, 95% confidence interval 9.40-22.10, respectively). The likelihood of authenticity was higher in level 3 hospitals than in level 2 hospitals (relative risk 9.32, 95% confidence interval 5.83-14.89). All randomized controlled trials of pre-market drug clinical trial were authentic by our criteria. Of the trials conducted at university-affiliated hospitals, 56.3% were authentic (95% confidence interval 32.0-81.0). Most reports of randomized controlled trials published in some Chinese journals lacked an adequate description of randomization. Similarly, most so called 'randomized controlled trials' were not real randomized controlled trials owing to a lack of adequate understanding on the part of the authors of rigorous clinical trial design. All randomized controlled trials of pre-market drug clinical trial included in this research were authentic. Randomized controlled trials conducted by authors in high level hospitals, especially in hospitals affiliated to medical universities had a higher rate of authenticity. That so many non-randomized controlled trials were published as randomized controlled trials reflected the fact that peer review needs to be improved and a good practice guide for peer review including how to identify the authenticity of the study urgently needs to be developed.
Randomized trials published in some Chinese journals: how many are randomized?
Wu, Taixiang; Li, Youping; Bian, Zhaoxiang; Liu, Guanjian; Moher, David
2009-01-01
Background The approximately 1100 medical journals now active in China are publishing a rapidly increasing number of research reports, including many studies identified by their authors as randomized controlled trials. It has been noticed that these reports mostly present positive results, and their quality and authenticity have consequently been called into question. We investigated the adequacy of randomization of clinical trials published in recent years in China to determine how many of them met acceptable standards for allocating participants to treatment groups. Methods The China National Knowledge Infrastructure electronic database was searched for reports of randomized controlled trials on 20 common diseases published from January 1994 to June 2005. From this sample, a subset of trials that appeared to have used randomization methods was selected. Twenty-one investigators trained in the relevant knowledge, communication skills and quality control issues interviewed the original authors of these trials about the participant randomization methods and related quality-control features of their trials. Results From an initial sample of 37,313 articles identified in the China National Knowledge Infrastructure database, we found 3137 apparent randomized controlled trials. Of these, 1452 were studies of conventional medicine (published in 411 journals) and 1685 were studies of traditional Chinese medicine (published in 352 journals). Interviews with the authors of 2235 of these reports revealed that only 207 studies adhered to accepted methodology for randomization and could on those grounds be deemed authentic randomized controlled trials (6.8%, 95% confidence interval 5.9–7.7). There was no statistically significant difference in the rate of authenticity between randomized controlled trials of traditional interventions and those of conventional interventions. Randomized controlled trials conducted at hospitals affiliated to medical universities were more likely to be authentic than trials conducted at level 3 and level 2 hospitals (relative risk 1.58, 95% confidence interval 1.18–2.13, and relative risk 14.42, 95% confidence interval 9.40–22.10, respectively). The likelihood of authenticity was higher in level 3 hospitals than in level 2 hospitals (relative risk 9.32, 95% confidence interval 5.83–14.89). All randomized controlled trials of pre-market drug clinical trial were authentic by our criteria. Of the trials conducted at university-affiliated hospitals, 56.3% were authentic (95% confidence interval 32.0–81.0). Conclusion Most reports of randomized controlled trials published in some Chinese journals lacked an adequate description of randomization. Similarly, most so called 'randomized controlled trials' were not real randomized controlled trials owing toa lack of adequate understanding on the part of the authors of rigorous clinical trial design. All randomized controlled trials of pre-market drug clinical trial included in this research were authentic. Randomized controlled trials conducted by authors in high level hospitals, especially in hospitals affiliated to medical universities had a higher rate of authenticity. That so many non-randomized controlled trials were published as randomized controlled trials reflected the fact that peer review needs to be improved and a good practice guide for peer review including how to identify the authenticity of the study urgently needs to be developed. PMID:19573242
Sampling guidelines for oral fluid-based surveys of group-housed animals.
Rotolo, Marisa L; Sun, Yaxuan; Wang, Chong; Giménez-Lirola, Luis; Baum, David H; Gauger, Phillip C; Harmon, Karen M; Hoogland, Marlin; Main, Rodger; Zimmerman, Jeffrey J
2017-09-01
Formulas and software for calculating sample size for surveys based on individual animal samples are readily available. However, sample size formulas are not available for oral fluids and other aggregate samples that are increasingly used in production settings. Therefore, the objective of this study was to develop sampling guidelines for oral fluid-based porcine reproductive and respiratory syndrome virus (PRRSV) surveys in commercial swine farms. Oral fluid samples were collected in 9 weekly samplings from all pens in 3 barns on one production site beginning shortly after placement of weaned pigs. Samples (n=972) were tested by real-time reverse-transcription PCR (RT-rtPCR) and the binary results analyzed using a piecewise exponential survival model for interval-censored, time-to-event data with misclassification. Thereafter, simulation studies were used to study the barn-level probability of PRRSV detection as a function of sample size, sample allocation (simple random sampling vs fixed spatial sampling), assay diagnostic sensitivity and specificity, and pen-level prevalence. These studies provided estimates of the probability of detection by sample size and within-barn prevalence. Detection using fixed spatial sampling was as good as, or better than, simple random sampling. Sampling multiple barns on a site increased the probability of detection with the number of barns sampled. These results are relevant to PRRSV control or elimination projects at the herd, regional, or national levels, but the results are also broadly applicable to contagious pathogens of swine for which oral fluid tests of equivalent performance are available. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.
Burt, Richard D; Thiede, Hanne
2014-11-01
Respondent-driven sampling (RDS) is a form of peer-based study recruitment and analysis that incorporates features designed to limit and adjust for biases in traditional snowball sampling. It is being widely used in studies of hidden populations. We report an empirical evaluation of RDS's consistency and variability, comparing groups recruited contemporaneously, by identical methods and using identical survey instruments. We randomized recruitment chains from the RDS-based 2012 National HIV Behavioral Surveillance survey of injection drug users in the Seattle area into two groups and compared them in terms of sociodemographic characteristics, drug-associated risk behaviors, sexual risk behaviors, human immunodeficiency virus (HIV) status and HIV testing frequency. The two groups differed in five of the 18 variables examined (P ≤ .001): race (e.g., 60% white vs. 47%), gender (52% male vs. 67%), area of residence (32% downtown Seattle vs. 44%), an HIV test in the previous 12 months (51% vs. 38%). The difference in serologic HIV status was particularly pronounced (4% positive vs. 18%). In four further randomizations, differences in one to five variables attained this level of significance, although the specific variables involved differed. We found some material differences between the randomized groups. Although the variability of the present study was less than has been reported in serial RDS surveys, these findings indicate caution in the interpretation of RDS results. Copyright © 2014 Elsevier Inc. All rights reserved.
Methods and analysis of realizing randomized grouping.
Hu, Liang-Ping; Bao, Xiao-Lei; Wang, Qi
2011-07-01
Randomization is one of the four basic principles of research design. The meaning of randomization includes two aspects: one is to randomly select samples from the population, which is known as random sampling; the other is to randomly group all the samples, which is called randomized grouping. Randomized grouping can be subdivided into three categories: completely, stratified and dynamically randomized grouping. This article mainly introduces the steps of complete randomization, the definition of dynamic randomization and the realization of random sampling and grouping by SAS software.
Tassie, Jean-Michel; Malateste, Karen; Pujades-Rodríguez, Mar; Poulet, Elisabeth; Bennett, Diane; Harries, Anthony; Mahy, Mary; Schechter, Mauro; Souteyrand, Yves; Dabis, François
2010-11-10
Retention of patients on antiretroviral therapy (ART) over time is a proxy for quality of care and an outcome indicator to monitor ART programs. Using existing databases (Antiretroviral in Lower Income Countries of the International Databases to Evaluate AIDS and Médecins Sans Frontières), we evaluated three sampling approaches to simplify the generation of outcome indicators. We used individual patient data from 27 ART sites and included 27,201 ART-naive adults (≥15 years) who initiated ART in 2005. For each site, we generated two outcome indicators at 12 months, retention on ART and proportion of patients lost to follow-up (LFU), first using all patient data and then within a smaller group of patients selected using three sampling methods (random, systematic and consecutive sampling). For each method and each site, 500 samples were generated, and the average result was compared with the unsampled value. The 95% sampling distribution (SD) was expressed as the 2.5(th) and 97.5(th) percentile values from the 500 samples. Overall, retention on ART was 76.5% (range 58.9-88.6) and the proportion of patients LFU, 13.5% (range 0.8-31.9). Estimates of retention from sampling (n = 5696) were 76.5% (SD 75.4-77.7) for random, 76.5% (75.3-77.5) for systematic and 76.0% (74.1-78.2) for the consecutive method. Estimates for the proportion of patients LFU were 13.5% (12.6-14.5), 13.5% (12.6-14.3) and 14.0% (12.5-15.5), respectively. With consecutive sampling, 50% of sites had SD within ±5% of the unsampled site value. Our results suggest that random, systematic or consecutive sampling methods are feasible for monitoring ART indicators at national level. However, sampling may not produce precise estimates in some sites.
Health Status of Individuals With Serious Mental Illness
Dickerson, Faith B.; Brown, Clayton H.; Daumit, Gail L.; LiJuan, Fang; Goldberg, Richard W.; Wohlheiter, Karen; Dixon, Lisa B.
2006-01-01
We examined indices of the health of persons with serious mental illness. A sample of 100 adults with schizophrenia and 100 with major mood disorder were recruited from randomly selected outpatients who were receiving community-based psychiatric treatment. Participants were surveyed about health indicators using items from the National Health and Nutrition Examination Study III and the National Health Interview Survey. Their responses were compared with those of matched samples from the general population surveys. A total of 1% of persons with serious mental illness, compared with 10% from the general population sample, met criteria for all 5 of selected health indicators: nonsmoker, exercise that meets recommended standards, good dentition, absence of obesity, and absence of serious medical co-occurring illness. Within the mentally ill group, educational level, but not a diagnosis of schizophrenia versus mood disorder, was independently associated with a composite measure of health behaviors. We conclude that an examination of multiple health indicators may be used to measure overall health status in persons with serious mental illness. PMID:16469943
Sadeghi, Fatemeh; Nasseri, Simin; Mosaferi, Mohammad; Nabizadeh, Ramin; Yunesian, Masud; Mesdaghinia, Alireza
2017-05-01
In this research, probable arsenic contamination in drinking water in the city of Ardabil was studied in 163 samples during four seasons. In each season, sampling was carried out randomly in the study area. Results were analyzed statistically applying SPSS 19 software, and the data was also modeled by Arc GIS 10.1 software. The maximum permissible arsenic concentration in drinking water defined by the World Health Organization and Iranian national standard is 10 μg/L. Statistical analysis showed 75, 88, 47, and 69% of samples in autumn, winter, spring, and summer, respectively, had concentrations higher than the national standard. The mean concentrations of arsenic in autumn, winter, spring, and summer were 19.89, 15.9, 10.87, and 14.6 μg/L, respectively, and the overall average in all samples through the year was 15.32 μg/L. Although GIS outputs indicated that the concentration distribution profiles changed in four consecutive seasons, variance analysis of the results showed that statistically there is no significant difference in arsenic levels in four seasons.
Thompson, Sanna J; Bender, Kimberly A; Lewis, Carol M; Watkins, Rita
2008-08-01
Homeless youth are at particularly high risk for teen pregnancy; research indicates as many as 20% of homeless young women become pregnant. These pregnant and homeless teens lack financial resources and adequate health care, resulting in increased risk for low-birth-weight babies and high infant mortality. This study investigated individual and family-level predictors of teen pregnancy among a national sample of runaway/homeless youth in order to better understand the needs of this vulnerable population. Data from the Runaway/Homeless Youth Management Information System (RHY MIS) provided a national sample of youth seeking services at crisis shelters. A sub-sample of pregnant females and a random sub-sample (matched by age) of nonpregnant females comprised the study sample (N = 951). Chi-square and t tests identified differences between pregnant and nonpregnant runaway females; maximum likelihood logistic regression identified individual and family-level predictors of teen pregnancy. Teen pregnancy was associated with being an ethnic minority, dropping out of school, being away from home for longer periods of time, having a sexually transmitted disease, and feeling abandoned by one's family. Family factors, such as living in a single parent household and experiencing emotional abuse by one's mother, increased the odds of a teen being pregnant. The complex problems associated with pregnant runaway/homeless teens create challenges for short-term shelter services. Suggestions are made for extending shelter services to include referrals and coordination with teen parenting programs and other systems of care.
Todd, Catherine S; Mansoor, Ghulam Farooq; Buhler, Cyril; Rahimi, Habiburrahman; Zekria, Rohullah; Fernandez, Stefan; Mikhail, Amy F W; Scott, Paul T; Yingst, Samuel L
2016-08-01
To measure prevalence of prior/current Plasmodium vivax and Plasmodium falciparum (PV and PF), Brucella spp. (BR), dengue virus (DENV), Leishmania donovani (visceral leishmaniasis; VL), and Crimean-Congo hemorrhagic fever (CCHF) virus exposure among Afghan National Army (ANA) recruits. Randomly chosen, nationally representative serum samples from consenting men aged 18-40 years and who were screened between February 2010 and January 2011 were tested, with ∼25 samples/province. Samples were screened for PV and PF antigens and VL antibody with rapid diagnostic tests. Reactive malaria screening results were confirmed with polymerase chain reaction assay. Enzyme-linked immunosorbent assays were used to screen for CCHF and DENV antibodies; reactive DENV samples were confirmed with the plaque-reduction neutralization test. BR screening and confirmatory testing was performed with slide and tube agglutination, respectively. Correlates of BR titres >1:80 were analyzed using logistic regression. Of 809 participants contributing specimens, 62% had previously lived outside Afghanistan, predominantly in Pakistan and Iran. CCHF (4.1%, n = 33), DENV (2.1%, n = 17), and VL (1.0%, n = 8) antibody prevalence was low. For PV and PF, only 7 out of 56 reactive samples had detectable nucleic acid. For BR, 8.0% (n = 65) of samples had screening titers >1:40, of which 83.1% had confirmatory titers >1:80. Participants from Kabul and surrounding provinces had lower odds (OR = 0.19, 95% CI: 0.04-1.00) of BR antibody compared with other regions. BR exposure was relatively common with a nearly national distribution, whereas geographic distribution for other pathogens aligned roughly with the expected vector distribution. Public health protection measures should include vector control, food safety, and enhanced diagnostics for acute febrile illness.
Drinking water quality assessment.
Aryal, J; Gautam, B; Sapkota, N
2012-09-01
Drinking water quality is the great public health concern because it is a major risk factor for high incidence of diarrheal diseases in Nepal. In the recent years, the prevalence rate of diarrhoea has been found the highest in Myagdi district. This study was carried out to assess the quality of drinking water from different natural sources, reservoirs and collection taps at Arthunge VDC of Myagdi district. A cross-sectional study was carried out using random sampling method in Arthunge VDC of Myagdi district from January to June,2010. 84 water samples representing natural sources, reservoirs and collection taps from the study area were collected. The physico-chemical and microbiological analysis was performed following standards technique set by APHA 1998 and statistical analysis was carried out using SPSS 11.5. The result was also compared with national and WHO guidelines. Out of 84 water samples (from natural source, reservoirs and tap water) analyzed, drinking water quality parameters (except arsenic and total coliform) of all water samples was found to be within the WHO standards and national standards.15.48% of water samples showed pH (13) higher than the WHO permissible guideline values. Similarly, 85.71% of water samples showed higher Arsenic value (72) than WHO value. Further, the statistical analysis showed no significant difference (P<0.05) of physico-chemical parameters and total coliform count of drinking water for collection taps water samples of winter (January, 2010) and summer (June, 2010). The microbiological examination of water samples revealed the presence of total coliform in 86.90% of water samples. The results obtained from physico-chemical analysis of water samples were within national standard and WHO standards except arsenic. The study also found the coliform contamination to be the key problem with drinking water.
Tran, Hang My; Mahdi, Abdull M; Sivasubramaniam, Selvaraj; Gudlavalleti, Murthy V S; Gilbert, Clare E; Shah, Shaheen P; Ezelum, C C; Abubakar, Tafida; Bankole, Olufunmilayo O
2011-12-01
To assess associations of visual function (VF) and quality of life (QOL) by visual acuity (VA), causes of blindness and types of cataract procedures in Nigeria. Multi-stage stratified cluster random sampling was used to identify a nationally representative sample of persons aged ≥ 40 years. VF/QOL questionnaires were administered to participants with VA <6/60 in one or both eyes and/or Mehra-Minassian cataract grade 2B or 3 in one or both eyes and a random sample of those with bilateral VA ≥ 6/12. VF/QOL questionnaires were administered to 2076 participants. Spearman's rank correlation showed a strong correlation between decreasing VA and VF/QOL scores (p<0.0001) with greatest impact on social (p<0.0001) and mobility-related activities (p<0.0001). People who were blind due to glaucoma had lower VF and QOL scores than those who were blind due to cataract. Mean VF and QOL scores were lower after couching compared with conventional cataract surgery (mean VF score=51.0 vs 63.0 and mean QOL score=71.3 vs 79.3). Finally, VF and QOL scores were lower among populations with specific characteristics. Populations with the following characteristics should be targeted to improve VF and QOL: people who are blind, older people, women, manual labourers, people living in rural areas, those living in the northern geopolitical zones, those practising Islamic and Traditionalism faith, those not currently married and those who have undergone couching.
Response of six non-native invasive plant species to wildfires in the northern Rocky Mountains, USA
Dennis E. Ferguson; Christine L. Craig
2010-01-01
This paper presents early results on the response of six non-native invasive plant species to eight wildfires on six National Forests (NFs) in the northern Rocky Mountains, USA. Stratified random sampling was used to choose 224 stands based on burn severity, habitat type series, slope steepness, stand height, and stand density. Data for this report are from 219 stands...
John F. Dwyer; Susan C. Barro
2001-01-01
A study of recreation behavior of residents of Cook County, Illinois was conducted in early 1999. Respondents were contacted via telephone and surveyed about their awareness and use of outdoor recreation sites in and around Chicago and as far away as the Shawnee National Forest in Southern Illinois. The sample was selected using random digit dialing and a quota for...
The effects of a low intensity fire on a mixed conifer forest in Bryce Canyon National Park, Utah
Henry V. Bastian
2001-01-01
Prescribed fire was used to reduce fuel loading and tree densities. Permanent vegetation and fuel loading plots were randomly established within prescribed burn units. The plots were established in 1995 and were sampled, immediately postburn (within 1 month of the fire), 1 year after the burn, and 2 years after the burn. The prescribed burns were implemented in August...
ERIC Educational Resources Information Center
Troia, Gary A.; Graham, Steve
2016-01-01
A random sample of 482 teachers in grades 3 through 8 from across the United States were surveyed about (a) their perceptions of the version of the Common Core writing and language standards adopted by their state and their state's writing assessment, (b) their preparation to teach writing, and (c) their self-efficacy beliefs for teaching writing.…
ERIC Educational Resources Information Center
Gubbins, E. Jean; McCoach, D. Betsy; Foreman, Jennifer L.; Gilson, Cindy M.; Bruce-Davis, Micah N.; Rubenstein, Lisa DaVia; Savino, Jennifer; Rambo, Karen; Waterman, Craig
2013-01-01
The present study seeks to determine how exposure to pre-differentiated and enriched curricula incorporating educative curriculum materials affects students' achievement as well as teacher and administrator responses to the intervention. A 2-year multi-site cluster randomized control trial study recruited a national sample of 4,530 grade 3…
John F. Dwyer; Susan C. Barro
2002-01-01
A study of recreation behavior of residents of Cook County, Illinois was conducted in early 1999. Respondents were contacted via telephone and surveyed about their awareness and use of outdoor recreation sites in and around Chicago and as far away as the Shawnee National Forest in Southern Illinois. The sample was selected using random digit dialing and a quota for...
Richardson, J Don; Naifeh, James A; Elhai, Jon D
2007-08-01
This study investigates posttraumatic stress disorder (PTSD) and its associated risk factors in a random, national, Canadian sample of United Nations peacekeeping veterans with service-related disabilities. Participants included 1016 male veterans (age < 65 years) who served in the Canadian Forces from 1990 to 1999 and were selected from a larger random sample of 1968 veterans who voluntarily and anonymously completed a general health survey conducted by Veterans Affairs Canada in 1999. Survey instruments included the PTSD Checklist-Military Version (PCL-M), Center for Epidemiological Studies-Depression Scale (CES-D), and questionnaires regarding life events during the past year, current stressors, sociodemographic characteristics, and military history. We found that rates of probable PTSD (PCL-M score > 50) among veterans were 10.92% for veterans deployed once and 14.84% for those deployed more than once. The rates of probable clinical depression (CES-D score > 16) were 30.35% for veterans deployed once and 32.62% for those deployed more than once. We found that, in multivariate analyses, probable PTSD rates and PTSD severity were associated with younger age, single marital status, and deployment frequency. PTSD is an important health concern in the veteran population. Understanding such risk factors as younger age and unmarried status can help predict morbidity among trauma-exposed veterans.
Izadi, Shahrokh; Zahraei, Seyed Mohsen; Salehi, Masoud; Mohammadi, Mahdi; Tabatabaei, Seyed Mehdi; Mokhtari-Azad, Talat
2018-01-29
A non-inferiority multi-centre parallel randomized double-blind trial was implemented in Zahedan district, Sistan-va-Baluchestan province, Iran, to compare the performance of the two measles vaccines which are in use in the National Immunization Programme of Iran and are of two different measles virus vaccine strains: Edmonston-Zagreb (EZ) strain vs. AIK-C strain. The main outcome measure was appearance of anti-measles antibody in sera. 200 infants, 8-12 months old, whose parents consented for their children to be included in the study, were randomized in permutation blocks of size 4-8 in four Urban Health Clinics. Having given a pre-vaccination blood sample, they received measles-rubella vaccine containing one of the vaccine strains mentioned before. After 60 days, the second blood sample was taken. The sera of the pre- and post-vaccination blood samples were tested for anti-measles antibodies in the National Reference Measles Laboratory. Parents, laboratory technicians and statistician were blind to groupings. Of the 200 children equally randomized in the two arms, 185 who were seronegative before vaccination (88 in the EZ arm and 97 in the AIK-C arm) were entered in the final analysis. The seroconversion rate in the EZ arm was 76.1% (95% CI: 60.2-85.2%), and that in the AIK-C arm was 58.7%; (95% CI: 48.8-68.7%). The absolute rate difference was 17. 4% (4.1-30.9%; P-value: .012), and the relative seroconversion rate of EZ to AIK-C was 1.3 (95% CI: 1.1-1.6; P-value: .012). No adverse events were reported during the study period. A considerable difference in the seropositivity of different measles containing vaccines could be demonstrated in the first year of life. Iranian Registry of Clinical Trials Registration Number: IRCT2016032827144N1; May 10, 2016 (www.who.int/ictrp/network/irct/en/). Copyright © 2017 Elsevier Ltd. All rights reserved.
Corporate social marketing: message design to recruit program participants.
Black, David R; Blue, Carolyn L; Coster, Daniel C; Chrysler, Lisa M
2002-01-01
To identify variables for a corporate social marketing (SM) health message based on the 4 Ps of SM in order to recruit future participants to an existing national, commercial, self-administered weight-loss program. A systematically evaluated, author-developed, 310-response survey was administered to a random sample of 270 respondents. A previously established research plan was used to empirically identify the audience segments and the "marketing mix" appropriate for the total sample and each segment. Tangible product, pertaining to the unique program features, should be emphasized rather than positive core product and outcome expectation related to use of the program.
[Krigle estimation and its simulated sampling of Chilo suppressalis population density].
Yuan, Zheming; Bai, Lianyang; Wang, Kuiwu; Hu, Xiangyue
2004-07-01
In order to draw up a rational sampling plan for the larvae population of Chilo suppressalis, an original population and its two derivative populations, random population and sequence population, were sampled and compared with random sampling, gap-range-random sampling, and a new systematic sampling integrated Krigle interpolation and random original position. As for the original population whose distribution was up to aggregative and dependence range in line direction was 115 cm (6.9 units), gap-range-random sampling in line direction was more precise than random sampling. Distinguishing the population pattern correctly is the key to get a better precision. Gap-range-random sampling and random sampling are fit for aggregated population and random population, respectively, but both of them are difficult to apply in practice. Therefore, a new systematic sampling named as Krigle sample (n = 441) was developed to estimate the density of partial sample (partial estimation, n = 441) and population (overall estimation, N = 1500). As for original population, the estimated precision of Krigle sample to partial sample and population was better than that of investigation sample. With the increase of the aggregation intensity of population, Krigel sample was more effective than investigation sample in both partial estimation and overall estimation in the appropriate sampling gap according to the dependence range.
NASA Astrophysics Data System (ADS)
Molinario, G.; Hansen, M.; Potapov, P.
2016-12-01
High resolution satellite imagery obtained from the National Geospatial Intelligence Agency through NASA was used to photo-interpret sample areas within the DRC. The area sampled is a stratifcation of the forest cover loss from circa 2014 that either occurred completely within the previosly mapped homogenous area of the Rural Complex, at it's interface with primary forest, or in isolated forest perforations. Previous research resulted in a map of these areas that contextualizes forest loss depending on where it occurs and with what spatial density, leading to a better understading of the real impacts on forest degradation of livelihood shifting cultivation. The stratified random sampling approach of these areas allows the characterization of the constituent land cover types within these areas, and their variability throughout the DRC. Shifting cultivation has a variable forest degradation footprint in the DRC depending on many factors that drive it, but it's role in forest degradation and deforestation had been disputed, leading us to investigate and quantify the clearing and reuse rates within the strata throughout the country.
Susukida, Ryoko; Crum, Rosa M; Ebnesajjad, Cyrus; Stuart, Elizabeth A; Mojtabai, Ramin
2017-07-01
To compare randomized controlled trial (RCT) sample treatment effects with the population effects of substance use disorder (SUD) treatment. Statistical weighting was used to re-compute the effects from 10 RCTs such that the participants in the trials had characteristics that resembled those of patients in the target populations. Multi-site RCTs and usual SUD treatment settings in the United States. A total of 3592 patients in 10 RCTs and 1 602 226 patients from usual SUD treatment settings between 2001 and 2009. Three outcomes of SUD treatment were examined: retention, urine toxicology and abstinence. We weighted the RCT sample treatment effects using propensity scores representing the conditional probability of participating in RCTs. Weighting the samples changed the significance of estimated sample treatment effects. Most commonly, positive effects of trials became statistically non-significant after weighting (three trials for retention and urine toxicology and one trial for abstinence); also, non-significant effects became significantly positive (one trial for abstinence) and significantly negative effects became non-significant (two trials for abstinence). There was suggestive evidence of treatment effect heterogeneity in subgroups that are under- or over-represented in the trials, some of which were consistent with the differences in average treatment effects between weighted and unweighted results. The findings of randomized controlled trials (RCTs) for substance use disorder treatment do not appear to be directly generalizable to target populations when the RCT samples do not reflect adequately the target populations and there is treatment effect heterogeneity across patient subgroups. © 2017 Society for the Study of Addiction.
Systematic versus random sampling in stereological studies.
West, Mark J
2012-12-01
The sampling that takes place at all levels of an experimental design must be random if the estimate is to be unbiased in a statistical sense. There are two fundamental ways by which one can make a random sample of the sections and positions to be probed on the sections. Using a card-sampling analogy, one can pick any card at all out of a deck of cards. This is referred to as independent random sampling because the sampling of any one card is made without reference to the position of the other cards. The other approach to obtaining a random sample would be to pick a card within a set number of cards and others at equal intervals within the deck. Systematic sampling along one axis of many biological structures is more efficient than random sampling, because most biological structures are not randomly organized. This article discusses the merits of systematic versus random sampling in stereological studies.
Palen, Lori-Ann; Ashley, Olivia Silber; Gard, Jennifer C; Kan, Marni L; Davis, Kevin C; Evans, W Douglas
2011-01-01
Using a randomized controlled trial, this study evaluated the effects of media messages targeting parents on the sexual beliefs of 404 adolescents. The messages aimed to increase parent-child communication about waiting to initiate sexual activity. Compared with children of unexposed parents, children of parents exposed to media messages were more likely to believe that teen sexual activity is psychologically harmful. However, effects varied by parent and adolescent gender; treatment effects were only significant among adolescents whose opposite-sex parent was exposed. Parent exposure strengthened beliefs that teen sexual activity is physically harmful only among adolescents with at least 1 sexually active friend.
Lönnqvist, Jan-Erik; Szabó, Zsolt Péter; Kelemen, Laszlo
2018-04-26
We investigated the "rigidity of the right" hypothesis in the context of the far-right breakthrough in the 2010 Hungarian parliamentary elections. This hypothesis suggests that psychological characteristics having to do with need for security and certainty attract people to a broad-based right-wing ideology. A nationally representative sample (N = 1000) in terms of age, gender and place of residence was collected by means of the random walking method and face-to-face interviews. Voters of JOBBIK (n = 124), the radically nationalist conservative far-right party, scored lower on System Justifying Belief, Belief in a Just World (Global) and higher on Need for Cognition than other voters. Our results contradict the "rigidity of the right" hypothesis: JOBBIK voters scored, on many measures, opposite to what the hypothesis would predict. © 2018 International Union of Psychological Science.
Simons, Kelsey V
2006-11-01
This research sought to identify organizational characteristics associated with the amount of professional qualifications among a nationally representative sample of nursing home social service directors. A self-administered survey was sent to directors in 675 facilities randomly sampled from a federal database, excluding facilities with fewer than 120 beds that are not required to staff a full-time social worker. The response rate was 45 percent (N = 299). Univariate results showed that most respondents possessed a social work degree, most lacked licensure, and few were clinically supervised. A multiple regression analysis found that nonprofit, independently owned facilities in rural areas staffed social service directors who were significantly more qualified than directors in for-profit, chain-affiliated facilities in urban and suburban areas. Facilities with fewer psychosocial deficiencies and higher occupancy rates employed social service directors with greater qualifications. The implications of these findings for social work education, practice, policy, and research are discussed.
Zhou, Hanzhi; Elliott, Michael R; Raghunathan, Trivellore E
2016-06-01
Multistage sampling is often employed in survey samples for cost and convenience. However, accounting for clustering features when generating datasets for multiple imputation is a nontrivial task, particularly when, as is often the case, cluster sampling is accompanied by unequal probabilities of selection, necessitating case weights. Thus, multiple imputation often ignores complex sample designs and assumes simple random sampling when generating imputations, even though failing to account for complex sample design features is known to yield biased estimates and confidence intervals that have incorrect nominal coverage. In this article, we extend a recently developed, weighted, finite-population Bayesian bootstrap procedure to generate synthetic populations conditional on complex sample design data that can be treated as simple random samples at the imputation stage, obviating the need to directly model design features for imputation. We develop two forms of this method: one where the probabilities of selection are known at the first and second stages of the design, and the other, more common in public use files, where only the final weight based on the product of the two probabilities is known. We show that this method has advantages in terms of bias, mean square error, and coverage properties over methods where sample designs are ignored, with little loss in efficiency, even when compared with correct fully parametric models. An application is made using the National Automotive Sampling System Crashworthiness Data System, a multistage, unequal probability sample of U.S. passenger vehicle crashes, which suffers from a substantial amount of missing data in "Delta-V," a key crash severity measure.
Zhou, Hanzhi; Elliott, Michael R.; Raghunathan, Trivellore E.
2017-01-01
Multistage sampling is often employed in survey samples for cost and convenience. However, accounting for clustering features when generating datasets for multiple imputation is a nontrivial task, particularly when, as is often the case, cluster sampling is accompanied by unequal probabilities of selection, necessitating case weights. Thus, multiple imputation often ignores complex sample designs and assumes simple random sampling when generating imputations, even though failing to account for complex sample design features is known to yield biased estimates and confidence intervals that have incorrect nominal coverage. In this article, we extend a recently developed, weighted, finite-population Bayesian bootstrap procedure to generate synthetic populations conditional on complex sample design data that can be treated as simple random samples at the imputation stage, obviating the need to directly model design features for imputation. We develop two forms of this method: one where the probabilities of selection are known at the first and second stages of the design, and the other, more common in public use files, where only the final weight based on the product of the two probabilities is known. We show that this method has advantages in terms of bias, mean square error, and coverage properties over methods where sample designs are ignored, with little loss in efficiency, even when compared with correct fully parametric models. An application is made using the National Automotive Sampling System Crashworthiness Data System, a multistage, unequal probability sample of U.S. passenger vehicle crashes, which suffers from a substantial amount of missing data in “Delta-V,” a key crash severity measure. PMID:29226161
Levine, Roger
2016-12-01
The objective of this study is to describe the Longitudinal Emergency Medical Technician (EMT) Attributes and Demographic Study (LEADS) design, instrument development, pilot testing, sampling procedures, and data collection methodology. Response rates are provided, along with results of follow-up surveys of non-responders (NRs) and a special survey of Emergency Medical Services (EMS) professionals who were not nationally certified. Annual surveys from 1999 to 2008 were mailed out to a random, stratified sample of nationally registered EMT-Basics and Paramedics. Survey weights were developed to reflect each respondent's probability of selection. A special survey of NRs was mailed out to individuals who did not respond to the annual survey to estimate the probable extent and direction of response bias. Individuals who indicated they were no longer in the profession were mailed a special exit survey to determine their reasons for leaving EMS. Given the large number of comparisons between NR and regular (annual) survey respondents, it is not surprising that some statistically significant differences were found. In general, there were few differences. However, NRs tended to report higher annual EMS incomes, were younger, healthier, more physically fit, and were more likely to report that they were not practicing EMS. Comparisons of the nationally certified EMS professionals with EMS professionals who were not nationally certified indicated that nationally certified EMS providers were younger, had less EMS experiences, earned less, were more likely to be female and work for private EMS services, and less likely to work for fire-based services. These differences may reflect state and local policy and practice, since many states and local agencies do not require maintenance of national certification as a requirement to practice. When these differences were controlled for statistically, there were few systematic differences between non-nationally certified and nationally certified EMS professionals. The LEADS study is the only national, randomized, and longitudinal data source for studying EMS professionals in the United States. Although not without flaws, this study remains an excellent source of information about EMS provider demographics, attributes, attitudes, workplace issues and concerns, and how the profession has changed from 1999 to 2008. Levine R . Longitudinal Emergency Medical Technician Attributes and Demographic Study (LEADS) design and methodology. Prehosp Disaster Med. 2016;31(Suppl. 1):s7-s17.
Abdulaziz, Kasim; Brehaut, Jamie; Taljaard, Monica; Émond, Marcel; Sirois, Marie-Josée; Lee, Jacques S; Wilding, Laura; Perry, Jeffrey J
2015-02-18
Physicians are a commonly targeted group in health research surveys, but their response rates are often relatively low. The goal of this paper was to evaluate the effect of unconditional incentives in the form of a coffee card on physician postal survey response rates. Following 13 key informant interviews and eight cognitive interviews a survey questionnaire was developed. A random sample of 534 physicians, stratified by physician group (geriatricians, family physicians, emergency physicians) was selected from a national medical directory. Using computer generated random numbers; half of the physicians in each stratum were allocated to receive a coffee card to a popular national coffee chain together with the first survey mailout. The intervention was a $10 Tim Hortons gift card given to half of the physicians who were randomly allocated to receive the incentive. 265 (57.0%) physicians completed the survey. The response rate was significantly higher in the group allocated to receive the incentive (62.7% vs 51.3% in the control group; p=0.01). Our results indicate that an unconditional incentive in the form of a coffee gift card can substantially improve physician response rates. Future research can look at the effect of varying amounts of cash on the gift cards on response rates. 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.
Kawasaki, Yohei; Ide, Kazuki; Akutagawa, Maiko; Yamada, Hiroshi; Yutaka, Ono; Furukawa, Toshiaki A.
2017-01-01
Background Several recent studies have shown that total scores on depressive symptom measures in a general population approximate an exponential pattern except for the lower end of the distribution. Furthermore, we confirmed that the exponential pattern is present for the individual item responses on the Center for Epidemiologic Studies Depression Scale (CES-D). To confirm the reproducibility of such findings, we investigated the total score distribution and item responses of the Kessler Screening Scale for Psychological Distress (K6) in a nationally representative study. Methods Data were drawn from the National Survey of Midlife Development in the United States (MIDUS), which comprises four subsamples: (1) a national random digit dialing (RDD) sample, (2) oversamples from five metropolitan areas, (3) siblings of individuals from the RDD sample, and (4) a national RDD sample of twin pairs. K6 items are scored using a 5-point scale: “none of the time,” “a little of the time,” “some of the time,” “most of the time,” and “all of the time.” The pattern of total score distribution and item responses were analyzed using graphical analysis and exponential regression model. Results The total score distributions of the four subsamples exhibited an exponential pattern with similar rate parameters. The item responses of the K6 approximated a linear pattern from “a little of the time” to “all of the time” on log-normal scales, while “none of the time” response was not related to this exponential pattern. Discussion The total score distribution and item responses of the K6 showed exponential patterns, consistent with other depressive symptom scales. PMID:28289560
Carrasquillo, Olveen; McCann, Sheila; Amofah, Antony; Pierre, Larry; Rodriguez, Brendaly; Alonzo, Yisel; Ilangovan, Kumar; Gonzalez, Martha; Trevil, Dinah; Byrne, Margaret M; Koru-Sengul, Tulay; Kobetz, Erin
2014-07-23
In the United States certain minority groups, such as racial/ethnic immigrant women, are less likely than non-Hispanic White women to be screened for cervical cancer. Barriers to such care include health insurance, cost, knowledge, attitudes, health literacy, and cultural norms and practices. Among the most promising approaches to increase screening in these groups are patient navigators that can link women to sources of appropriate care. Another recent promising approach is using human papilloma virus (HPV) self-sampling. In this manuscript, we describe our National Cancer Institute-sponsored study testing such approaches among immigrant minority women. The South Florida Center for the Reduction of Cancer Health Disparities (SUCCESS) is conducting a three-arm randomized trial among Hispanic, Haitian, and African American women in Miami-Dade County. Community health workers (CHW) based in each of three communities are recruiting 200 women at each site (600 total). Eligibility criteria include women aged 30-65 years who have not had a Pap smear test in the last 3 years. Prior to randomization, all women undergo a standardized structured interview. Women randomized to public health outreach, Group 1, receive culturally tailored educational materials. Women in Group 2 receive an individualized comprehensive cervical cancer CHW-led education session followed by patient navigation to obtain the Pap smear test at community-based facilities. Women in Group 3 have the option of navigation to a Pap smear test or performing HPV self-sampling. The primary outcome is self-report of completed screening through a Pap smear test or HPV self-sampling within 6 months after enrollment. SUCCESS is one of the first trials testing HPV self-sampling as a screening strategy among underserved minority women. If successful, HPV self-sampling may be an important option in community outreach programs aimed at reducing disparities in cervical cancer. Clinical Trials.gov # NCT02121548, registered April 21, 2014.
Improved Compressive Sensing of Natural Scenes Using Localized Random Sampling
Barranca, Victor J.; Kovačič, Gregor; Zhou, Douglas; Cai, David
2016-01-01
Compressive sensing (CS) theory demonstrates that by using uniformly-random sampling, rather than uniformly-spaced sampling, higher quality image reconstructions are often achievable. Considering that the structure of sampling protocols has such a profound impact on the quality of image reconstructions, we formulate a new sampling scheme motivated by physiological receptive field structure, localized random sampling, which yields significantly improved CS image reconstructions. For each set of localized image measurements, our sampling method first randomly selects an image pixel and then measures its nearby pixels with probability depending on their distance from the initially selected pixel. We compare the uniformly-random and localized random sampling methods over a large space of sampling parameters, and show that, for the optimal parameter choices, higher quality image reconstructions can be consistently obtained by using localized random sampling. In addition, we argue that the localized random CS optimal parameter choice is stable with respect to diverse natural images, and scales with the number of samples used for reconstruction. We expect that the localized random sampling protocol helps to explain the evolutionarily advantageous nature of receptive field structure in visual systems and suggests several future research areas in CS theory and its application to brain imaging. PMID:27555464
Serological status of Canadian cattle for brucellosis, anaplasmosis, and bluetongue in 2007-2008.
Paré, Julie; Geale, Dorothy W; Koller-Jones, Maria; Hooper-McGrevy, Kathleen; Golsteyn-Thomas, Elizabeth J; Power, Christine A
2012-09-01
A national bovine serological survey was conducted to confirm that the prevalence of brucellosis, bluetongue, and anaplasmosis does not exceed 0.02% (95% confidence) in live cattle in Canada. Sampling consisted of a systematic random sample of 15 482 adult cattle slaughtered in federally inspected abattoirs, stratified by province. Samples were tested to detect antibodies for brucellosis, bluetongue, and anaplasmosis. All samples were negative for brucellosis. Three samples were seroreactors to bluetongue, 2 of which originated from the Okanagan Valley in British Columbia and 1 from Ontario, which after follow-up, was considered an atypical result. A total of 244 samples were seroreactors to Anaplasma and follow-up identified infection in Saskatchewan, Manitoba, and Quebec. In conclusion, the Canadian cattle population remains free of brucellosis and free of bluetongue outside the Okanagan Valley. Canada is no longer free of anaplasmosis and will be unable to claim freedom until eradication measures are completed.
MacMillan, Harriet L; Jamieson, Ellen; Walsh, Christine; Boyle, Michael; Crawford, Allison; MacMillan, Angus
2010-04-01
Reports on child health in Canada often refer to the disproportionate burden of poor health experienced by Aboriginal children and youth, yet little national data are available. This paper describes the health of First Nations and Inuit children and youth based on the First Nations and Inuit Regional Health Survey (FNIRHS). The FNIRHS combines data from 9 regional surveys conducted in 1996-1997 in Aboriginal reserve communities in all provinces. The target population consisted of all on-reserve communities. All households or a random sample of households or adults (depending on province) were selected based on their population representation. One child was randomly selected from each participating household, except in Ontario and Nova Scotia, where children were randomly selected based upon their population representation. Alberta did not include the section on children's health in their regional survey. Approximately 84% of adults, who were proxy respondents for their child, rated their children's health as very good or excellent. The most frequently reported conditions were ear problems (15%), followed by allergies (13%) and asthma (12%). Broken bones or fractures were the most frequently reported injuries (13%). Respondents reported that 17% of children had behavioural or emotional problems. Overall, 76% of children were reported to get along with the family "very well" or "quite well." While most respondents rated their child's health as very good or excellent, injuries, emotional and behavioural problems, respiratory conditions and ear problems were reported among many Aboriginal children. Issues such as substance abuse, exposure to violence and academic performance were not addressed in the 10 core survey questions. Clearly there is a need for more in-depth information about both the physical and emotional health of Aboriginal children and youth.
Jain, Nidhi; Singleton, James A; Montgomery, Margrethe; Skalland, Benjamin
2009-01-01
Since 1994, the Centers for Disease Control and Prevention has funded the National Immunization Survey (NIS), a large telephone survey used to estimate vaccination coverage of U.S. children aged 19-35 months. The NIS is a two-phase survey that obtains vaccination receipt information from a random-digit-dialed survey, designed to identify households with eligible children, followed by a provider record check, which obtains provider-reported vaccination histories for eligible children. In 2006, the survey was expanded for the first time to include a national sample of adolescents aged 13-17 years, called the NIS-Teen. This article summarizes the methodology used in the NIS-Teen. In 2008, the NIS-Teen was expanded to collect state-specific and national-level data to determine vaccination coverage estimates. This survey provides valuable information to guide immunization programs for adolescents.
Injury severity data for front and second row passengers in frontal crashes.
Atkinson, Theresa; Leszek Gawarecki; Tavakoli, Massoud
2016-06-01
The data contained here were obtained from the National Highway Transportation Safety Administration׳s National Automotive Sampling System - Crashworthiness Data System (NASS-CDS) for the years 2008-2014. This publically available data set monitors motor vehicle crashes in the United States, using a stratified random sample frame, resulting in information on approximately 5000 crashes each year that can be utilized to create national estimates for crashes. The NASS-CDS data sets document vehicle, crash, and occupant factors. These data can be utilized to examine public health, law enforcement, roadway planning, and vehicle design issues. The data provided in this brief are a subset of crash events and occupants. The crashes provided are exclusively frontal crashes. Within these crashes, only restrained occupants who were seated in the right front seat position or the second row outboard seat positions were included. The front row and second row data sets were utilized to construct occupant pairs crashes where both a right front seat occupant and a second row occupant were available. Both unpaired and paired data sets are provided in this brief.
Injury severity data for front and second row passengers in frontal crashes
Atkinson, Theresa; Leszek Gawarecki; Tavakoli, Massoud
2016-01-01
The data contained here were obtained from the National Highway Transportation Safety Administration׳s National Automotive Sampling System – Crashworthiness Data System (NASS-CDS) for the years 2008–2014. This publically available data set monitors motor vehicle crashes in the United States, using a stratified random sample frame, resulting in information on approximately 5000 crashes each year that can be utilized to create national estimates for crashes. The NASS-CDS data sets document vehicle, crash, and occupant factors. These data can be utilized to examine public health, law enforcement, roadway planning, and vehicle design issues. The data provided in this brief are a subset of crash events and occupants. The crashes provided are exclusively frontal crashes. Within these crashes, only restrained occupants who were seated in the right front seat position or the second row outboard seat positions were included. The front row and second row data sets were utilized to construct occupant pairs crashes where both a right front seat occupant and a second row occupant were available. Both unpaired and paired data sets are provided in this brief. PMID:27077084
Racial Convergence in Cigarette Use from Adolescence to the Mid-Thirties*
PAMPEL, FRED C.
2011-01-01
Cigarette smoking by whites and African Americans shows puzzling age differences: An African American advantage during the teen years no longer appears in mid-adulthood. This study uses two data sets to examine whether the life-course change is real–and not due to misleading comparisons across different cohorts–and then whether the racial convergence is consistent with resource or stress arguments emphasizing, respectively, cessation among whites or late initiation among African Americans. First, multilevel growth models using data from the National Youth Survey–a prospective, longitudinal study of a randomly selected national sample of teens followed from ages 12 to 18 in 1977 to ages 26 to 34 in 1992–reveal that the racial convergence in smoking prevalence over the life course among this cohort is due primarily to greater white cessation. Second, consecutive cross-sectional samples of the National Health Survey replicate the broad patterns found in the NYS and show that convergence in smoking trajectories by race has strengthened over time. Together, the results most favor a resource explanation of the different life-course patterns of smoking among whites and African Americans. PMID:19181051
Validation of Statistical Sampling Algorithms in Visual Sample Plan (VSP): Summary Report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nuffer, Lisa L; Sego, Landon H.; Wilson, John E.
2009-02-18
The U.S. Department of Homeland Security, Office of Technology Development (OTD) contracted with a set of U.S. Department of Energy national laboratories, including the Pacific Northwest National Laboratory (PNNL), to write a Remediation Guidance for Major Airports After a Chemical Attack. The report identifies key activities and issues that should be considered by a typical major airport following an incident involving release of a toxic chemical agent. Four experimental tasks were identified that would require further research in order to supplement the Remediation Guidance. One of the tasks, Task 4, OTD Chemical Remediation Statistical Sampling Design Validation, dealt with statisticalmore » sampling algorithm validation. This report documents the results of the sampling design validation conducted for Task 4. In 2005, the Government Accountability Office (GAO) performed a review of the past U.S. responses to Anthrax terrorist cases. Part of the motivation for this PNNL report was a major GAO finding that there was a lack of validated sampling strategies in the U.S. response to Anthrax cases. The report (GAO 2005) recommended that probability-based methods be used for sampling design in order to address confidence in the results, particularly when all sample results showed no remaining contamination. The GAO also expressed a desire that the methods be validated, which is the main purpose of this PNNL report. The objective of this study was to validate probability-based statistical sampling designs and the algorithms pertinent to within-building sampling that allow the user to prescribe or evaluate confidence levels of conclusions based on data collected as guided by the statistical sampling designs. Specifically, the designs found in the Visual Sample Plan (VSP) software were evaluated. VSP was used to calculate the number of samples and the sample location for a variety of sampling plans applied to an actual release site. Most of the sampling designs validated are probability based, meaning samples are located randomly (or on a randomly placed grid) so no bias enters into the placement of samples, and the number of samples is calculated such that IF the amount and spatial extent of contamination exceeds levels of concern, at least one of the samples would be taken from a contaminated area, at least X% of the time. Hence, "validation" of the statistical sampling algorithms is defined herein to mean ensuring that the "X%" (confidence) is actually met.« less
Thompson, Sanna J.; Bender, Kimberly A.; Lewis, Carol M.; Watkins, Rita
2009-01-01
Purpose Homeless youth are at particularly high risk for teen pregnancy; research indicates as many as 20% of homeless young women become pregnant. These pregnant and homeless teens lack financial resources and adequate health care, resulting in increased risk for low– birth-weight babies and high infant mortality. This study investigated individual and family-level predictors of teen pregnancy among a national sample of runaway/homeless youth in order to better understand the needs of this vulnerable population. Methods Data from the Runaway/Homeless Youth Management Information System (RHY MIS) provided a national sample of youth seeking services at crisis shelters. A sub-sample of pregnant females and a random sub-sample (matched by age) of nonpregnant females comprised the study sample (N= 951). Chi-square and t tests identified differences between pregnant and nonpregnant runaway females; maximum likelihood logistic regression identified individual and family-level predictors of teen pregnancy. Results Teen pregnancy was associated with being an ethnic minority, dropping out of school, being away from home for longer periods of time, having a sexually transmitted disease, and feeling abandoned by one's family. Family factors, such as living in a single parent household and experiencing emotional abuse by one's mother, increased the odds of a teen being pregnant. Conclusions The complex problems associated with pregnant runaway/homeless teens create challenges for short-term shelter services. Suggestions are made for extending shelter services to include referrals and coordination with teen parenting programs and other systems of care. PMID:18639785
Binakonsky, Jane; Giga, Noreen; Ross, Craig; Siegel, Michael
2011-01-01
We investigated the extent of jello shot consumption among underage youth. We conducted a pilot study among a non-random national sample of 108 drinkers, ages 16-20 years, recruited from the Knowledge Networks internet panel in 2010 using consecutive sampling. The prevalence of past 30-day jello shot consumption among the 108 16-20 year-old drinkers in our sample was 21.4% and among those who consumed jello shots, the percentage of alcohol consumption attributable to jello shots averaged 14.5%. We conclude that jello shot use is prevalent among youth, representing a substantial proportion of their alcohol intake. Surveillance of youth alcohol use should include jello shot consumption. PMID:21174500
Protocol for monitoring forest-nesting birds in National Park Service parks
Dawson, Deanna K.; Efford, Murray G.
2013-01-01
These documents detail the protocol for monitoring forest-nesting birds in National Park Service parks in the National Capital Region Network (NCRN). In the first year of sampling, counts of birds should be made at 384 points on the NCRN spatially randomized grid, developed to sample terrestrial resources. Sampling should begin on or about May 20 and continue into early July; on each day the sampling period begins at sunrise and ends five hours later. Each point should be counted twice, once in the first half of the field season and once in the second half, with visits made by different observers, balancing the within-season coverage of points and their spatial coverage by observers, and allowing observer differences to be tested. Three observers, skilled in identifying birds of the region by sight and sound and with previous experience in conducting timed counts of birds, will be needed for this effort. Observers should be randomly assigned to ‘routes’ consisting of eight points, in close proximity and, ideally, in similar habitat, that can be covered in one morning. Counts are 10 minutes in length, subdivided into four 2.5-min intervals. Within each time interval, new birds (i.e., those not already detected) are recorded as within or beyond 50 m of the point, based on where first detected. Binomial distance methods are used to calculate annual estimates of density for species. The data are also amenable to estimation of abundance and detection probability via the removal method. Generalized linear models can be used to assess between-year changes in density estimates or unadjusted count data. This level of sampling is expected to be sufficient to detect a 50% decline in 10 years for approximately 50 bird species, including 14 of 19 species that are priorities for conservation efforts, if analyses are based on unadjusted count data, and for 30 species (6 priority species) if analyses are based on density estimates. The estimates of required sample sizes are based on the mean number of individuals detected per 10 minutes in available data from surveys in three NCRN parks. Once network-wide data from the first year of sampling are available, this and other aspects of the protocol should be re-assessed, and changes made as desired or necessary before the start of the second field season. Thereafter, changes should not be made to the field methods, and sampling should be conducted annually for at least ten years. NCRN staff should keep apprised of new analytical methods developed for analysis of point-count data.
The Design and Implementation of the 2016 National Survey of Children's Health.
Ghandour, Reem M; Jones, Jessica R; Lebrun-Harris, Lydie A; Minnaert, Jessica; Blumberg, Stephen J; Fields, Jason; Bethell, Christina; Kogan, Michael D
2018-05-09
Introduction Since 2001, the Health Resources and Services Administration's Maternal and Child Health Bureau (HRSA MCHB) has funded and directed the National Survey of Children's Health (NSCH) and the National Survey of Children with Special Health Care Needs (NS-CSHCN), unique sources of national and state-level data on child health and health care. Between 2012 and 2015, HRSA MCHB redesigned the surveys, combining content into a single survey, and shifting from a periodic interviewer-assisted telephone survey to an annual self-administered web/paper-based survey utilizing an address-based sampling frame. Methods The U.S. Census Bureau fielded the redesigned NSCH using a random sample of addresses drawn from the Census Master Address File, supplemented with a unique administrative flag to identify households most likely to include children. Data were collected June 2016-February 2017 using a multi-mode design, encouraging web-based responses while allowing for paper mail-in responses. A parent/caregiver knowledgeable about the child's health completed an age-appropriate questionnaire. Experiments on incentives, branding, and contact strategies were conducted. Results Data were released in September 2017. The final sample size was 50,212 children; the overall weighted response rate was 40.7%. Comparison of 2016 estimates to those from previous survey iterations are not appropriate due to sampling and mode changes. Discussion The NSCH remains an invaluable data source for key measures of child health and attendant health care system, family, and community factors. The redesigned survey extended the utility of this resource while seeking a balance between previous strengths and innovations now possible.
Intentions to donate to a biobank in a national sample of African Americans.
McDonald, Jasmine A; Vadaparampil, Susan; Bowen, Deborah; Magwood, Gayenell; Obeid, Jihad S; Jefferson, Melanie; Drake, Richard; Gebregziabher, Mulugeta; Hughes Halbert, Chanita
2014-01-01
Despite the investments being made to develop biobanks, African Americans are under-represented in genomic studies. We identified factors having significant independent associations with intentions to donate personal health information and blood and/or tissue samples to a biobank in a national random sample of African Americans (n = 1,033). We conducted a national survey from October 2010 through February 2011. Twenty-three percent of respondents reported that it was not at all likely that they would donate to a biobank, 18% reported it was a little likely, 36% reported it was somewhat likely, and 23% reported it was very likely. Respondents who were likely to donate to a biobank had greater positive expectations about participating in cancer genetics research and reported more participation facilitators relative to barriers. Respondents who were distrustful of researchers had a significantly lower likelihood of being willing to donate to a biobank compared to those who were less distrustful. African Americans have diverse attitudes about participating in genetics research, and many are likely to donate to a biobank based on expectations of positive outcomes. It may be important to address attitudes about genetics research as part of recruitment to enhance the quality of informed consent for participation in biobanks among African Americans. © 2014 S. Karger AG, Basel.
Intentions to Donate to a Biobank in a National Sample of African Americans
McDonald, Jasmine A.; Vadaparampil, Susan; Bowen, Deborah; Magwood, Gayenell; Obeid, Jihad S.; Jefferson, Melanie; Drake, Richard; Gebregziabher, Mulugeta; Halbert, Chanita Hughes
2015-01-01
Background/Aims Despite the investments being made to develop biobanks, African Americans are under-represented in genomic studies. We identified factors having significant independent associations with intentions to donate personal health information and blood and/or tissue samples to a biobank in a national, random sample of African Americans (n=1,033). Methods National survey conducted from October 2010 through February 2011. Results 23% of respondents reported that it was not at all likely that they would donate to a biobank, 18% reported a little likely, 36% reported somewhat likely, and 23% reported very likely. Respondents who were likely to donate to a biobank had greater positive expectations about participating in cancer genetics research and reported more participation facilitators relative to barriers. Respondents who were distrustful of researchers had a significantly lower likelihood of being willing to donate to a biobank compared to those who were less distrustful. Conclusions African Americans have diverse attitudes about participating in genetics research and many are likely to donate to a biobank based on expectations of positive outcomes. It may be important to address attitudes about genetics research as part of recruitment to enhance the quality of informed consent for participation in biobanks among African Americans. PMID:24942180
Effect of Map-vaccination in ewes on body condition score, weight and Map-shedding.
Hüttner, Klim; Krämer, Ulla; Kleist, Petra
2012-01-01
Vaccination against Mycobacterium avium subspecies paratuberculosis (Map) in sheep receives growing attention worldwide, particularly in countries with national Map control strategies. A field study was conducted, investigating the effect of GUDAIR on body condition, weight and Map-shedding in a professionally managed but largely Map-affected suffolk flock prior and after vaccination. For this, 80 ewes out of 1000 animals were randomly sampled. In the univariate analysis body condition scores of ewes twelve months after vaccination improved significantly compared to those sampled prior to vaccination. At the same time the rate of ewes shedding Map was reduced by 37%.
Handa, Sudhanshu; Peterman, Amber; Seidenfeld, David; Tembo, Gelson
2016-02-01
There is promising recent evidence that poverty-targeted social cash transfers have potential to improve maternal health outcomes; however, questions remain surrounding design features responsible for impacts. In addition, virtually no evidence exists from the African region. This study explores the impact of Zambia's Child Grant Program on a range of maternal health utilization outcomes using a randomized design and difference-in-differences multivariate regression from data collected over 24 months from 2010 to 2012. Results indicate that while there are no measurable program impacts among the main sample, there are heterogeneous impacts on skilled attendance at birth among a sample of women residing in households having better access to maternal health services. The latter result is particularly interesting because of the overall low level of health care availability in program areas suggesting that dedicated program design or matching supply-side interventions may be necessary to leverage unconditional cash transfers in similar settings to impact maternal health. Copyright © 2015 John Wiley & Sons, Ltd.
Handa, Sudhanshu; Peterman, Amber; Seidenfeld, David; Tembo, Gelson
2017-01-01
There is promising recent evidence that poverty-targeted social cash transfers have potential to improve maternal health outcomes, however questions remain surrounding design features responsible for impacts. In addition, virtually no evidence exists from the African region. This study explores the impact of Zambia’s Child Grant Program on a range of maternal health utilization outcomes using a randomized design and difference-in-differences multivariate regression from data collected over 24 months from 2010 to 2012. Results indicate that while there are no measurable program impacts among the main sample, there are heterogeneous impacts on skilled attendance at birth among a sample of women residing in households having better access to maternal health services. The latter result is particularly interesting because of the overall low level of healthcare availability in program areas suggesting dedicated program design or matching supply-side interventions may be necessary to leverage unconditional cash transfers in similar settings to impact maternal health. PMID:25581062
Visitor and community survey results for Prime Hook National Wildlife Refuge: Completion report
Sexton, Natalie R.; Stewart, Susan C.; Koontz, Lynne; Ponds, Phadrea; Walters, Katherine D.
2007-01-01
Community residents’ perceptions and opinions Data for this study were collected using a survey administered to visitors to Prime Hook NWR and individuals living in the communities surrounding the Refuge. Surveys were randomly distributed to both consumptive and nonconsumptive use visitors over a one year period (September 2004 to September 2005) to account for seasonal variation in Refuge use. Three hundred thirty-two visitor surveys were returned for a response rate of 80 percent with a confidence interval of ± 5.4. Surveys were also distributed to a stratified random sample of community members in adjacent and surrounding areas (Slaughter Beach, Broadkill Beach, Prime Hook Beach, Milton, Lewes, Milford, and surrounding communities). Four hundred ninety-one surveys from the overall community sample were returned for a response rate of 39 percent with a ± 4.4 confidence interval. Community member results were weighted by U.S. Census Bureau data to correct for age and gender bias, and for community proportionality.
Cha, Sarah; Erar, Bahar; Niaura, Raymond S.; Graham, Amanda L.
2016-01-01
Background The potential for sampling bias in Internet smoking cessation studies is widely recognized. However, few studies have explicitly addressed the issue of sample representativeness in the context of an Internet smoking cessation treatment trial. Purpose To examine the generalizability of participants enrolled in a randomized controlled trial of an Internet smoking cessation intervention using weighted data from the National Health Interview Survey (NHIS). Methods A total of 5,290 new users on a smoking cessation website enrolled in the trial between March 2012–January 2015. Descriptive statistics summarized baseline characteristics of screened and enrolled participants and multivariate analysis examined predictors of enrollment. Generalizability analyses compared demographic and smoking characteristics of trial participants to current smokers in the 2012–2014 waves of NHIS (n=19,043), and to an NHIS subgroup based on Internet use and cessation behavior (n=3,664). Effect sizes were obtained to evaluate the magnitude of differences across variables. Results Predictors of study enrollment were age, gender, race, education, and motivation to quit. Compared to NHIS smokers, trial participants were more likely to be female, college educated, daily smokers, and to have made a quit attempt in the past year (all effect sizes 0.25–0.60). In comparisons with the NHIS subgroup, differences in gender and education were attenuated while differences in daily smoking and smoking rate were amplified. Conclusions Few differences emerged between Internet trial participants and nationally representative samples of smokers, and all were in expected directions. This study highlights the importance of assessing generalizability in a focused and specific manner. PMID:27283295
Cha, Sarah; Erar, Bahar; Niaura, Raymond S; Graham, Amanda L
2016-10-01
The potential for sampling bias in Internet smoking cessation studies is widely recognized. However, few studies have explicitly addressed the issue of sample representativeness in the context of an Internet smoking cessation treatment trial. The purpose of the present study is to examine the generalizability of participants enrolled in a randomized controlled trial of an Internet smoking cessation intervention using weighted data from the National Health Interview Survey (NHIS). A total of 5290 new users on a smoking cessation website enrolled in the trial between March 2012 and January 2015. Descriptive statistics summarized baseline characteristics of screened and enrolled participants, and multivariate analysis examined predictors of enrollment. Generalizability analyses compared demographic and smoking characteristics of trial participants to current smokers in the 2012-2014 waves of NHIS (n = 19,043) and to an NHIS subgroup based on Internet use and cessation behavior (n = 3664). Effect sizes were obtained to evaluate the magnitude of differences across variables. Predictors of study enrollment were age, gender, race, education, and motivation to quit. Compared to NHIS smokers, trial participants were more likely to be female, college educated, and daily smokers and to have made a quit attempt in the past year (all effect sizes 0.25-0.60). In comparisons with the NHIS subgroup, differences in gender and education were attenuated, while differences in daily smoking and smoking rate were amplified. Few differences emerged between Internet trial participants and nationally representative samples of smokers, and all were in expected directions. This study highlights the importance of assessing generalizability in a focused and specific manner. CLINICALTRIALS.GOV: #NCT01544153.
Shifting the focus to practice quality improvement in radiation oncology.
Crozier, Cheryl; Erickson-Wittmann, Beth; Movsas, Benjamin; Owen, Jean; Khalid, Najma; Wilson, J Frank
2011-09-01
To demonstrate how the American College of Radiology, Quality Research in Radiation Oncology (QRRO) process survey database can serve as an evidence base for assessing quality of care in radiation oncology. QRRO has drawn a stratified random sample of radiation oncology facilities in the USA and invited those facilities to participate in a Process Survey. Information from a prior QRRO Facilities Survey has been used along with data collected under the current National Process Survey to calculate national averages and make statistically valid inferences for national process measures for selected cancers in which radiation therapy plays a major role. These measures affect outcomes important to patients and providers and measure quality of care. QRRO's survey data provides national benchmark data for numerous quality indicators. The Process Survey is "fully qualified" as a Practice Quality Improvement project by the American Board of Radiology under its Maintenance of Certification requirements for radiation oncology and radiation physics. © 2011 National Association for Healthcare Quality.
Lim, Raymond Boon Tar; Tham, Dede Kam Tyng; Müller-Riemenschneider, Falk; Wong, Mee Lian
2017-04-01
Data are lacking on fruit and vegetable (FV) consumption among young adults in the Asia-Pacific region. The aim of this study is to assess the prevalence of students who met the international and national recommendation of daily consumption of 5 and 4 FV servings, respectively, in a university in Singapore and the factors associated with meeting the national recommendation. A cross-sectional survey using proportional stratified random sampling was conducted on 884 undergraduates in 2013. The prevalence of meeting the international and national recommendation was 13.6% and 27.1%, respectively. The significant factors of meeting national recommendation were those from higher socioeconomic status, those making conscious effort to eat food high in fiber, those not skipping breakfast, those having a lower frequency of deep fried food consumption and those with higher meal frequency. Behavioral and structural interventions to educate, motivate and nudge university students to promote FV consumption are required in Singapore.
Assessing relative abundance and reproductive success of shrubsteppe raptors
Lehman, Robert N.; Carpenter, L.B.; Steenhof, Karen; Kochert, Michael N.
1998-01-01
From 1991-1994, we quantified relative abundance and reproductive success of the Ferruginous Hawk (Buteo regalis), Northern Harrier (Circus cyaneus), Burrowing Owl (Speotytoc unicularia), and Short-eared Owl (Asio flammeus) on the shrubsteppe plateaus (benchlands) in and near the Snake River Birds of Prey National Conservation Area in southwestern Idaho. To assess relative abundance, we searched randomly selected plots using four sampling methods: point counts, line transects, and quadrats of two sizes. On a persampling-effort basis, transects were slightly more effective than point counts and quadrats for locating raptor nests (3.4 pairs detected/100 h of effort vs. 2.2-3.1 pairs). Random sampling using quadrats failed to detect a Short-eared Owl population increase from 1993 to 1994. To evaluate nesting success, we tried to determine reproductive outcome for all nesting attempts located during random, historical, and incidental nest searches. We compared nesting success estimates based on all nesting attempts, on attempts found during incubation, and the Mayfield model. Most pairs used to evaluate success were pairs found incidentally. Visits to historical nesting areas yielded the highest number of pairs per sampling effort (14.6/100 h), but reoccupancy rates for most species decreased through time. Estimates based on all attempts had the highest sample sizes but probably overestimated success for all species except the Ferruginous Hawk. Estimates of success based on nesting attempts found during incubation had the lowest sample sizes. All three methods yielded biased nesting snccess estimates for the Northern Harrier and Short-eared Owl. The estimate based on pairs found during incubation probably provided the least biased estimate for the Burrowing Owl. Assessments of nesting success were hindered by difficulties in confirming egg laying and nesting success for all species except the Ferruginous hawk.
Liew, Zeyan; Ritz, Beate; von Ehrenstein, Ondine S; Bech, Bodil Hammer; Nohr, Ellen Aagaard; Fei, Chunyuan; Bossi, Rossana; Henriksen, Tine Brink; Bonefeld-Jørgensen, Eva Cecilie; Olsen, Jørn
2015-04-01
Perfluoroalkyl substances (PFASs) are persistent pollutants found to be endocrine disruptive and neurotoxic in animals. Positive correlations between PFASs and neurobehavioral problems in children were reported in cross-sectional data, but findings from prospective studies are limited. We investigated whether prenatal exposure to PFASs is associated with attention deficit/hyperactivity disorder (ADHD) or childhood autism in children. Among 83,389 mother-child pairs enrolled in the Danish National Birth Cohort during 1996-2002, we identified 890 ADHD cases and 301 childhood autism cases from the Danish National Hospital Registry and the Danish Psychiatric Central Registry. From this cohort, we randomly selected 220 cases each of ADHD and autism, and we also randomly selected 550 controls frequency matched by child's sex. Sixteen PFASs were measured in maternal plasma collected in early or mid-pregnancy. We calculated risk ratios (RRs) using generalized linear models, taking into account sampling weights. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were detected in all samples; four other PFASs were quantified in ≥ 90% of the samples. We did not find consistent evidence of associations between mother's PFAS plasma levels and ADHD [per natural log nanograms per milliliter increase: PFOS RR = 0.87 (95% CI: 0.74, 1.02); PFOA RR = 0.98 (95% CI: 0.82, 1.16)] or autism [per natural log nanograms per milliliter increase: PFOS RR = 0.92 (95% CI: 0.69, 1.22); PFOA RR = 0.98 (95% CI: 0.73, 1.31)]. We found positive as well as negative associations between higher PFAS quartiles and ADHD in models that simultaneously adjusted for all PFASs, but these estimates were imprecise. In this study we found no consistent evidence to suggest that prenatal PFAS exposure increases the risk of ADHD or childhood autism in children.
Contaminants in fish tissue from US lakes and reservoirs: A ...
An unequal probability design was used to develop national estimates for 268 persistent, bioaccumulative, and toxic chemicals in fish tissue from lakes and reservoirs of the conterminous United States (excluding the Laurentian Great Lakes and Great Salt Lake). Predator (fillet) and bottom-dweller (whole-body) composites were collected from 500 lakes selected randomly from the target population of 147,343 lakes in the lower 48 states. Each of these composite types comprised nationally representative samples whose results were extrapolated to the sampled population of an estimated 76,559 lakes for predators and 46,190 lakes for bottom dwellers. Mercury and PCBs were detected in all fish samples. Dioxins and furans were detected in 81% and 99% of predator and bottom-dweller samples, respectively. Cumulative frequency distributions showed that mercury concentrations exceeded the EPA 300 ppb mercury fish tissue criterion at nearly half of the lakes in the sampled population. Total PCB concentrations exceeded a 12 ppb human health risk-based consumption limit at nearly 17% of lakes, and dioxins and furans exceeded a 0.15 ppt (toxic equivalent or TEQ) risk-based threshold at nearly 8% of lakes in the sampled population. In contrast, 43 target chemicals were not detected in any samples. No detections were reported for nine organophosphate pesticides, one PCB congener, 16 polycyclic aromatic hydrocarbons, or 17 other semivolatile organic chemicals. An unequal prob
Stromberg, Bert E; Gasbarre, Louis C; Ballweber, Lora R; Dargatz, David A; Rodriguez, Judith M; Kopral, Christine A; Zarlenga, Dante S
2015-10-01
During the United States Department of Agriculture (USDA) National Animal Health Monitoring System's (NAHMS) 2007-2008 beef study, 567 producers from 24 US States were offered the opportunity to collect fecal samples from weaned beef calves and have them evaluated for the presence of parasite eggs (Phase 1). Participating producers were provided with instructions and materials for sample collection. Up to 20 fresh fecal samples were collected from each of the 99 participating operations. Fresh fecal samples were submitted to one of 3 randomly assigned laboratories for evaluation. Upon arrival at the laboratories, all samples were processed for the enumeration of strongyle, Nematodirus, and Trichuris eggs using the modified Wisconsin technique. The presence or absence of coccidian oocysts and tapeworm eggs was also noted. In submissions where the strongyle eggs per gram exceeded 30, aliquots from 2 to 6 animals were pooled for DNA extraction. Extracted DNA was subjected to genus level polymerase chain reaction (PCR) identification for the presence of Ostertagia, Cooperia, Haemonchus, Oesophagostomum, and Trichostrongylus. In this study, 85.6% of the samples had strongyle type, Nematodirus, and Trichuris eggs. Among the samples evaluated, 91% had Cooperia, 79% Ostertagia, 53% Haemonchus, 38% Oesophagostomum, 18% Nematodirus, 7% Trichuris, and 3% Trichostrongylus. The prevalence of coccidia and tapeworm eggs was 59.9% and 13.7%, respectively.
Stromberg, Bert E.; Gasbarre, Louis C.; Ballweber, Lora R.; Dargatz, David A.; Rodriguez, Judith M.; Kopral, Christine A.; Zarlenga, Dante S.
2015-01-01
During the United States Department of Agriculture (USDA) National Animal Health Monitoring System’s (NAHMS) 2007–2008 beef study, 567 producers from 24 US States were offered the opportunity to collect fecal samples from weaned beef calves and have them evaluated for the presence of parasite eggs (Phase 1). Participating producers were provided with instructions and materials for sample collection. Up to 20 fresh fecal samples were collected from each of the 99 participating operations. Fresh fecal samples were submitted to one of 3 randomly assigned laboratories for evaluation. Upon arrival at the laboratories, all samples were processed for the enumeration of strongyle, Nematodirus, and Trichuris eggs using the modified Wisconsin technique. The presence or absence of coccidian oocysts and tapeworm eggs was also noted. In submissions where the strongyle eggs per gram exceeded 30, aliquots from 2 to 6 animals were pooled for DNA extraction. Extracted DNA was subjected to genus level polymerase chain reaction (PCR) identification for the presence of Ostertagia, Cooperia, Haemonchus, Oesophagostomum, and Trichostrongylus. In this study, 85.6% of the samples had strongyle type, Nematodirus, and Trichuris eggs. Among the samples evaluated, 91% had Cooperia, 79% Ostertagia, 53% Haemonchus, 38% Oesophagostomum, 18% Nematodirus, 7% Trichuris, and 3% Trichostrongylus. The prevalence of coccidia and tapeworm eggs was 59.9% and 13.7%, respectively. PMID:26424909
Breslow, Norman E.; Lumley, Thomas; Ballantyne, Christie M; Chambless, Lloyd E.; Kulich, Michal
2009-01-01
The case-cohort study involves two-phase sampling: simple random sampling from an infinite super-population at phase one and stratified random sampling from a finite cohort at phase two. Standard analyses of case-cohort data involve solution of inverse probability weighted (IPW) estimating equations, with weights determined by the known phase two sampling fractions. The variance of parameter estimates in (semi)parametric models, including the Cox model, is the sum of two terms: (i) the model based variance of the usual estimates that would be calculated if full data were available for the entire cohort; and (ii) the design based variance from IPW estimation of the unknown cohort total of the efficient influence function (IF) contributions. This second variance component may be reduced by adjusting the sampling weights, either by calibration to known cohort totals of auxiliary variables correlated with the IF contributions or by their estimation using these same auxiliary variables. Both adjustment methods are implemented in the R survey package. We derive the limit laws of coefficients estimated using adjusted weights. The asymptotic results suggest practical methods for construction of auxiliary variables that are evaluated by simulation of case-cohort samples from the National Wilms Tumor Study and by log-linear modeling of case-cohort data from the Atherosclerosis Risk in Communities Study. Although not semiparametric efficient, estimators based on adjusted weights may come close to achieving full efficiency within the class of augmented IPW estimators. PMID:20174455
ERIC Educational Resources Information Center
1999
This report presents the data from a national, random sample survey designed by the Kaiser Family Foundation and Princeton Survey Research Associates (PSRA) and conducted by PSRA by telephone between April 6-26, 1999, when 1001 parents of children ages 2-17 were interviewed about their opinions of television, the V-Chip, and the TV ratings system.…
Café, Ana Carolina Corrêa; Lopes, Carlos Alexandre de Oliveira; Novais, Rommel Larcher Rachid; Bila, Wendell Costa; da Silva, Daniely Karoline; Romano, Márcia Christina Caetano; Lamounier, Joel Alves
2018-01-01
ABSTRACT Objective: To systematize literature references addressing the association of sugar-sweetened beverage (SSB) and milk intake with body mass index (BMI) in adolescents. Data source: A search was carried out in PubMed (US National Library of Medicine National Institutes of Health) and BVS (Virtual Library in Health). The descriptors used were: adolescents, young adult, beverages, drinking, obesity, overweight, BMI, and nutritional status. The following filters were applied: age ranging from 10 to 19 years, studies published in Portuguese or English language between 2011-2015. Data synthesis: Thirty studies were selected (22 cross-sectional studies, 4 cohort studies, 1 randomized clinical trial, 1 case-control study, and 1 quasi-experimental study). There was association between the intake of these beverages and increase in BMI in 55% of all 20 studies that dealt with sugary drinks. When it came to soft drinks, 100% of studies reported association with increase in BMI. As to milk intake, only one article showed association with increased BMI. Three articles reported milk as a protection factor against increase in BMI; three studies found no association between this intake and BMI. Nineteen studies had representative samples and 20 surveys reported random samples. Among papers using questionnaires, 84% had been validated. Conclusions: There is no consensus in the literature about the association between SSB or milk intake and BMI in adolescents. PMID:29513855
Wheelock, Ana; Miraldo, Marisa; Thomson, Angus; Vincent, Charles; Sevdalis, Nick
2017-01-01
Objectives Despite continuous efforts to improve influenza vaccination coverage, uptake among high-risk groups remains suboptimal. We aimed to identify policy amenable factors associated with vaccination and to measure their importance in order to assist in the monitoring of vaccination sentiment and the design of communication strategies and interventions to improve vaccination rates. Setting The USA, the UK and France. Participants A total of 2412 participants were surveyed across the three countries. Outcome measures Self-reported influenza vaccination. Methods Between March and April 2014, a stratified random sampling strategy was employed with the aim of obtaining nationally representative samples in the USA, the UK and France through online databases and random-digit dialling. Participants were asked about vaccination practices, perceptions and feelings. Multivariable logistic regression was used to identify factors associated with past influenza vaccination. Results The models were able to explain 64%–80% of the variance in vaccination behaviour. Overall, sociopsychological variables, which are inherently amenable to policy, were better at explaining past vaccination behaviour than demographic, socioeconomic and health variables. Explanatory variables included social influence (physician), influenza and vaccine risk perceptions and traumatic childhood experiences. Conclusions Our results indicate that evidence-based sociopsychological items should be considered for inclusion into national immunisation surveys to gauge the public’s views, identify emerging concerns and thus proactively and opportunely address potential barriers and harness vaccination drivers. PMID:28706088
Café, Ana Carolina Corrêa; Lopes, Carlos Alexandre de Oliveira; Novais, Rommel Larcher Rachid; Bila, Wendell Costa; Silva, Daniely Karoline da; Romano, Márcia Christina Caetano; Lamounier, Joel Alves
2018-01-01
To systematize literature references addressing the association of sugar-sweetened beverage (SSB) and milk intake with body mass index (BMI) in adolescents. A search was carried out in PubMed (US National Library of Medicine National Institutes of Health) and BVS (Virtual Library in Health). The descriptors used were: adolescents, young adult, beverages, drinking, obesity, overweight, BMI, and nutritional status. The following filters were applied: age ranging from 10 to 19 years, studies published in Portuguese or English language between 2011-2015. Thirty studies were selected (22 cross-sectional studies, 4 cohort studies, 1 randomized clinical trial, 1 case-control study, and 1 quasi-experimental study). There was association between the intake of these beverages and increase in BMI in 55% of all 20 studies that dealt with sugary drinks. When it came to soft drinks, 100% of studies reported association with increase in BMI. As to milk intake, only one article showed association with increased BMI. Three articles reported milk as a protection factor against increase in BMI; three studies found no association between this intake and BMI. Nineteen studies had representative samples and 20 surveys reported random samples. Among papers using questionnaires, 84% had been validated. There is no consensus in the literature about the association between SSB or milk intake and BMI in adolescents.
Lin, Po-Hung; Lin, Shun-Ku; Hsu, Ren-Jun; Cheng, Kuan-Chen; Liu, Jui-Ming
2016-01-01
To investigate the pattern of Traditional Chinese Medicine (TCM) usage for urolithiasis patients in Taiwan and to determine the most common Chinese herbal products used for urolithiasis. Retrospective review of urolithiasis patients treated with TCM treatment. One million randomly selected samples in the Taiwanese National Health Insurance Research Database between 1997 and 2008. Eighty-two thousand five hundred and fifty-one newly diagnosed urolithiasis patients. The correlation between TCM treatment, demographic factors, or medical conditions. A total of 62.6% of urolithiasis patients use TCM treatment. A younger age, female gender, polypharmacy, multiple comorbidities, and stone in the lower urinary tract result in a greater tendency to use TCM, after adjusting for demographic factors. Jia-Wei-Xiao-Yao-San Extract Powder and Ji-Sheng-Shen-Qi-Wan Extract Powder are the most frequently prescribed Chinese medicine formulae. This is the first study to examine the use of and the prescription pattern for TCM in urolithiasis patients using a random, national population-based sample. More than 62% of urolithiasis patients use TCM, and patients with polypharmacy, multiple comorbidities, and stone in the ureter are more likely to use TCM. The most frequently prescribed Chinese medicine formulae were Jia-Wei-Xiao-Yao-San Extract Powder and Ji-Sheng-Shen-Qi-Wan Extract Powder, which were reported to retard the progression of renal failure and alleviate flank pain or tenderness.
Forsberg, Lars Georg; Ernst, Denise; Sundqvist, Kristina; Farbring, Carl Åke
2011-01-01
A sample of 296 drug-using inmates in 14 Swedish prisons was randomized during 2004-2006 into three intervention groups; Motivational Interviewing delivered by counselors with workshop-only training, or by counselors with workshop training followed by peer group supervision, and controls. Drug and alcohol use was measured by the Addiction Severity Index (ASI) at intake and at 10 months after release. Complete data from 114 clients were analyzed by a stepwise regression analysis. All three groups reduced alcohol and drug use. Limitations in the study are discussed and future research is suggested. The study is financed by grants from the Research Committee of the National Prison and Probation Administration.
Thomas, Hannah J; Connor, Jason P; Lawrence, David M; Hafekost, Jennifer M; Zubrick, Stephen R; Scott, James G
2017-09-01
Bullying prevalence studies are limited by varied measurement methods and a lack of representative samples. This study estimated the national prevalence of bullying victimisation, perpetration and combined victim-perpetration experiences in a representative population-based sample of Australian youth. The relationships between the three types of bullying involvement with a range of mental health symptoms and diagnoses were also examined. A randomly selected nationally representative sample aged 11-17 years ( N = 2967, M age = 14.6 years; 51.6% male) completed the youth component of the Second Australian Child and Adolescent Survey of Mental Health and Wellbeing (Young Minds Matter). Parents or carers also completed a structured face-to-face interview that asked questions about a single randomly selected child in the household. The youth survey comprised self-reported bullying victimisation and perpetration (Olweus Bully-Victim Questionnaire-adapted), psychological distress (K10), emotional and behavioural problems (Strengths and Difficulties Questionnaire), as well as self-harm, suicide attempts and substance use. Modules from the Diagnostic Interview Schedule for Children Version IV were administered to all youth and parents to assess for mental disorder diagnoses (major depressive disorder, any anxiety disorder and any externalising disorder [attention-deficit hyperactivity disorder, oppositional defiant disorder and conduct disorder]). The 12-month prevalence of bullying victimisation was 13.3%, perpetration 1.6% and victim-perpetration 1.9%. Logistic regression models showed all forms of involvement in bullying were associated with increased risk of psychological distress, emotional and behavioural problems, substance use, self-harm and attempted suicide. Victimisation and victim-perpetration were associated with youth-reported major depressive disorder. There were also significant associations between bullying involvement and parent-reported diagnoses of major depressive disorder, any anxiety disorder and any externalising disorder. Bullying continues to be frequently experienced by Australian adolescents. The current findings showed that involvement in any bullying behaviour was associated with increased risk of concurrent mental health problems. This evidence can be used to inform decisions concerning the allocation of resources to address this important health issue.
Thompson, William L.; Miller, Amy E.; Mortenson, Dorothy C.; Woodward, Andrea
2011-01-01
Monitoring natural resources in Alaskan national parks is challenging because of their remoteness, limited accessibility, and high sampling costs. We describe an iterative, three-phased process for developing sampling designs based on our efforts to establish a vegetation monitoring program in southwest Alaska. In the first phase, we defined a sampling frame based on land ownership and specific vegetated habitats within the park boundaries and used Path Distance analysis tools to create a GIS layer that delineated portions of each park that could be feasibly accessed for ground sampling. In the second phase, we used simulations based on landcover maps to identify size and configuration of the ground sampling units (single plots or grids of plots) and to refine areas to be potentially sampled. In the third phase, we used a second set of simulations to estimate sample size and sampling frequency required to have a reasonable chance of detecting a minimum trend in vegetation cover for a specified time period and level of statistical confidence. Results of the first set of simulations indicated that a spatially balanced random sample of single plots from the most common landcover types yielded the most efficient sampling scheme. Results of the second set of simulations were compared with field data and indicated that we should be able to detect at least a 25% change in vegetation attributes over 31. years by sampling 8 or more plots per year every five years in focal landcover types. This approach would be especially useful in situations where ground sampling is restricted by access.
Design and analysis of group-randomized trials in cancer: A review of current practices.
Murray, David M; Pals, Sherri L; George, Stephanie M; Kuzmichev, Andrey; Lai, Gabriel Y; Lee, Jocelyn A; Myles, Ranell L; Nelson, Shakira M
2018-06-01
The purpose of this paper is to summarize current practices for the design and analysis of group-randomized trials involving cancer-related risk factors or outcomes and to offer recommendations to improve future trials. We searched for group-randomized trials involving cancer-related risk factors or outcomes that were published or online in peer-reviewed journals in 2011-15. During 2016-17, in Bethesda MD, we reviewed 123 articles from 76 journals to characterize their design and their methods for sample size estimation and data analysis. Only 66 (53.7%) of the articles reported appropriate methods for sample size estimation. Only 63 (51.2%) reported exclusively appropriate methods for analysis. These findings suggest that many investigators do not adequately attend to the methodological challenges inherent in group-randomized trials. These practices can lead to underpowered studies, to an inflated type 1 error rate, and to inferences that mislead readers. Investigators should work with biostatisticians or other methodologists familiar with these issues. Funders and editors should ensure careful methodological review of applications and manuscripts. Reviewers should ensure that studies are properly planned and analyzed. These steps are needed to improve the rigor and reproducibility of group-randomized trials. The Office of Disease Prevention (ODP) at the National Institutes of Health (NIH) has taken several steps to address these issues. ODP offers an online course on the design and analysis of group-randomized trials. ODP is working to increase the number of methodologists who serve on grant review panels. ODP has developed standard language for the Application Guide and the Review Criteria to draw investigators' attention to these issues. Finally, ODP has created a new Research Methods Resources website to help investigators, reviewers, and NIH staff better understand these issues. Published by Elsevier Inc.
Evaluation of bias and logistics in a survey of adults at increased risk for oral health decrements.
Gilbert, G H; Duncan, R P; Kulley, A M; Coward, R T; Heft, M W
1997-01-01
Designing research to include sufficient respondents in groups at highest risk for oral health decrements can present unique challenges. Our purpose was to evaluate bias and logistics in this survey of adults at increased risk for oral health decrements. We used a telephone survey methodology that employed both listed numbers and random digit dialing to identify dentate persons 45 years old or older and to oversample blacks, poor persons, and residents of nonmetropolitan counties. At a second stage, a subsample of the respondents to the initial telephone screening was selected for further study, which consisted of a baseline in-person interview and a clinical examination. We assessed bias due to: (1) limiting the sample to households with telephones, (2) using predominantly listed numbers instead of random digit dialing, and (3) nonresponse at two stages of data collection. While this approach apparently created some biases in the sample, they were small in magnitude. Specifically, limiting the sample to households with telephones biased the sample overall toward more females, larger households, and fewer functionally impaired persons. Using predominantly listed numbers led to a modest bias toward selection of persons more likely to be younger, healthier, female, have had a recent dental visit, and reside in smaller households. Blacks who were selected randomly at a second stage were more likely to participate in baseline data gathering than their white counterparts. Comparisons of the data obtained in this survey with those from recent national surveys suggest that this methodology for sampling high-risk groups did not substantively bias the sample with respect to two important dental parameters, prevalence of edentulousness and dental care use, nor were conclusions about multivariate associations with dental care recency substantively affected. This method of sampling persons at high risk for oral health decrements resulted in only modest bias with respect to the population of interest.
Clinical growth charts for pre-school children.
Al-Amoud, Maysoon M; Al-Mazrou, Yagob Y; El-Gizouli, Sirrag E; Khoja, Tawfik A; Al-Turki, Khalid A
2004-11-01
Growth standards are indicators for normal growth of the children and growth charts are important tools for their growth monitoring. Children from different populations are different in their growth pattern, it is important to create national standards for the growth of children in each population to develop local growth charts, and since these were not available in the Kingdom of Saudi Arabia (KSA), the aim of this study was to construct national growth standards and to develop growth charts for 0-5-years Saudi children. A cross-sectional study following World Health Organization (WHO) criteria in determining sample size was adopted, where by 24000 children from 5 regions in the KSA were selected during the period 1992 to 1995 to be the desired sample. One hundred and two Primary Health Care centers (PHCCs) were selected randomly from the 5 regions, from where the sample was drawn, and a special questionnaire was designed. Weight, height and head circumference were measured by standard procedures. The total number of children examined was 23821 (11913 boys and 11908 girls). Saudi (0-5-years) boys weight and height for age measurements were significantly different from girls. The same difference was found between urban and rural boys and girls and between boys and girls from the different regions of the country (p<0.05). These national standards derived from this study were used to develop national growth charts that are currently utilized to monitor growth in all Saudi health institutes.
The effects of race and racial priming on self-report of contamination anxiety
Williams, Monnica T.; Turkheimer, Eric; Magee, Emily; Guterbock, Thomas
2011-01-01
African Americans show unusually high endorsement rates on self-report measures of contamination anxiety. The purpose of this study was to replicate this finding in a nationally representative sample and conduct a randomized experiment to determine the effect of salience of race as a causal factor. Black and White participants were given contamination items from two popular measures of obsessive-compulsive disorder, half prior to being primed about ethnic identity and half after being primed, via the administration of an ethnic identity measure. The experiment took the form of a 2 (Black and White participant) X 2 (ethnicity salient and ethnicity non-salient) double-blind design, with ethnic saliency assigned at random by computer. Participants consisted of a geographically representative US sample of African Americans supplemented with a similar sample of European Americans (N=258). Black participants scored significantly higher than White participants on contamination scales. Participants from Southern states scored higher than those from other regions. Over-endorsements by Black participants were greater when awareness of ethnic and racial identification was increased. Clinical and research implications were discussed; these measures should be used with caution in African Americans. PMID:22163374
Beck, Jeffrey L; Dauwalter, Daniel C; Gerow, Kenneth G; Hayward, Gregory D
2010-05-01
Wildlife conservationists design monitoring programs to assess population dynamics, project future population states, and evaluate the impacts of management actions on populations. Because agency mandates and conservation laws call for monitoring data to elicit management responses, it is imperative to design programs that match the administrative scale for which management decisions are made. We describe a program to monitor population trends in American beaver (Castor canadensis) on the US Department of Agriculture, Black Hills National Forest (BHNF) in southwestern South Dakota and northeastern Wyoming, USA. Beaver have been designated as a management indicator species on the BHNF because of their association with riparian and aquatic habitats and its status as a keystone species. We designed our program to monitor the density of beaver food caches (abundance) within sampling units with beaver and the proportion of sampling units with beavers present at the scale of a national forest. We designated watersheds as sampling units in a stratified random sampling design that we developed based on habitat modeling results. Habitat modeling indicated that the most suitable beaver habitat was near perennial water, near aspen (Populus tremuloides) and willow (Salix spp.), and in low gradient streams at lower elevations. Results from the initial monitoring period in October 2007 allowed us to assess costs and logistical considerations, validate our habitat model, and conduct power analyses to assess whether our sampling design could detect the level of declines in beaver stated in the monitoring objectives. Beaver food caches were located in 20 of 52 sampled watersheds. Monitoring 20 to 25 watersheds with beaver should provide sufficient power to detect 15-40% declines in the beaver food cache index as well as a twofold decline in the odds of beaver being present in watersheds. Indices of abundance, such as the beaver food cache index, provide a practical measure of population status to conduct long-term monitoring across broad landscapes such as national forests.
Campbell Grant, Evan H.; Jung, Robin E.; Rice, Karen C.
2005-01-01
Stream salamanders are sensitive to acid mine drainage and may be sensitive to acidification and low acid neutralizing capacity (ANC) of a watershed. Streams in Shenandoah National Park, Virginia, are subject to episodic acidification from precipitation events. We surveyed 25 m by 2 m transects located on the stream bank adjacent to the water channel in Shenandoah National Park for salamanders using a stratified random sampling design based on elevation, aspect and bedrock geology. We investigated the relationships of four species (Eurycea bislineata, Desmognathus fuscus, D. monticola and Gyrinophilus porphyriticus) to habitat and water quality variables. We did not find overwhelming evidence that stream salamanders are affected by the acid-base status of streams in Shenandoah National Park. Desmognathus fuscus and D. monticola abundance was greater both in streams that had a higher potential to neutralize acidification, and in higher elevation (>700 m) streams. Neither abundance of E. bislineata nor species richness were related to any of the habitat variables. Our sampling method preferentially detected the adult age class of the study species and did not allow us to estimate population sizes. We suggest that continued monitoring of stream salamander populations in SNP will determine the effects of stream acidification on these taxa.
Seclen, Segundo Nicolas; Rosas, Moises Ernesto; Arias, Arturo Jaime; Medina, Cecilia Alexandra
2017-01-01
Objective A recent report from a non-nationally representative, geographically diverse sample in four separate communities in Peru suggests an unusually high diabetes incidence. We aimed to estimate the national diabetes incidence rate using PERUDIAB, a probabilistic, national urban population-based longitudinal study. Research design and methods 662 subjects without diabetes, selected by multistage, cluster, random sampling of households, representing the 24 administrative and the 3 (coast, highlands and jungle) natural regions across the country, from both sexes, aged 25+ years at baseline, enrolled in 2010–2012, were followed for 3.8 years. New diabetes cases were defined as fasting blood glucose ≥126 mg/dL or on medical diabetes treatment. Results There were 49 cases of diabetes in 2408 person-years follow-up. The weighted cumulative incidence of diabetes was 7.2% while the weighted incidence rate was estimated at 19.5 (95% CI 13.9 to 28.3) new cases per 1000 person-years. Older age, obesity and technical or higher education were statistically associated with the incidence of diabetes. Conclusion Our results confirm that the incidence of diabetes in Peru is among the highest reported globally. The fast economic growth in the last 20 years, high overweight and obesity rates may have triggered this phenomenon. PMID:28878935
Seclen, Segundo Nicolas; Rosas, Moises Ernesto; Arias, Arturo Jaime; Medina, Cecilia Alexandra
2017-01-01
A recent report from a non-nationally representative, geographically diverse sample in four separate communities in Peru suggests an unusually high diabetes incidence. We aimed to estimate the national diabetes incidence rate using PERUDIAB, a probabilistic, national urban population-based longitudinal study. 662 subjects without diabetes, selected by multistage, cluster, random sampling of households, representing the 24 administrative and the 3 (coast, highlands and jungle) natural regions across the country, from both sexes, aged 25+ years at baseline, enrolled in 2010-2012, were followed for 3.8 years. New diabetes cases were defined as fasting blood glucose ≥126 mg/dL or on medical diabetes treatment. There were 49 cases of diabetes in 2408 person-years follow-up. The weighted cumulative incidence of diabetes was 7.2% while the weighted incidence rate was estimated at 19.5 (95% CI 13.9 to 28.3) new cases per 1000 person-years. Older age, obesity and technical or higher education were statistically associated with the incidence of diabetes. Our results confirm that the incidence of diabetes in Peru is among the highest reported globally. The fast economic growth in the last 20 years, high overweight and obesity rates may have triggered this phenomenon.
Nonuniform sampling theorems for random signals in the linear canonical transform domain
NASA Astrophysics Data System (ADS)
Shuiqing, Xu; Congmei, Jiang; Yi, Chai; Youqiang, Hu; Lei, Huang
2018-06-01
Nonuniform sampling can be encountered in various practical processes because of random events or poor timebase. The analysis and applications of the nonuniform sampling for deterministic signals related to the linear canonical transform (LCT) have been well considered and researched, but up to now no papers have been published regarding the various nonuniform sampling theorems for random signals related to the LCT. The aim of this article is to explore the nonuniform sampling and reconstruction of random signals associated with the LCT. First, some special nonuniform sampling models are briefly introduced. Second, based on these models, some reconstruction theorems for random signals from various nonuniform samples associated with the LCT have been derived. Finally, the simulation results are made to prove the accuracy of the sampling theorems. In addition, the latent real practices of the nonuniform sampling for random signals have been also discussed.
Ahnquist, Johanna; Wamala, Sarah P
2011-10-11
Possible accumulative effects of a combined economic hardship's measure, including both income and non-income related economic hardships measures, on mental health has not been well investigated. The aim of this paper was to investigate; (i) independent associations between multiple measures of economic hardships and mental health problems, and (ii) associations between a combined economic hardships measure and mental health problems. We analysed data from the 2009 Swedish National Survey of Public Health comprising a randomly selected representative national sample combined with a randomly selected supplementary sample from four county councils and three municipalities consisting of 23,153 men and 28,261 women aged 16-84 years. Mental health problems included; psychological distress (GHQ-12), severe anxiety and use of antidepressant medication. Economic hardship was measured by a combined economic hardships measure including low household income, inability to meet expenses and lacking cash reserves. The results from multivariate adjusted (age, country of birth, educational level, occupational status, employment status, family status and long term illness) logistic regression analysis indicate that self-reported current economic difficulties (inability to pay for ordinary bills and lack of cash reserves), were significantly associated with both women's and men's mental health problems (all indicators), while low income was not. In addition, we found a statistically significant graded association between mental health problems and levels of economic hardships. The findings indicate that indicators of self-reported current economic difficulties seem to be more strongly associated with poor mental health outcomes than the more conventional measure low income. Furthermore, the likelihood of mental health problems differed significantly in a graded fashion in relation to levels of economic hardships.
Biederman, Joseph; Petty, Carter R; Woodworth, K Yvonne; Lomedico, Alexandra; O'Connor, Katherine B; Wozniak, Janet; Faraone, Stephen V
2012-03-01
To examine the informativeness of open-label trials toward predicting results in subsequent randomized, placebo-controlled clinical trials of psychopharmacologic treatments for pediatric bipolar disorder. We searched journal articles through PubMed at the National Library of Medicine using bipolar disorder, mania, pharmacotherapy, treatment and clinical trial as keywords. This search was supplemented with scientific presentations at national and international scientific meetings and submitted manuscripts from our group. Selection criteria included (1) enrollment of children diagnosed with DSM-IV bipolar disorder; (2) prospective assessment of at least 3 weeks; (3) monotherapy of a pharmacologic treatment for bipolar disorder; (4) use of a randomized placebo-controlled design or an open-label design for the same therapeutic compound; and (5) repeated use of the Young Mania Rating Scale (YMRS) as an outcome. The following information and data were extracted from 14 studies: study design, name of medication, class of medication, dose of medication, sample size, age, sex, trial length, and YMRS mean and standard deviation baseline and follow-up scores. For both study designs, the pooled effect size was statistically significant (open-label studies, z = 8.88, P < .001; randomized placebo-controlled studies, z = 13.75, P < .001), indicating a reduction in the YMRS from baseline to endpoint in both study designs. In a meta-analysis regression, study design was not a significant predictor of mean change in the YMRS. We found similarities in the treatment effects between open-label and randomized placebo-controlled studies in youth with bipolar disorder indicating that open-label studies are useful predictors of the potential safety and efficacy of a given compound in the treatment of pediatric bipolar disorder. © Copyright 2012 Physicians Postgraduate Press, Inc.
Wallmo, Kristy; Lew, Daniel K
2016-09-01
It is generally acknowledged that willingness-to-pay (WTP) estimates for environmental goods exhibit some degree of spatial variation. In a policy context, spatial variation in threatened and endangered species values is important to understand, as the benefit stream from policies affecting threatened and endangered species may vary locally, regionally, or among certain population segments. In this paper we present WTP estimates for eight different threatened and endangered marine species estimated from a stated preference choice experiment. WTP is estimated at two different spatial scales: (a) a random sample of over 5000 U.S. households and (b) geographically embedded samples (relative to the U.S. household sample) of nine U.S. Census regions. We conduct region-to-region and region-to-nation statistical comparisons to determine whether species values differ among regions and between each region and the entire U.S. Our results show limited spatial variation between national values and values estimated from regionally embedded samples, and differences are only found for three of the eight species. More variation exists between regions, and for all species there is a significant difference in at least one region-to-region comparison. Given that policy analyses involving threatened and endangered marine species can often be regional in scope (e.g., ecosystem management) or may disparately affect different regions, our results should be of high interest to the marine management community. Published by Elsevier Ltd.
[Growth and development of children in Cuba].
Jordán Rodríguez, J; Bebel Agua, A; Rubén, M; Hernández, J
1980-01-01
During the years 1972 to 1974, a great scale study was carried out on development and growth taking at random a stratified sample of multiple stages of 50,311 children from birth to 20 years. Fifteen anthropometric dimensions were considered and evaluation was made of sexual development in both sexes. In girls, the age of menarche was registered. An X-ray of the hand was taken to 10% of the sample. One year later, 30% of the sample was X-rayed again to determine speed of growth. Response of the population was close to 94%. The importance of a national system of growth is recognized, together with the colaboration of the orgaism of masses to achieve these purposes. Information related with some of measurements reported is offered and comments related with these findings are made.
Kulongoski, Justin T.; Belitz, Kenneth; Dawson, Barbara J.
2006-01-01
Ground-water samples were analyzed for major and minor ions, trace elements, nutrients, volatile organic compounds, pesticides and pesticide degradates, waste-water indicators, dissolved methane, nitrogen, carbon dioxide and noble gases (in collaboration with Lawrence Livermore National Laboratory). Naturally occurring isotopes (tritium, carbon-14, oxygen-18, deuterium and helium-4) also were measured in the samples to help identify the source and age of the ground water. Results show that no anthropogenic constituents were detected at concentrations higher than those levels set for regulatory purposes, and relatively few naturally-occurring constituents were detected at concentrations greater than regulatory levels. In this study, 21 of the 88 volatile organic compounds (VOCs) and gasoline additives and (or) oxygenates investigated were detected in ground-water samples, however, detected concentrations were one-half to one-forty-thousandth the maximum contaminant levels (MCL). Thirty-two percent of the randomized wells sampled had at least a single detection of a VOC or gasoline additive and (or) oxygenate. The most frequently detected compounds were chloroform, found in 12 of the 84 randomized wells; carbon disulfide, found in 8 of the 84 randomized wells; and toluene, found in 4 of the 84 randomized wells. Trihalomethanes were the most frequently detected class of VOCs. Nine of the 122 pesticides and (or) pesticide degradates investigated were detected in ground-water samples, however, concentrations were one-seventieth to one-eight-hundredth the MCLs. Seventeen percent of the randomized wells sampled had at least a single detection of pesticide and pesticide degradate. Herbicides were the most frequently detected class of pesticides. The most frequently detected compound was simazine, found in 8 of the 84 of the randomized wells. Chlordiamino-s-triazine and deisopropyl atrazine were both found in 2 of the 84 randomized wells sampled. Thirteen out of 63 compounds that may be indicative of the prescence of waste-water were detected in ground-water samples. Twenty-six percent of the randomized wells sampled for waste-water indicators had at least one detection. Isophorone was the most frequently detected in 6 of the 84 randomized wells. Bisphenol-A, caffeine, and indole each were detected in 3 of the 84 randomized wells. Major and minor ions and dissolved solids (DS) samples were collected at 33 public-supply wells; 3 samples had DS concentrations above the secondary maximum contaminant level (SMCL) of 500 mg/L. Ground-water samples from 32 public-supply wells were analyzed for trace elements. Arsenic concentrations above the MCL of 10 μg/L were measured at 4 public-supply wells, boron concentrations above the detection level for the purpose of reporting (DLR) of 100 μg/L were measured at 19 wells. Iron concentrations above the SMCL of 300 μg/L were measured at 7 wells, a lead concentration above the California notification level (NL) of 15 μg/L at one well, and manganese concentrations above the SMCL of 50 μg/L were measured at 17 wells. Vanadium concentrations above the DLR of 3 μg/L were measured at 9 public-supply wells; and chromium(VI) concentrations above the DLR of 1 μg/L were measured at 48 public-supply wells. Major and minor ions and dissolved solids (DS) samples were collected at 33 public-supply wells; 3 samples had DS concentrations above the secondary maximum contaminant level (SMCL) of 500 mg/L. Ground-water samples from 32 public-supply wells were analyzed for trace elements. Arsenic concentrations above the MCL of 10 μg/L were measured at 4 public-supply wells, boron concentrations above the detection level for the purpose of reporting (DLR) of 100 μg/L were measured at 19 wells. Iron concentrations above the SMCL of 300 μg/L were measured at 7 wells, a lead concentration above the California notification level (NL) of 15 μg/L at one well, and manganese concentrations above the SMCL of 50 μg/L were measured at 17 wells. Vanadium concentrations above the DLR of 3 μg/L were measured at 9 public-supply wells; and chromium(VI) concentrations above the DLR of 1 μg/L were measured at 48 public-supply wells. Microbial constituents were analyzed in 22 ground-water samples. Total coliform was detected in three wells. Counts ranged from 2 colonies per 100 mL to 20 colonies per 100 mL. MCLs for microbial constituents are based on reoccurring detection, and will be monitored during future sampling.
Lead shot incidence on a New Mexico public hunting area
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schranck, B.W.; Dollahon, G.R.
The incidence of lead shot was investigated on a 20.2-ha (50-acre) seasonal marsh used for waterfowl hunting at the Bitter Lake National Wildlife Refuge, Roswell, New Mexico. Of the 162 soil samples taken randomly, 59% contained 1 to 5 lead shot. A minimum lead shot incidence of 98,985 shot per ha (40,075 per acre) was calculated. More shot was found in firm than in mucky soils. Management recommendations to limit waterfowl exposure to lead ingestion are offered.
Public opinion about doctors' pay.
Ross, C E; Lauritsen, J
1985-01-01
Public opinion about doctors' incomes was examined in a national random sample of 843 respondents; 70.1 per cent of those questioned felt physicians are overpaid. There was a high degree of agreement among various groups that physicians are overpaid, but older people and Whites were more likely to think so than younger people and other ethnic groups. People who believe that the United States is characterized by unequal educational opportunity, unfair income distribution, and limited resources were also more likely to think physicians are overpaid. PMID:4003637
Measuring market orientation: further evidence on Narver and Slater's three-component scale.
Chakrabarty, Subhra; Rogé, Joseph N
2003-12-01
A mail survey of a national random sample of 2,000 marketing managers was conducted. The data provided by 222 respondents were analyzed to assess the dimensionality of Narver and Slater's 15-item measure of market orientation. A confirmatory factor analysis, using LISREL 8.53, provided support for each of the separate dimensions of customer orientation, competitor orientation, and interfunctional coordination. However, a combined 3-factor model of market orientation was not supported. Directions for research are suggested.
Public opinion about doctors' pay.
Ross, C E; Lauritsen, J
1985-06-01
Public opinion about doctors' incomes was examined in a national random sample of 843 respondents; 70.1 per cent of those questioned felt physicians are overpaid. There was a high degree of agreement among various groups that physicians are overpaid, but older people and Whites were more likely to think so than younger people and other ethnic groups. People who believe that the United States is characterized by unequal educational opportunity, unfair income distribution, and limited resources were also more likely to think physicians are overpaid.
Teacher drug use: a response to occupational stress.
Watts, W D; Short, A P
1990-01-01
Work-related stress is predicted to be correlated with wanting to leave the teaching profession and drug use. A stratified random sample of 500 Texas teachers was surveyed (56.5% responded), regarding working conditions, collegial and supervisory relationships, job satisfaction, rigidity of attitudes and drug use. Two-thirds of teachers may want to quit the profession, while 36.4 percent are likely to quit. Teachers report higher rates than a national sample of lifetime alcohol, amphetamine, and tranquilizer use and higher rates of alcohol use in the last year and last month. Selected measures of stress are correlated with drug use, particularly amphetamine use, over the lifetime, last year, and last month.
The relationship among dental status, nutrient intake, and nutritional status in older people.
Sheiham, A; Steele, J G; Marcenes, W; Lowe, C; Finch, S; Bates, C J; Prentice, A; Walls, A W
2001-02-01
Dental health status may influence nutrition. The objective of this part of the National Diet and Nutrition Survey was to assess if there is a relationship between dental status in people 65 years and older and intake of certain nutrients and any link between dental status and blood-derived values of key nutrients. Random national samples of independently living subjects and those living in institutions had dental examinations, interviews, four-day food diaries, and blood and urine analyzed. In the sample living independently, intakes of most nutrients were lower in edentate than dentate subjects. Intake of non-starch polysaccharides, protein, calcium, non-heme iron, niacin, and vitamin C was significantly lower in edentate subjects. People with 21 or more teeth consumed more of most nutrients, particularly of non-starch polysaccharide. This relationship in intake was not apparent in the hematological analysis. Plasma ascorbate and plasma retinol were the only analytes significantly associated with dental status.
Blosnich, John; Bossarte, Robert
2012-01-01
Lesbian, gay, and bisexual (ie, sexual minority) populations have increased prevalence of both self-injurious and suicidal behaviors, but reasons for these disparities are poorly understood. To test the association between socially based stressors (eg, victimization, discrimination) and self-injurious behavior, suicide ideation, and suicide attempt. A national sample of college-attending 18- to 24-year-olds. Random or census samples from postsecondary educational institutions that administered the National College Health Assessment during the Fall 2008 and Spring 2009 semesters. Sexual minorities reported more socially based stressors than heterosexuals. Bisexuals exhibited greatest prevalence of self-injurious and suicidal behaviors. In adjusted models, intimate partner violence was most consistently associated with self-injurious behaviors. Sexual minorities' elevated risks of self-injurious and suicidal behaviors may stem from higher exposure to socially based stressors. Within-group differences among sexual minorities offer insight to specific risk factors that may contribute to elevated self-injurious and suicidal behaviors in sexual minority populations.
Wright, Paul J; McKinley, Christopher J
2010-09-01
One factor that may prevent a small but significant percentage of college students from achieving sexual health is sexual compulsivity, a problem of sexual control that is associated with a number of negative health outcomes, including high HIV risk behavior. In this study we content analyzed a randomly selected stratified national sample of 203 4-year U.S. colleges' counseling center websites to assess the degree to which such sites feature information and reference services for sexually compulsive students. Results revealed that sexual compulsivity communications were rare, especially in comparison with communications for other mental health issues. For instance, less than 5% of counseling centers spoke of individual counseling opportunities for students struggling with sexual compulsivity, while between 60% and 80% of counseling centers advertised their capacity to provide individual counseling for students struggling with alcohol and substance abuse, depression, stress/anxiety, and pathological eating. Possible explanations for the paucity of sexual compulsivity messages are discussed.
USGS Blind Sample Project: monitoring and evaluating laboratory analytical quality
Ludtke, Amy S.; Woodworth, Mark T.
1997-01-01
The U.S. Geological Survey (USGS) collects and disseminates information about the Nation's water resources. Surface- and ground-water samples are collected and sent to USGS laboratories for chemical analyses. The laboratories identify and quantify the constituents in the water samples. Random and systematic errors occur during sample handling, chemical analysis, and data processing. Although all errors cannot be eliminated from measurements, the magnitude of their uncertainty can be estimated and tracked over time. Since 1981, the USGS has operated an independent, external, quality-assurance project called the Blind Sample Project (BSP). The purpose of the BSP is to monitor and evaluate the quality of laboratory analytical results through the use of double-blind quality-control (QC) samples. The information provided by the BSP assists the laboratories in detecting and correcting problems in the analytical procedures. The information also can aid laboratory users in estimating the extent that laboratory errors contribute to the overall errors in their environmental data.
Serological status of Canadian cattle for brucellosis, anaplasmosis, and bluetongue in 2007–2008
Paré, Julie; Geale, Dorothy W.; Koller-Jones, Maria; Hooper-McGrevy, Kathleen; Golsteyn-Thomas, Elizabeth J.; Power, Christine A.
2012-01-01
A national bovine serological survey was conducted to confirm that the prevalence of brucellosis, bluetongue, and anaplasmosis does not exceed 0.02% (95% confidence) in live cattle in Canada. Sampling consisted of a systematic random sample of 15 482 adult cattle slaughtered in federally inspected abattoirs, stratified by province. Samples were tested to detect antibodies for brucellosis, bluetongue, and anaplasmosis. All samples were negative for brucellosis. Three samples were seroreactors to bluetongue, 2 of which originated from the Okanagan Valley in British Columbia and 1 from Ontario, which after follow-up, was considered an atypical result. A total of 244 samples were seroreactors to Anaplasma and follow-up identified infection in Saskatchewan, Manitoba, and Quebec. In conclusion, the Canadian cattle population remains free of brucellosis and free of bluetongue outside the Okanagan Valley. Canada is no longer free of anaplasmosis and will be unable to claim freedom until eradication measures are completed. PMID:23450858
Occurrence of MTBE and other gasoline oxygenates in CWS source waters
Carter, Janet M.; Grady, Stephen J.; Delzer, Gregory C.; Koch, Bart; Zogorski, John S.
2006-01-01
Results from two national surveys indicate that the gasoline oxygenate methyl tertiary butyl ether (MTBE) is one of the most frequently detected volatile organic compounds in source waters used by community water systems in the United States. Three other ether oxygenates were detected infrequently but almost always co-occurred with MTBE. A random sampling of source waters across the United States found MTBE in almost 9% of samples. In geographic areas with high MTBE use, the compound was detected in 23% of source water samples. Although MTBE concentrations were low (<1 µg/L) in most samples, some concentrations equaled or exceeded the drinking water advisory of 20 µg/L set by the US Environmental Protection Agency. The frequent detection of even low concentrations of MTBE demonstrates the vulnerability of US source waters to anthropogenic compounds, indicating a need to include MTBE in monitoring programs to track the trend of contamination.
Surgical Site Infections Following Pediatric Ambulatory Surgery: An Epidemiologic Analysis.
Rinke, Michael L; Jan, Dominique; Nassim, Janelle; Choi, Jaeun; Choi, Steven J
2016-08-01
OBJECTIVE To identify surgical site infection (SSI) rates following pediatric ambulatory surgery, SSI outcomes and risk factors, and sensitivity and specificity of SSI administrative billing codes. DESIGN Retrospective chart review of pediatric ambulatory surgeries with International Classification of Disease, Ninth Revision (ICD-9) codes for SSI, and a systematic random sampling of 5% of surgeries without SSI ICD-9 codes, all adjudicated for SSI on the basis of an ambulatory-adapted National Healthcare Safety Network definition. SETTING Urban pediatric tertiary care center April 1, 2009-March 31, 2014. METHODS SSI rates and sensitivity and specificity of ICD-9 codes were estimated using sampling design, and risk factors were analyzed in case-rest of cohort, and case-control, designs. RESULTS In 15,448 pediatric ambulatory surgeries, 34 patients had ICD-9 codes for SSI and 25 met the adapted National Healthcare Safety Network criteria. One additional SSI was identified with systematic random sampling. The SSI rate following pediatric ambulatory surgery was 2.9 per 1,000 surgeries (95% CI, 1.2-6.9). Otolaryngology surgeries demonstrated significantly lower SSI rates compared with endocrine (P=.001), integumentary (P=.001), male genital (P<.0001), and respiratory (P=.01) surgeries. Almost half of patients with an SSI were admitted, 88% received antibiotics, and 15% returned to the operating room. No risk factors were associated with SSI. The sensitivity of ICD-9 codes for SSI following ambulatory surgery was 55.31% (95% CI, 12.69%-91.33%) and specificity was 99.94% (99.89%-99.97%). CONCLUSIONS SSI following pediatric ambulatory surgery occurs at an appreciable rate and conveys morbidity on children. Infect Control Hosp Epidemiol 2016;37:931-938.
A national report of nursing home information technology: year 1 results.
Alexander, Gregory L; Madsen, Richard W; Miller, Erin L; Schaumberg, Melissa K; Holm, Allison E; Alexander, Rachel L; Wise, Keely K; Dougherty, Michelle L; Gugerty, Brian
2017-01-01
To provide a report on year 1 results of a national study investigating nursing home information technology (IT) adoption, called IT sophistication. A reliable and valid survey was used to measure IT sophistication. The target goal was 10% from each state in the United States, 1570 nursing homes. A random sample of homes from each state was recruited from Nursing Home Compare. The team reached 2627 nursing home administrators, among whom 1799 administrators agreed to participate and were sent a survey. A total of 815 surveys were completed (45.3% response rate), which was below the goal. Facilities in the participating sample have similar demographic characteristics (ownership, total population in a location, and bed size) to the remaining homes not participating. There are greater IT capabilities in resident care and administrative activities, less in clinical support. The extent of use of these capabilities appears to be highest in administrative activities and lowest in clinical support. IT in resident care appears to be the most integrated with internal and external stakeholders. IT capabilities appear to be greater than IT extent of use in all health domains, with the greatest difference in resident care. National evaluations of nursing home IT are rare. Measuring trends in IT adoption in a nationally representative sample provides meaningful analytics that could be more useful for policy makers and nursing home leaders in the future. Discovering national baseline assessments is a first step toward recognizing nursing home trends in IT adoption. © The Author 2016. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tonn, Bruce Edward; Rose, Erin M.; Hawkins, Beth A.
This report presents results from the national survey of weatherization recipients. This research was one component of the retrospective and Recovery Act evaluations of the U.S. Department of Energy s Weatherization Assistance Program. Survey respondents were randomly selected from a nationally representative sample of weatherization recipients. The respondents and a comparison group were surveyed just prior to receiving their energy audits and then again approximately 18 months post-weatherization. This report focuses on budget issues faced by WAP households pre- and post-weatherization, whether household energy behaviors changed from pre- to post, the effectiveness of approaches to client energy education, and usemore » and knowledge about thermostats.« less
Probability Distributions for Random Quantum Operations
NASA Astrophysics Data System (ADS)
Schultz, Kevin
Motivated by uncertainty quantification and inference of quantum information systems, in this work we draw connections between the notions of random quantum states and operations in quantum information with probability distributions commonly encountered in the field of orientation statistics. This approach identifies natural sample spaces and probability distributions upon these spaces that can be used in the analysis, simulation, and inference of quantum information systems. The theory of exponential families on Stiefel manifolds provides the appropriate generalization to the classical case. Furthermore, this viewpoint motivates a number of additional questions into the convex geometry of quantum operations relative to both the differential geometry of Stiefel manifolds as well as the information geometry of exponential families defined upon them. In particular, we draw on results from convex geometry to characterize which quantum operations can be represented as the average of a random quantum operation. This project was supported by the Intelligence Advanced Research Projects Activity via Department of Interior National Business Center Contract Number 2012-12050800010.
Implications of sampling design and sample size for national carbon accounting systems.
Köhl, Michael; Lister, Andrew; Scott, Charles T; Baldauf, Thomas; Plugge, Daniel
2011-11-08
Countries willing to adopt a REDD regime need to establish a national Measurement, Reporting and Verification (MRV) system that provides information on forest carbon stocks and carbon stock changes. Due to the extensive areas covered by forests the information is generally obtained by sample based surveys. Most operational sampling approaches utilize a combination of earth-observation data and in-situ field assessments as data sources. We compared the cost-efficiency of four different sampling design alternatives (simple random sampling, regression estimators, stratified sampling, 2-phase sampling with regression estimators) that have been proposed in the scope of REDD. Three of the design alternatives provide for a combination of in-situ and earth-observation data. Under different settings of remote sensing coverage, cost per field plot, cost of remote sensing imagery, correlation between attributes quantified in remote sensing and field data, as well as population variability and the percent standard error over total survey cost was calculated. The cost-efficiency of forest carbon stock assessments is driven by the sampling design chosen. Our results indicate that the cost of remote sensing imagery is decisive for the cost-efficiency of a sampling design. The variability of the sample population impairs cost-efficiency, but does not reverse the pattern of cost-efficiency of the individual design alternatives. Our results clearly indicate that it is important to consider cost-efficiency in the development of forest carbon stock assessments and the selection of remote sensing techniques. The development of MRV-systems for REDD need to be based on a sound optimization process that compares different data sources and sampling designs with respect to their cost-efficiency. This helps to reduce the uncertainties related with the quantification of carbon stocks and to increase the financial benefits from adopting a REDD regime.
A nationwide population-based study on incidence and cost of non-fatal injuries in Iran.
Hafezi-Nejad, Nima; Rahimi-Movaghar, Afarin; Motevalian, Abbas; Amin-Esmaeili, Masoumeh; Sharifi, Vandad; Hajebi, Ahmad; Radgoodarzi, Reza; Hefazi, Mitra; Eslami, Vahid; Saadat, Soheil; Rahimi-Movaghar, Vafa
2014-10-01
Elucidating the epidemiological status of injuries is a critical component of preventive strategies in countries with high incidence of injuries, like Iran. Population-based surveys are able to estimate all types of non-fatal injuries. This study protocol is the core unit in describing Iran's national cost and epidemiology of non-fatal injuries, and also as a guide for other studies. In a cross-sectional study, 1525 primary sampling units are randomly selected with probability proportional to size regarding the number of households in each enumeration area based on Iran's 2006 national census. Six of the households are randomly selected. One member of each household is chosen using Kish Grid tables. In all, 9150 subjects are selected. Data on demographics are collected. For each injury during the past three months, activity, place, mechanism, site, type and the place of treatment are coded to match the International Classification of Diseases, 10th revision 2012 (ICD10-2012) classifications. Subjects are contacted via telephone to obtain data on cost of injury. Finally, sampling weights are calculated so that data for each respondent can be inflated to represent other individuals in Iran. Quality control and quality assurance issues are discussed. Our objectives will describe the present impact and the future priorities of injury prevention in Iran. 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.
Recovery practice in community mental health teams: national survey
Leamy, M.; Clarke, E.; Le Boutillier, C.; Bird, V.; Choudhury, R.; MacPherson, R.; Pesola, F.; Sabas, K.; Williams, J.; Williams, P.; Slade, M.
2016-01-01
Background There is consensus about the importance of ‘recovery’ in mental health services, but the link between recovery orientation of mental health teams and personal recovery of individuals has been underresearched. Aims To investigate differences in team leader, clinician and service user perspectives of recovery orientation of community adult mental health teams in England. Method In six English mental health National Health Service (NHS) trusts, randomly chosen community adult mental health teams were surveyed. A random sample of ten patients, one team leader and a convenience sample of five clinicians were surveyed from each team. All respondents rated the recovery orientation of their team using parallel versions of the Recovery Self Assessment (RSA). In addition, service users also rated their own personal recovery using the Questionnaire about Processes of Recovery (QPR). Results Team leaders (n = 22) rated recovery orientation higher than clinicians (n = 109) or patients (n = 120) (Wald(2) = 7.0, P = 0.03), and both NHS trust and team type influenced RSA ratings. Patient-rated recovery orientation was a predictor of personal recovery (b = 0.58, 95% CI 0.31–0.85, P<0.001). Team leaders and clinicians with experience of mental illness (39%) or supporting a family member or friend with mental illness (76%) did not differ in their RSA ratings from other team leaders or clinicians. Conclusions Compared with team leaders, frontline clinicians and service users have less positive views on recovery orientation. Increasing recovery orientation may support personal recovery. PMID:27340113
Wheelock, Ana; Miraldo, Marisa; Thomson, Angus; Vincent, Charles; Sevdalis, Nick
2017-07-12
Despite continuous efforts to improve influenza vaccination coverage, uptake among high-risk groups remains suboptimal. We aimed to identify policy amenable factors associated with vaccination and to measure their importance in order to assist in the monitoring of vaccination sentiment and the design of communication strategies and interventions to improve vaccination rates. The USA, the UK and France. A total of 2412 participants were surveyed across the three countries. Self-reported influenza vaccination. Between March and April 2014, a stratified random sampling strategy was employed with the aim of obtaining nationally representative samples in the USA, the UK and France through online databases and random-digit dialling. Participants were asked about vaccination practices, perceptions and feelings. Multivariable logistic regression was used to identify factors associated with past influenza vaccination. The models were able to explain 64%-80% of the variance in vaccination behaviour. Overall, sociopsychological variables, which are inherently amenable to policy, were better at explaining past vaccination behaviour than demographic, socioeconomic and health variables. Explanatory variables included social influence (physician), influenza and vaccine risk perceptions and traumatic childhood experiences. Our results indicate that evidence-based sociopsychological items should be considered for inclusion into national immunisation surveys to gauge the public's views, identify emerging concerns and thus proactively and opportunely address potential barriers and harness vaccination drivers. © 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.
Methodology Series Module 5: Sampling Strategies.
Setia, Maninder Singh
2016-01-01
Once the research question and the research design have been finalised, it is important to select the appropriate sample for the study. The method by which the researcher selects the sample is the ' Sampling Method'. There are essentially two types of sampling methods: 1) probability sampling - based on chance events (such as random numbers, flipping a coin etc.); and 2) non-probability sampling - based on researcher's choice, population that accessible & available. Some of the non-probability sampling methods are: purposive sampling, convenience sampling, or quota sampling. Random sampling method (such as simple random sample or stratified random sample) is a form of probability sampling. It is important to understand the different sampling methods used in clinical studies and mention this method clearly in the manuscript. The researcher should not misrepresent the sampling method in the manuscript (such as using the term ' random sample' when the researcher has used convenience sample). The sampling method will depend on the research question. For instance, the researcher may want to understand an issue in greater detail for one particular population rather than worry about the ' generalizability' of these results. In such a scenario, the researcher may want to use ' purposive sampling' for the study.
Trajković-Pavlović, Ljiljana; Novaković, Budimka; Martinov-Cvejin, Mirjana; Gusman, Vera; Bijelović, Sanja; Dragnić, Natasa; Balać, Dragana
2010-08-01
According to the literature that has been published over the last two decades Campylobacter spp i Listeria monocitogens can be identified as causes of numerous diseases derived by consuming food of animal origin. The purpose of this paper was to find out how established national microbiological criteria of the Republic of Serbia on food safety in retailed food of animal origin could contribute to consumer's protection against exposition to foodborne pathogens such as Campylobacter spp. and Listeria monocytogenes. During a routine microbiological safety control of randomly selected 60 samples of fresh poultry meat, 30 samples of other fresh meat readymade for grilling, 30 samples of sausage products, 37 samples of heat-treated meat, 39 samples of toppings for fast food of animal origin and 31 samples of dairy products a national food safety criteria (Escherichia coli, aerobic plate count, Salmonella spp., coagulasa positive Staphylococcus, Proteus spp., sulphito-reducting Clostridia) were applied and, as well as, testing to Campylobacter spp. and Listeria monocitogens. In determination of Campylobacter spp. and Listeria monocytogenes, food quality control methods of the Food and Agriculture Organization (FAO) were applied, while in determination of the other above motioned bacteria, national provisions on microbiological methods were applied who are adjusted to the FAO ones. Related to the national criteria on microbiological food safety, 88 (38.8%) samples, out of the total 227 tested, were rejected. When to these results, the results of laboratory tests on Listeria monocytogens were added, a terminal number of rejected samples were not changed. When to these results, the results of Campylobacter spp. testing were added, 91 (40.1%) out of the 227 samples were unsatisfied. Results of logistic regression model with occurrence of Escherichia coli as dependent variable indicated that Escherichia coli was 4.5 times likely to occur among samples with Campylobacter spp. than among samples without Campylobacter spp. (OR = 4.515, 95% CI: 1.019-20.002). Sensitivity of the fitted model (Hosmer-Lemeshowp = 0.268) was 76.8% and its specificity was 75.0%. At the same time Escherichia coli was confound in all (100%) food samples that were contaminated by Listeria monocytogenes. Statistical analysis indicated that Escherichia coli was completely sensitive to identify all samples contaminated with Listeria monocytogenas and highly sensitive to identify samples contaminated with Campylobacter spp. Nevertheless, 3 (1.3%) of the tested samples were not covered with Escherichia coli.
Melvin, Neal R; Poda, Daniel; Sutherland, Robert J
2007-10-01
When properly applied, stereology is a very robust and efficient method to quantify a variety of parameters from biological material. A common sampling strategy in stereology is systematic random sampling, which involves choosing a random sampling [corrected] start point outside the structure of interest, and sampling relevant objects at [corrected] sites that are placed at pre-determined, equidistant intervals. This has proven to be a very efficient sampling strategy, and is used widely in stereological designs. At the microscopic level, this is most often achieved through the use of a motorized stage that facilitates the systematic random stepping across the structure of interest. Here, we report a simple, precise and cost-effective software-based alternative to accomplishing systematic random sampling under the microscope. We believe that this approach will facilitate the use of stereological designs that employ systematic random sampling in laboratories that lack the resources to acquire costly, fully automated systems.
Sampling procedures for inventory of commercial volume tree species in Amazon Forest.
Netto, Sylvio P; Pelissari, Allan L; Cysneiros, Vinicius C; Bonazza, Marcelo; Sanquetta, Carlos R
2017-01-01
The spatial distribution of tropical tree species can affect the consistency of the estimators in commercial forest inventories, therefore, appropriate sampling procedures are required to survey species with different spatial patterns in the Amazon Forest. For this, the present study aims to evaluate the conventional sampling procedures and introduce the adaptive cluster sampling for volumetric inventories of Amazonian tree species, considering the hypotheses that the density, the spatial distribution and the zero-plots affect the consistency of the estimators, and that the adaptive cluster sampling allows to obtain more accurate volumetric estimation. We use data from a census carried out in Jamari National Forest, Brazil, where trees with diameters equal to or higher than 40 cm were measured in 1,355 plots. Species with different spatial patterns were selected and sampled with simple random sampling, systematic sampling, linear cluster sampling and adaptive cluster sampling, whereby the accuracy of the volumetric estimation and presence of zero-plots were evaluated. The sampling procedures applied to species were affected by the low density of trees and the large number of zero-plots, wherein the adaptive clusters allowed concentrating the sampling effort in plots with trees and, thus, agglutinating more representative samples to estimate the commercial volume.
Williams, Nathaniel J; Glisson, Charles
2014-04-01
Theories of organizational culture and climate (OCC) applied to child welfare systems hypothesize that strategic dimensions of organizational culture influence organizational climate and that OCC explains system variance in youth outcomes. This study provides the first structural test of the direct and indirect effects of culture and climate on youth outcomes in a national sample of child welfare systems and isolates specific culture and climate dimensions most associated with youth outcomes. The study applies multilevel path analysis (ML-PA) to a U.S. nationwide sample of 2,380 youth in 73 child welfare systems participating in the second National Survey of Child and Adolescent Well-being. Youths were selected in a national, two-stage, stratified random sample design. Youths' psychosocial functioning was assessed by caregivers' responses to the Child Behavior Checklist at intake and at 18-month follow-up. OCC was assessed by front-line caseworkers' (N=1,740) aggregated responses to the Organizational Social Context measure. Comparison of the a priori and subsequent trimmed models confirmed a reduced model that excluded rigid organizational culture and explained 70% of the system variance in youth outcomes. Controlling for youth- and system-level covariates, systems with more proficient and less resistant organizational cultures exhibited more functional, more engaged, and less stressful climates. Systems with more proficient cultures and more engaged, more functional, and more stressful climates exhibited superior youth outcomes. Findings suggest child welfare administrators can support service effectiveness with interventions that improve specific dimensions of culture and climate. Copyright © 2013 Elsevier Ltd. All rights reserved.
Williams, Nathaniel J.; Glisson, Charles
2013-01-01
Theories of organizational culture and climate (OCC) applied to child welfare systems hypothesize that strategic dimensions of organizational culture influence organizational climate and that OCC explains system variance in youth outcomes. This study provides the first structural test of the direct and indirect effects of culture and climate on youth outcomes in a national sample of child welfare systems and isolates specific culture and climate dimensions most associated with youth outcomes. The study applies multilevel path analysis (ML-PA) to a U.S. nationwide sample of 2,380 youth in 73 child welfare systems participating in the second National Survey of Child and Adolescent Well-being. Youths were selected in a national, two-stage, stratified random sample design. Youths’ psychosocial functioning was assessed by caregivers’ responses to the Child Behavior Checklist at intake and at 18-month follow-up. OCC was assessed by front-line caseworkers’ (N=1,740) aggregated responses to the Organizational Social Context measure. Comparison of the a priori and subsequent trimmed models confirmed a reduced model that excluded rigid organizational culture and explained 70% of the system variance in youth outcomes. Controlling for youth- and system-level covariates, systems with more proficient and less resistant organizational cultures exhibited more functional, more engaged, and less stressful climates. Systems with more proficient cultures and more engaged, more functional, and more stressful climates exhibited superior youth outcomes. Findings suggest child welfare administrators can support service effectiveness with interventions that improve specific dimensions of culture and climate. PMID:24094999
Efficient sampling of complex network with modified random walk strategies
NASA Astrophysics Data System (ADS)
Xie, Yunya; Chang, Shuhua; Zhang, Zhipeng; Zhang, Mi; Yang, Lei
2018-02-01
We present two novel random walk strategies, choosing seed node (CSN) random walk and no-retracing (NR) random walk. Different from the classical random walk sampling, the CSN and NR strategies focus on the influences of the seed node choice and path overlap, respectively. Three random walk samplings are applied in the Erdös-Rényi (ER), Barabási-Albert (BA), Watts-Strogatz (WS), and the weighted USAir networks, respectively. Then, the major properties of sampled subnets, such as sampling efficiency, degree distributions, average degree and average clustering coefficient, are studied. The similar conclusions can be reached with these three random walk strategies. Firstly, the networks with small scales and simple structures are conducive to the sampling. Secondly, the average degree and the average clustering coefficient of the sampled subnet tend to the corresponding values of original networks with limited steps. And thirdly, all the degree distributions of the subnets are slightly biased to the high degree side. However, the NR strategy performs better for the average clustering coefficient of the subnet. In the real weighted USAir networks, some obvious characters like the larger clustering coefficient and the fluctuation of degree distribution are reproduced well by these random walk strategies.
Socioeconomic differences in attitudes and beliefs about healthy lifestyles.
Wardle, J; Steptoe, A
2003-06-01
s: The factors underlying socioeconomic status differences in smoking, leisure time physical activity, and dietary choice are poorly understood. This study investigated attitudes and beliefs that might underlie behavioural choices, including health locus of control, future salience, subjective life expectancy, and health consciousness, in a nationally representative sample. Data were collected as part of the monthly Omnibus survey of the Office of National Statistics in Britain. A stratified, probability sample of 2728 households was selected by random sampling of addresses. One adult from each household was interviewed. Higher SES respondents were less likely to smoke and more likely to exercise and eat fruit and vegetables daily. Lower SES was associated with less health consciousness (thinking about things to do to keep healthy), stronger beliefs in the influence of chance on health, less thinking about the future, and lower life expectancies. These attitudinal factors were in turn associated with unhealthy behavioural choices, independently of age, sex, and self rated health. Socioeconomic differences in healthy lifestyles are associated with differences in attitudes to health that may themselves arise through variations in life opportunities and exposure to material hardship and ill health over the life course.
Methodology Series Module 5: Sampling Strategies
Setia, Maninder Singh
2016-01-01
Once the research question and the research design have been finalised, it is important to select the appropriate sample for the study. The method by which the researcher selects the sample is the ‘ Sampling Method’. There are essentially two types of sampling methods: 1) probability sampling – based on chance events (such as random numbers, flipping a coin etc.); and 2) non-probability sampling – based on researcher's choice, population that accessible & available. Some of the non-probability sampling methods are: purposive sampling, convenience sampling, or quota sampling. Random sampling method (such as simple random sample or stratified random sample) is a form of probability sampling. It is important to understand the different sampling methods used in clinical studies and mention this method clearly in the manuscript. The researcher should not misrepresent the sampling method in the manuscript (such as using the term ‘ random sample’ when the researcher has used convenience sample). The sampling method will depend on the research question. For instance, the researcher may want to understand an issue in greater detail for one particular population rather than worry about the ‘ generalizability’ of these results. In such a scenario, the researcher may want to use ‘ purposive sampling’ for the study. PMID:27688438
DOE Office of Scientific and Technical Information (OSTI.GOV)
Novotny, Anthony J.; Zaugg, Waldo S.
The National Marine Fisheries Service (NMFS), under contract to the Bonneville Power Administration, is conducting research on imprinting salmon and steelhead for homing (Slatick et al. 1979, 1980; Novotny and Zaugg 1979). The studies were begun with little background knowledge of the effects of disease or certain physiological functions on imprinting and homing in salmonids. Consequently, work aimed at filling this void was begun by the authors in 1978 (Novotny and Zaugg 1979) and continued in 1979. In 1979, we examined random samples of normal populations of homing test fish at the hatcheries to determine the physiological readiness to migratemore » and adapt to seawater and general fish health. At the Manchester Marine Experimental Station, Manchester, Washington, we determined the survival of samples of the test fish maintained in marine net-pens after release from the hatcheries. Hatcheries and stocks sampled are listed in Table 1.« less
Judge, Seth W.; Camp, Richard J.; Vaivai, Visa; Hart, Patrick J.
2013-01-01
NPSA canopy and understory composition was predominantly native, and trees formed a dense closed canopy at nearly 90% of the stations sampled. More than half of the tree heights in both units were taller than 5 m and the majority of slopes were steeper than 20 degrees. There were no clear dominant tree species in the mixed native forests. The most common tree species documented included Syzygium spp., Dysoxylum spp., Ficus spp., Hibiscus tiliaceus and Rhus taitensis (among others). There were significant differences in the distribution of bird densities between legacy and random transects. Determining differences in detection probabilities cannot be definitively assessed from a single survey. We recommend both panels be sampled in the future until bias in density and abundance can be evaluated, or if sampling may be reduced.
Bays, Harold E; Bazata, Debbra D; Clark, Nathaniel G; Gavin, James R; Green, Andrew J; Lewis, Sandra J; Reed, Michael L; Stewart, Walter; Chapman, Richard H; Fox, Kathleen M; Grandy, Susan
2007-01-01
Background Studies derived from continuous national surveys have shown that the prevalence of diagnosed diabetes mellitus in the US is increasing. This study estimated the prevalence in 2004 of self-reported diagnosis of diabetes and other conditions in a community-based population, using data from the Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes (SHIELD). Methods The initial screening questionnaire was mailed in 2004 to a stratified random sample of 200,000 households in the US, to identify individuals, age ≥ 18 years of age, with diabetes or risk factors associated with diabetes. Follow-up disease impact questionnaires were then mailed to a representative, stratified random sample of individuals (n = 22,001) in each subgroup of interest (those with diabetes or different numbers of risk factors for diabetes). Estimated national prevalence of diabetes and other conditions was calculated, and compared to prevalence estimates from the National Health and Nutrition Examination Survey (NHANES) 1999–2002. Results Response rates were 63.7% for the screening, and 71.8% for the follow-up baseline survey. The SHIELD screening survey found overall prevalence of self-reported diagnosis of diabetes (either type 1 or type 2) was 8.2%, with increased prevalence with increasing age and decreasing income. In logistic regression modeling, individuals were more likely to be diagnosed with type 2 diabetes if they had abdominal obesity (odds ratio [OR] = 3.50; p < 0.0001), BMI ≥28 kg/m2 (OR = 4.04; p < 0.0001), or had been diagnosed with dyslipidemia (OR = 3.95; p < 0.0001), hypertension (OR = 4.82; p < 0.0001), or with cardiovascular disease (OR = 3.38; p < 0.0001). Conclusion The SHIELD design allowed for a very large, community-based sample with broad demographic representation of the population of interest. When comparing results from the SHIELD screening survey (self-report only) to those from NHANES 1999–2002 (self-report, clinical and laboratory evaluations), the prevalence of diabetes was similar. SHIELD allows the identification of respondents with and without a current diagnosis of the illness of interest, and potential longitudinal evaluation of risk factors for future diagnosis of that illness. PMID:17915014
Liew, Zeyan; Ritz, Beate; von Ehrenstein, Ondine S.; Bech, Bodil Hammer; Nohr, Ellen Aagaard; Fei, Chunyuan; Bossi, Rossana; Henriksen, Tine Brink; Bonefeld-Jørgensen, Eva Cecilie
2014-01-01
Background: Perfluoroalkyl substances (PFASs) are persistent pollutants found to be endocrine disruptive and neurotoxic in animals. Positive correlations between PFASs and neurobehavioral problems in children were reported in cross-sectional data, but findings from prospective studies are limited. Objectives: We investigated whether prenatal exposure to PFASs is associated with attention deficit/hyperactivity disorder (ADHD) or childhood autism in children. Methods: Among 83,389 mother–child pairs enrolled in the Danish National Birth Cohort during 1996–2002, we identified 890 ADHD cases and 301 childhood autism cases from the Danish National Hospital Registry and the Danish Psychiatric Central Registry. From this cohort, we randomly selected 220 cases each of ADHD and autism, and we also randomly selected 550 controls frequency matched by child’s sex. Sixteen PFASs were measured in maternal plasma collected in early or mid-pregnancy. We calculated risk ratios (RRs) using generalized linear models, taking into account sampling weights. Results: Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were detected in all samples; four other PFASs were quantified in ≥ 90% of the samples. We did not find consistent evidence of associations between mother’s PFAS plasma levels and ADHD [per natural log nanograms per milliliter increase: PFOS RR = 0.87 (95% CI: 0.74, 1.02); PFOA RR = 0.98 (95% CI: 0.82, 1.16)] or autism [per natural log nanograms per milliliter increase: PFOS RR = 0.92 (95% CI: 0.69, 1.22); PFOA RR = 0.98 (95% CI: 0.73, 1.31)]. We found positive as well as negative associations between higher PFAS quartiles and ADHD in models that simultaneously adjusted for all PFASs, but these estimates were imprecise. Conclusions: In this study we found no consistent evidence to suggest that prenatal PFAS exposure increases the risk of ADHD or childhood autism in children. Citation: Liew Z, Ritz B, von Ehrenstein OS, Bech BH, Nohr EA, Fei CY, Bossi R, Henriksen TB, Bonefeld-Jørgensen EC, Olsen J. 2015. Attention deficit/hyperactivity disorder and childhood autism in association with prenatal exposure to perfluoroalkyl substances: a nested case–control study in the Danish National Birth Cohort. Environ Health Perspect 123:367–373; http://dx.doi.org/10.1289/ehp.1408412 PMID:25616253
Makowski, David; Bancal, Rémi; Bensadoun, Arnaud; Monod, Hervé; Messéan, Antoine
2017-09-01
According to E.U. regulations, the maximum allowable rate of adventitious transgene presence in non-genetically modified (GM) crops is 0.9%. We compared four sampling methods for the detection of transgenic material in agricultural non-GM maize fields: random sampling, stratified sampling, random sampling + ratio reweighting, random sampling + regression reweighting. Random sampling involves simply sampling maize grains from different locations selected at random from the field concerned. The stratified and reweighting sampling methods make use of an auxiliary variable corresponding to the output of a gene-flow model (a zero-inflated Poisson model) simulating cross-pollination as a function of wind speed, wind direction, and distance to the closest GM maize field. With the stratified sampling method, an auxiliary variable is used to define several strata with contrasting transgene presence rates, and grains are then sampled at random from each stratum. With the two methods involving reweighting, grains are first sampled at random from various locations within the field, and the observations are then reweighted according to the auxiliary variable. Data collected from three maize fields were used to compare the four sampling methods, and the results were used to determine the extent to which transgene presence rate estimation was improved by the use of stratified and reweighting sampling methods. We found that transgene rate estimates were more accurate and that substantially smaller samples could be used with sampling strategies based on an auxiliary variable derived from a gene-flow model. © 2017 Society for Risk Analysis.
Latter, Sue; Maben, Jill; Myall, Michelle; Young, Amanda
2007-10-01
The number of nurses able to independently prescribe medicines in England has risen steadily in recent years. To evaluate the adequacy of nurses' educational preparation for independent prescribing and to describe nurses' experiences of their continuing professional development as prescribers in practice. Postal questionnaire survey. Random sample of 246 nurses registered as nurse independent prescribers with the Nursing and Midwifery Council. The majority of nurses considered that the initial taught course element of their education programme met their needs, either to some extent (61% 151/246), or completely (22% 54/246). Most nurses (77% 190/246) received the specified 12 days support from their supervising medical practitioner and most were satisfied and positive about this experience. Nearly all of the nurses (>95%) reported that they were able to maintain a range of specified prescribing competencies in practice. Two thirds (62% 152/246) of the sample reported that they were receiving support/supervision for prescribing. Ninety five per cent (233/246) of the sample also reported that they engaged in self-directed informal continuing professional development, but only half of the sample had experience of formally provided professional development opportunities. Approximately half (52% 127/246) of the sample identified needs for continuing professional development. This first national survey of the education and professional development experiences of nurse independent prescribers in England provides evidence which highlights areas in which national policy is working well, and also points up issues which may need addressing as the roll out of nurse prescribing continues. The study also highlights characteristics and issues that health care policy makers and nurse educationalists internationally may wish to consider in developing and refining their own nurse prescriber education programmes.
Sampling Large Graphs for Anticipatory Analytics
2015-05-15
low. C. Random Area Sampling Random area sampling [8] is a “ snowball ” sampling method in which a set of random seed vertices are selected and areas... Sampling Large Graphs for Anticipatory Analytics Lauren Edwards, Luke Johnson, Maja Milosavljevic, Vijay Gadepally, Benjamin A. Miller Lincoln...systems, greater human-in-the-loop involvement, or through complex algorithms. We are investigating the use of sampling to mitigate these challenges
Electromagnetic Scattering by Fully Ordered and Quasi-Random Rigid Particulate Samples
NASA Technical Reports Server (NTRS)
Mishchenko, Michael I.; Dlugach, Janna M.; Mackowski, Daniel W.
2016-01-01
In this paper we have analyzed circumstances under which a rigid particulate sample can behave optically as a true discrete random medium consisting of particles randomly moving relative to each other during measurement. To this end, we applied the numerically exact superposition T-matrix method to model far-field scattering characteristics of fully ordered and quasi-randomly arranged rigid multiparticle groups in fixed and random orientations. We have shown that, in and of itself, averaging optical observables over movements of a rigid sample as a whole is insufficient unless it is combined with a quasi-random arrangement of the constituent particles in the sample. Otherwise, certain scattering effects typical of discrete random media (including some manifestations of coherent backscattering) may not be accurately replicated.
Pesticide residues in orange fruit from citrus orchards in Nuevo Leon State, Mexico.
Suárez-Jacobo, Angela; Alcantar-Rosales, Victor Manuel; Alonso-Segura, Diana; Heras-Ramírez, Maria; Elizarragaz-De La Rosa, Dalau; Lugo-Melchor, Ofelia; Gaspar-Ramirez, Octavio
2017-09-01
Some international organisations established maximum residue limits (MRLs) in food to protect human health. Mexico lacks regulations in this matter, affecting national and international trade from agroindustry. The aim of this study was to diagnose pesticide residues in oranges from Nuevo Leon, México, in citrus orchards. In May 2014, 100 orange fruit samples were taken randomly from orchards and subjected to analysis for 93 pesticides at residual level by GC/QQQ-MS and LCQ-TOF-MS. Results showed the presence of 15 pesticide residues in the samples. The comparison of the residual levels of pesticides found in orange samples among the MRLs allowed by USA, EU and Japanese regulations demonstrated that all samples were below MRLs issued by USA and Japan. Some orange samples were above MRLs issued by the EU. This provides a basis to establish strategies in order to satisfy International Standards to protect human health and encourage Food Safety in Mexico.
Hassan, Fauziya; Davis, Matthew M; Chervin, Ronald D
2011-04-15
Prior studies have supported an association between insufficient sleep and childhood obesity, but most have not examined nationally representative samples or considered potential sociodemographic confounders. The main objective of this study was to use a large, nationally representative dataset to examine the possibility that insufficient sleep is associated with obesity in children, independent of sociodemographic factors. The National Survey of Children's Health is a national survey of U.S. households contacted by random digit dialing. In 2003, caregivers of 102,353 US children were surveyed. Age- and sex-specific body mass index (BMI) based on parental report of child height and weight, was available for 81,390 children aged 6-17 years. Caregivers were asked, "How many nights of sufficient sleep did your child have in the past week?" The odds of obesity (BMI ≥ 95th percentile) versus healthy weight (BMI 5th-84th percentile) was regressed on reported nights of sufficient sleep per week (categorized as 0-2, 3-5, or 6-7). Sociodemographic variables included gender, race, household education, and family income. Analyses incorporated sampling weights to derive nationally representative estimates for a 2003 population of 34 million youth. Unadjusted bivariate analyses indicated that children aged 6-11 years with 0-2 nights of sufficient sleep, in comparison to those with 6-7 nights, were more likely to be obese (OR = 1.7, 95% CI [1.2-2.3]). Among children aged 12-17 years, odds of obesity were lower among children with 3-5 nights of sufficient sleep in comparison to those with 6-7 nights (0.8, 95% CI: 0.7-0.9). However, in both age groups, adjustment for race/ethnicity, gender, family income, and household education left no remaining statistical significance for the association between sufficient nights of sleep and BMI. In this national sample, insufficient sleep, as judged by parents, is inconsistently associated with obesity in bivariate analyses, and not associated with obesity after adjustment for sociodemographic variables. These findings from a nationally representative sample are necessarily subject to parental perceptions, but nonetheless serve as an important reminder that the role of insufficient sleep in the childhood obesity epidemic remains unproven.
Identity adjustment among Afghanistan and Iraq war veterans with reintegration difficulty.
Orazem, Robert J; Frazier, Patricia A; Schnurr, Paula P; Oleson, Heather E; Carlson, Kathleen F; Litz, Brett T; Sayer, Nina A
2017-08-01
To examine perceptions of identity adjustment in a diverse, national sample of U.S. veterans of the wars in Afghanistan and Iraq. The authors conducted a planned thematic analysis of text written by Afghanistan and Iraq war veterans when they were asked to describe their reintegration difficulties as part of a randomized controlled trial (RCT) of online expressive writing (Sayer et al., 2015). Participants were 100 randomly selected veterans from the larger study (42 women and 58 men, 60 active duty and 38 reserves or National Guard). Nearly 2/3s of participants wrote about their identity adjustment. The 5 interrelated areas of identity adjustment difficulty were (a) feeling like one does not belong in civilian society, (b) missing the military's culture and structured lifestyle, (c) holding negative views of civilian society, (d) feeling left behind compared to civilian counterparts due to military service, and (e) having difficulty finding meaning in the civilian world. The authors did not observe differences by gender. However, those deployed from active duty were particularly likely to feel as if they did not belong in civilian society and that they had not acquired needed skills, whereas those deployed from the reserves or National Guard experienced difficulty in reestablishing former civilian identities. Identity adjustment is a critical yet understudied aspect of veteran reintegration into community life following combat deployment. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Miller, Michael A; Colby, Alison C C; Kanehl, Paul D; Blocksom, Karen
2009-03-01
The Wisconsin Department of Natural Resources (WDNR), with support from the U.S. EPA, conducted an assessment of wadeable streams in the Driftless Area ecoregion in western Wisconsin using a probabilistic sampling design. This ecoregion encompasses 20% of Wisconsin's land area and contains 8,800 miles of perennial streams. Randomly-selected stream sites (n = 60) equally distributed among stream orders 1-4 were sampled. Watershed land use, riparian and in-stream habitat, water chemistry, macroinvertebrate, and fish assemblage data were collected at each true random site and an associated "modified-random" site on each stream that was accessed via a road crossing nearest to the true random site. Targeted least-disturbed reference sites (n = 22) were also sampled to develop reference conditions for various physical, chemical, and biological measures. Cumulative distribution function plots of various measures collected at the true random sites evaluated with reference condition thresholds, indicate that high proportions of the random sites (and by inference the entire Driftless Area wadeable stream population) show some level of degradation. Study results show no statistically significant differences between the true random and modified-random sample sites for any of the nine physical habitat, 11 water chemistry, seven macroinvertebrate, or eight fish metrics analyzed. In Wisconsin's Driftless Area, 79% of wadeable stream lengths were accessible via road crossings. While further evaluation of the statistical rigor of using a modified-random sampling design is warranted, sampling randomly-selected stream sites accessed via the nearest road crossing may provide a more economical way to apply probabilistic sampling in stream monitoring programs.
Caries status in 16 year-olds with varying exposure to water fluoridation in Ireland.
Mullen, J; McGaffin, J; Farvardin, N; Brightman, S; Haire, C; Freeman, R
2012-12-01
Most of the Republic of Ireland's public water supplies have been fluoridated since the mid-1960s while Northern Ireland has never been fluoridated, apart from some small short-lived schemes in east Ulster. This study examines dental caries status in 16 year-olds in a part of Ireland straddling fluoridated and non-fluoridated water supply areas and compares two methods of assessing the effectiveness of water fluoridation. The cross-sectional survey tested differences in caries status by two methods: 1, Estimated Fluoridation Status as used previously in national and regional studies in the Republic and in the All-Island study of 2002; 2, Percentage Lifetime Exposure, a modification of a system described by Slade in 1995 and used in Australian caries research. Adolescents were selected for the study by a two-part random sampling process. Firstly, schools were selected in each area by creating three tiers based on school size, and selecting schools randomly from each tier. Then random sampling of 16-year-olds from these schools, based on a pre-set sampling fraction for each tier of schools. With both systems of measurement, significantly lower caries levels were found in those children with the greatest exposure to fluoridated water when compared to those with the least exposure. The survey provides further evidence of the effectiveness in reducing dental caries experience up to 16 years of age. The extra intricacies involved in using the Percentage Lifetime Exposure method did not provide much more information when compared to the simpler Estimated Fluoridation Status method.
Szirovicza, Leonóra; López, Pilar; Kopena, Renáta; Benkő, Mária; Martín, José; Pénzes, Judit J.
2016-01-01
Here, we report the results of a large-scale PCR survey on the prevalence and diversity of adenoviruses (AdVs) in samples collected randomly from free-living reptiles. On the territories of the Guadarrama Mountains National Park in Central Spain and of the Chafarinas Islands in North Africa, cloacal swabs were taken from 318 specimens of eight native species representing five squamate reptilian families. The healthy-looking animals had been captured temporarily for physiological and ethological examinations, after which they were released. We found 22 AdV-positive samples in representatives of three species, all from Central Spain. Sequence analysis of the PCR products revealed the existence of three hitherto unknown AdVs in 11 Carpetane rock lizards (Iberolacerta cyreni), nine Iberian worm lizards (Blanus cinereus), and two Iberian green lizards (Lacerta schreiberi), respectively. Phylogeny inference showed every novel putative virus to be a member of the genus Atadenovirus. This is the very first description of the occurrence of AdVs in amphisbaenian and lacertid hosts. Unlike all squamate atadenoviruses examined previously, two of the novel putative AdVs had A+T rich DNA, a feature generally deemed to mirror previous host switch events. Our results shed new light on the diversity and evolution of atadenoviruses. PMID:27399970
NASA Astrophysics Data System (ADS)
Holmquist, Jeffrey G.; Schmidt-Gengenbach, Jutta; Ballenger, Elizabeth A.
2014-06-01
Assessments of vertebrate disturbance to plant and animal assemblages often contrast grazed versus ungrazed meadows or other larger areas of usage, and this approach can be powerful. Random sampling of such habitats carries the potential, however, for smaller, more intensely affected patches to be missed and for other responses that are only revealed at smaller scales to also escape detection. We instead sampled arthropod assemblages and vegetation structure at the patch scale (400-900 m2 patches) within subalpine wet meadows of Yosemite National Park (USA), with the goal of determining if there were fine-scale differences in magnitude and directionality of response at three levels of grazing intensity. Effects were both stronger and more nuanced than effects evidenced by previous random sampling of paired grazed and ungrazed meadows: (a) greater negative effects on vegetation structure and fauna in heavily used patches, but (b) some positive effects on fauna in lightly grazed patches, suggested by trends for mean richness and total and population abundances. Although assessment of disturbance at either patch or landscape scales should be appropriate, depending on the management question at hand, our patch-scale work demonstrated that there can be strong local effects on the ecology of these wetlands that may not be detected by comparing larger scale habitats.
Szirovicza, Leonóra; López, Pilar; Kopena, Renáta; Benkő, Mária; Martín, José; Pénzes, Judit J
2016-01-01
Here, we report the results of a large-scale PCR survey on the prevalence and diversity of adenoviruses (AdVs) in samples collected randomly from free-living reptiles. On the territories of the Guadarrama Mountains National Park in Central Spain and of the Chafarinas Islands in North Africa, cloacal swabs were taken from 318 specimens of eight native species representing five squamate reptilian families. The healthy-looking animals had been captured temporarily for physiological and ethological examinations, after which they were released. We found 22 AdV-positive samples in representatives of three species, all from Central Spain. Sequence analysis of the PCR products revealed the existence of three hitherto unknown AdVs in 11 Carpetane rock lizards (Iberolacerta cyreni), nine Iberian worm lizards (Blanus cinereus), and two Iberian green lizards (Lacerta schreiberi), respectively. Phylogeny inference showed every novel putative virus to be a member of the genus Atadenovirus. This is the very first description of the occurrence of AdVs in amphisbaenian and lacertid hosts. Unlike all squamate atadenoviruses examined previously, two of the novel putative AdVs had A+T rich DNA, a feature generally deemed to mirror previous host switch events. Our results shed new light on the diversity and evolution of atadenoviruses.
Sulaiman, Nabil; Albadawi, Salah; Abusnana, Salah; Fikri, Mahmoud; Madani, Abdulrazzag; Mairghani, Maisoon; Alawadi, Fatheya; Zimmet, Paul; Shaw, Jonathan
2015-09-01
The prevalence of diabetes has risen rapidly in the Middle East, particularly in the Gulf Region. However, some prevalence estimates have not fully accounted for large migrant worker populations and have focused on minority indigenous populations. The objectives of the UAE National Diabetes and Lifestyle Study are to: (i) define the prevalence of, and risk factors for, T2DM; (ii) describe the distribution and determinants of T2DM risk factors; (iii) study health knowledge, attitudes, and (iv) identify gene-environment interactions; and (v) develop baseline data for evaluation of future intervention programs. Given the high burden of diabetes in the region and the absence of accurate data on non-UAE nationals in the UAE, a representative sample of the non-UAE nationals was essential. We used an innovative methodology in which non-UAE nationals were sampled when attending the mandatory biannual health check that is required for visa renewal. Such an approach could also be used in other countries in the region. Complete data were available for 2719 eligible non-UAE nationals (25.9% Arabs, 70.7% Asian non-Arabs, 1.1% African non-Arabs, and 2.3% Westerners). Most were men < 65 years of age. The response rate was 68%, and the non-response was greater among women than men; 26.9% earned less than UAE Dirham (AED) 24 000 (US$6500) and the most common areas of employment were as managers or professionals, in service and sales, and unskilled occupations. Most (37.4%) had completed high school and 4.1% had a postgraduate degree. This novel methodology could provide insights for epidemiological studies in the UAE and other Gulf States, particularly for expatriates. © 2015 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.
Carli, Vladimir; Wasserman, Camilla; Wasserman, Danuta; Sarchiapone, Marco; Apter, Alan; Balazs, Judit; Bobes, Julio; Brunner, Romuald; Corcoran, Paul; Cosman, Doina; Guillemin, Francis; Haring, Christian; Kaess, Michael; Kahn, Jean Pierre; Keeley, Helen; Keresztény, Agnes; Iosue, Miriam; Mars, Ursa; Musa, George; Nemes, Bogdan; Postuvan, Vita; Reiter-Theil, Stella; Saiz, Pilar; Varnik, Peeter; Varnik, Airi; Hoven, Christina W
2013-05-16
Mental health problems and risk behaviours among young people are of great public health concern. Consequently, within the VII Framework Programme, the European Commission funded the Saving and Empowering Young Lives in Europe (SEYLE) project. This Randomized Controlled Trial (RCT) was conducted in eleven European countries, with Sweden as the coordinating centre, and was designed to identify an effective way to promote mental health and reduce suicidality and risk taking behaviours among adolescents. To describe the methodological and field procedures in the SEYLE RCT among adolescents, as well as to present the main characteristics of the recruited sample. Analyses were conducted to determine: 1) representativeness of study sites compared to respective national data; 2) response rate of schools and pupils, drop-out rates from baseline to 3 and 12 month follow-up, 3) comparability of samples among the four Intervention Arms; 4) properties of the standard scales employed: Beck Depression Inventory, Second Edition (BDI-II), Zung Self-Rating Anxiety Scale (Z-SAS), Strengths and Difficulties Questionnaire (SDQ), World Health Organization Well-Being Scale (WHO-5). Participants at baseline comprised 12,395 adolescents (M/F: 5,529/6,799; mean age=14.9±0.9) from Austria, Estonia, France, Germany, Hungary, Ireland, Israel, Italy, Romania, Slovenia and Spain. At the 3 and 12 months follow up, participation rates were 87.3% and 79.4%, respectively. Demographic characteristics of participating sites were found to be reasonably representative of their respective national population. Overall response rate of schools was 67.8%. All scales utilised in the study had good to very good internal reliability, as measured by Cronbach's alpha (BDI-II: 0.864; Z-SAS: 0.805; SDQ: 0.740; WHO-5: 0.799). SEYLE achieved its objective of recruiting a large representative sample of adolescents within participating European countries. Analysis of SEYLE data will shed light on the effectiveness of important interventions aimed at improving adolescent mental health and well-being, reducing risk-taking and self-destructive behaviour and preventing suicidality. US National Institute of Health (NIH) clinical trial registry (NCT00906620) and the German Clinical Trials Register (DRKS00000214).
Koroma, Joseph B; Peterson, Jen; Gbakima, Aiah A; Nylander, Francis E; Sahr, Foday; Soares Magalhães, Ricardo J; Zhang, Yaobi; Hodges, Mary H
2010-11-23
A national baseline mapping of schistosomiasis and soil-transmitted helminthiasis (STH) was performed in Sierra Leone. The aim was to provide necessary tools for the Ministry of Health and Sanitation to plan the intervention strategies in the national integrated control program on neglected tropical diseases according to the World Health Organization (WHO) guidelines for preventative chemotherapy (PCT) and for future monitoring and evaluation. 53 primary schools were randomly selected through a two-staged random sampling throughout the country. Approximately one hundred children aged 5-16 years of age were systematically selected from each school and their stool samples examined in a field laboratory. A total of 5,651 samples were examined. Data were analyzed with multivariable logistic regression models using model-based geostatistics. Spatial analysis predicted that S. mansoni infection was positively associated with population density and elevation and that there was a large cluster of high risk of S. mansoni infection (prevalence >70%) in the north and most of the eastern areas of the country, in line with the observed prevalence in Kono (63.8-78.3%), Koinadugu (21.6-82.1%), Kailahun (43.5-52.6%), Kenema (6.1-68.9%) and Tonkolili (0-57.3%). Hookworm infection was negatively associated with population density and land surface temperature, and was high across Sierra Leone with a large cluster of high infection risk (prevalence >70%) in the north-eastern part of the country. Remarkably low prevalence of Ascaris lumbricoides (7.2%) and Trichuris trichiura (3.3%) was recorded when compared with results published in the 1990s. Results justify PCT for schistosomiasis for school age children and at-risk adults every year in high-risk communities in five districts and every two years in moderate-risk communities in one more district. The high prevalence of STH, particularly hookworm, coupled with widespread anemia according to a national report in Sierra Leone, suggests all but one district justifying biannual PCT for STH for pre-school children, school age children, and at-risk adults. PCT for STH in the remaining district, Kono is justified annually.
Koroma, Joseph B.; Peterson, Jen; Gbakima, Aiah A.; Nylander, Francis E.; Sahr, Foday; Soares Magalhães, Ricardo J.; Zhang, Yaobi; Hodges, Mary H.
2010-01-01
Background A national baseline mapping of schistosomiasis and soil-transmitted helminthiasis (STH) was performed in Sierra Leone. The aim was to provide necessary tools for the Ministry of Health and Sanitation to plan the intervention strategies in the national integrated control program on neglected tropical diseases according to the World Health Organization (WHO) guidelines for preventative chemotherapy (PCT) and for future monitoring and evaluation. Methodology/Principal Findings 53 primary schools were randomly selected through a two-staged random sampling throughout the country. Approximately one hundred children aged 5–16 years of age were systematically selected from each school and their stool samples examined in a field laboratory. A total of 5,651 samples were examined. Data were analyzed with multivariable logistic regression models using model-based geostatistics. Spatial analysis predicted that S. mansoni infection was positively associated with population density and elevation and that there was a large cluster of high risk of S. mansoni infection (prevalence >70%) in the north and most of the eastern areas of the country, in line with the observed prevalence in Kono (63.8–78.3%), Koinadugu (21.6–82.1%), Kailahun (43.5–52.6%), Kenema (6.1–68.9%) and Tonkolili (0–57.3%). Hookworm infection was negatively associated with population density and land surface temperature, and was high across Sierra Leone with a large cluster of high infection risk (prevalence >70%) in the north-eastern part of the country. Remarkably low prevalence of Ascaris lumbricoides (7.2%) and Trichuris trichiura (3.3%) was recorded when compared with results published in the 1990s. Conclusions/Significance Results justify PCT for schistosomiasis for school age children and at-risk adults every year in high-risk communities in five districts and every two years in moderate-risk communities in one more district. The high prevalence of STH, particularly hookworm, coupled with widespread anemia according to a national report in Sierra Leone, suggests all but one district justifying biannual PCT for STH for pre-school children, school age children, and at-risk adults. PCT for STH in the remaining district, Kono is justified annually. PMID:21124881
Health benefits for the terminally ill: reality and perception.
Gabel, J R; Hurst, K M; Hunt, K A
1998-01-01
This paper examines the availability and scope of hospice benefits as well as employers' attitudes and knowledge about care for the terminally ill. Data are drawn from a national random sample of 1,502 employers with 200 or more workers and from focus groups with employee benefits managers and their insurance advisers, brokers, and consultants. Major findings are that 83 percent of employers offer explicit hospice benefits, with most other firms covering hospice through high-cost case management. Most employers support the concept of hospice care because they believe that it reduces medical expenses.
News media framing of serious mental illness and gun violence in the United States, 1997-2012.
McGinty, Emma E; Webster, Daniel W; Jarlenski, Marian; Barry, Colleen L
2014-03-01
Recent mass shootings by persons seemingly afflicted with serious mental illness (SMI) have received extensive news media coverage and prompted national dialogue about the causes of, and policy responses to, mass shootings. News media framing of SMI as a cause of gun violence may influence public attitudes about persons with SMI and support for gun violence prevention proposals. We analyzed the content of a 25% random sample of news stories on SMI and gun violence published in 14 national and regional news sources from 1997 to 2012. Across the study period, most news coverage occurred in the wake of mass shootings, and "dangerous people" with SMI were more likely than "dangerous weapons" to be mentioned as a cause of gun violence.
News Media Framing of Serious Mental Illness and Gun Violence in the United States, 1997-2012
Webster, Daniel W.; Jarlenski, Marian; Barry, Colleen L.
2014-01-01
Recent mass shootings by persons seemingly afflicted with serious mental illness (SMI) have received extensive news media coverage and prompted national dialogue about the causes of, and policy responses to, mass shootings. News media framing of SMI as a cause of gun violence may influence public attitudes about persons with SMI and support for gun violence prevention proposals. We analyzed the content of a 25% random sample of news stories on SMI and gun violence published in 14 national and regional news sources from 1997 to 2012. Across the study period, most news coverage occurred in the wake of mass shootings, and “dangerous people” with SMI were more likely than “dangerous weapons” to be mentioned as a cause of gun violence. PMID:24432874
Naidoo, Pamela; Simbayi, Leickness; Labadarios, Demetre; Ntsepe, Yoliswa; Bikitsha, Nwabisa; Khan, Gadija; Sewpaul, Ronel; Moyo, Sizulu; Rehle, Thomas
2016-03-18
South Africa is one of the 22 high tuberculosis burden countries that contribute 80% of the global tuberculosis cases. Tuberculosis is infectious and due to its rapid and easy transmission route poses a threat to population health. Considering the importance of social and psychological factors in influencing health outcomes, appraising knowledge and awareness of tuberculosis, remain vital for effective tuberculosis control. The main aim of this study was to investigate the factors that predict knowledge about tuberculosis among 18-64 year old adults in South Africa. A cross-sectional survey method was used. Multi-stage disproportionate, stratified cluster sampling was used to select households within enumeration areas stratified by province and locality type. Based on the Human Sciences Research Council 2007 master sample, 500 Enumerator Areas representative of the socio-demographic profile of South Africa were identified and a random sample of 20 households was randomly selected from each Enumerator Area, yielding an overall sample of 10,000 households. The tuberculosis module contained in the South African National Health And Nutrition Examination Survey I was the only module that examined the social determinants of an infectious disease. This module was questionnaire-based with no biomarkers obtained to screen for the presence of tuberculosis disease among the participants. Data was collected by administering a researcher developed individual level questionnaire. Simple and multiple linear regression was used to determine the independent variables associated with tuberculosis knowledge. Half the sample (52.6%) was female and the majority of the respondents were black African (76.5%). More than two thirds (68.0%) resided in urban areas, 56.9% did not complete high school and half were not in formal employment. Significant predictors of tuberculosis knowledge were race, sex, completion of high school, being in employment, having a diagnosis of the disease in ones' life-time and learning about tuberculosis from television, brochures, health workers, and teachers. To reduce the burden of tuberculosis in South Africa, media campaigns targeting both rural and urban communities should include conveying accurate information about the disease. Policy makers should also address structural barriers that vulnerable communities face.
Verdugo, Cristobal; Jones, Geoff; Johnson, Wes; Wilson, Peter; Stringer, Lesley; Heuer, Cord
2014-12-01
The study aimed to estimate the national- and island-level flock/herd true prevalence (HTP) of Mycobacterium avium subsp. paratuberculosis (MAP) infection in pastoral farmed sheep, beef cattle and deer in New Zealand. A random sample of 238 single- or multi-species farms was selected from a postal surveyed population of 1940 farms. The sample included 162 sheep flocks, 116 beef cattle and 99 deer herds from seven of 16 geographical regions. Twenty animals from each species present on farm were randomly selected for blood and faecal sampling. Pooled faecal culture testing was conducted using a single pool (sheep flocks) or two pools (beef cattle/deer herds) of 20 and 10 samples per pool, respectively. To increase flock/herd-level sensitivity, sera from all 20 animals from culture negative flocks/herds were individually tested by Pourquier(®) ELISA (sheep and cattle) or Paralisa™ (deer). Results were adjusted for sensitivity and specificity of diagnostic tests using a novel Bayesian latent class model. Outcomes were adjusted by their sampling fractions to obtain HTP estimates at national level. For each species, the posterior probability (POPR) of HTP differences between New Zealand North (NI) and South (SI) Islands was obtained. Across all species, 69% of farms had at least one species test positive. Sheep flocks had the highest HTP estimate (76%, posterior probability interval (PPI) 70-81%), followed by deer (46%, PPI 38-55%) and beef herds (42%, PPI 35-50%). Differences were observed between the two main islands of New Zealand, with higher HTP in sheep and beef cattle flocks/herds in the NI. Sheep flock HTP was 80% in the NI compared with 70% (POPR=0.96) in the SI, while the HTP for beef cattle was 44% in the NI and 38% in the SI (POPR=0.80). Conversely, deer HTP was higher in the SI (54%) than the NI (33%, POPR=0.99). Infection with MAP is endemic at high prevalence in sheep, beef cattle and deer flocks/herds across New Zealand. Copyright © 2014 Elsevier B.V. All rights reserved.
Using practical and social information to influence flood adaptation behavior
NASA Astrophysics Data System (ADS)
Allaire, Maura C.
2016-08-01
As the prospect for more frequent and severe extreme weather events gains scientific support, many nations are evaluating mitigation and adaptation options. Insurance and home retrofits could reduce household welfare losses due to flood events. Yet even after disasters, households often fail to take risk mitigation actions. This paper presents the first randomized field experiment that tests the effect of information provision on household uptake of flood insurance and home retrofits. A sample of 364 flood-prone households in Bangkok was randomly split into treatment and control groups. The treatment group received practical details on home retrofits and flood insurance as well as social information regarding the insurance purchase decisions of peers. Results indicate that the information intervention increased insurance purchases by about five percentage points, while no effect was detected for home retrofits. This effect is nearly equal to the increase in uptake that the national insurance program in Thailand has achieved through all other means since its establishment in 2012. If scaled up to include all uninsured, flood-prone households in Bangkok, nearly 70,000 additional households could be insured. The results suggest that well-designed information interventions could increase uptake of flood insurance, without additional premium subsidies or mandates.
Reduction of display artifacts by random sampling
NASA Technical Reports Server (NTRS)
Ahumada, A. J., Jr.; Nagel, D. C.; Watson, A. B.; Yellott, J. I., Jr.
1983-01-01
The application of random-sampling techniques to remove visible artifacts (such as flicker, moire patterns, and paradoxical motion) introduced in TV-type displays by discrete sequential scanning is discussed and demonstrated. Sequential-scanning artifacts are described; the window of visibility defined in spatiotemporal frequency space by Watson and Ahumada (1982 and 1983) and Watson et al. (1983) is explained; the basic principles of random sampling are reviewed and illustrated by the case of the human retina; and it is proposed that the sampling artifacts can be replaced by random noise, which can then be shifted to frequency-space regions outside the window of visibility. Vertical sequential, single-random-sequence, and continuously renewed random-sequence plotting displays generating 128 points at update rates up to 130 Hz are applied to images of stationary and moving lines, and best results are obtained with the single random sequence for the stationary lines and with the renewed random sequence for the moving lines.
Pragmatic Randomized Trials Without Standard Informed Consent?: A National Survey.
Nayak, Rahul K; Wendler, David; Miller, Franklin G; Kim, Scott Y H
2015-09-01
Significant debate surrounds the issue of whether written consent is necessary for pragmatic randomized, controlled trials (RCTs) with low risk. To assess the U.S. public's views on alternatives to written consent for low-risk pragmatic RCTs. National experimental survey (2 × 2 factorial design) examining support for written consent versus general notification or verbal consent in 2 research scenarios. Web-based survey conducted in December 2014. 2130 U.S. adults sampled from a nationally representative, probability-based online panel (response rate, 64.0%). Respondent's recommendation to an ethics review board and personal preference as a potential participant on how to obtain consent or notification in the 2 research scenarios. Most respondents in each of the 4 groups (range, 60.3% to 71.5%) recommended written informed consent, and personal preferences were generally in accord with that advice. Most (78.9%) believed that the pragmatic RCTs did not pose additional risks, but 62.5% of these respondents would still recommend written consent. In contrast, a substantial minority in all groups (28.5% to 39.7%) recommended the alternative option (general notification or verbal consent) over written consent. Framing effects could have affected respondents' attitudes, and nonrespondents may have differed in levels of trust toward research or health care institutions. Most of the public favored written informed consent over the most widely advocated alternatives for low-risk pragmatic RCTs; however, a substantial minority favored general notification or verbal consent. Time-sharing Experiments for the Social Sciences and Intramural Research Program of the National Institutes of Health Clinical Center.
Machado, Flavia R; Cavalcanti, Alexandre Biasi; Bozza, Fernando Augusto; Ferreira, Elaine M; Angotti Carrara, Fernanda Sousa; Sousa, Juliana Lubarino; Caixeta, Noemi; Salomao, Reinaldo; Angus, Derek C; Pontes Azevedo, Luciano Cesar
2017-11-01
The sepsis burden on acute care services in middle-income countries is a cause for concern. We estimated incidence, prevalence, and mortality of sepsis in adult Brazilian intensive care units (ICUs) and association of ICU organisational factors with outcome. We did a 1-day point prevalence study with follow-up of patients in ICU with sepsis in a nationally representative pseudo-random sample. We produced a sampling frame initially stratified by geographical region. Each stratum was then stratified by hospitals' main source of income (serving general public vs privately insured individuals) and ICU size (ten or fewer beds vs more than ten beds), finally generating 40 strata. In each stratum we selected a random sample of ICUs so as to enrol the total required beds in 1690 Brazilian adult ICUs. We followed up patients until hospital discharge censored at 60 days, estimated incidence from prevalence and length of stay, and generated national estimates. We assessed mortality prognostic factors using random-effects logistic regression models. On Feb 27, 2014, 227 (72%) of 317 ICUs that were randomly selected provided data on 2632 patients, of whom 794 had sepsis (30·2 septic patients per 100 ICU beds, 95% CI 28·4-31·9). The ICU sepsis incidence was 36·3 per 1000 patient-days (95% CI 29·8-44·0) and mortality was observed in 439 (55·7%) of 788 patients (95% CI 52·2-59·2). Low availability of resources (odds ratio [OR] 1·67, 95% CI 1·02-2·75, p=0·045) and adequacy of treatment (OR 0·56, 0·37-0·84, p=0·006) were independently associated with mortality. The projected incidence rate is 290 per 100 000 population (95% CI 237·9-351·2) of adult cases of ICU-treated sepsis per year, which yields about 420 000 cases annually, of whom 230 000 die in hospital. The incidence, prevalence, and mortality of ICU-treated sepsis is high in Brazil. Outcome varies considerably, and is associated with access to adequate resources and treatment. Our results show the burden of sepsis in resource-limited settings, highlighting the need to establish programmes aiming for sepsis prevention, early diagnosis, and adequate treatment. Fundação de Apoio a Pesquisa do Estado de São Paulo (FAPESP). Copyright © 2017 Elsevier Ltd. All rights reserved.
Revisiting sample size: are big trials the answer?
Lurati Buse, Giovanna A L; Botto, Fernando; Devereaux, P J
2012-07-18
The superiority of the evidence generated in randomized controlled trials over observational data is not only conditional to randomization. Randomized controlled trials require proper design and implementation to provide a reliable effect estimate. Adequate random sequence generation, allocation implementation, analyses based on the intention-to-treat principle, and sufficient power are crucial to the quality of a randomized controlled trial. Power, or the probability of the trial to detect a difference when a real difference between treatments exists, strongly depends on sample size. The quality of orthopaedic randomized controlled trials is frequently threatened by a limited sample size. This paper reviews basic concepts and pitfalls in sample-size estimation and focuses on the importance of large trials in the generation of valid evidence.
THE PREVALENCE OF CANNABIS-INVOLVED DRIVING IN CALIFORNIA
Johnson, Mark B.; Kelley-Baker, Tara; Voas, Robert B.; Lacey, John H.
2013-01-01
Background Various national surveys suggest that cannabis use is rising nationally, and many States have passed legislation that has potential to increase usage even further. This presents a problem for public roadways, as research suggests that cannabis impairs driving ability. Methods Anonymous oral fluid samples and breath tests were obtained from more than 900 weekend nighttime drivers randomly sampled from six jurisdictions in California. Oral fluid samples were assayed for the presence of Schedule I drugs. Drivers also completed information on self-reported drug use and possession of a medical cannabis permit. Data from the 2007 National Roadside Survey (collected using comparable methods) were used as a comparison. Results Using the 2010 data, a total of 14.4% of weekend nighttime drivers tested positive for illegal drugs, with 8.5% testing positive for delta-9-tetrahydrocannabinol (THC). THC-positive rates varied considerably among jurisdictions, from a low of 4.3% in Fresno to a high of 18.3% in Eureka. A comparison with the 2007 NRS data found an increase in THC-positive drivers in 2010, but no increase in illegal drugs other than cannabis. Drivers who reported having a medical cannabis permit were significantly more likely to test positive for THC. Conclusions Cannabis-involved driving has increased in California since 2007. Nearly 1-in-10 weekend, nighttime drivers tested positive for THC, and in some jurisdictions, the rate was nearly 1-in-5. The possible contribution of cannabis legislation, such as decriminalization and medical cannabis usage, is discussed. PMID:22101027
NASA Astrophysics Data System (ADS)
Justice, C. J.
2015-12-01
80% of Tanzania's population is involved in the agriculture sector. Despite this national dependence, agricultural reporting is minimal and monitoring efforts are in their infancy. The cropland mask developed through this study provides the framework for agricultural monitoring through informing analysis of crop conditions, dispersion, and intensity at a national scale. Tanzania is dominated by smallholder agricultural systems with an average field size of less than one hectare (Sarris et al, 2006). At this field scale, previous classifications of agricultural land in Tanzania using MODIS course resolution data are insufficient to inform a working monitoring system. The nation-wide cropland mask in this study was developed using composited Landsat tiles from a 2010-2013 time series. Decision tree classifiers methods were used in the study with representative training areas collected for agriculture and no agriculture using appropriate indices to separate these classes (Hansen et al, 2013). Validation was done using random sample and high resolution satellite images to compare Agriculture and No agriculture samples from the study area. The techniques used in this study were successful and have the potential to be adapted for other countries, allowing targeted monitoring efforts to improve food security, market price, and inform agricultural policy.
Ogunrin, Olubunmi A; Daniel, Folasade; Ansa, Victor
2016-12-01
Responsibility for protection of research participants from harm and exploitation rests on Research Ethics Committees and principal investigators. The Nigerian National Code of Health Research Ethics defines responsibilities of stakeholders in research so its knowledge among researchers will likely aid ethical conduct of research. The levels of awareness and knowledge of the Code among biomedical researchers in southern Nigerian research institutions was assessed. Four institutions were selected using a stratified random sampling technique. Research participants were selected by purposive sampling and completed a pre-tested structured questionnaire. A total of 102 biomedical researchers completed the questionnaires. Thirty percent of the participants were aware of the National Code though 64% had attended at least one training seminar in research ethics. Twenty-five percent had a fairly acceptable knowledge (scores 50%-74%) and 10% had excellent knowledge of the code (score ≥75%). Ninety-five percent expressed intentions to learn more about the National Code and agreed that it is highly relevant to the ethical conduct of research. Awareness and knowledge of the Code were found to be very limited among biomedical researchers in southern Nigeria. There is need to improve awareness and knowledge through ethics seminars and training. Use of existing Nigeria-specific online training resources is also encouraged.
Optimum allocation for a dual-frame telephone survey.
Wolter, Kirk M; Tao, Xian; Montgomery, Robert; Smith, Philip J
2015-12-01
Careful design of a dual-frame random digit dial (RDD) telephone survey requires selecting from among many options that have varying impacts on cost, precision, and coverage in order to obtain the best possible implementation of the study goals. One such consideration is whether to screen cell-phone households in order to interview cell-phone only (CPO) households and exclude dual-user household, or to take all interviews obtained via the cell-phone sample. We present a framework in which to consider the tradeoffs between these two options and a method to select the optimal design. We derive and discuss the optimum allocation of sample size between the two sampling frames and explore the choice of optimum p , the mixing parameter for the dual-user domain. We illustrate our methods using the National Immunization Survey , sponsored by the Centers for Disease Control and Prevention.
Weatherred, Jane Long
2017-01-01
The way in which the news media frame child sexual abuse can influence public perception. This content analysis of the child sexual abuse coverage of eight national news organizations in the United States from 2002 to 2012 includes the two dominant events of the Catholic Church and Pennsylvania State University child sexual abuse scandals. Census and systematic stratified sampling techniques were applied to articles obtained from the Lexis/Nexis Academic database, resulting in a sample of 503 articles. Intercoder reliability was ensured by double coding a randomly selected sample. Study findings indicate a shift in the attribution of responsibility of child sexual abuse among news organizations over the past decade from an individual-level problem with individual-level solutions to a societal-level problem with institutional culpability. Nevertheless, individual-level solutions continue to be framed as the best possible solution.
Colman, John A.; Sanzolone, R.F.
1991-01-01
Geochemical data are presented from a synoptic survey of 46 elements in fine-fraction streambed sediments of the Upper Illinois River Basin during the fall of 1987. The survey was a component study of the Illinois pilot project of the U.S. Geological Survey's National Water-Quality Assessment program. Most of the sampling sites were randomly chosen--135 on main stems of rivers and 238 on first- and second-order streams. In addition, 196 samples were collected for quality-assurance and special-study purposes. The report includes element concentration data and summary-statistics tables of percentiles, nested analysis of variance, and correlation coefficients. All concentration data are included in tabular form and can be selected by map reference number, latitude and longitude, or remark code indicating purpose for collecting sample.
An, Zhao; Wen-Xin, Zhang; Zhong, Yao; Yu-Kuan, Ma; Qing, Liu; Hou-Lang, Duan; Yi-di, Shang
2016-06-29
To optimize and simplify the survey method of Oncomelania hupensis snail in marshland endemic region of schistosomiasis and increase the precision, efficiency and economy of the snail survey. A quadrate experimental field was selected as the subject of 50 m×50 m size in Chayegang marshland near Henghu farm in the Poyang Lake region and a whole-covered method was adopted to survey the snails. The simple random sampling, systematic sampling and stratified random sampling methods were applied to calculate the minimum sample size, relative sampling error and absolute sampling error. The minimum sample sizes of the simple random sampling, systematic sampling and stratified random sampling methods were 300, 300 and 225, respectively. The relative sampling errors of three methods were all less than 15%. The absolute sampling errors were 0.221 7, 0.302 4 and 0.047 8, respectively. The spatial stratified sampling with altitude as the stratum variable is an efficient approach of lower cost and higher precision for the snail survey.
Evaluating the implementation of RxNorm in ambulatory electronic prescriptions
Ward-Charlerie, Stacy; Rupp, Michael T; Kilbourne, John; Amin, Vishal P; Ruiz, Joshua
2016-01-01
Objective RxNorm is a standardized drug nomenclature maintained by the National Library of Medicine that has been recommended as an alternative to the National Drug Code (NDC) terminology for use in electronic prescribing. The objective of this study was to evaluate the implementation of RxNorm in ambulatory care electronic prescriptions (e-prescriptions). Methods We analyzed a random sample of 49 997 e-prescriptions that were received by 7391 locations of a national retail pharmacy chain during a single day in April 2014. The e-prescriptions in the sample were generated by 37 801 ambulatory care prescribers using 519 different e-prescribing software applications. Results We found that 97.9% of e-prescriptions in the study sample could be accurately represented by an RxNorm identifier. However, RxNorm identifiers were actually used as drug identifiers in only 16 433 (33.0%) e-prescriptions. Another 431 (2.5%) e-prescriptions that used RxNorm identifiers had a discrepancy in the corresponding Drug Database Code qualifier field or did not have a qualifier (Term Type) at all. In 10 e-prescriptions (0.06%), the free-text drug description and the RxNorm concept unique identifier pointed to completely different drug concepts, and in 7 e-prescriptions (0.04%), the NDC and RxNorm drug identifiers pointed to completely different drug concepts. Discussion The National Library of Medicine continues to enhance the RxNorm terminology and expand its scope. This study illustrates the need for technology vendors to improve their implementation of RxNorm; doing so will accelerate the adoption of RxNorm as the preferred alternative to using the NDC terminology in e-prescribing. PMID:26510879
NASA Astrophysics Data System (ADS)
Wang, Shao-Jiang; Guo, Qi; Cai, Rong-Gen
2017-12-01
We investigate the impact of different redshift distributions of random samples on the baryon acoustic oscillations (BAO) measurements of D_V(z)r_d^fid/r_d from the two-point correlation functions of galaxies in the Data Release 12 of the Baryon Oscillation Spectroscopic Survey (BOSS). Big surveys, such as BOSS, usually assign redshifts to the random samples by randomly drawing values from the measured redshift distributions of the data, which would necessarily introduce fiducial signals of fluctuations into the random samples, weakening the signals of BAO, if the cosmic variance cannot be ignored. We propose a smooth function of redshift distribution that fits the data well to populate the random galaxy samples. The resulting cosmological parameters match the input parameters of the mock catalogue very well. The significance of BAO signals has been improved by 0.33σ for a low-redshift sample and by 0.03σ for a constant-stellar-mass sample, though the absolute values do not change significantly. Given the precision of the measurements of current cosmological parameters, it would be appreciated for the future improvements on the measurements of galaxy clustering.
Marcenes, Wagner; Steele, Jimmy George; Sheiham, Aubrey; Walls, Angus Willian Gilmour
2003-01-01
This paper reviewed the findings from a national survey in Great Britain which assessed whether dental status affected older people's food selection, nutrient intake, and nutritional status. The survey analyzed national random samples of free-living and institution subjects for dental examination, interview, and four-day food diary as well as blood and urine tests In the free-living sample, intakes of non-starch polysaccharides, protein, calcium, non-heme iron, niacin, and vitamin C were significantly lower in edentulous as compared to dentate subjects. People with 21 or more teeth consumed more of most nutrients, particularly non-starch polysaccharides. This relationship in intake was not apparent in the hematological analysis. Plasma ascorbate and retinol were the only analytes significantly associated with dental status. Having 21 or more teeth increased the likelihood of having an acceptable body mass index (BMI). Thus, maintaining a natural and functional dentition defined as having more than twenty teeth into old age plays an important role in having a healthy diet rich in fruits and vegetables, a satisfactory nutritional status, and an acceptable BMI.
Wittek, Charlotte Thoresen; Finserås, Turi Reiten; Pallesen, Ståle; Mentzoni, Rune Aune; Hanss, Daniel; Griffiths, Mark D; Molde, Helge
Video gaming has become a popular leisure activity in many parts of the world, and an increasing number of empirical studies examine the small minority that appears to develop problems as a result of excessive gaming. This study investigated prevalence rates and predictors of video game addiction in a sample of gamers, randomly selected from the National Population Registry of Norway ( N = 3389). Results showed there were 1.4 % addicted gamers, 7.3 % problem gamers, 3.9 % engaged gamers, and 87.4 % normal gamers. Gender (being male) and age group (being young) were positively associated with addicted-, problem-, and engaged gamers. Place of birth (Africa, Asia, South- and Middle America) were positively associated with addicted- and problem gamers. Video game addiction was negatively associated with conscientiousness and positively associated with neuroticism. Poor psychosomatic health was positively associated with problem- and engaged gaming. These factors provide insight into the field of video game addiction, and may help to provide guidance as to how individuals that are at risk of becoming addicted gamers can be identified.
Blosnich, John; Bossarte, Robert
2012-01-01
Lesbian, gay, and bisexual (i.e., sexual minority) populations have increased prevalence of both self-injurious and suicidal behaviors, but reasons for these disparities are poorly understood. Objective To test the association between socially-based stressors (e.g., victimization, discrimination) and self-injurious behavior, suicide ideation, and suicide attempt. Participants A national sample of college-attending 18- to 24-year-olds. Methods Random or census samples from post-secondary educational institutions that administered the National College Health Assessment during the Fall 2008 and Spring 2009 semesters. Results Sexual minorities reported more socially-based stressors than heterosexuals. Bisexuals exhibited greatest prevalence of self-injurious and suicidal behaviors. In adjusted models, intimate partner violence was most consistently associated with self-injurious behaviros. Conclusions Sexual minorities' elevated risks of self-injurious and suicidal behaviors may stem from higher exposure to socially-based stressors. Within-group differences among sexual minorities offer insight to specific risk factors that may contribute to elevated self-injurious and suicidal behaviors in sexual minority populations. PMID:22316411
Urban land-use study plan for the National Water-Quality Assessment Program
Squillace, P.J.; Price, C.V.
1996-01-01
This study plan is for Urban Land-Use Studies initiated as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program. There are two Urban Land-Use Study objectives: (1) Define the water quality in recharge areas of shallow aquifers underlying areas of new residential and commercial land use in large metropolitan areas, and (2) determine which natural and human factors most strongly affect the occurrence of contaminants in these shallow aquifers. To meet objective 1, each NAWQA Study Unit will install and collect water samples from at least 30 randomly located monitoring wells in a metropolitan area. To meet objective 2, aquifer characteristics and land-use information will be documented. This includes particle-size analysis of each major lithologic unit both in the unsaturated zone and in the aquifer near the water table. The percentage of organic carbon also will be determined for each lithologic unit. Geographic information system coverages will be created that document existing land use around the wells. These data will aid NAWQA personnel in relating natural and human factors to the occurrence of contaminants. Water samples for age dating also will be collected from all monitoring wells, but the samples will be stored until the occurrence of contaminants has been determined. Age-date analysis will be done only on those samples that have no detectable concentrations of anthropogenic contaminants.
Nazzaro, Ann-Marie; Owens, Sally; Hoots, W Keith; Larson, Kelly L
2006-09-01
The National Hemophilia Foundation and the Centers for Disease Control and Prevention conducted a national survey focusing on knowledge about, attitudes toward, and behaviors associated with key prevention activities among youths with hemophilia and used the data gathered to design a health promotion campaign. A national, random sample of 459 patients was drawn from 20 hemophilia treatment centers and 8 hemophilia associations; 110 (24%) of the respondents were young people. A telephone questionnaire was used to measure knowledge, behaviors, and barriers to prevention. Thirty-six percent of the youth respondents believed that joint disease cannot be prevented; 60% managed hemophilia by avoiding physical activity. Only 31% of the respondents treated bleeding episodes within 1 hour. Although hepatitis was a clear threat to this hemophilic cohort, 78% did now know transmission routes for hepatitis C, and 67% did not know transmission routes for hepatitis B. Young people with chronic disorders need help understanding that they can prevent complications. We identified key messages for a hemophilia prevention campaign, including exercising to ensure healthy joints and treating bleeding episodes early and adequately.
Silvestre, Maria Asuncion A; Mannava, Priya; Corsino, Marie Ann; Capili, Donna S; Calibo, Anthony P; Tan, Cynthia Fernandez; Murray, John C S; Kitong, Jacqueline; Sobel, Howard L
2018-03-31
To determine whether intrapartum and newborn care practices improved in 11 large hospitals between 2008 and 2015. Secondary data analysis of observational assessments conducted in 11 hospitals in 2008 and 2015. Eleven large government hospitals from five regions in the Philippines. One hundred and seven randomly sampled postpartum mother-baby pairs in 2008 and 106 randomly sampled postpartum mothers prior to discharge from hospitals after delivery. A national initiative to improve quality of newborn care starting in 2009 through development of a standard package of intrapartum and newborn care services, practice-based training, formation of multidisciplinary hospital working groups, and regular assessments and meetings in hospitals to identify actions to improve practices, policies and environments. Quality improvement was supported by policy development, health financing packages, health facility standards, capacity building and health communication. Sixteen intrapartum and newborn care practices. Between 2008 and 2015, initiation of drying within 5 s of birth, delayed cord clamping, dry cord care, uninterrupted skin-to-skin contact, timing and duration of the initial breastfeed, and bathing deferred until 6 h after birth all vastly improved (P<0.001). The proportion of newborns receiving hygienic cord handling and the hepatitis B birth dose decreased by 11-12%. Except for reduced induction of labor, inappropriate maternal care practices persisted. Newborn care practices have vastly improved through an approach focused on improving hospital policies, environments and health worker practices. Maternal care practices remain outdated largely due to the ineffective didactic training approaches adopted for maternal care.
Bitran, Stella; Farabaugh, Amy H; Ameral, Victoria E; LaRocca, Rachel A; Clain, Alisabet J; Fava, Maurizio; Mischoulon, David
2011-07-01
To assess whether early changes in Hamilton Depression Rating Scale-17 anxiety/somatization items predict remission in two controlled studies of Hypericum perforatum (St John's wort) versus selective serotonin reuptake inhibitors for major depressive disorder. The Hypericum Depression Trial Study Group (National Institute of Mental Health) randomized 340 patients to Hypericum, sertraline, or placebo for 8 weeks, whereas the Massachusetts General Hospital study randomized 135 patients to Hypericum, fluoxetine, or placebo for 12 weeks. The investigators examined whether remission was associated with early changes in anxiety/somatization symptoms. In the National Institute of Mental Health study, significant associations were observed between remission and early improvement in the anxiety (psychic) item (sertraline arm), somatic (gastrointestinal item; Hypericum arm), and somatic (general) symptoms (placebo arm). None of the three treatment arms of the Massachusetts General Hospital study showed significant associations between anxiety/somatization symptoms and remission. When both study samples were pooled, we found associations for anxiety (psychic; selective serotonin reuptake inhibitors arm), somatic (gastrointestinal), and hypochondriasis (Hypericum arm), and anxiety (psychic) and somatic (general) symptoms (placebo arm). In the entire sample, remission was associated with the improvement in the anxiety (psychic), somatic (gastrointestinal), and somatic (general) items. The number and the type of anxiety/somatization items associated with remission varied depending on the intervention. Early scrutiny of the Hamilton Depression Rating Scale-17 anxiety/somatization items may help to predict remission of major depressive disorder.
Balestrieri, Matteo; Baldacci, Sandra; Bellomo, Antonello; Bellantuono, Cesario; Conti, Luciano; Perugi, Giulio; Nardini, Marcello; Borbotti, Marco; Viegi, Giovanni
2007-01-01
To assess in a national sample the ability of GPs to detect psychiatric disorders using a clinical vs. a standardized interview and to characterize the patients that were falsely diagnosed with an anxiety or affective disorder. This is a national, cross-sectional, epidemiological survey, carried out by GPs on a random sample of their patients. The GPs were randomly divided into two groups. Apart from the routine clinical interview, the experimental group (group A) had to administer the Mini-International Neuropsychiatric Interview (MINI). Data was collected by 143 GPs. 17.2% of all patients had a clinical diagnosis of an affective disorder, and 25.4% a clinical diagnosis of an anxiety disorder. In group A, the number of clinical diagnoses was about twice that of MINI diagnoses for affective disorders and one and a half times that for anxiety disorders. The majority of clinical diagnoses were represented by MINI subsyndromal cases (52.3%). Females showed a higher OR of being over-detected by GPs with anxiety disorders or of not being diagnosed with an affective disorder. Being divorced/separated/widowed increased the OR of over-detection of affective and anxiety disorders. The OR of over-detection of an affective or an anxiety disorder was higher for individuals with a moderate to poor quality of life. In the primary care a gap exists between clinical and standardized interviews in the detection of affective and anxiety disorders. Some experiential and social factors can increase this tendency. The use of a psycho.
NASA Astrophysics Data System (ADS)
Hanike, Yusrianti; Sadik, Kusman; Kurnia, Anang
2016-02-01
This research implemented unemployment rate in Indonesia that based on Poisson distribution. It would be estimated by modified the post-stratification and Small Area Estimation (SAE) model. Post-stratification was one of technique sampling that stratified after collected survey data. It's used when the survey data didn't serve for estimating the interest area. Interest area here was the education of unemployment which separated in seven category. The data was obtained by Labour Employment National survey (Sakernas) that's collected by company survey in Indonesia, BPS, Statistic Indonesia. This company served the national survey that gave too small sample for level district. Model of SAE was one of alternative to solved it. According the problem above, we combined this post-stratification sampling and SAE model. This research gave two main model of post-stratification sampling. Model I defined the category of education was the dummy variable and model II defined the category of education was the area random effect. Two model has problem wasn't complied by Poisson assumption. Using Poisson-Gamma model, model I has over dispersion problem was 1.23 solved to 0.91 chi square/df and model II has under dispersion problem was 0.35 solved to 0.94 chi square/df. Empirical Bayes was applied to estimate the proportion of every category education of unemployment. Using Bayesian Information Criteria (BIC), Model I has smaller mean square error (MSE) than model II.
Derlet, Robert Wayne; Carlson, James Reynolds
2002-01-01
To determine the prevalence of microorganisms that are potentially pathogenic for humans in horse/mule manure along the John Muir Trail (JMT). Random samples of horse/mule manure were collected along sections of the JMT in Yosemite, Kings Canyon, and Sequoia national parks (NP), as well as in portions of the Pacific Crest Trail (PCT) and selected JMT/PCT access trails. Convenience samples of wild animal scat found within I mile of trails were also collected. The fresh specimens were individually preserved both in 0.9% saline and polyvinyl alcohol (PVA)-containing tubes and stored at 4 degrees C until time of analysis. Bacteriological analysis was performed using standard microbiology laboratory procedures. PVA samples were stained with trichrome and were then examined by a parasitologist. Collection: A total of 186 trail miles were sampled, including 113 on the JMT (Yosemite 37, Kings 53, and Sequoia 23). The PCT samplings included 24 miles, and NP and wilderness area access trails added an additional 49 miles. A total of 102 samples were collected, which included 81 samples from pack animals and 21 identified as having come from wild animals. Pack Animal Bacteria: All plated specimens grew large numbers of commensal gut flora. Potential pathogenic bacteria were found in only 12 samples and included Hafnia alvei (4), Serratia odorifera (1), Citrobacter freundii (1), Escherichia vulneris (1), Clostridium clostridioforme (1), Yersinia enterocolitica (1), Sherwinella putraformus (1), and Enterobacter spp (4). No Escherichia coli O157, Salmonella, or Aeromonas were found. Microscopic examination for protozoal organisms revealed occasional commensal ciliates and I Giardia. Wild Animal Pathogens: One specimen grew Y enterocolitica, and another grew Enterobacter amnigenus. We found a low prevalence of human pathogens in pack animal manure on the JMT.
Inventory of montane-nesting birds in the Arctic Network of National Parks, Alaska
Tibbitts, T.L.; Ruthrauff, D.R.; Gill, Robert E.; Handel, Colleen M.
2006-01-01
The Alaska Science Center of the U.S. Geological Survey conducted an inventory of birds in montane areas of the four northern parks in the Arctic Network of National Parks, Alaska. This effort represents the first comprehensive assessment of breeding range and habitat associations for the majority of avian species in the Arctic Network. Ultimately, these data provide a framework upon which to design future monitoring programs.A stratified random sampling design was used to select sample plots (n = 73 plots) that were allocated in proportion to the availability of ecological subsections. Point counts (n = 1,652) were conducted to quantify abundance, distribution, and habitat associations of birds. Field work occurred over three years (2001 to 2003) during two-week-long sessions in late May through early June that coincided with peak courtship activity of breeding birds.Totals of 53 species were recorded in Cape Krusenstern National Monument, 91 in Noatak National Preserve, 57 in Kobuk Valley National Park, and 96 in Gates of the Arctic National Park and Preserve. Substantial proportions of species in individual parks are considered species of conservation concern (18 to 26%) or species of stewardship responsibility of the land managers in the region (8 to 18%). The most commonly detected passerines on point counts included Redpoll spp. (Carduelis flammea and C. hornemanni), Savannah Sparrow (Passerculus sandwichensis), and American Tree Sparrow (Spizella arborea). The most numerous shorebirds were American Golden-Plover (Pluvialis dominica), Wilson’s Snipe (Gallinago delicata), and Whimbrel (Numenius phaeopus). Most species were detected at low rates, reflecting the low breeding densities (and/or low detectabilities) of birds in the montane Arctic. Suites of species were associated with particular ranges of elevation and showed strong associations with particular habitat types.
Frixione, Eugenio; Ruiz-Zamarripa, Lourdes; Hernández, Gerardo
2016-01-01
Assessing the research of individual scholars is currently a matter of serious concern and worldwide debate. In order to gauge the long-term efficacy and efficiency of this practice, we carried out a limited survey of the operation and outcome of Mexico’s 30-year old National System of Investigators or SNI, the country’s main instrument for stimulating competitive research in science and technology. A statistical random sample of researchers listed in the area of Humanities and Behavioral Sciences—one of SNI’s first and better consolidated academic divisions comprising a wide range of research disciplines, from philosophy to pedagogy to archaeology to experimental brain research—was screened comparing individual ranks or "Levels of distinction" to actual compliance with the SNI’s own evaluation criteria, as reflected in major public databases of scholarly production. The same analysis was applied to members of a recent Review Committee, integrated by top-level researchers belonging to that general area of knowledge, who have been in charge of assessing and ranking their colleagues. Our results for both sets of scholars show wide disparity of individual productivity within the same SNI Level, according to all key indicators officially required (books issued by prestigious publishers, research articles appeared in indexed journals, and formation of new scientists), as well as in impact estimated by numbers of citations. Statistical calculation from the data indicates that 36% of members in the Review Committee and 53% of researchers in the random sample do not satisfy the official criteria requested for their appointed SNI Levels. The findings are discussed in terms of possible methodological errors in our study, of relevance for the SNI at large in relation to independent appraisals, of the cost-benefit balance of the organization as a research policy tool, and of possible alternatives for its thorough restructuring. As it currently stands SNI is not a model for efficient and effectual national systems of research assessment. PMID:27195701
Frixione, Eugenio; Ruiz-Zamarripa, Lourdes; Hernández, Gerardo
2016-01-01
Assessing the research of individual scholars is currently a matter of serious concern and worldwide debate. In order to gauge the long-term efficacy and efficiency of this practice, we carried out a limited survey of the operation and outcome of Mexico's 30-year old National System of Investigators or SNI, the country's main instrument for stimulating competitive research in science and technology. A statistical random sample of researchers listed in the area of Humanities and Behavioral Sciences-one of SNI's first and better consolidated academic divisions comprising a wide range of research disciplines, from philosophy to pedagogy to archaeology to experimental brain research-was screened comparing individual ranks or "Levels of distinction" to actual compliance with the SNI's own evaluation criteria, as reflected in major public databases of scholarly production. The same analysis was applied to members of a recent Review Committee, integrated by top-level researchers belonging to that general area of knowledge, who have been in charge of assessing and ranking their colleagues. Our results for both sets of scholars show wide disparity of individual productivity within the same SNI Level, according to all key indicators officially required (books issued by prestigious publishers, research articles appeared in indexed journals, and formation of new scientists), as well as in impact estimated by numbers of citations. Statistical calculation from the data indicates that 36% of members in the Review Committee and 53% of researchers in the random sample do not satisfy the official criteria requested for their appointed SNI Levels. The findings are discussed in terms of possible methodological errors in our study, of relevance for the SNI at large in relation to independent appraisals, of the cost-benefit balance of the organization as a research policy tool, and of possible alternatives for its thorough restructuring. As it currently stands SNI is not a model for efficient and effectual national systems of research assessment.
Community Participation Of Coastal Area On Management Of National Park, Karimunjawa Island
NASA Astrophysics Data System (ADS)
Wibowo, Bambang A.; Aditomo, Aryo B.; Prihantoko, Kukuh E.
2018-02-01
Karimunjawa island located in Jepara Regacy, Central Java has potential marine and fishing resources. Since 1998, this area has been selected as conservation for its natural resources. National park of Karimunjawa is managed by Balai Taman Nasional Karimunjawa (Karimunjawa National Park Beuroue). Some activities involved community have been done in order to get effective management. Community participation is an important component for success in coastal area management. The level of community/people awareness anual on natural resource conservation can increate sustainable resource. However, it is necesssary to provide tools in resource utilization for the community, so that their economic life can be secured. This study observe the level of community participation in the effort of Karimunjawa National Park management. Descriptive method and purposive random sampling were used to carry out the study parameters observed in this study include community participation related to level of knowladge and obedience on the rule of area zonation, an its impact to community. The result show that community knowledge was quite high (40%) with obedience (56%) on the rule of area zonation. Impact area zonation rule was less significant to community. The level of community participation to Karimunjawa National Park management was performed will low to medium level.
The energy content of restaurant foods without stated calorie information.
Urban, Lorien E; Lichtenstein, Alice H; Gary, Christine E; Fierstein, Jamie L; Equi, Ashley; Kussmaul, Carolyn; Dallal, Gerard E; Roberts, Susan B
2013-07-22
National recommendations for the prevention and treatment of obesity emphasize reducing energy intake through self-monitoring food consumption. However, little information is available on the energy content of foods offered by nonchain restaurants, which account for approximately 50% of restaurant locations in the United States. To measure the energy content of foods from independent and small-chain restaurants that do not provide stated information on energy content. We used bomb calorimetry to determine the dietary energy content of the 42 most frequently purchased meals from the 9 most common restaurant categories. Independent and small-chain restaurants were randomly selected, and 157 individual meals were analyzed. Area within 15 miles of downtown Boston. A random sample of independent and small-chain restaurants. Dietary energy. All meal categories provided excessive dietary energy. The mean energy content of individual meals was 1327 (95% CI, 1248-1406) kcal, equivalent to 66% of typical daily energy requirements. We found a significant effect of food category on meal energy (P ≤ .05), and 7.6% of meals provided more than 100% of typical daily energy requirements. Within-meal variability was large (average SD, 271 kcal), and we found no significant effect of restaurant establishment or size. In addition, meal energy content averaged 49% greater than those of popular meals from the largest national chain restaurants (P < .001) and in subset analyses contained 19% more energy than national food database information for directly equivalent items (P < .001). National chain restaurants have been criticized for offering meals with excess dietary energy. This study finds that independent and small-chain restaurants, which provide no nutrition information, also provide excessive dietary energy in amounts apparently greater than popular meals from chain restaurants or information in national food databases. A national requirement for accurate calorie labeling in all restaurants may discourage menus offering unhealthy portions and would allow consumers to make informed choices about ordering meals that promote weight gain and obesity.
Chien, I-Chia; Lin, Yu-Chung; Chou, Yiing-Jenq; Lin, Ching-Heng; Bih, Shin-Huey; Lee, Cheng-Hua; Chou, Pesus
2008-06-01
The National Health Insurance database to determine the treated prevalence and incidence of dementia in Taiwan was used in this study. A population-based random sample of 22 118 subjects aged 65 or older was obtained as a dynamic cohort. Those study subjects who had filed at least one service claim from 1996 to 2003 for either outpatient care or inpatient care with a principal diagnosis of dementia were identified. The annual treated prevalence increased from 0.71% to 1.92% from 1996 to 2003. The annual treated incidence rates were around 0.76% to 1.04% per year from 1997 to 2003. The annual treated incidence rates for the 5-year age groups, from 65 to 90 years and older, were 0.44%, 0.65%, 0.98%, 1.46%, 1.81%, and 1.80%, respectively. Both the treated prevalence and incidence rates of dementia in National Health Insurance were lower than those of community studies.
Théodore, Florence L; Moreno-Saracho, Jessica E; Bonvecchio, Anabelle; Morales-Ruán, María Del Carmen; Tolentino-Mayo, Lizbeth; López-Olmedo, Nancy; Shamah-Levy, Teresa; Rivera, Juan A
2018-01-01
Obesity is a serious problem among children in Mexico. In 2010, the government implemented a national food and physical activity policy in elementary schools, to prevent obesity. The goal of this study is to assess the implementation of this policy, using the logic model from a descriptive survey with national representativeness at the elementary school level and based on a stratified cluster design. We used a systematic random sampling of schools (n = 122), stratified into public and private. We administered questionnaires to 116 principals, 165 members of the Food and Physical Activity Committees, 132 food school food vendors, 119 teachers, 348 parents. This study evidences a significant deviation in implementation from what had been planned. Our lessons learned are the importance to: base the design/implementation of the policy on a theoretical framework, make programs appealing to stakeholders, select concrete and measurable objective or goals, and support stakeholders during the implementation process.
Hirani, Vasant; Tabassum, Faiza; Aresu, Maria; Mindell, Jennifer
2010-08-01
Various measures have been used to estimate height when assessing nutritional status. Current equations to obtain demi-span equivalent height (DEH(Bassey)) are based on a small sample from a single study. The objectives of this study were to develop more robust DEH equations from a large number of men (n = 591) and women (n = 830) aged 25-45 y from a nationally representative cross-sectional sample (Health Survey for England 2007). Sex-specific regression equations were produced from young adults' (aged 25-45 y) measured height and demi-span to estimate new DEH equations (DEH(new)). DEH in people aged >or= 65 y was calculated using DEH(new). DEH(new) estimated current height in people aged 25-45 y with a mean difference of 0.04 in men (P = 0.80) and -0.29 in women (P = 0.05). Height, demi-span, DEH(new), and DEH(Bassey) declined by age group in both sexes aged >or=65 y (P < 0.05); DEH were larger than the measured height for all age groups (mean difference between DEH(new) and current height was -2.64 in men and -3.16 in women; both P < 0.001). Comparisons of DEH estimates showed good agreement, but DEH(new) was significantly higher than DEH(Bassey) in each age and sex group in older people. The new equations that are based on a large, randomly selected, nationally representative sample of young adults are more robust for predicting current height in young adults when height measurements are unavailable and can be used in the future to predict maximal adult height more accurately in currently young adults as they age.
Shah, R; Worner, S P; Chapman, R B
2012-10-01
Pesticide resistance monitoring includes resistance detection and subsequent documentation/ measurement. Resistance detection would require at least one (≥1) resistant individual(s) to be present in a sample to initiate management strategies. Resistance documentation, on the other hand, would attempt to get an estimate of the entire population (≥90%) of the resistant individuals. A computer simulation model was used to compare the efficiency of simple random and systematic sampling plans to detect resistant individuals and to document their frequencies when the resistant individuals were randomly or patchily distributed. A patchy dispersion pattern of resistant individuals influenced the sampling efficiency of systematic sampling plans while the efficiency of random sampling was independent of such patchiness. When resistant individuals were randomly distributed, sample sizes required to detect at least one resistant individual (resistance detection) with a probability of 0.95 were 300 (1%) and 50 (10% and 20%); whereas, when resistant individuals were patchily distributed, using systematic sampling, sample sizes required for such detection were 6000 (1%), 600 (10%) and 300 (20%). Sample sizes of 900 and 400 would be required to detect ≥90% of resistant individuals (resistance documentation) with a probability of 0.95 when resistant individuals were randomly dispersed and present at a frequency of 10% and 20%, respectively; whereas, when resistant individuals were patchily distributed, using systematic sampling, a sample size of 3000 and 1500, respectively, was necessary. Small sample sizes either underestimated or overestimated the resistance frequency. A simple random sampling plan is, therefore, recommended for insecticide resistance detection and subsequent documentation.
Investigating the Randomness of Numbers
ERIC Educational Resources Information Center
Pendleton, Kenn L.
2009-01-01
The use of random numbers is pervasive in today's world. Random numbers have practical applications in such far-flung arenas as computer simulations, cryptography, gambling, the legal system, statistical sampling, and even the war on terrorism. Evaluating the randomness of extremely large samples is a complex, intricate process. However, the…
Moulton, Stephen R.; Carter, James L.; Grotheer, Scott A.; Cuffney, Thomas F.; Short, Terry M.
2000-01-01
Qualitative and quantitative methods to process benthic macroinvertebrate (BMI) samples have been developed and tested by the U.S. Geological Survey?s National Water Quality Laboratory Biological Group. The qualitative processing method is based on visually sorting a sample for up to 2 hours. Sorting focuses on attaining organisms that are likely to result in taxonomic identifications to lower taxonomic levels (for example, Genus or Species). Immature and damaged organisms are also sorted when they are likely to result in unique determinations. The sorted sample remnant is scanned briefly by a second person to determine if obvious taxa were missed. The quantitative processing method is based on a fixed-count approach that targets some minimum count, such as 100 or 300 organisms. Organisms are sorted from randomly selected 5.1- by 5.1-centimeter parts of a gridded subsampling frame. The sorted remnant from each sample is resorted by a second individual for at least 10 percent of the original sort time. A large-rare organism search is performed on the unsorted remnant to sort BMI taxa that were not likely represented in the sorted grids. After either qualitatively or quantitatively sorting the sample, BMIs are identified by using one of three different types of taxonomic assessment. The Standard Taxonomic Assessment is comparable to the U.S. Environmental Protection Agency Rapid Bioassessment Protocol III and typically provides Genus- or Species-level taxonomic resolution. The Rapid Taxonomic Assessment is comparable to the U.S. Environmental Protection Agency Rapid Bioassessment Protocol II and provides Familylevel and higher taxonomic resolution. The Custom Taxonomic Assessment provides Species-level resolution whenever possible for groups identified to higher taxonomic levels by using the Standard Taxonomic Assessment. The consistent use of standardized designations and notes facilitates the interpretation of BMI data within and among water-quality studies. Taxonomic identifications are quality assured by verifying all referenced taxa and randomly reviewing 10 percent of the taxonomic identifications performed weekly by Biological Group taxonomists. Taxonomic errors discovered during this review are corrected. BMI data are reviewed for accuracy and completeness prior to release. BMI data are released phylogenetically in spreadsheet format and unprocessed abundances are corrected for laboratory and field subsampling when necessary.
How to design and write a clinical research protocol in Cosmetic Dermatology*
Bagatin, Ediléia; Miot, Helio A.
2013-01-01
Cosmetic Dermatology is a growing subspecialty. High-quality basic science studies have been published; however, few double-blind, randomized controlled clinical trials, which are the major instrument for evidence-based medicine, have been conducted in this area. Clinical research is essential for the discovery of new knowledge, improvement of scientific basis, resolution of challenges, and good clinical practice. Some basic principles for a successful researcher include interest, availability, persistence, and honesty. It is essential to learn how to write a protocol research and to know the international and national regulatory rules. A complete clinical trial protocol should include question, background, objectives, methodology (design, variable description, sample size, randomization, inclusion and exclusion criteria, intervention, efficacy and safety measures, and statistical analysis), consent form, clinical research form, and references. Institutional ethical review board approval and financial support disclosure are necessary. Publication of positive or negative results should be an authors' commitment. PMID:23539006
Nagel, Corey L; Kirby, Miles A; Zambrano, Laura D; Rosa, Ghislane; Barstow, Christina K; Thomas, Evan A; Clasen, Thomas F
2016-12-15
In Rwanda, pneumonia and diarrhea are the first and second leading causes of death, respectively, among children under five. Household air pollution (HAP) resultant from cooking indoors with biomass fuels on traditional stoves is a significant risk factor for pneumonia, while consumption of contaminated drinking water is a primary cause of diarrheal disease. To date, there have been no large-scale effectiveness trials of programmatic efforts to provide either improved cookstoves or household water filters at scale in a low-income country. In this paper we describe the design of a cluster-randomized trial to evaluate the impact of a national-level program to distribute and promote the use of improved cookstoves and advanced water filters to the poorest quarter of households in Rwanda. We randomly allocated 72 sectors (administratively defined units) in Western Province to the intervention, with the remaining 24 sectors in the province serving as controls. In the intervention sectors, roughly 100,000 households received improved cookstoves and household water filters through a government-sponsored program targeting the poorest quarter of households nationally. The primary outcome measures are the incidence of acute respiratory infection (ARI) and diarrhea among children under five years of age. Over a one-year surveillance period, all cases of acute respiratory infection (ARI) and diarrhea identified by health workers in the study area will be extracted from records maintained at health facilities and by community health workers (CHW). In addition, we are conducting intensive, longitudinal data collection among a random sample of households in the study area for in-depth assessment of coverage, use, environmental exposures, and additional health measures. Although previous research has examined the impact of providing household water treatment and improved cookstoves on child health, there have been no studies of national-level programs to deliver these interventions at scale in a developing country. The results of this study, the first RCT of a large-scale programmatic cookstove or household water filter intervention, will inform global efforts to reduce childhood morbidity and mortality from diarrheal disease and pneumonia. This trial is registered at Clinicaltrials.gov (NCT02239250).
The male-taller norm: Lack of evidence from a developing country.
Sohn, K
2015-08-01
In general, women prefer men taller than themselves; this is referred to as the male-taller norm. However, since women are shorter than men on average, it is difficult to determine whether the fact that married women are on average shorter than their husbands results from the norm or is a simple artifact generated by the shorter stature of women. This study addresses the question by comparing the rate of adherence to the male-taller norm between actual mating and hypothetical random mating. A total of 7954 actually married couples are drawn from the last follow-up of the Indonesian Family Life Survey, a nationally representative survey. Their heights were measured by trained nurses. About 10,000 individuals are randomly sampled from the actual couples and randomly matched. An alternative random mating of about 100,000 couples is also performed, taking into account an age difference of 5 years within a couple. The rate of adherence to the male-taller norm is 93.4% for actual couples and 88.8% for random couples. The difference between the two figures is statistically significant, but it is emphasized that it is very small. The alternative random mating produces a rate of 91.4%. The male-taller norm exists in Indonesia, but only in a statistical sense. The small difference suggests that the norm is mostly explained by the fact that women are shorter than men on average. Copyright © 2015 Elsevier GmbH. All rights reserved.
RECAL: A Computer Program for Selecting Sample Days for Recreation Use Estimation
D.L. Erickson; C.J. Liu; H. Ken Cordell; W.L. Chen
1980-01-01
Recreation Calendar (RECAL) is a computer program in PL/I for drawing a sample of days for estimating recreation use. With RECAL, a sampling period of any length may be chosen; simple random, stratified random, and factorial designs can be accommodated. The program randomly allocates days to strata and locations.
Sample Selection in Randomized Experiments: A New Method Using Propensity Score Stratified Sampling
ERIC Educational Resources Information Center
Tipton, Elizabeth; Hedges, Larry; Vaden-Kiernan, Michael; Borman, Geoffrey; Sullivan, Kate; Caverly, Sarah
2014-01-01
Randomized experiments are often seen as the "gold standard" for causal research. Despite the fact that experiments use random assignment to treatment conditions, units are seldom selected into the experiment using probability sampling. Very little research on experimental design has focused on how to make generalizations to well-defined…
Mhaskar, Rahul; Djulbegovic, Benjamin; Magazin, Anja; Soares, Heloisa P.; Kumar, Ambuj
2011-01-01
Objectives To assess whether reported methodological quality of randomized controlled trials (RCTs) reflect the actual methodological quality, and to evaluate the association of effect size (ES) and sample size with methodological quality. Study design Systematic review Setting Retrospective analysis of all consecutive phase III RCTs published by 8 National Cancer Institute Cooperative Groups until year 2006. Data were extracted from protocols (actual quality) and publications (reported quality) for each study. Results 429 RCTs met the inclusion criteria. Overall reporting of methodological quality was poor and did not reflect the actual high methodological quality of RCTs. The results showed no association between sample size and actual methodological quality of a trial. Poor reporting of allocation concealment and blinding exaggerated the ES by 6% (ratio of hazard ratio [RHR]: 0.94, 95%CI: 0.88, 0.99) and 24% (RHR: 1.24, 95%CI: 1.05, 1.43), respectively. However, actual quality assessment showed no association between ES and methodological quality. Conclusion The largest study to-date shows poor quality of reporting does not reflect the actual high methodological quality. Assessment of the impact of quality on the ES based on reported quality can produce misleading results. PMID:22424985
An overview of patient safety climate in the VA.
Hartmann, Christine W; Rosen, Amy K; Meterko, Mark; Shokeen, Priti; Zhao, Shibei; Singer, Sara; Falwell, Alyson; Gaba, David M
2008-08-01
To assess variation in safety climate across VA hospitals nationally. Data were collected from employees at 30 VA hospitals over a 6-month period using the Patient Safety Climate in Healthcare Organizations survey. We sampled 100 percent of senior managers and physicians and a random 10 percent of other employees. At 10 randomly selected hospitals, we sampled an additional 100 percent of employees working in units with intrinsically higher hazards (high-hazard units [HHUs]). Data were collected using an anonymous survey design. We received 4,547 responses (49 percent response rate). The percent problematic response--lower percent reflecting higher levels of patient safety climate--ranged from 12.0-23.7 percent across hospitals (mean=17.5 percent). Differences in safety climate emerged by management level, clinician status, and workgroup. Supervisors and front-line staff reported lower levels of safety climate than senior managers; clinician responses reflected lower levels of safety climate than those of nonclinicians; and responses of employees in HHUs reflected lower levels of safety climate than those of workers in other areas. This is the first systematic study of patient safety climate in VA hospitals. Findings indicate an overall positive safety climate across the VA, but there is room for improvement.
Verger, Pierre; Ménard, Colette; Richard, Jean-Baptiste; Demortière, Gérard; Beck, François
2014-02-01
To study the perceptions that general practitioners (GPs) and occupational physicians (OPs) have of GPs' role in occupational health and their willingness to work together to prevent the exclusion of patients with disabilities from the workplace. Cross-sectional telephone survey of two randomly selected national samples of GPs and OPs was conducted. The majority of GPs and OPs are in favor of cooperation, especially to prevent exclusion from the workplace. However, some GPs lack trust in OPs' independence, an attitude associated negatively with the practice of GP referral to OPs to anticipate disability-related problems likely to occur when returning to work after a prolonged sick leave. There are some barriers to cooperation, on the part of both OPs and GPs. Initiatives are needed to encourage cooperation between these two types of physicians.
Thumbs up for privacy?: Differences in online self-disclosure behavior across national cultures.
Reed, Philip J; Spiro, Emma S; Butts, Carter T
2016-09-01
This study investigates relationships between national-level culture and online self-disclosure behavior. We operationalize culture through the GLOBE dimensions, a set of nine variables measuring cultural practices and another nine measuring values. Our observations of self-disclosure come from the privacy settings of approximately 200,000 randomly sampled Facebook users who designated a geographical network in 2009. We model privacy awareness as a function of one or more GLOBE variables with demographic covariates, evaluating the relative influence of each factor. In the top-performing models, we find that the majority of the cultural dimensions are significantly related to privacy awareness behavior. We also find that the hypothesized directions of several of these relationships, based largely on cultural attitudes towards threat mitigation, are confirmed. Copyright © 2016. Published by Elsevier Inc.
Davis, Kristen S; Burgeson, Charlene R; Brener, Nancy D; McManus, Tim; Wechsler, Howell
2005-06-01
The authors analyzed data from the School Health Policies and Programs Study 2000 to assess the associations between the presence of a district physical education coordinator and district-level physical education policies and practices recommended by federal government agencies and national organizations. The authors also examined the relationship between teacher qualifications and staff development related to physical education and self-reported implementation of recommended teachingpractices. District-level data were collected by self-administered mail questionnaires from a nationally representative sample of school districts. Classroom-level data were collected by computer-assisted personal interviews with teachers of randomly selected classes in elementary schools and randomly selected required physical education courses in middle/junior high and senior high schools. Nearly two thirds (62.2%) of districts had a physical education coordinator, and those were generally more likely than other districts to report having policies and practices that corresponded with national recommendations for high-quality physical education programs. More than two thirds of teachers (66.9%) met the criteria for teacher qualifications based on their education and certification. These teachers were more likely than others to report use of certain recommended physical education teaching practices. Teachers who participated in staff development also were more likely to use recommended teaching practices in their classrooms. Using a district physical education coordinator and teachers with appropriate qualifications as well as offering staff development opportunities on physical education may enhance school physical education programs.
Xu, Chonggang; Gertner, George
2013-01-01
Fourier Amplitude Sensitivity Test (FAST) is one of the most popular uncertainty and sensitivity analysis techniques. It uses a periodic sampling approach and a Fourier transformation to decompose the variance of a model output into partial variances contributed by different model parameters. Until now, the FAST analysis is mainly confined to the estimation of partial variances contributed by the main effects of model parameters, but does not allow for those contributed by specific interactions among parameters. In this paper, we theoretically show that FAST analysis can be used to estimate partial variances contributed by both main effects and interaction effects of model parameters using different sampling approaches (i.e., traditional search-curve based sampling, simple random sampling and random balance design sampling). We also analytically calculate the potential errors and biases in the estimation of partial variances. Hypothesis tests are constructed to reduce the effect of sampling errors on the estimation of partial variances. Our results show that compared to simple random sampling and random balance design sampling, sensitivity indices (ratios of partial variances to variance of a specific model output) estimated by search-curve based sampling generally have higher precision but larger underestimations. Compared to simple random sampling, random balance design sampling generally provides higher estimation precision for partial variances contributed by the main effects of parameters. The theoretical derivation of partial variances contributed by higher-order interactions and the calculation of their corresponding estimation errors in different sampling schemes can help us better understand the FAST method and provide a fundamental basis for FAST applications and further improvements. PMID:24143037
Xu, Chonggang; Gertner, George
2011-01-01
Fourier Amplitude Sensitivity Test (FAST) is one of the most popular uncertainty and sensitivity analysis techniques. It uses a periodic sampling approach and a Fourier transformation to decompose the variance of a model output into partial variances contributed by different model parameters. Until now, the FAST analysis is mainly confined to the estimation of partial variances contributed by the main effects of model parameters, but does not allow for those contributed by specific interactions among parameters. In this paper, we theoretically show that FAST analysis can be used to estimate partial variances contributed by both main effects and interaction effects of model parameters using different sampling approaches (i.e., traditional search-curve based sampling, simple random sampling and random balance design sampling). We also analytically calculate the potential errors and biases in the estimation of partial variances. Hypothesis tests are constructed to reduce the effect of sampling errors on the estimation of partial variances. Our results show that compared to simple random sampling and random balance design sampling, sensitivity indices (ratios of partial variances to variance of a specific model output) estimated by search-curve based sampling generally have higher precision but larger underestimations. Compared to simple random sampling, random balance design sampling generally provides higher estimation precision for partial variances contributed by the main effects of parameters. The theoretical derivation of partial variances contributed by higher-order interactions and the calculation of their corresponding estimation errors in different sampling schemes can help us better understand the FAST method and provide a fundamental basis for FAST applications and further improvements.
Spline methods for approximating quantile functions and generating random samples
NASA Technical Reports Server (NTRS)
Schiess, J. R.; Matthews, C. G.
1985-01-01
Two cubic spline formulations are presented for representing the quantile function (inverse cumulative distribution function) of a random sample of data. Both B-spline and rational spline approximations are compared with analytic representations of the quantile function. It is also shown how these representations can be used to generate random samples for use in simulation studies. Comparisons are made on samples generated from known distributions and a sample of experimental data. The spline representations are more accurate for multimodal and skewed samples and to require much less time to generate samples than the analytic representation.
Kim, Logyoung; Kim, Jee-Ae; Kim, Sanghyun
2014-01-01
The claims data of the Health Insurance Review and Assessment Service (HIRA) is an important source of information for healthcare service research. The claims data of HIRA is collected when healthcare service providers submit a claim to HIRA to be reimbursed for a service that they provided to patients. To improve the accessibility of healthcare service researchers to claims data of HIRA, HIRA has developed the Patient Samples which are extracted using a stratified randomized sampling method. The Patient Samples of HIRA consist of five tables: a table for general information (Table 20) containing socio-demographic information such as gender, age and medical aid, indicators for inpatient and outpatient services; a table for specific information on healthcare services provided (Table 30); a table for diagnostic information (Table 40); a table for outpatient prescriptions (Table 53) and a table for information on healthcare service providers (Table of providers). Researchers who are interested in using the Patient Sample data for research can apply via HIRA’s website (https://www.hira.or.kr). PMID:25078381
Evaluating a fear appeal message to reduce alcohol use among "Greeks".
Moscato, S; Black, D R; Blue, C L; Mattson, M; Galer-Unti, R A; Coster, D C
2001-01-01
To evaluate the impact of a fear appeal message on college students' drinking behavior using the extended parallel process model. A survey was administered to a random sample of undergraduates (n=224) in 38 national fraternal organizations. Both perceived efficacy and perceived threat were significantly correlated with drinking behavior. There was a significant difference both in drinking behavior and attendance at alcohol-free events between those who heard and those who did not hear the message. Theoretically based fear appeal messages may be a useful way to promote responsible drinking among college students.
Sudbury-Riley, Lynn; FitzPatrick, Mary; Schulz, Peter J
2017-02-27
The eHealth Literacy Scale (eHEALS) is one of only a few available measurement scales to assess eHealth literacy. Perhaps due to the relative paucity of such measures and the rising importance of eHealth literacy, the eHEALS is increasingly a choice for inclusion in a range of studies across different groups, cultures, and nations. However, despite its growing popularity, questions have been raised over its theoretical foundations, and the factorial validity and multigroup measurement properties of the scale are yet to be investigated fully. The objective of our study was to examine the factorial validity and measurement invariance of the eHEALS among baby boomers (born between 1946 and 1964) in the United States, United Kingdom, and New Zealand who had used the Internet to search for health information in the last 6 months. Online questionnaires collected data from a random sample of baby boomers from the 3 countries of interest. The theoretical underpinning to eHEALS comprises social cognitive theory and self-efficacy theory. Close scrutiny of eHEALS with analysis of these theories suggests a 3-factor structure to be worth investigating, which has never before been explored. Structural equation modeling tested a 3-factor structure based on the theoretical underpinning to eHEALS and investigated multinational measurement invariance of the eHEALS. We collected responses (N=996) to the questionnaires using random samples from the 3 countries. Results suggest that the eHEALS comprises a 3-factor structure with a measurement model that falls within all relevant fit indices (root mean square error of approximation, RMSEA=.041, comparative fit index, CFI=.986). Additionally, the scale demonstrates metric invariance (RMSEA=.040, CFI=.984, ΔCFI=.002) and even scalar invariance (RMSEA=.042, CFI=.978, ΔCFI=.008). To our knowledge, this is the first study to demonstrate multigroup factorial equivalence of the eHEALS, and did so based on data from 3 diverse nations and random samples drawn from an increasingly important cohort. The results give increased confidence to researchers using the scale in a range of eHealth assessment applications from primary care to health promotions. ©Lynn Sudbury-Riley, Mary FitzPatrick, Peter J Schulz. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 27.02.2017.
2017-01-01
Background The eHealth Literacy Scale (eHEALS) is one of only a few available measurement scales to assess eHealth literacy. Perhaps due to the relative paucity of such measures and the rising importance of eHealth literacy, the eHEALS is increasingly a choice for inclusion in a range of studies across different groups, cultures, and nations. However, despite its growing popularity, questions have been raised over its theoretical foundations, and the factorial validity and multigroup measurement properties of the scale are yet to be investigated fully. Objective The objective of our study was to examine the factorial validity and measurement invariance of the eHEALS among baby boomers (born between 1946 and 1964) in the United States, United Kingdom, and New Zealand who had used the Internet to search for health information in the last 6 months. Methods Online questionnaires collected data from a random sample of baby boomers from the 3 countries of interest. The theoretical underpinning to eHEALS comprises social cognitive theory and self-efficacy theory. Close scrutiny of eHEALS with analysis of these theories suggests a 3-factor structure to be worth investigating, which has never before been explored. Structural equation modeling tested a 3-factor structure based on the theoretical underpinning to eHEALS and investigated multinational measurement invariance of the eHEALS. Results We collected responses (N=996) to the questionnaires using random samples from the 3 countries. Results suggest that the eHEALS comprises a 3-factor structure with a measurement model that falls within all relevant fit indices (root mean square error of approximation, RMSEA=.041, comparative fit index, CFI=.986). Additionally, the scale demonstrates metric invariance (RMSEA=.040, CFI=.984, ΔCFI=.002) and even scalar invariance (RMSEA=.042, CFI=.978, ΔCFI=.008). Conclusions To our knowledge, this is the first study to demonstrate multigroup factorial equivalence of the eHEALS, and did so based on data from 3 diverse nations and random samples drawn from an increasingly important cohort. The results give increased confidence to researchers using the scale in a range of eHealth assessment applications from primary care to health promotions. PMID:28242590
Methods for sample size determination in cluster randomized trials
Rutterford, Clare; Copas, Andrew; Eldridge, Sandra
2015-01-01
Background: The use of cluster randomized trials (CRTs) is increasing, along with the variety in their design and analysis. The simplest approach for their sample size calculation is to calculate the sample size assuming individual randomization and inflate this by a design effect to account for randomization by cluster. The assumptions of a simple design effect may not always be met; alternative or more complicated approaches are required. Methods: We summarise a wide range of sample size methods available for cluster randomized trials. For those familiar with sample size calculations for individually randomized trials but with less experience in the clustered case, this manuscript provides formulae for a wide range of scenarios with associated explanation and recommendations. For those with more experience, comprehensive summaries are provided that allow quick identification of methods for a given design, outcome and analysis method. Results: We present first those methods applicable to the simplest two-arm, parallel group, completely randomized design followed by methods that incorporate deviations from this design such as: variability in cluster sizes; attrition; non-compliance; or the inclusion of baseline covariates or repeated measures. The paper concludes with methods for alternative designs. Conclusions: There is a large amount of methodology available for sample size calculations in CRTs. This paper gives the most comprehensive description of published methodology for sample size calculation and provides an important resource for those designing these trials. PMID:26174515
Accuracy of angina pectoris and acute coronary syndrome in the Danish National Patient Register.
Bork, Christian Sørensen; Al-Zuhairi, Karam Sadoon; Hansen, Steen Møller; Delekta, Joanna; Joensen, Albert Marni
2017-05-01
The Danish National Patient Register (DNPR)is widely used for research and administrative purposes. However, its usability is highly dependent of the validity of the registered data. We therefore aimed to determine the positive predictive value (PPV) of angina pectoris and acute coronary syndrome (ACS) in the DNPR. We selected a random sample of 500 patients registered with angina pectoris and a random sample of 500 patients registered with ACS among all hospitalisations at any department in Northern Denmark between 1 January 2007 and 31 December 2007. We reviewed the medical records of the sample patients and recorded whether the angina pectoris and the ACS diagnoses were valid, based on the European Society of Cardiology criteria. The PPV of definite and probable angina pectoris was 45.9% (95% confidence interval (CI): 41.3-50.6%), whereas the PPV of verified ACS was 86.6% (95% CI: 83.3-89.5%). Stratification by hospital department revealed significantly higher PPVs for diagnoses received in a cardiology unit for both angina pectoris (61.7%; 95% CI: 53.4-69.6%) and ACS (95.5%; 95% CI: 91.3-98.0%). Stratification by gender showed a significantly higher PPV among men registered with angina pectoris (51.2%; 95% CI: 45.3-57.1%). The angina pectoris and ACS data contained in the DNPR should be used with caution in register studies if validation is not possible. Restricting analyses of ACS data to patients discharged from cardiology wards may be a useful option in register-based studies. none. not relevant. Articles published in the DMJ are “open access”. This means that the articles are distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits any non-commercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.
Greenfield, Shelly F; Rosa, Carmen; Putnins, Susan I; Green, Carla A; Brooks, Audrey J; Calsyn, Donald A; Cohen, Lisa R; Erickson, Sarah; Gordon, Susan M; Haynes, Louise; Killeen, Therese; Miele, Gloria; Tross, Susan; Winhusen, Theresa
2011-09-01
The National Institute of Drug Abuse's National Drug Abuse Treatment Clinical Trials Network (CTN) was established to foster translation of research into practice in substance abuse treatment settings. The CTN provides a unique opportunity to examine in multi-site, translational clinical trials, the outcomes of treatment interventions targeting vulnerable subgroups of women; the comparative effectiveness of gender-specific protocols to reduce risk behaviors; and gender differences in clinical outcomes. To review gender-related findings from published CTN clinical trials and related studies from January 2000 to March 2010. CTN studies were selected for review if they focused on treatment outcomes or services for special populations of women with substance use disorders (SUDs) including those with trauma histories, pregnancy, co-occurring eating and other psychiatric disorders, and HIV risk behaviors; or implemented gender-specific protocols. The CTN has randomized 11,500 participants (41% women) across 200 clinics in 24 randomized controlled trials in community settings, of which 4 have been gender-specific. This article summarizes gender-related findings from CTN clinical trials and related studies, focusing on trauma histories, pregnancy, co-occurring eating and other psychiatric disorders, and HIV risk behaviors. These published studies have expanded the evidence base regarding interventions for vulnerable groups of women with SUDs as well as gender-specific interventions to reduce HIV risk behaviors in substance-using men and women. The results also underscore the complexity of accounting for gender in the design of clinical trials and analysis of results. To fully understand the relevance of gender-specific moderators and mediators of outcome, it is essential that future translational studies adopt more sophisticated approaches to understanding and measuring gender-relevant factors and plan sample sizes that are adequate to support more nuanced analytic methods.
Grady, Stephen J.
2002-01-01
Methyl tert-butyl ether (MTBE) was detected in source water used by 8.7 percent of randomly selected community water systems (CWSs) in the United States at concentrations that ranged from 0.2 to 20 micrograms per liter (μg/L). The Random Survey conducted by the U.S. Geological Survey, in cooperation with the Metropolitan Water District of Southern California and the Oregon Health & Science University, was designed to provide an assessment of the frequency of detection, concentration, and distribution of MTBE, three other ether gasoline oxygenates, and 62 other volatile organic compounds (VOCs) in ground- and surface-water sources used for drinking-water supplies. The Random Survey was the first of two components of a national assessment of the quality of source water supplying CWSs sponsored by the American Water Works Association Research Foundation. A total of 954 CWSs were selected for VOC sampling from the population of nearly 47,000 active, self-supplied CWSs in all 50 States, Native American Lands, and Puerto Rico based on a statistical design that stratified on CWS size (population served), type of source water (ground and surface water), and geographic distribution (State).At a reporting level of 0.2 μg/L, VOCs were detected in 27 percent of source-water samples collected from May 3, 1999 through October 23, 2000. Chloroform (in 13 percent of samples) was the most frequently detected of 42 VOCs present in the source-water samples, followed by MTBE. VOC concentrations were generally less than 10 μg/L 95 percent of the 530 detections and 63 percent were less than 1.0 μg/L. Concentrations of 1,1-dichloroethene, tetrachloroethene, trichloroethene, vinyl chloride, and total trihalomethanes (TTHMs), however, exceeded drinking-water regulations in eight samples.Detections of most VOCs were more frequent in surface-water sources than in ground-water sources, with gasoline compounds collectively and MTBE individually detected significantly more often in surface water. Use of personal and commercial motorized watercraft on surface-water bodies that are drinking-water sources is probably the reason for the elevated detections of gasoline contaminants relative to ground water. MTBE detections demonstrated a seasonal pattern with more frequent detections in surface water in summer months, which is consistent with seasonal watercraft use.The detection frequency of most VOCs was significantly related to urban land use and population density. Detections of any VOC, non-trihalo-methane compounds, gasoline compounds collectively, the specific gasoline compounds benzene, toluene, ethylbenzene, and xylenes (BTEX), MTBE, solvents, and refrigerants were significantly greater in areas with more than 60 percent urban land use and (or) population density greater than 1,000 people per square mile than in source waters from less urbanized or lower population-density areas. MTBE detections were five times more frequent in source waters from areas with high MTBE use than in source waters from low or no MTBE use, but, unlike other gasoline compounds, MTBE detections were not significantly related to the density of gasoline storage tanks near drinking-water sources.
Nurse Family Partnership: Comparing Costs per Family in Randomized Trials Versus Scale-Up.
Miller, Ted R; Hendrie, Delia
2015-12-01
The literature that addresses cost differences between randomized trials and full-scale replications is quite sparse. This paper examines how costs differed among three randomized trials and six statewide scale-ups of nurse family partnership (NFP) intensive home visitation to low income first-time mothers. A literature review provided data on pertinent trials. At our request, six well-established programs reported their total expenditures. We adjusted the costs to national prices based on mean hourly wages for registered nurses and then inflated them to 2010 dollars. A centralized data system provided utilization. Replications had fewer home visits per family than trials (25 vs. 31, p = .05), lower costs per client ($8860 vs. $12,398, p = .01), and lower costs per visit ($354 vs. $400, p = .30). Sample size limited the significance of these differences. In this type of labor intensive program, costs probably were lower in scale-up than in randomized trials. Key cost drivers were attrition and the stable caseload size possible in an ongoing program. Our estimates reveal a wide variation in cost per visit across six state programs, which suggests that those planning replications should not expect a simple rule to guide cost estimations for scale-ups. Nevertheless, NFP replications probably achieved some economies of scale.
NASA Astrophysics Data System (ADS)
Lai, Xiaoming; Zhu, Qing; Zhou, Zhiwen; Liao, Kaihua
2017-12-01
In this study, seven random combination sampling strategies were applied to investigate the uncertainties in estimating the hillslope mean soil water content (SWC) and correlation coefficients between the SWC and soil/terrain properties on a tea + bamboo hillslope. One of the sampling strategies is the global random sampling and the other six are the stratified random sampling on the top, middle, toe, top + mid, top + toe and mid + toe slope positions. When each sampling strategy was applied, sample sizes were gradually reduced and each sampling size contained 3000 replicates. Under each sampling size of each sampling strategy, the relative errors (REs) and coefficients of variation (CVs) of the estimated hillslope mean SWC and correlation coefficients between the SWC and soil/terrain properties were calculated to quantify the accuracy and uncertainty. The results showed that the uncertainty of the estimations decreased as the sampling size increasing. However, larger sample sizes were required to reduce the uncertainty in correlation coefficient estimation than in hillslope mean SWC estimation. Under global random sampling, 12 randomly sampled sites on this hillslope were adequate to estimate the hillslope mean SWC with RE and CV ≤10%. However, at least 72 randomly sampled sites were needed to ensure the estimated correlation coefficients with REs and CVs ≤10%. Comparing with all sampling strategies, reducing sampling sites on the middle slope had the least influence on the estimation of hillslope mean SWC and correlation coefficients. Under this strategy, 60 sites (10 on the middle slope and 50 on the top and toe slopes) were enough to ensure the estimated correlation coefficients with REs and CVs ≤10%. This suggested that when designing the SWC sampling, the proportion of sites on the middle slope can be reduced to 16.7% of the total number of sites. Findings of this study will be useful for the optimal SWC sampling design.
Sequential time interleaved random equivalent sampling for repetitive signal.
Zhao, Yijiu; Liu, Jingjing
2016-12-01
Compressed sensing (CS) based sampling techniques exhibit many advantages over other existing approaches for sparse signal spectrum sensing; they are also incorporated into non-uniform sampling signal reconstruction to improve the efficiency, such as random equivalent sampling (RES). However, in CS based RES, only one sample of each acquisition is considered in the signal reconstruction stage, and it will result in more acquisition runs and longer sampling time. In this paper, a sampling sequence is taken in each RES acquisition run, and the corresponding block measurement matrix is constructed using a Whittaker-Shannon interpolation formula. All the block matrices are combined into an equivalent measurement matrix with respect to all sampling sequences. We implemented the proposed approach with a multi-cores analog-to-digital converter (ADC), whose ADC cores are time interleaved. A prototype realization of this proposed CS based sequential random equivalent sampling method has been developed. It is able to capture an analog waveform at an equivalent sampling rate of 40 GHz while sampled at 1 GHz physically. Experiments indicate that, for a sparse signal, the proposed CS based sequential random equivalent sampling exhibits high efficiency.
Sampling large random knots in a confined space
NASA Astrophysics Data System (ADS)
Arsuaga, J.; Blackstone, T.; Diao, Y.; Hinson, K.; Karadayi, E.; Saito, M.
2007-09-01
DNA knots formed under extreme conditions of condensation, as in bacteriophage P4, are difficult to analyze experimentally and theoretically. In this paper, we propose to use the uniform random polygon model as a supplementary method to the existing methods for generating random knots in confinement. The uniform random polygon model allows us to sample knots with large crossing numbers and also to generate large diagrammatically prime knot diagrams. We show numerically that uniform random polygons sample knots with large minimum crossing numbers and certain complicated knot invariants (as those observed experimentally). We do this in terms of the knot determinants or colorings. Our numerical results suggest that the average determinant of a uniform random polygon of n vertices grows faster than O(e^{n^2}) . We also investigate the complexity of prime knot diagrams. We show rigorously that the probability that a randomly selected 2D uniform random polygon of n vertices is almost diagrammatically prime goes to 1 as n goes to infinity. Furthermore, the average number of crossings in such a diagram is at the order of O(n2). Therefore, the two-dimensional uniform random polygons offer an effective way in sampling large (prime) knots, which can be useful in various applications.
[Evaluation of using statistical methods in selected national medical journals].
Sych, Z
1996-01-01
The paper covers the performed evaluation of frequency with which the statistical methods were applied in analyzed works having been published in six selected, national medical journals in the years 1988-1992. For analysis the following journals were chosen, namely: Klinika Oczna, Medycyna Pracy, Pediatria Polska, Polski Tygodnik Lekarski, Roczniki Państwowego Zakładu Higieny, Zdrowie Publiczne. Appropriate number of works up to the average in the remaining medical journals was randomly selected from respective volumes of Pol. Tyg. Lek. The studies did not include works wherein the statistical analysis was not implemented, which referred both to national and international publications. That exemption was also extended to review papers, casuistic ones, reviews of books, handbooks, monographies, reports from scientific congresses, as well as papers on historical topics. The number of works was defined in each volume. Next, analysis was performed to establish the mode of finding out a suitable sample in respective studies, differentiating two categories: random and target selections. Attention was also paid to the presence of control sample in the individual works. In the analysis attention was also focussed on the existence of sample characteristics, setting up three categories: complete, partial and lacking. In evaluating the analyzed works an effort was made to present the results of studies in tables and figures (Tab. 1, 3). Analysis was accomplished with regard to the rate of employing statistical methods in analyzed works in relevant volumes of six selected, national medical journals for the years 1988-1992, simultaneously determining the number of works, in which no statistical methods were used. Concurrently the frequency of applying the individual statistical methods was analyzed in the scrutinized works. Prominence was given to fundamental statistical methods in the field of descriptive statistics (measures of position, measures of dispersion) as well as most important methods of mathematical statistics such as parametric tests of significance, analysis of variance (in single and dual classifications). non-parametric tests of significance, correlation and regression. The works, in which use was made of either multiple correlation or multiple regression or else more complex methods of studying the relationship for two or more numbers of variables, were incorporated into the works whose statistical methods were constituted by correlation and regression as well as other methods, e.g. statistical methods being used in epidemiology (coefficients of incidence and morbidity, standardization of coefficients, survival tables) factor analysis conducted by Jacobi-Hotellng's method, taxonomic methods and others. On the basis of the performed studies it has been established that the frequency of employing statistical methods in the six selected national, medical journals in the years 1988-1992 was 61.1-66.0% of the analyzed works (Tab. 3), and they generally were almost similar to the frequency provided in English language medical journals. On a whole, no significant differences were disclosed in the frequency of applied statistical methods (Tab. 4) as well as in frequency of random tests (Tab. 3) in the analyzed works, appearing in the medical journals in respective years 1988-1992. The most frequently used statistical methods in analyzed works for 1988-1992 were the measures of position 44.2-55.6% and measures of dispersion 32.5-38.5% as well as parametric tests of significance 26.3-33.1% of the works analyzed (Tab. 4). For the purpose of increasing the frequency and reliability of the used statistical methods, the didactics should be widened in the field of biostatistics at medical studies and postgraduation training designed for physicians and scientific-didactic workers.
NASA Technical Reports Server (NTRS)
Rao, R. G. S.; Ulaby, F. T.
1977-01-01
The paper examines optimal sampling techniques for obtaining accurate spatial averages of soil moisture, at various depths and for cell sizes in the range 2.5-40 acres, with a minimum number of samples. Both simple random sampling and stratified sampling procedures are used to reach a set of recommended sample sizes for each depth and for each cell size. Major conclusions from statistical sampling test results are that (1) the number of samples required decreases with increasing depth; (2) when the total number of samples cannot be prespecified or the moisture in only one single layer is of interest, then a simple random sample procedure should be used which is based on the observed mean and SD for data from a single field; (3) when the total number of samples can be prespecified and the objective is to measure the soil moisture profile with depth, then stratified random sampling based on optimal allocation should be used; and (4) decreasing the sensor resolution cell size leads to fairly large decreases in samples sizes with stratified sampling procedures, whereas only a moderate decrease is obtained in simple random sampling procedures.
Bergh, Daniel
2015-01-01
Chi-square statistics are commonly used for tests of fit of measurement models. Chi-square is also sensitive to sample size, which is why several approaches to handle large samples in test of fit analysis have been developed. One strategy to handle the sample size problem may be to adjust the sample size in the analysis of fit. An alternative is to adopt a random sample approach. The purpose of this study was to analyze and to compare these two strategies using simulated data. Given an original sample size of 21,000, for reductions of sample sizes down to the order of 5,000 the adjusted sample size function works as good as the random sample approach. In contrast, when applying adjustments to sample sizes of lower order the adjustment function is less effective at approximating the chi-square value for an actual random sample of the relevant size. Hence, the fit is exaggerated and misfit under-estimated using the adjusted sample size function. Although there are big differences in chi-square values between the two approaches at lower sample sizes, the inferences based on the p-values may be the same.
Inequalities in use of health services among Jews and Arabs in Israel.
Baron-Epel, Orna; Garty, Noga; Green, Manfred S
2007-06-01
To compare the levels of utilization of health services in Jews and Arabs taking into account differences in levels of socioeconomic status (SES) in a country with a National Health Insurance Law (NHIL). A cross-sectional National Health Interview Survey was carried out in Israel based on a random sample of telephone numbers as part of the EUROHIS project (WHO European Health Interview Survey 2003-2004). A random telephone survey included 9,352 interviews. Questions included use of health care services, health status, and socioeconomic variables. After adjusting for sex, age, income, education, marital status, and self-reported chronic diseases, Arabs more often reported visiting a family physician (odds ratio [OR]=1.56, 95 percent confidence interval [CI]=1.35-1.81) and less often reported visiting a specialist (OR=0.73, 95 percent CI=0.60-0.89) compared with Jews. In addition, the odds ratio for hospitalization was similar among Arabs and Jews (OR=1.16, 95 percent CI=0.97-1.38). SES was associated with utilization of health care services only in the Jewish population. A different pattern of utilization of health care services was observed in Arabs and Jews. This was not explained by differences in socioeconomic levels. More research is needed regarding the distribution of services between Jews and Arabs.
Roberts, Mary Ellen; Wheeler, Kathy J; Tyler, Diane O; Padden, Diane L
2017-08-01
The aim of two national studies was to identify characteristics of nurse practitioners (NPs) who precept and the benefits, incentives, and barriers associated with the NP preceptor role. Stratified randomized sampling was used to invite a representative number of NPs from each state to participate in a 2015 survey and a follow-up survey in 2016. These descriptive, exploratory studies distributed electronic questionnaires to 5000 randomly selected NPs in the 2015 survey and 40,000 NPs in the 2016 survey. Responses from 10.9% (n = 548) and 9.9% (n = 3970), respectively, were analyzed. The findings show strong support among our NP colleagues to assist with educating future NPs. Several benefits, barriers, and motivators among stakeholders were identified that need to be considered when working with preceptors. This study provides a basis for understanding the current climate in education when working with clinical preceptors. Many areas become apparent where NP education could enhance the experience for both the student and the preceptor. Educational settings need to consider preceptor time, issues with online learning, and the rise of specialty practices. Offering incentives linked to the most valued, positive aspects of the role and methods to overcome barriers should be explored. ©2017 American Association of Nurse Practitioners.
Pollen and mold exposure impairs the work performance of employees with allergic rhinitis.
Kessler, R C; Almeida, D M; Berglund, P; Stang, P
2001-10-01
Although quality of life studies suggest that allergic rhinitis has a substantial impact on work impairment, national survey estimates of the magnitude of this impairment have varied widely. Retrospective recall bias is likely to be a major cause of this variability. This study used a nationally representative daily diary sample to obtain prospective data that improve on previous estimates of the work impairment because of allergic rhinitis. The MacArthur Foundation National Survey of Daily Experience is a daily diary survey that included a nationally representative subsample of 739 employed people, each of whom provided daily reports on work performance for 1 randomly assigned week of the calendar year. National Allergy Bureau monitoring station data were merged with the survey data to study the association of time-space variation in pollen/mold exposure with impaired daily work quality and quantity. National Allergy Bureau pollen/mold counts are significantly related to work impairments only among respondents with self-reported allergic rhinitis. The average estimated monthly salary-equivalent work impairment costs associated with pollen/mold exposure for each allergy sufferer is between $109 and $156, with an annualized national projection of between $5.4 billion and $7.7 billion. The extent to which these costs can be recovered by increasing the proportion of allergy sufferers who are successfully treated remains unknown and can only be evaluated definitively in effectiveness trials.
Health plan auditing: 100-percent-of-claims vs. random-sample audits.
Sillup, George P; Klimberg, Ronald K
2011-01-01
The objective of this study was to examine the relative efficacy of two different methodologies for auditing self-funded medical claim expenses: 100-percent-of-claims auditing versus random-sampling auditing. Multiple data sets of claim errors or 'exceptions' from two Fortune-100 corporations were analysed and compared to 100 simulated audits of 300- and 400-claim random samples. Random-sample simulations failed to identify a significant number and amount of the errors that ranged from $200,000 to $750,000. These results suggest that health plan expenses of corporations could be significantly reduced if they audited 100% of claims and embraced a zero-defect approach.
NASA Astrophysics Data System (ADS)
WANG, P. T.
2015-12-01
Groundwater modeling requires to assign hydrogeological properties to every numerical grid. Due to the lack of detailed information and the inherent spatial heterogeneity, geological properties can be treated as random variables. Hydrogeological property is assumed to be a multivariate distribution with spatial correlations. By sampling random numbers from a given statistical distribution and assigning a value to each grid, a random field for modeling can be completed. Therefore, statistics sampling plays an important role in the efficiency of modeling procedure. Latin Hypercube Sampling (LHS) is a stratified random sampling procedure that provides an efficient way to sample variables from their multivariate distributions. This study combines the the stratified random procedure from LHS and the simulation by using LU decomposition to form LULHS. Both conditional and unconditional simulations of LULHS were develpoed. The simulation efficiency and spatial correlation of LULHS are compared to the other three different simulation methods. The results show that for the conditional simulation and unconditional simulation, LULHS method is more efficient in terms of computational effort. Less realizations are required to achieve the required statistical accuracy and spatial correlation.
Smatti, Maria K.; Yassine, Hadi M.; AbuOdeh, Raed; AlMarawani, Asmaa; Taleb, Sara A.; Althani, Asmaa A.
2017-01-01
Background The Epstein–Barr virus (EBV) is the causative agent of infectious mononucleosis. EBV is highly prevalent lymphotropic herpesvirus and has been linked to several malignancies. Transmission is generally by oral secretions, but can be through blood transfusions and organ transplantations. This study aimed to determine the seroprevalence, viremia rates, and circulating genotypes of EBV in healthy blood donors in Qatar. Methods Blood samples from 673 blood donors of different nationalities residing in Qatar (mainly Qatar, Egypt, Syria, Jordan, Pakistan, and India) were collected and tested for anti-EBV capsid (VCA; IgG & IgM), nuclear (EBNA; IgG), and early (EA-D; IgG) antigens. Avidity testing was determined when active infection was suspected. DNA was extracted from the buffy coat and subjected to EBV-DNA quantification using qRT-PCR. Genotyping was performed using nested-PCR targeting EBV-EBNA2 gene, and phylogeny by sequence analysis of the LMP-1 gene. Results 97.9% (673/659) of the samples were seropositive as indicated by the presence VCA-IgG, while 52.6% (354/673) had detectible EBV-DNA. EBV seroprevalence and viremia rates increased significantly with age. Genotyping of 51 randomly selected samples showed predominance of Genotype 1 (72.5%, 37/51) as compared to genotype 2 (3.5%), and mixed infections were detected in 4% of the samples. Sub-genotyping for these samples revealed that the Mediterranean strain was predominant (65.3%), followed by B95.8 prototype and North Carolina strains (12.2% each), and China1 strain (6%). Conclusion As a first study to evaluate EBV infection in highly diverse population in Qatar, where expatriates represent more than 85% of the population, our results indicated high seroprevalence and viremia rate of EBV in different nationalities, with genotype 1 and Mediterranean strain being predominant. Clinical significance of these finding have not been investigated and shall be evaluated in future studies. PMID:29228016
Smatti, Maria K; Yassine, Hadi M; AbuOdeh, Raed; AlMarawani, Asmaa; Taleb, Sara A; Althani, Asmaa A; Nasrallah, Gheyath K
2017-01-01
The Epstein-Barr virus (EBV) is the causative agent of infectious mononucleosis. EBV is highly prevalent lymphotropic herpesvirus and has been linked to several malignancies. Transmission is generally by oral secretions, but can be through blood transfusions and organ transplantations. This study aimed to determine the seroprevalence, viremia rates, and circulating genotypes of EBV in healthy blood donors in Qatar. Blood samples from 673 blood donors of different nationalities residing in Qatar (mainly Qatar, Egypt, Syria, Jordan, Pakistan, and India) were collected and tested for anti-EBV capsid (VCA; IgG & IgM), nuclear (EBNA; IgG), and early (EA-D; IgG) antigens. Avidity testing was determined when active infection was suspected. DNA was extracted from the buffy coat and subjected to EBV-DNA quantification using qRT-PCR. Genotyping was performed using nested-PCR targeting EBV-EBNA2 gene, and phylogeny by sequence analysis of the LMP-1 gene. 97.9% (673/659) of the samples were seropositive as indicated by the presence VCA-IgG, while 52.6% (354/673) had detectible EBV-DNA. EBV seroprevalence and viremia rates increased significantly with age. Genotyping of 51 randomly selected samples showed predominance of Genotype 1 (72.5%, 37/51) as compared to genotype 2 (3.5%), and mixed infections were detected in 4% of the samples. Sub-genotyping for these samples revealed that the Mediterranean strain was predominant (65.3%), followed by B95.8 prototype and North Carolina strains (12.2% each), and China1 strain (6%). As a first study to evaluate EBV infection in highly diverse population in Qatar, where expatriates represent more than 85% of the population, our results indicated high seroprevalence and viremia rate of EBV in different nationalities, with genotype 1 and Mediterranean strain being predominant. Clinical significance of these finding have not been investigated and shall be evaluated in future studies.
Perfluorinated compounds in fish from U.S. urban rivers and the Great Lakes.
Stahl, Leanne L; Snyder, Blaine D; Olsen, Anthony R; Kincaid, Thomas M; Wathen, John B; McCarty, Harry B
2014-11-15
Perfluorinated compounds (PFCs) have recently received scientific and regulatory attention due to their broad environmental distribution, persistence, bioaccumulative potential, and toxicity. Studies suggest that fish consumption may be a source of human exposure to perfluorooctane sulfonate (PFOS) or long-chain perfluorocarboxylic acids. Most PFC fish tissue literature focuses on marine fish and waters outside of the United States (U.S.). To broaden assessments in U.S. fish, a characterization of PFCs in freshwater fish was initiated on a national scale using an unequal probability design during the U.S. Environmental Protection Agency's (EPA's) 2008-2009 National Rivers and Streams Assessment (NRSA) and the Great Lakes Human Health Fish Tissue Study component of the 2010 EPA National Coastal Condition Assessment (NCCA/GL). Fish were collected from randomly selected locations--164 urban river sites and 157 nearshore Great Lake sites. The probability design allowed extrapolation to the sampled population of 17,059 km in urban rivers and a nearshore area of 11,091 km(2) in the Great Lakes. Fillets were analyzed for 13 PFCs using high-performance liquid chromatography tandem mass spectrometry. Results showed that PFOS dominated in frequency of occurrence, followed by three other longer-chain PFCs (perfluorodecanoic acid, perfluoroundecanoic acid, and perfluorododecanoic acid). Maximum PFOS concentrations were 127 and 80 ng/g in urban river samples and Great Lakes samples, respectively. The range of NRSA PFOS detections was similar to literature accounts from targeted riverine fish sampling. NCCA/GL PFOS levels were lower than those reported by other Great Lakes researchers, but generally higher than values in targeted inland lake studies. The probability design allowed development of cumulative distribution functions (CDFs) to quantify PFOS concentrations versus the sampled population, and the application of fish consumption advisory guidance to the CDFs resulted in an estimation of the proportion of urban rivers and the Great Lakes that exceed human health protection thresholds. Copyright © 2014. Published by Elsevier B.V.
Harding-Esch, Emma M.; Edwards, Tansy; Sillah, Ansumana; Sarr, Isatou; Roberts, Chrissy H.; Snell, Paul; Aryee, Esther; Molina, Sandra; Holland, Martin J.; Mabey, David C. W.; Bailey, Robin L.
2009-01-01
Background Trachoma has been endemic in The Gambia for decades. National trachoma control activities have been in place since the mid-1980's, but with no mass antibiotic treatment campaign. We aimed to assess the prevalence of active trachoma and of actual ocular Chlamydia trachomatis infection as measured by polymerase chain reaction (PCR) in the two Gambian regions that had had the highest prevalence of trachoma in the last national survey in 1996 prior to planned national mass antibiotic treatment distribution in 2006. Methodology/Principal Findings Two stage random sampling survey in 61 randomly selected Enumeration Areas (EAs) in North Bank Region (NBR) and Lower River Region (LRR). Fifty randomly selected children aged under 10 years were examined per EA for clinical signs of trachoma. In LRR, swabs were taken to test for ocular C. trachomatis infection. Unadjusted prevalences of active trachoma were calculated, as would be done in a trachoma control programme. The prevalence of trachomatous inflammation, follicular (TF) in the 2777 children aged 1–9 years was 12.3% (95% CI 8.8%–17.0%) in LRR and 10.0% (95% CI 7.7%–13.0%) in NBR, with significant variation within divisions (p<0.01), and a design effect of 3.474. Infection with C. trachomatis was found in only 0.3% (3/940) of children in LRR. Conclusions/Significance This study shows a large discrepancy between the prevalence of trachoma clinical signs and ocular C. trachomatis infection in two Gambian regions. Assessment of trachoma based on clinical signs alone may lead to unnecessary treatment, since the prevalence of active trachoma remains high but C. trachomatis infection has all but disappeared. Assuming that repeated infection is required for progression to blinding sequelae, blinding trachoma is on course for elimination by 2020 in The Gambia. PMID:20027217
Inventory of Amphibians and Reptiles in Southern Colorado Plateau National Parks
Persons, Trevor B.; Nowak, Erika M.
2006-01-01
In fiscal year 2000, the National Park Service (NPS) initiated a nationwide program to inventory vertebrates andvascular plants within the National Parks, and an inventory plan was developed for the 19 park units in the Southern Colorado Plateau Inventory & Monitoring Network. We surveyed 12 parks in this network for reptiles and amphibians between 2001 and 2003. The overall goals of our herpetofaunal inventories were to document 90% of the species present, identify park-specific species of special concern, and, based on the inventory results, make recommendations for the development of an effective monitoring program. We used the following standardized herpetological methods to complete the inventories: time-area constrained searches, visual encounter ('general') surveys, and nighttime road cruising. We also recorded incidental species sightings and surveyed existing literature and museum specimen databases. We found 50 amphibian and reptile species during fieldwork. These included 1 salamander, 11 anurans, 21 lizards, and 17 snakes. Literature reviews, museum specimen data records, and personal communications with NPS staff added an additional eight species, including one salamander, one turtle, one lizard, and five snakes. It was necessary to use a variety of methods to detect all species in each park. Randomly-generated 1-ha time-area constrained searches and night drives produced the fewest species and individuals of all the methods, while general surveys and randomly-generated 10-ha time-areas constrained searches produced the most. Inventory completeness was likely compromised by a severe drought across the region during our surveys. In most parks we did not come close to the goal of detecting 90% of the expected species present; however, we did document several species range extensions. Effective monitoring programs for herpetofauna on the Colorado Plateau should use a variety of methods to detect species, and focus on taxa-specific methods. Randomly-generated plots must take into account microhabitat and aquatic features to be effective at sampling for herpetofauna.
ERIC Educational Resources Information Center
Thomas, Henry B.; Kaplan, E. Joseph
A national survey was conducted of randomly selected chief student personnel officers as listed in the 1979 "Education Directory of Colleges and Universities." The survey addressed specific institutional demographics, policy-making authority, reporting structure, and areas of responsibility of the administrators. Over 93 percent of the respondents…
Under-reporting of sputum smear-positive tuberculosis cases in Kenya.
Tollefson, D; Ngari, F; Mwakala, M; Gethi, D; Kipruto, H; Cain, K; Bloss, E
2016-10-01
Although an estimated three million tuberculosis (TB) cases worldwide are missed by national TB programs annually, the level of under-reporting of diagnosed cases in high TB burden settings is largely unknown. To quantify and describe under-reporting of sputum smear-positive TB cases in Kenya. A national-level retrospective TB inventory study was conducted. All sputum smear-positive TB cases diagnosed by public or private laboratories during 1 April-30 June 2013 were extracted from laboratory registers in 73 randomly sampled subcounties and matched to TB cases in the national TB surveillance system (TIBU). Bivariate and multivariate analyses were conducted. In the subcounties sampled, 715 of 3409 smear-positive TB cases in laboratory registers were not found in TIBU. The estimated level of under-reporting of smear-positive TB cases in Kenya was 20.7% (95%CI 18.4-23.0). Under-reporting was greatest in subcounties with a high TB burden. Unreported cases were more likely to be patients aged ⩾55 years, have scanty smear results, and be diagnosed at large facilities, private facilities, and facilities in high TB burden regions. In Kenya, one fifth of smear-positive TB cases diagnosed during the study period went unreported, suggesting that the true TB burden is higher than reported. TB surveillance in Kenya should be strengthened to ensure all diagnosed TB cases are reported.
Carbon Storage in US Wetlands. | Science Inventory | US EPA
Background/Question/Methods Wetland soils contain some of the highest stores of soil carbon in the biosphere. However, there is little understanding of the quantity and distribution of carbon stored in US wetlands or of the potential effects of human disturbance on these stocks. We provide unbiased estimates of soil carbon stocks for wetlands at regional and national scales and describe how soil carbon stocks vary by anthropogenic disturbance to the wetland. To estimate the quantity and distribution of carbon stocks in wetlands of the conterminous US, we used data gathered in the field as part of the 2011 National Wetland Condition Assessment (NWCA) conducted by USEPA. During the growing season, field crews collected soil samples by horizon from 120-cm deep soil pits at 967 randomly selected wetland sites. Soil samples were analyzed for bulk density and organic carbon. We applied site carbon stock averages by soil depth back to the national population of wetlands and to several subpopulations, including five geographic areas and anthropogenic disturbance level. Disturbance levels were categorized by the NWCA as least, intermediately, or most disturbed using a priori defined physical, chemical, and biological indicators that were observable at the time of the site visit.Results/Conclusions We find that wetlands in the conterminous US store a total of 11.52 PgC – roughly equivalent to four years of annual carbon emissions by the US, with the greatest soil ca
BLAKE, KELLY D.; PORTNOY, DAVID B.; KAUFMAN, ANNETTE R.; LIN, CHUNG-TUNG JORDAN; LO, SERENA C.; BACKLUND, ERIC; CANTOR, DAVID; HICKS, LLOYD; LIN, AMY; CAPORASO, ANDREW; DAVIS, TERISA; MOSER, RICHARD P.; HESSE, BRADFORD W.
2016-01-01
The National Cancer Institute (NCI) developed the Health Information National Trends Survey (HINTS) to monitor population trends in cancer communication practices, information preferences, health risk behaviors, attitudes, and cancer knowledge. The U.S. Food and Drug Administration (FDA) recognized HINTS as a unique data resource for informing its health communication endeavors and partnered with NCI to field HINTS-FDA 2015. HINTS-FDA 2015 was a self-administered paper instrument sent by mail May 29 to September 8, 2015, using a random probability-based sample of U.S. postal addresses stratified by county-level smoking rates, with an oversampling of high and medium-high smoking strata to increase the yield of current smokers responding to the survey. The response rate for HINTS-FDA 2015 was 33% (N = 3,738). The yield of current smokers (n = 495) was lower than expected, but the sampling strategy achieved the goal of obtaining more former smokers (n = 1,132). Public-use HINTS-FDA 2015 data and supporting documentation have been available for download and secondary data analyses since June 2016 at http://hints.cancer.gov. NCI and FDA encourage the use of HINTS-FDA for health communication research and practice related to tobacco-related communications, public knowledge, and behaviors as well as beliefs and actions related to medical products and dietary supplements. PMID:27892827
Blake, Kelly D; Portnoy, David B; Kaufman, Annette R; Lin, Chung-Tung Jordan; Lo, Serena C; Backlund, Eric; Cantor, David; Hicks, Lloyd; Lin, Amy; Caporaso, Andrew; Davis, Terisa; Moser, Richard P; Hesse, Bradford W
2016-12-01
The National Cancer Institute (NCI) developed the Health Information National Trends Survey (HINTS) to monitor population trends in cancer communication practices, information preferences, health risk behaviors, attitudes, and cancer knowledge. The U.S. Food and Drug Administration (FDA) recognized HINTS as a unique data resource for informing its health communication endeavors and partnered with NCI to field HINTS-FDA 2015. HINTS-FDA 2015 was a self-administered paper instrument sent by mail May 29 to September 8, 2015, using a random probability-based sample of U.S. postal addresses stratified by county-level smoking rates, with an oversampling of high and medium-high smoking strata to increase the yield of current smokers responding to the survey. The response rate for HINTS-FDA 2015 was 33% (N = 3,738). The yield of current smokers (n = 495) was lower than expected, but the sampling strategy achieved the goal of obtaining more former smokers (n = 1,132). Public-use HINTS-FDA 2015 data and supporting documentation have been available for download and secondary data analyses since June 2016 at http://hints.cancer.gov . NCI and FDA encourage the use of HINTS-FDA for health communication research and practice related to tobacco-related communications, public knowledge, and behaviors as well as beliefs and actions related to medical products and dietary supplements.
Ryan Clarke, P; Frey, Rebecca K; Rhyan, Jack C; McCollum, Matt P; Nol, Pauline; Aune, Keith
2014-03-01
OBJECTIVE--To determine the feasibility of qualifying individuals or groups of Yellowstone National Park bison as free from brucellosis. DESIGN--Cohort study. SAMPLE--Serum, blood, and various samples from live bison and tissues taken at necropsy from 214 bison over 7 years. PROCEDURES--Blood was collected from bison every 30 to 45 days for serologic tests and microbiological culture of blood for Brucella abortus. Seropositive bison were euthanized until all remaining bison had 2 consecutive negative test results. Half the seronegative bison were randomly euthanized, and tissues were collected for bacteriologic culture. The remaining seronegative bison were bred, and blood was tested at least twice per year. Cow-calf pairs were sampled immediately after calving and 6 months after calving for evidence of B abortus. RESULTS--Post-enrollment serial testing for B abortus antibodies revealed no bison that seroconverted after 205 days (first cohort) and 180 days (second cohort). During initial serial testing, 85% of bison seroconverted within 120 days after removal from the infected population. Brucella abortus was not cultured from any euthanized seronegative bison (0/88). After parturition, no cows or calves had a positive test result for B abortus antibodies, nor was B abortus cultured from any samples. CONCLUSIONS AND CLINICAL RELEVANCE--Results suggested it is feasible to qualify brucellosis-free bison from an infected herd following quarantine procedures as published in the USDA APHIS brucellosis eradication uniform methods and rules. Latent infection was not detected in this sample of bison when applying the USDA APHIS quarantine protocol.
Optimising mHealth helpdesk responsiveness in South Africa: towards automated message triage
Engelhard, Matthew; Copley, Charles; Watson, Jacqui; Pillay, Yogan; Barron, Peter
2018-01-01
In South Africa, a national-level helpdesk was established in August 2014 as a social accountability mechanism for improving governance, allowing recipients of public sector services to send complaints, compliments and questions directly to a team of National Department of Health (NDoH) staff members via text message. As demand increases, mechanisms to streamline and improve the helpdesk must be explored. This work aims to evaluate the need for and feasibility of automated message triage to improve helpdesk responsiveness to high-priority messages. Drawing from 65 768 messages submitted between October 2016 and July 2017, the quality of helpdesk message handling was evaluated via detailed inspection of (1) a random sample of 481 messages and (2) messages reporting mistreatment of women, as identified using expert-curated keywords. Automated triage was explored by training a naïve Bayes classifier to replicate message labels assigned by NDoH staff. Classifier performance was evaluated on 12 526 messages withheld from the training set. 90 of 481 (18.7%) NDoH responses were scored as suboptimal or incorrect, with median response time of 4.0 hours. 32 reports of facility-based mistreatment and 39 of partner and family violence were identified; NDoH response time and appropriateness for these messages were not superior to the random sample (P>0.05). The naïve Bayes classifier had average accuracy of 85.4%, with ≥98% specificity for infrequently appearing (<50%) labels. These results show that helpdesk handling of mistreatment of women could be improved. Keyword matching and naïve Bayes effectively identified uncommon messages of interest and could support automated triage to improve handling of high-priority messages. PMID:29713508
Ortu, Giuseppina; Ndayishimiye, Onésime; Clements, Michelle; Kayugi, Donatien; Campbell, Carl H.; Lamine, Mariama Sani; Zivieri, Antonio; Magalhaes, Ricardo Soares; Binder, Sue; King, Charles H.; Fenwick, Alan; Colley, Daniel G.; Jourdan, Peter Mark
2017-01-01
Following implementation of the national control program, a reassessment of Schistosoma mansoni prevalence was conducted in Burundi to determine the feasibility of moving toward elimination. A countrywide cluster-randomized cross-sectional study was performed in May 2014. At least 25 schools were sampled from each of five eco-epidemiological risk zones for schistosomiasis. Fifty randomly selected children 13–14 years of age per school were included for a single urine-circulating cathodic antigen (CCA) rapid test and, in a subset of schools, for duplicate Kato-Katz slide preparation from a single stool sample. A total of 17,331 children from 347 schools were tested using CCA. The overall prevalence of S. mansoni infection, when CCA trace results were considered negative, was 13.5% (zone range [zr] = 4.6–17.8%), and when CCA trace results were considered positive, it was 42.8% (zr = 34.3–49.9%). In 170 schools, prevalence of this infection determined using Kato-Katz method was 1.5% (zr ==0–2.7%). The overall mean intensity of S. mansoni infection determined using Kato-Katz was 0.85 eggs per gram (standard deviation = 10.86). A majority of schools (84%) were classified as non-endemic (prevalence = 0) using Kato-Katz; however, a similar proportion of schools were classified as endemic when CCA trace results were considered negative (85%) and nearly all (98%) were endemic when CCA trace results were considered positive. The findings of this nationwide reassessment using a CCA rapid test indicate that Schistosoma infection is still widespread in Burundi, although its average intensity is probably low. Further evidence is now needed to determine the association between CCA rapid test positivity and low-intensity disease transmission. PMID:28115675
Lee, Kyung Sik; Nam, Ki Heon; Kim, Dong Wook; Kang, Eui Chun; Koh, Hyoung Jun
2018-01-01
The present study aimed to evaluate the risk of retinal vein occlusion (RVO) in Korean patients with end-stage renal disease (ESRD). In this retrospective, nationwide, propensity score-matched cohort study, subjects were randomly enrolled from the 12-year longitudinal Korean National Health Insurance Service-National Sample Cohort 2002-2013 database comprising 1 million subjects. The ESRD group comprised 988 patients newly diagnosed with ESRD from 2003 onward by washing out data from 2002. The comparison group comprised 4940 (5 for each patient with ESRD) randomly selected propensity score-matched individuals not diagnosed with ESRD. Each sampled patient was tracked until 2013 for RVO development. Multiple conditional Cox regression analysis was performed to compare the risk of RVO between the two groups. The mean follow-up period was 7.37 years. The incidence of RVO was 3.95% in the ESRD group and 2.17% in the comparison group (P = 0.001). ESRD was associated with greater risk of RVO development after adjustment for possible confounders (adjusted hazard ratio [HR], 2.122; 95% confidence interval [CI], 1.396-3.226; P = 0.0004). The 50- to 60-year (adjusted HR, 2.635; 95% CI, 1.100-6.313; P = 0.0297) and 60- to 70-year (adjusted HR, 2.544; 95% CI, 1.059-6.110; P = 0.0368) age groups exhibited higher risk of RVO compared with the <40-year age group. Hyperlipidemia (adjusted HR, 1.670; 95% CI, 1.176-2.371; P = 0.0042) and hypertension (adjusted HR, 1.896; 95% CI, 1.165-3.086; P = 0.01) were also associated with RVO. An association between ESRD and subsequent RVO development was found after adjustment for possible confounding factors.
2017-01-01
Indicators of compliance and efficiency in combatting money laundering, collected by EUROSTAT, are plagued with shortcomings. In this paper, I have carried out a forensic analysis on a 2003–2010 dataset of indicators of compliance and efficiency in combatting money laundering, that European Union member states self-reported to EUROSTAT, and on the basis of which, their efforts were evaluated. I used Benford’s law to detect any anomalous statistical patterns and found that statistical anomalies were also consistent with strategic manipulation. According to Benford’s law, if we pick a random sample of numbers representing natural processes, and look at the distribution of the first digits of these numbers, we see that, contrary to popular belief, digit 1 occurs most often, then digit 2, and so on, with digit 9 occurring in less than 5% of the sample. Without prior knowledge of Benford’s law, since people are not intuitively good at creating truly random numbers, deviations thereof can capture strategic alterations. In order to eliminate other sources of deviation, I have compared deviations in situations where incentives and opportunities for manipulation existed and in situations where they did not. While my results are not a conclusive proof of strategic manipulation, they signal that countries that faced incentives and opportunities to misinform the international community about their efforts to combat money laundering may have manipulated these indicators. Finally, my analysis points to the high potential for disruption that the manipulation of national statistics has, and calls for the acknowledgment that strategic manipulation can be an unintended consequence of the international community’s pressure on countries to put combatting money laundering on the top of their national agenda. PMID:28122058
Deleanu, Ioana Sorina
2017-01-01
Indicators of compliance and efficiency in combatting money laundering, collected by EUROSTAT, are plagued with shortcomings. In this paper, I have carried out a forensic analysis on a 2003-2010 dataset of indicators of compliance and efficiency in combatting money laundering, that European Union member states self-reported to EUROSTAT, and on the basis of which, their efforts were evaluated. I used Benford's law to detect any anomalous statistical patterns and found that statistical anomalies were also consistent with strategic manipulation. According to Benford's law, if we pick a random sample of numbers representing natural processes, and look at the distribution of the first digits of these numbers, we see that, contrary to popular belief, digit 1 occurs most often, then digit 2, and so on, with digit 9 occurring in less than 5% of the sample. Without prior knowledge of Benford's law, since people are not intuitively good at creating truly random numbers, deviations thereof can capture strategic alterations. In order to eliminate other sources of deviation, I have compared deviations in situations where incentives and opportunities for manipulation existed and in situations where they did not. While my results are not a conclusive proof of strategic manipulation, they signal that countries that faced incentives and opportunities to misinform the international community about their efforts to combat money laundering may have manipulated these indicators. Finally, my analysis points to the high potential for disruption that the manipulation of national statistics has, and calls for the acknowledgment that strategic manipulation can be an unintended consequence of the international community's pressure on countries to put combatting money laundering on the top of their national agenda.
Children's use of general practitioner services in the five Nordic countries
Virtanen, J I; Berntsson, L T; Lahelma, E; Köhler, L
2006-01-01
Objective To compare socioeconomic, sociodemographic, and living area differences in children's use of GP services in five Nordic countries from the 1980s to the 1990s and to analyse trends during the period. Design Cross sectional population surveys using random samples comprising 3000 children aged 2–17 years were conducted in 1984 and 1996 in five Nordic countries. Time trends in use of GP services were studied in each country by age, sex, parents' highest level of education, and living area. Setting Five Nordic countries, Denmark, Finland, Iceland, Norway, and Sweden in 1984 and 1996. Participants A total sample of 15 000 children aged 2–17 years. Altogether 3000 children were selected at random from the national population registers of the national bureaus of statistics in each country. Main outcome Health services utilisation on the basis of responses to a questionnaire item asking whether the parents had consulted a GP with regard to their children's health during the previous three months. Main results The prevalence of children's utilisation of GP services varied from 14% in 1984 in Sweden to 28% in 1996 in Iceland. A clear time trend towards increasing utilisation of GP services (p<0.05) was found in all countries except in Denmark. Odds ratios for time trends (1984 = 1.00) varied from 1.22 (1.02 to 1.46) in Sweden to 1.92 (1.62 to 2.30) in Norway. After adjusting for independent variables, a statistically borderline significant declining utilisation trend (OR = 0.85 (0.70 to 1.03)) was found for Denmark. Conclusion Children's use of GP services has increased significantly in four of the five Nordic countries. PMID:16415268
A national survey on health department capacity for community engagement in emergency preparedness.
Schoch-Spana, Monica; Selck, Frederic W; Goldberg, Lisa A
2015-01-01
Limited systematic knowledge exists about how public health practitioners and policy makers can best strengthen community engagement in public health emergency preparedness ("CE-PHEP"), a top priority for US national health security. To investigate local health department (LHD) adoption of federally recommended participatory approaches to PHEP and to identify LHD organizational characteristics associated with more intense CE-PHEP. National survey in 2012 of LHDs using a self-administered Web-based questionnaire regarding LHD practices and resources for CE-PHEP ("The Community Engagement for Public Health Emergency Preparedness Survey"). Differences in survey responses were examined, and a multivariate analysis was used to test whether LHD organizational characteristics were associated with differences in CE-PHEP intensity. A randomized sample of 754 LHDs drawn from the 2565 LHDs that had been invited to participate in the 2010 National Profile of LHDs. Sample selection was stratified by the size of population served and geographic location. Emergency preparedness coordinators reporting on their respective LHDs. CE-PHEP intensity as measured with a scoring system that rated specific CE-PHEP practices by LHD according to the relative degrees of public participation and community capacity they represented. Survey response rate was 61%. The most common reported CE-PHEP activity was disseminating personal preparedness materials (90%); the least common was convening public forums on PHEP planning (22%). LHD characteristics most strongly associated with more intense CE-PHEP were having a formal CE-PHEP policy, allocating funds for CE-PHEP, having strong support from community-based organizations, and employing a coordinator with prior CE experience. Promising ways to engage community partners more fully in the PHEP enterprise are institutionalizing CE-PHEP objectives, employing sufficient and skilled staff, leveraging current community-based organization support, and aligning budgets with the value of CE-PHEP to US national health security.
Mitchell, Alex J; Crowfoot, Daniel; Leaver, James; Hughes, Samantha
2011-01-01
Objectives Given the uncertainty about factors that influence receipt of Clinical Excellence Awards (CEA) and recent availability of advanced research metrics, we examined the factors that predict CEA success using a convenience sample of English psychiatrists. Design Observational study examining region, subspecialty, H-index, M-index, number of publications, years since registration and years in specialty. Setting ACCEA Nominal Roll, cross-referenced with data from the GMC's list of registered medical practitioners and Thompson's Web of Science database. Participants A total of 494 psychiatrists including 245 with national levels awards and a random sample with local level awards. Main outcome measures Receipt of local or national CEA awards in 2008 and 2009. Results Of those with national awards, 126 had university contracts and 119 NHS contracts. Across all staff, years since qualification in medicine and H-index were the dominant influences. For local awards we found that years worked in the specialty was the main predictor of a CEA award with a smaller contribution from H-index. For national awards to university staff (academics) years on the medical register and publication rate were significant predictors. For national awards to NHS staff (non-academics) H-index and total cites were predictive, but these were themselves related to age. Conclusions Progression in CEAs among psychiatrists is strongly influenced by age (years spent in specialty and years on the medical register) with an additional contribution from research productivity. Currently, research impact is crudely assessed in the CEA process. We suggest that CEA committees formally assess the impact of NHS-related research using standardized research metrics which are openly available. We also suggest that supporting organizations and local trusts adhere to the rules mandated by the ACCEA. PMID:21541089
Chaitanya, Lakshmi; van Oven, Mannis; Brauer, Silke; Zimmermann, Bettina; Huber, Gabriela; Xavier, Catarina; Parson, Walther; de Knijff, Peter; Kayser, Manfred
2016-03-01
The use of mitochondrial DNA (mtDNA) for maternal lineage identification often marks the last resort when investigating forensic and missing-person cases involving highly degraded biological materials. As with all comparative DNA testing, a match between evidence and reference sample requires a statistical interpretation, for which high-quality mtDNA population frequency data are crucial. Here, we determined, under high quality standards, the complete mtDNA control-region sequences of 680 individuals from across the Netherlands sampled at 54 sites, covering the entire country with 10 geographic sub-regions. The complete mtDNA control region (nucleotide positions 16,024-16,569 and 1-576) was amplified with two PCR primers and sequenced with ten different sequencing primers using the EMPOP protocol. Haplotype diversity of the entire sample set was very high at 99.63% and, accordingly, the random-match probability was 0.37%. No population substructure within the Netherlands was detected with our dataset. Phylogenetic analyses were performed to determine mtDNA haplogroups. Inclusion of these high-quality data in the EMPOP database (accession number: EMP00666) will improve its overall data content and geographic coverage in the interest of all EMPOP users worldwide. Moreover, this dataset will serve as (the start of) a national reference database for mtDNA applications in forensic and missing person casework in the Netherlands. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
2013-01-01
Background Mental health problems and risk behaviours among young people are of great public health concern. Consequently, within the VII Framework Programme, the European Commission funded the Saving and Empowering Young Lives in Europe (SEYLE) project. This Randomized Controlled Trial (RCT) was conducted in eleven European countries, with Sweden as the coordinating centre, and was designed to identify an effective way to promote mental health and reduce suicidality and risk taking behaviours among adolescents. Objective To describe the methodological and field procedures in the SEYLE RCT among adolescents, as well as to present the main characteristics of the recruited sample. Methods Analyses were conducted to determine: 1) representativeness of study sites compared to respective national data; 2) response rate of schools and pupils, drop-out rates from baseline to 3 and 12 month follow-up, 3) comparability of samples among the four Intervention Arms; 4) properties of the standard scales employed: Beck Depression Inventory, Second Edition (BDI-II), Zung Self-Rating Anxiety Scale (Z-SAS), Strengths and Difficulties Questionnaire (SDQ), World Health Organization Well-Being Scale (WHO-5). Results Participants at baseline comprised 12,395 adolescents (M/F: 5,529/6,799; mean age=14.9±0.9) from Austria, Estonia, France, Germany, Hungary, Ireland, Israel, Italy, Romania, Slovenia and Spain. At the 3 and 12 months follow up, participation rates were 87.3% and 79.4%, respectively. Demographic characteristics of participating sites were found to be reasonably representative of their respective national population. Overall response rate of schools was 67.8%. All scales utilised in the study had good to very good internal reliability, as measured by Cronbach’s alpha (BDI-II: 0.864; Z-SAS: 0.805; SDQ: 0.740; WHO-5: 0.799). Conclusions SEYLE achieved its objective of recruiting a large representative sample of adolescents within participating European countries. Analysis of SEYLE data will shed light on the effectiveness of important interventions aimed at improving adolescent mental health and well-being, reducing risk-taking and self-destructive behaviour and preventing suicidality. Trial registration US National Institute of Health (NIH) clinical trial registry (NCT00906620) and the German Clinical Trials Register (DRKS00000214). PMID:23679917
Thapa, Narbada; Aryal, Krishna Kumar; Puri, Rupendra; Shrestha, Saraswoti; Shrestha, Sheela; Thapa, Pukar; Mehata, Suresh; Thapa, Pushpa; Banjara, Megha Raj; Stray-Pedersen, Babill
2016-01-01
Background Alcohol chemically known as ethanol, causes several health, economic and social consequences across the world. Literatures suggest potential harm of alcohol drinking by pregnant women especially to the fetus and the mother. Despite anumber of significant public health problems related to alcohol consumption, this area has been ignored in Nepal and information at the national level is limited. Thus this study aimed at finding the prevalence of alcohol consumption among married women of reproductive age. Methods A nationally representative household survey was carried out from April to August 2013 by taking 16 districts across all 15 eco administrative regions. From the selected districts, 86 village development committees and 14 municipalities were selected as primary sampling units using probability proportionate to size, followed by random selection of 3 wards from each primary sampling unit. Finally, 30 households within each ward were selected using systematic random sampling, and one married women of reproductive age from each household. A total of 9000 married women of reproductive age were interviewed using a semi-structured questionnaire, on alcohol consumption practices including environmental factors and socio demographic characteristics and were included in the analysis. Results National prevalence of alcohol consumption ever among married women of reproductive age was 24.7% (95% CI:21.7–28.0), last 12 months 17.9% (95% CI:15.3–20.7) and last 30 days (current drinking) 11.8% (95% CI:9.8–14.1). There was substantial variation among the districts ranging from 2% to 60%. Multivariable analysis suggests women with no education or within formal education, dalit and janajatis ethnicity, whose husbands drink alcohol, who brew alcohol at home and women from mountains were significantly at higher risk of consuming alcohol. Among the women who drank alcohol in last 12 months, a substantial proportion of them drank home brewed alcoholic beverages (95.9%, 95% CI:94.3–97.4). Conclusion Alcohol consumption was common practice among married women of reproductive age in Nepal with variation among the subgroups of population. Thus, further investigation and behavior change communication interventions to reduce alcohol consumption especially among the women with higher risk of drinking is essential. PMID:27035722
40 CFR 761.130 - Sampling requirements.
Code of Federal Regulations, 2010 CFR
2010-07-01
... sampling scheme and the guidance document are available on EPA's PCB Web site at http://www.epa.gov/pcb, or... § 761.125(c) (2) through (4). Using its best engineering judgment, EPA may sample a statistically valid random or grid sampling technique, or both. When using engineering judgment or random “grab” samples, EPA...
40 CFR 761.130 - Sampling requirements.
Code of Federal Regulations, 2011 CFR
2011-07-01
... sampling scheme and the guidance document are available on EPA's PCB Web site at http://www.epa.gov/pcb, or... § 761.125(c) (2) through (4). Using its best engineering judgment, EPA may sample a statistically valid random or grid sampling technique, or both. When using engineering judgment or random “grab” samples, EPA...
Williamson, Graham R
2003-11-01
This paper discusses the theoretical limitations of the use of random sampling and probability theory in the production of a significance level (or P-value) in nursing research. Potential alternatives, in the form of randomization tests, are proposed. Research papers in nursing, medicine and psychology frequently misrepresent their statistical findings, as the P-values reported assume random sampling. In this systematic review of studies published between January 1995 and June 2002 in the Journal of Advanced Nursing, 89 (68%) studies broke this assumption because they used convenience samples or entire populations. As a result, some of the findings may be questionable. The key ideas of random sampling and probability theory for statistical testing (for generating a P-value) are outlined. The result of a systematic review of research papers published in the Journal of Advanced Nursing is then presented, showing how frequently random sampling appears to have been misrepresented. Useful alternative techniques that might overcome these limitations are then discussed. REVIEW LIMITATIONS: This review is limited in scope because it is applied to one journal, and so the findings cannot be generalized to other nursing journals or to nursing research in general. However, it is possible that other nursing journals are also publishing research articles based on the misrepresentation of random sampling. The review is also limited because in several of the articles the sampling method was not completely clearly stated, and in this circumstance a judgment has been made as to the sampling method employed, based on the indications given by author(s). Quantitative researchers in nursing should be very careful that the statistical techniques they use are appropriate for the design and sampling methods of their studies. If the techniques they employ are not appropriate, they run the risk of misinterpreting findings by using inappropriate, unrepresentative and biased samples.
ERIC Educational Resources Information Center
Vardeman, Stephen B.; Wendelberger, Joanne R.
2005-01-01
There is a little-known but very simple generalization of the standard result that for uncorrelated random variables with common mean [mu] and variance [sigma][superscript 2], the expected value of the sample variance is [sigma][superscript 2]. The generalization justifies the use of the usual standard error of the sample mean in possibly…
De La O, Ana L; Martel García, Fernando
2014-09-03
Poor governance and accountability compromise young democracies' efforts to provide public services critical for human development, including water, sanitation, health, and education. Evidence shows that accountability agencies like superior audit institutions can reduce corruption and waste in federal grant programs financing service infrastructure. However, little is know about their effect on compliance with grant reporting and resource allocation requirements, or about the causal mechanisms. This study protocol for an exploratory randomized controlled trial tests the hypothesis that federal and state audits increase compliance with a federal grant program to improve municipal service infrastructure serving marginalized households. The AUDIT study is a block randomized, controlled, three-arm parallel group exploratory trial. A convenience sample of 5 municipalities in each of 17 states in Mexico (n=85) were block randomized to be audited by federal auditors (n=17), by state auditors (n=17), and a control condition outside the annual program of audits (n=51) in a 1:1:3 ratio. Replicable and verifiable randomization was performed using publicly available lottery numbers. Audited municipalities were included in the national program of audits and received standard audits on their use of federal public service infrastructure grants. Municipalities receiving moderate levels of grant transfers were recruited, as these were outside the auditing sampling frame--and hence audit program--or had negligible probabilities of ever being audited. The primary outcome measures capture compliance with the grant program and markers for the causal mechanisms, including deterrence and information effects. Secondary outcome measure include differences in audit reports across federal and state auditors, and measures like career concerns, political promotions, and political clientelism capturing synergistic effects with municipal accountability systems. The survey firm and research assistants assessing outcomes were blind to treatment status. This study will improve our understanding of local accountability systems for public service delivery in the 17 states under study, and may have downstream policy implications. The study design also demonstrates the use of verifiable and replicable randomization, and of sequentially partitioned hypotheses to reduce the Type I error rate in multiple hypothesis tests. Controlled-trials.com Identifier ISRCTN22381841: Date registered 02/11/2012.
Hartmann, Christine W; Meterko, Mark; Rosen, Amy K; Shibei Zhao; Shokeen, Priti; Singer, Sara; Gaba, David M
2009-06-01
Improving safety climate could enhance patient safety, yet little evidence exists regarding the relationship between hospital characteristics and safety climate. This study assessed the relationship between hospitals' organizational culture and safety climate in Veterans Health Administration (VA) hospitals nationally. Data were collected from a sample of employees in a stratified random sample of 30 VA hospitals over a 6-month period (response rate = 50%; n = 4,625). The Patient Safety Climate in Healthcare Organizations (PSCHO) and the Zammuto and Krakower surveys were used to measure safety climate and organizational culture, respectively. Higher levels of safety climate were significantly associated with higher levels of group and entrepreneurial cultures, while lower levels of safety climate were associated with higher levels of hierarchical culture. Hospitals could use these results to design specific interventions aimed at improving safety climate.
Thoma, Nathan C; Cecero, John J
2009-12-01
This study sought to investigate the extent to which therapists endorse techniques outside of their self-identified orientation and which techniques are endorsed across orientations. A survey consisting of 127 techniques from 8 major theories of psychotherapy was administered via U.S. mail to a national random sample of doctoral-level psychotherapy practitioners. The 201 participants endorsed substantial numbers of techniques from outside their respective orientations. Many of these techniques were quite different from those of the core theories of the respective orientations. Further examining when and why experienced practitioners switch to techniques outside their primary orientation may help reveal where certain techniques fall short and where others excel, indicating a need for further research that taps the collective experience of practitioners. (PsycINFO Database Record (c) 2010 APA, all rights reserved).
Anderson, Dudley G.; Clark, John L.
1974-01-01
From the spring of 1971 to September 1973, neighborhood surveys were conducted in 58 communities throughout the nation to determine whether children with confirmed elevated blood lead levels could be identified. Another purpose of these screenings was to assist communities in identifying children with elevated blood lead levels and thereby demonstrate to community officials that such children do exist in communities screened. The children screened were not a random sample. In those communities where the initial elevated blood levels were confirmed all but seven had one or more children requiring followup and/or treatment. Of those children screened, black children had an elevated rate about three times as great as nonblack children. With few exceptions, the homes in the neighborhoods had at least one interior surface with sufficient quantities of lead paint to be dangerous if the paint were ingested. PMID:4831146
Physician assistants and nurse practitioners in the National Health Service Corps.
Pathman, Donald E; Konrad, Thomas R; Hooker, Roderick S
2014-12-01
This study describes the experiences of physician assistants (PAs) and nurse practitioners (NPs) in the National Health Service Corps' (NHSC) loan repayment program in 2010. In 2011, a stratified random sample of NHSC clinicians was surveyed. Data from the 148 PA and 137 NP respondents were analyzed (52.4% response rate). PAs were younger than NPs (mean age 31 versus 35 years), less often female (68% versus 91%), and more often carried educational debt over $100,000 (56% versus 24%). Both groups were serving in states familiar to them and within communities where they felt accepted. The groups were generally satisfied on most measures of work, with PAs more satisfied than NPs on some measures. The NHSC's PAs and NPs are well matched to communities and satisfied with their work. Maximizing their NHSC experiences and retention requires recognizing their differences in demographics, debt, and areas of job satisfaction.
Shannon, Candice A.; Rospenda, Kathleen M.; Richman, Judith A.; Minich, Lisa M.
2014-01-01
Objective: This study examines whether workplace racial harassment/discrimination mediates the relationship between race/ethnicity and work-related illness, injury or assault across time. Methods: A national random-digit dial phone survey was conducted at two points in time (W1: 2003-2004; W2: 2004-2005) among a sample of Black, Hispanic and non-Hispanic white workers. As part of the survey, respondents indicated their experiences with racial harassment or discrimination, and occupational illness, injury, or assault in the past 12 months. Results: Hispanic respondents were more likely than whites to experience work-related illness, injury or assault, and these associations were mediated by experiences of racial harassment/discrimination. Conclusions: Interventions to reduce workplace harassment and discrimination may help decrease risk for work-related illness, injury, or assault among Hispanic workers. PMID:19339900
Frey, Jodi Jacobson; Osteen, Philip J; Berglund, Patricia A; Jinnett, Kimberly; Ko, Jungyai
2015-04-01
Examine associations of chronic health conditions on workplace productivity and accidents among US Department of Energy employees. The Health and Work Performance Questionnaire-Select was administered to a random sample of two Department of Energy national laboratory employees (46% response rate; N = 1854). The majority (87.4%) reported having one or more chronic health conditions, with 43.4% reporting four or more conditions. A population-attributable risk proportions analysis suggests improvements of 4.5% in absenteeism, 5.1% in presenteeism, 8.9% in productivity, and 77% of accidents by reducing the number of conditions by one level. Depression was the only health condition associated with all four outcomes. Results suggest that chronic conditions in this workforce are prevalent and costly. Efforts to prevent or reduce condition comorbidity among employees with multiple conditions can significantly reduce costs and workplace accident rates.
The characteristics and use patterns of all-terrain vehicle drivers in the United States.
Rodgers, G B
1999-07-01
The consent decrees between the US Consumer Product Safety Commission and the major distributors of all-terrain vehicles (ATV), which were designed to address ATV-related injuries and deaths, expired in April, 1998. While national estimates of nonfatal and fatal injuries involving ATVs declined after the consent decrees went into effect 10 years ago, the injury estimates have stabilized in recent years. To gain a better understanding of current ATV use patterns, the CPSC sponsored a national probability survey of ATV drivers in the fall of 1997. The survey was designed to collect information about the characteristics and use patterns of ATV drivers and to quantify the numbers and types of ATVs in use. It employed a single stage list-assisted random-digit-dial sample design. This article describes the results of the survey, and discusses long term ATV usage trends.
Family History Collection Practices: National Survey of Pediatric Primary Care Providers.
Tarini, Beth A; Gornick, Michele C; Zikmund-Fisher, Brian J; Saal, Howard M; Edmondson, Laurie; Uhlmann, Wendy R
2018-05-01
While family history (FH) collection is a core responsibility of pediatric primary care providers (PCPs), few details about this practice are known. We surveyed a random national sample of 1200 pediatricians and family medicine physicians about FH collection practices. A total of 86% of respondents (n = 289 pediatricians; n = 152 family medicine physicians) indicated that they collect a FH "always" or "most of the time" with 77% reporting collection at the first visit, regardless of whether it is a health maintenance or problem-focused visit. Less than half ask about relatives other than parents, siblings, or grandparents (36.3%). Among respondents, 42% routinely update the FH at every health maintenance visit while 6% updated FH at every visit. Pediatric PCPs use a variety of methods to collect a FH that is limited in scope and variably updated. Our results suggest that interventions are needed to help pediatric PCPs collect a systematic, efficient, and updated FH.
Che, W W; Frey, H Christopher; Lau, Alexis K H
2014-12-01
Population and diary sampling methods are employed in exposure models to sample simulated individuals and their daily activity on each simulation day. Different sampling methods may lead to variations in estimated human exposure. In this study, two population sampling methods (stratified-random and random-random) and three diary sampling methods (random resampling, diversity and autocorrelation, and Markov-chain cluster [MCC]) are evaluated. Their impacts on estimated children's exposure to ambient fine particulate matter (PM2.5 ) are quantified via case studies for children in Wake County, NC for July 2002. The estimated mean daily average exposure is 12.9 μg/m(3) for simulated children using the stratified population sampling method, and 12.2 μg/m(3) using the random sampling method. These minor differences are caused by the random sampling among ages within census tracts. Among the three diary sampling methods, there are differences in the estimated number of individuals with multiple days of exposures exceeding a benchmark of concern of 25 μg/m(3) due to differences in how multiday longitudinal diaries are estimated. The MCC method is relatively more conservative. In case studies evaluated here, the MCC method led to 10% higher estimation of the number of individuals with repeated exposures exceeding the benchmark. The comparisons help to identify and contrast the capabilities of each method and to offer insight regarding implications of method choice. Exposure simulation results are robust to the two population sampling methods evaluated, and are sensitive to the choice of method for simulating longitudinal diaries, particularly when analyzing results for specific microenvironments or for exposures exceeding a benchmark of concern. © 2014 Society for Risk Analysis.
Chu, Hui-May; Ette, Ene I
2005-09-02
his study was performed to develop a new nonparametric approach for the estimation of robust tissue-to-plasma ratio from extremely sparsely sampled paired data (ie, one sample each from plasma and tissue per subject). Tissue-to-plasma ratio was estimated from paired/unpaired experimental data using independent time points approach, area under the curve (AUC) values calculated with the naïve data averaging approach, and AUC values calculated using sampling based approaches (eg, the pseudoprofile-based bootstrap [PpbB] approach and the random sampling approach [our proposed approach]). The random sampling approach involves the use of a 2-phase algorithm. The convergence of the sampling/resampling approaches was investigated, as well as the robustness of the estimates produced by different approaches. To evaluate the latter, new data sets were generated by introducing outlier(s) into the real data set. One to 2 concentration values were inflated by 10% to 40% from their original values to produce the outliers. Tissue-to-plasma ratios computed using the independent time points approach varied between 0 and 50 across time points. The ratio obtained from AUC values acquired using the naive data averaging approach was not associated with any measure of uncertainty or variability. Calculating the ratio without regard to pairing yielded poorer estimates. The random sampling and pseudoprofile-based bootstrap approaches yielded tissue-to-plasma ratios with uncertainty and variability. However, the random sampling approach, because of the 2-phase nature of its algorithm, yielded more robust estimates and required fewer replications. Therefore, a 2-phase random sampling approach is proposed for the robust estimation of tissue-to-plasma ratio from extremely sparsely sampled data.
Nazzaro, Ann-Marie; Owens, Sally; Hoots, W. Keith; Larson, Kelly L.
2006-01-01
Objectives. The National Hemophilia Foundation and the Centers for Disease Control and Prevention conducted a national survey focusing on knowledge about, attitudes toward, and behaviors associated with key prevention activities among youths with hemophilia and used the data gathered to design a health promotion campaign. Methods. A national, random sample of 459 patients was drawn from 20 hemophilia treatment centers and 8 hemophilia associations; 110 (24%) of the respondents were young people. A telephone questionnaire was used to measure knowledge, behaviors, and barriers to prevention. Results. Thirty-six percent of the youth respondents believed that joint disease cannot be prevented; 60% managed hemophilia by avoiding physical activity. Only 31% of the respondents treated bleeding episodes within 1 hour. Although hepatitis was a clear threat to this hemophilic cohort, 78% did now know transmission routes for hepatitis C, and 67% did not know transmission routes for hepatitis B. Conclusions. Young people with chronic disorders need help understanding that they can prevent complications. We identified key messages for a hemophilia prevention campaign, including exercising to ensure healthy joints and treating bleeding episodes early and adequately. PMID:16873741
Hicks, Taylor B; Shahidullah, Jeffrey D; Carlson, John S; Palejwala, Mohammed H
2014-12-01
The purpose of this study was to empirically investigate Nationally Certified School Psychologists' (NCSP) training in and use of evidence-based interventions (EBIs) for child behavior concerns as well as their reported implementation barriers. A modified Tailored Design Method (TDM; Dillman, Smyth, & Christian, 2009) using up to four mail-based participant contacts was used to obtain survey data (72% usable response rate; n = 392) from a randomly selected national sample of 548 currently practicing NCSPs. Lack of time was rated as the most serious barrier to behavioral EBI implementation, followed by a lack of necessary resources, and financial constraints. Nearly three-quarters (71%) of respondents reported a perceived inadequacy of graduate program training in behavioral EBIs, with a statistically significant difference found between respondents who attended American Psychological Association (APA)-accredited/National Association of School Psychologists (NASP)-approved programs and those who did not. These findings highlight the significant barriers school psychologists encounter when attempting to implement behavioral EBIs within applied practice, as well as the importance of graduate program training in implementation science. Implications for training, practice, and research are discussed. PsycINFO Database Record (c) 2014 APA, all rights reserved.
ERIC Educational Resources Information Center
Lacey, John H.; Kelley-Baker, Tara; Voas, Robert B.; Romano, Eduardo; Furr-Holden, C. Debra; Torres, Pedro; Berning, Amy
2011-01-01
This article describes the methodology used in the 2007 U.S. National Roadside Survey to estimate the prevalence of alcohol- and drug-impaired driving and alcohol- and drug-involved driving. This study involved randomly stopping drivers at 300 locations across the 48 continental U.S. states at sites selected through a stratified random sampling…
Reducing the Risks of Firearm Violence in High Schools: Principals' Perceptions and Practices.
Price, James H; Khubchandani, Jagdish; Payton, Erica; Thompson, Amy
2016-04-01
This study assessed the perceptions and practices of a national sample of secondary school principals regarding reducing firearm violence in high schools. Data were collected via three-wave postal mailings. A 59-item valid and reliable questionnaire was mailed to a national random sample of 800 secondary school principals. Of the 349 principals (46 %) that responded, 17 % reported a firearm incident at their school in the past 5 years. Principals perceived inadequate parental monitoring (70 %), inadequate mental health services (64 %), peer harassment/bullying (59 %), and easy access to firearms (50 %) as the main causes of firearm violence in schools. The three barriers to implementing firearm violence prevention practices were: lack of expertise as to which practices to implement (33 %), lack of time (30 %), and lack of research as to which practices are most effective (30 %). Less than half of schools trained school personnel regarding firearm violence issues. The findings indicate that firearm incidents at schools may be more common than previously thought. A significant portion of principals are at a loss as to what to implement because of a lack of empirical evidence on what is effective. More research is needed to find the most effective school interventions for reducing firearm violence.
Cultural, economic, and psychological predictors of colonoscopy in a national sample.
Halbert, Chanita Hughes; Barg, Frances K; Guerra, Carmen E; Shea, Judy A; Armstrong, Katrina; Ferguson, Monica; Weathers, Benita; Coyne, James; Troxel, Andrea B
2011-11-01
Although colorectal cancer (CRC) is the second leading cause of cancer death among adults in the US and colonoscopy is efficacious in reducing morbidity and mortality from CRC, screening rates are sub-optimal. Understanding the socioeconomic, cultural, and health care context within which decisions about colonoscopy are made allows physicians to address patients' most salient beliefs and values and other constraints when making screening recommendations. To evaluate the direct and interactive effects of socioeconomics, health care variables, psychological characteristics, and cultural values on colonoscopy use. National survey completed between January-August 2009 in a random sample of African American, white, and Hispanic adults ages 50-75 without cancer (n = 582). Self-reported colonoscopy use. Only 59% of respondents reported having a colonoscopy. The likelihood of colonoscopy increased with having health insurance (OR = 2.82, 95% CI = 1.24, 6.43, p = 0.004), and increasing age (OR = 1.40, 95% CI = 1.11, 1.77, p = 0.001). In addition, respondents with greater self-efficacy were more likely to have a colonoscopy (OR = 2.41, 95% CI = 1.35, 4.29, p = 0.003). Programs that help patients to overcome access and psychological barriers to screening are needed.
Craig, C D; Sprang, G
2010-05-01
For behavioral health professionals working with traumatized clients, continuous and prolonged exposure to the stress of working with the myriad of trauma-related stressors experienced by their clients can lead to various responses including burnout, compassion fatigue, and compassion satisfaction. The present study investigates the impact of using evidence-based practices on compassion fatigue, burnout, and compassion satisfaction in a random, national sample of self-identified trauma specialists (N=532). The 30-item Professional Quality of Life Scale (Stamm, 2005) and the 19-item Trauma Practices Questionnaire (Craig & Sprang, 2009) were included in a survey to licensed social workers and psychologists from professional membership rosters. Age and years of experience proved to be powerful predictors of only two of the three criterion variables, with younger professionals reporting higher levels of burnout and more experienced providers endorsing higher levels of compassion satisfaction. The utilization of evidence-based practices predicted statistically significant decreases in compassion fatigue and burnout, and increases in compassion satisfaction. The utility of these findings in understanding the process of trauma transmission between therapist and client as well as directions for future research are discussed.
Bjornstrom, Eileen E.S.; Kaufman, Robert L.; Peterson, Ruth D.; Slater, Michael D.
2010-01-01
Research on racial-ethnic portrayals in television crime news is limited and questions remain about the sources of representations and how these vary for perpetrators versus victims. We draw from power structure, market share, normal crimes, racial threat, and racial privileging perspectives to further this research. The reported race or ethnicity of violent crime perpetrators and victims are modeled as functions of: (1) situational characteristics of crime stories; and (2) contextual characteristics of television market areas. The primary data are from a stratified random sample of television newscasts in 2002–2003 (Long et al. 2005). An important innovation of our work is the use of a national, more generalizeable, sample of local news stories than prior researchers who tended to focus on single market areas. Results indicate that both the context of the story itself and the social structural context within which news stories are reported are relevant to ethnic and racial portrayals in crime news. We find limited support for power structure, market share, normal crimes and racial threat explanations of patterns of reporting. Racial privileging arguments receive more extensive support. PMID:20640244
A Short History of Randomized Experiments in Criminology: A Meager Feast.
ERIC Educational Resources Information Center
Farrington, David P.
2003-01-01
Discusses advantages of randomized experiments and key issues raised in this special issue. Focuses on growth and decrease in the use of randomized experiments by the California Youth Authority, the U.S. National Institute of Justice, and the British Home Office. Calls for increased recognition of the importance of randomized experiments. (SLD)
Serang, Oliver
2012-01-01
Linear programming (LP) problems are commonly used in analysis and resource allocation, frequently surfacing as approximations to more difficult problems. Existing approaches to LP have been dominated by a small group of methods, and randomized algorithms have not enjoyed popularity in practice. This paper introduces a novel randomized method of solving LP problems by moving along the facets and within the interior of the polytope along rays randomly sampled from the polyhedral cones defined by the bounding constraints. This conic sampling method is then applied to randomly sampled LPs, and its runtime performance is shown to compare favorably to the simplex and primal affine-scaling algorithms, especially on polytopes with certain characteristics. The conic sampling method is then adapted and applied to solve a certain quadratic program, which compute a projection onto a polytope; the proposed method is shown to outperform the proprietary software Mathematica on large, sparse QP problems constructed from mass spectometry-based proteomics. PMID:22952741
Point-Sampling and Line-Sampling Probability Theory, Geometric Implications, Synthesis
L.R. Grosenbaugh
1958-01-01
Foresters concerned with measuring tree populations on definite areas have long employed two well-known methods of representative sampling. In list or enumerative sampling the entire tree population is tallied with a known proportion being randomly selected and measured for volume or other variables. In area sampling all trees on randomly located plots or strips...
Slight, Sarah P; Seger, Diane L; Franz, Calvin; Wong, Adrian; Bates, David W
2018-06-22
To estimate the national cost of ADEs resulting from inappropriate medication-related alert overrides in the U.S. inpatient setting. We used three different regression models (Basic, Model 1, Model 2) with model inputs taken from the medical literature. A random sample of 40 990 adult inpatients at the Brigham and Women's Hospital (BWH) in Boston with a total of 1 639 294 medication orders was taken. We extrapolated BWH medication orders using 2014 National Inpatient Sample (NIS) data. Using three regression models, we estimated that 29.7 million adult inpatient discharges in 2014 resulted in between 1.02 billion and 1.07 billion medication orders, which in turn generated between 75.1 million and 78.8 million medication alerts, respectively. Taking the basic model (78.8 million), we estimated that 5.5 million medication-related alerts might have been inappropriately overridden, resulting in approximately 196 600 ADEs nationally. This was projected to cost between $871 million and $1.8 billion for treating preventable ADEs. We also estimated that clinicians and pharmacists would have jointly spent 175 000 hours responding to 78.8 million alerts with an opportunity cost of $16.9 million. These data suggest that further optimization of hospitals computerized provider order entry systems and their associated clinical decision support is needed and would result in substantial savings. We have erred on the side of caution in developing this range, taking two conservative cost estimates for a preventable ADE that did not include malpractice or litigation costs, or costs of injuries to patients.
Harry T. Valentine
2002-01-01
Randomized branch sampling (RBS) is a special application of multistage probability sampling (see Sampling, environmental), which was developed originally by Jessen [3] to estimate fruit counts on individual orchard trees. In general, the method can be used to obtain estimates of many different attributes of trees or other branched plants. The usual objective of RBS is...
Vegetation responses to natural regulation of elk in Rocky Mountain National Park
Zeigenfuss, Linda C.; Singer, Francis J.; Bowden, David
1999-01-01
Some grazing-induced responses were detected. Grazing-resistant species such as sedges (native), timothy (exotic), and club mosses increased and the amount of bare ground increased on some grazed sites. However, the changes within this sampling program alone were not alarming. The amount of bare ground increase was minor (4%), and grass and shrub cover increased in the shrub plots. The inferential power ofthis sample design was limited to the study plots only. Other factors (climate change, succession) were not controlled for using fenced plots and the sensitivity ofthe methods and plots to detect change were limited. For example, the low number oftransects in willow was not adequate to monitor conditions on the entire winter range. Lacking controls, observed changes may have been due to other factors (climate trends, beaver dam abandonment, stream channel changes), not elk herbivory alone. We recommend using a new sampling design that would include controls, pretreatment data, random site selection, and much more replication.
Comparing population size estimators for plethodontid salamanders
Bailey, L.L.; Simons, T.R.; Pollock, K.H.
2004-01-01
Despite concern over amphibian declines, few studies estimate absolute abundances because of logistic and economic constraints and previously poor estimator performance. Two estimation approaches recommended for amphibian studies are mark-recapture and depletion (or removal) sampling. We compared abundance estimation via various mark-recapture and depletion methods, using data from a three-year study of terrestrial salamanders in Great Smoky Mountains National Park. Our results indicate that short-term closed-population, robust design, and depletion methods estimate surface population of salamanders (i.e., those near the surface and available for capture during a given sampling occasion). In longer duration studies, temporary emigration violates assumptions of both open- and closed-population mark-recapture estimation models. However, if the temporary emigration is completely random, these models should yield unbiased estimates of the total population (superpopulation) of salamanders in the sampled area. We recommend using Pollock's robust design in mark-recapture studies because of its flexibility to incorporate variation in capture probabilities and to estimate temporary emigration probabilities.
Factors associated with work satisfaction of registered nurses.
Kovner, Christine; Brewer, Carol; Wu, Yow-Wu; Cheng, Ying; Suzuki, Miho
2006-01-01
To examine the factors that influence the work satisfaction of a national sample of registered nurses in metropolitan statistical areas (MSAs). A cross-sectional mailed survey design was used. The sample consisted of RNs randomly selected from 40 MSAs in 29 states; 1,907 RNs responded (48%). The sample of 1,538 RNs working in nursing was used for analysis. The questionnaire included measures of work attitudes and demographic characteristics. The data were analyzed using ordinary least-squares regression. More than 40% of the variance in satisfaction was explained by the various work attitudes: supervisor support, work-group cohesion, variety of work, autonomy, organizational constraint, promotional opportunities, work and family conflict, and distributive justice. RNs who were White, self-perceived as healthy, and working in nursing education were more satisfied. RNs that were more career oriented were more satisfied. Of the benefits options, only paid time off was related to satisfaction. Work-related factors were significantly related to RNs' work satisfaction.
NASA Astrophysics Data System (ADS)
Ajithra, A. K.; Shanthi, G.
2016-07-01
Natural radionuclides of terrestrial origin have very long half - lives or driven from very long - lived parent radionuclides, which have been created in stellar processes before the earth formation. The study of natural radioactivity in marine and coastal environments is of significant importance for better understanding of oceanographic and sedimentological processes. The sampling sites are selected to cover randomly to cover the southern part. The soil samples have been collected in beach sides. In situ gamma measurements were conducted using a high-purity germanium (HPGe) detector (coaxial cylinder of 50.1 mm in diameter and 44 mm in length) with a relative efficiency of 50% and an energy resolution (FWHM) of 1.8 keV at the 1.33 MeV reference transition of 60Co. The measurements shows that the values of the absorbed dose rates in air in the investigated area are lower than the recommended limit by the United Nations Scientific Committee on the Effect of Atomic Radiation.
Clutch sizes and nests of tailed frogs from the Olympic Peninsula, Washington
Bury, R. Bruce; Loafman, P.; Rofkar, D.; Mike, K.
2001-01-01
In the summers 1995-1998, we sampled 168 streams (1,714 in of randomly selected 1-m bands) to determine distribution and abundance of stream amphibians in Olympic National Park, Washington. We found six nests (two in one stream) of the tailed frog, compared to only two nests with clutch sizes reported earlier for coastal regions. This represents only one nest per 286 in searched and one nest per 34 streams sampled. Tailed frogs occurred only in 94 (60%) of the streams and, for these waters, we found one nest per 171 in searched or one nest per 20 streams sampled. The numbers of eggs for four masses ((x) over bar = 48.3, range 40-55) were low but one single strand in a fifth nest had 96 eggs. One nest with 185 eggs likely represented communal egg deposition. Current evidence indicates a geographic trend with yearly clutches of relatively few eggs in coastal tailed frogs compared to biennial nesting with larger clutches for inland populations in the Rocky Mountains.
Bostock, Deborah J; Daley, James G
2007-09-01
From a stratified random sample, 2,018 active-duty United States Air Force women completed a telephone survey dealing with sexual assault and harassment. The lifetime prevalence of rape among Air Force women (28%) was more than twice as high as the prevalence in a national sample (13%). Nearly half of the military sample had been the victims of rape, molestation, or attempted sexual assault. The majority of both initial rapes (75%) and most recent rapes (56%) involved assault by civilians when the victims were civilians. Family members perpetrated 29% of initial rapes and 33% of most recent rapes. Regarding military status of the perpetrator, 14% of first-time victims were raped by a military member, 26% of multiple-time victims were raped by a military member, 31.8% of military women were sexually harassed by a military supervisor or boss, and 26.7% of military women were sexually harassed by a military coworker.
Sabina, Chiara
2013-01-01
This study expands previous work by examining individual and national level effects of economic deprivation on partner violence among college students. Three main hypotheses were tested: (1) individual level economic deprivation (i.e., ability to meet daily needs and family income) is associated with partner violence, (2) gross national income is associated with the mean rates of partner violence across nations, and (3) the association between individual level economic deprivation and partner violence varies according to the economic national context as measured by gross national income. Data for 14,090 participants from 31 nations came from the International Dating Violence Study that queried university students about violence in their relationships and relevant risk factors. A series of overdispersed Poisson hierarchical linear regression models were specified to test the hypotheses. Ability to meet daily needs, but not family income, was associated with rates of partner violence. Gross national income was also associated with mean rates of partner violence across nations as well as the relationships between ability to meet daily and partner violence and between family income and partner violence. The findings show the importance of context, as indicated by national economic standing, on rates of partner violence. Not only do economically deprived individuals experience more partner violence, but those living in poorer nations experience more partner violence, regardless of individual economic deprivation. Limitations of the study include a non-random sample and substantial variation in the study sites beyond economic standing. Nonetheless, findings indicate efforts to confront partner violence must also call for cross-national economic development. © 2013 Wiley Periodicals, Inc.
Deterministic multidimensional nonuniform gap sampling.
Worley, Bradley; Powers, Robert
2015-12-01
Born from empirical observations in nonuniformly sampled multidimensional NMR data relating to gaps between sampled points, the Poisson-gap sampling method has enjoyed widespread use in biomolecular NMR. While the majority of nonuniform sampling schemes are fully randomly drawn from probability densities that vary over a Nyquist grid, the Poisson-gap scheme employs constrained random deviates to minimize the gaps between sampled grid points. We describe a deterministic gap sampling method, based on the average behavior of Poisson-gap sampling, which performs comparably to its random counterpart with the additional benefit of completely deterministic behavior. We also introduce a general algorithm for multidimensional nonuniform sampling based on a gap equation, and apply it to yield a deterministic sampling scheme that combines burst-mode sampling features with those of Poisson-gap schemes. Finally, we derive a relationship between stochastic gap equations and the expectation value of their sampling probability densities. Copyright © 2015 Elsevier Inc. All rights reserved.
Burt, Richard D.; Oster, Alexandra M.; Golden, Mathew R.; Thiede, Hanne
2013-01-01
There is no gold standard for recruiting unbiased samples of men who have sex with men (MSM). To assess differing recruitment methods, we compared Seattle-area MSM samples from: venue-day-time sampling-based National HIV Behavioral Surveillance (NHBS) surveys in 2008 and 2011, random-digit-dialed (RDD) surveys in 2003 and 2006, and STD clinic patient data 2001–2011. We compared sociodemographics, sexual and drug-associated behavior, and HIV status and testing. There was generally good consistency between the two NHBS surveys and within STD clinic data across time. NHBS participants reported higher levels of drug-associated and lower levels of sexual risk than STD clinic patients. RDD participants differed from the other study populations in sociodemographics and some risk behaviors. While neither NHBS nor the STD clinic study populations may be representative of all MSM, both appear to provide consistent samples of MSM subpopulations across time that can provide useful information to guide HIV prevention. PMID:23900958
Radon in harvested rainwater at the household level, Palestine.
Al-Khatib, Issam A; Al Zabadi, Hamzeh; Saffarini, Ghassan
2017-04-01
The main objective of this study was to assess Radon concentration in the harvested rainwater (HRW) at the household level in Yatta area, Palestine. HRW is mainly used for drinking as it is the major source of water for domestic uses due to water scarcity. Ninety HRW samples from the household cisterns were collected from six localities (a town and five villages) and Radon concentrations were measured. The samples were randomly collected from different households to represent the Yatta area. Fifteen samples were collected from each locality at the same day. RAD7 device was used for analysis and each sample was measured in duplicate. Radon concentrations ranged from 0.037 to 0.26 Bq/L with a mean ± standard deviation of 0.14 ± 0.06 Bq/L. The estimated annual effective radiation doses for babies, children and adults were all far below the maximum limit of 5 mSvy -1 set by the National Council on Radiation Protection and Measurements. Copyright © 2017 Elsevier Ltd. All rights reserved.
Observational studies of patients in the emergency department: a comparison of 4 sampling methods.
Valley, Morgan A; Heard, Kennon J; Ginde, Adit A; Lezotte, Dennis C; Lowenstein, Steven R
2012-08-01
We evaluate the ability of 4 sampling methods to generate representative samples of the emergency department (ED) population. We analyzed the electronic records of 21,662 consecutive patient visits at an urban, academic ED. From this population, we simulated different models of study recruitment in the ED by using 2 sample sizes (n=200 and n=400) and 4 sampling methods: true random, random 4-hour time blocks by exact sample size, random 4-hour time blocks by a predetermined number of blocks, and convenience or "business hours." For each method and sample size, we obtained 1,000 samples from the population. Using χ(2) tests, we measured the number of statistically significant differences between the sample and the population for 8 variables (age, sex, race/ethnicity, language, triage acuity, arrival mode, disposition, and payer source). Then, for each variable, method, and sample size, we compared the proportion of the 1,000 samples that differed from the overall ED population to the expected proportion (5%). Only the true random samples represented the population with respect to sex, race/ethnicity, triage acuity, mode of arrival, language, and payer source in at least 95% of the samples. Patient samples obtained using random 4-hour time blocks and business hours sampling systematically differed from the overall ED patient population for several important demographic and clinical variables. However, the magnitude of these differences was not large. Common sampling strategies selected for ED-based studies may affect parameter estimates for several representative population variables. However, the potential for bias for these variables appears small. Copyright © 2012. Published by Mosby, Inc.
Sareen, Jitender; Isaak, Corinne; Bolton, Shay-Lee; Enns, Murray W; Elias, Brenda; Deane, Frank; Munro, Garry; Stein, Murray B; Chateau, Dan; Gould, Madelyn; Katz, Laurence Y
2013-10-01
Gatekeeper training aims to train people to recognize and identify those who are at risk for suicide and assist them in getting care. Applied Suicide Intervention Skills Training (ASIST), a form of gatekeeper training, has been implemented around the world without a controlled evaluation. We hypothesized that participants in 2 days of ASIST gatekeeper training would have increased knowledge and preparedness to help people with suicidal ideation in comparison to participants who received a 2-day Resilience Retreat that did not focus on suicide awareness and intervention skills (control condition). First Nations on reserve people in Northwestern Manitoba, aged 16 years and older, were recruited and randomized to two arms of the study. Self-reported measures were collected at three time points-immediately pre-, immediately post-, and 6 months post intervention. The primary outcome was the Suicide Intervention Response Inventory, a validated scale that assesses the capacity for individuals to intervene with suicidal behavior. Secondary outcomes included self-reported preparedness measures and gatekeeper behaviors. In comparison with the Resilience Retreat (n = 24), ASIST training (n = 31) was not associated with a significant impact on all outcomes of the study based on intention-to-treat analysis. There was a trend toward an increase in suicidal ideation among those who participated in the ASIST in comparison to those who were in the Resilience Retreat. The lack of efficacy of ASIST in a First Nations on-reserve sample is concerning in the context of widespread policies in Canada on the use of gatekeeper training in suicide prevention. © 2013 Wiley Periodicals, Inc.
Matzopoulos, Richard; Prinsloo, Megan; Pillay-van Wyk, Victoria; Gwebushe, Nomonde; Mathews, Shanaaz; Martin, Lorna J; Laubscher, Ria; Abrahams, Naeemah; Msemburi, William; Lombard, Carl; Bradshaw, Debbie
2015-05-01
To investigate injury-related mortality in South Africa using a nationally representative sample and compare the results with previous estimates. We conducted a retrospective descriptive study of medico-legal postmortem investigation data from mortuaries using a multistage random sample, stratified by urban and non-urban areas and mortuary size. We calculated age-specific and age-standardized mortality rates for external causes of death. Postmortem reports revealed 52,493 injury-related deaths in 2009 (95% confidence interval, CI: 46,930-58,057). Almost half (25,499) were intentionally inflicted. Age-standardized mortality rates per 100,000 population were as follows: all injuries: 109.0 (95% CI: 97.1-121.0); homicide 38.4 (95% CI: 33.8-43.0; suicide 13.4 (95% CI: 11.6-15.2) and road-traffic injury 36.1 (95% CI: 30.9-41.3). Using postmortem reports, we found more than three times as many deaths from homicide and road-traffic injury than had been recorded by vital registration for this period. The homicide rate was similar to the estimate for South Africa from a global analysis, but road-traffic and suicide rates were almost fourfold higher. This is the first nationally representative sample of injury-related mortality in South Africa. It provides more accurate estimates and cause-specific profiles that are not available from other sources.
Validated scales to assess adult self-efficacy to eat fruits and vegetables.
Mainvil, Louise A; Lawson, Rob; Horwath, Caroline C; McKenzie, Joanne E; Reeder, Anthony I
2009-01-01
An audience-centered approach was used to develop valid and reliable scales to measure adult self-efficacy to eat fruit and vegetables. Cross-sectional survey of a national population. New Zealand. A sample of 350 adults ages 25 to 60 years was randomly selected from a nationally representative sampling frame. Overall, 231 questionnaires were returned, producing a 72% response rate. The mean age of subjects was 42.7years; 58% were female; 80% were of European descent; 11% were indigenous Maori. The 76-item, self-administered questionnaire collected data on demographics, fruit and vegetable intakes, stages of change, decisional balance, and self-efficacy (24 items). Principal components analysis with oblimin rotation was performed. Principal components analysis yielded three distinct and reliable scales for self-efficacy to eat "vegetables," "fruit," and "fruit and vegetables" (Cronbach alpha = .80, .85, and .73, respectively). These scales were correlated, but only the "vegetable" scale was positively correlated with the "fruit and vegetable" scale (Kendall tau r = 0.30, -0.26 [fruit, "fruit and vegetables"], -0.38 [fruit, vegetable]). As predicted, self-efficacy was associated with intake (r = 0.30 [fruit], 0.34 [vegetables]). Assuming the factor structure is confirmed in independent samples, these brief psychometrically sound scales may be used to assess adult self-efficacy to eat fruit and to eat vegetables (separately) but not self-efficacy to eat "fruit and vegetables."
Abou Abbas, Oraynab; AlBuhairan, Fadia
2017-01-01
Depression and anxiety among adolescents require further attention as they have profound harmful implications on several aspects of adolescents' wellbeing and can be associated with life threatening risk behaviors such as suicide. To examine the underlying risk factors for feeling so sad or hopeless and for feeling worried among adolescents in Saudi Arabia. Data from Jeeluna ® national survey was used. A cross-sectional, multi-stage, stratified, cluster random sampling technique was applied among a sample of students aged 10-19 years attending intermediate and secondary schools in Saudi Arabia. A self-administered questionnaire assessing several domains, including feeling so sad or hopeless and worried, was used to collect data. Logistic regression models were fitted to determine the different factors associated with mental health. A sample of 12,121 students was included in this study. Feeling so sad or hopeless and feeling worried were significantly more prevalent among females and older adolescents ( p < 0.0001). The results showed that poor relationship with parents, negative body image, and chronic illness to be significantly associated with feeling so sad or hopeless and worried. Symptoms suggestive of mental health problems among adolescents in Saudi Arabia are prevalent and deserve special attention. Adopting effective strategies, including regular screening and intervention programs are highly needed to better address, detect, and control early signs of these problems.
2011-01-01
Background Cigarette smoking is the number one cause of preventable death among American Indian and Alaska Natives, AI/ANs. Two out of every five AI/AN will die from tobacco-related diseases if the current smoking rates of AI/ANs (40.8%) persist. Currently, there is no proven, effective culturally-tailored smoking cessation program designed specifically for a heterogeneous population of AI. The primary aim of this group randomized clinical trial is to test the efficacy of "All Nations Breath of Life" (ANBL) program compared to a non-tailored "Current Best Practices" smoking cessation program among AI smokers. Methods We will randomize 56 groups (8 smokers per group) to the tailored program or non-tailored program for a total sample size of 448 American Indian smokers. All participants in the proposed study will be offered pharmacotherapy, regardless of group assignment. This study is the first controlled trial to examine the efficacy of a culturally-tailored smoking cessation program for American Indians. If the intervention is successful, the potential health impact is significant because the prevalence of smoking is the highest in this population. Trial Registration ClinicalTrials.gov: NCT01106456 PMID:21592347
A Bayesian sequential design with adaptive randomization for 2-sided hypothesis test.
Yu, Qingzhao; Zhu, Lin; Zhu, Han
2017-11-01
Bayesian sequential and adaptive randomization designs are gaining popularity in clinical trials thanks to their potentials to reduce the number of required participants and save resources. We propose a Bayesian sequential design with adaptive randomization rates so as to more efficiently attribute newly recruited patients to different treatment arms. In this paper, we consider 2-arm clinical trials. Patients are allocated to the 2 arms with a randomization rate to achieve minimum variance for the test statistic. Algorithms are presented to calculate the optimal randomization rate, critical values, and power for the proposed design. Sensitivity analysis is implemented to check the influence on design by changing the prior distributions. Simulation studies are applied to compare the proposed method and traditional methods in terms of power and actual sample sizes. Simulations show that, when total sample size is fixed, the proposed design can obtain greater power and/or cost smaller actual sample size than the traditional Bayesian sequential design. Finally, we apply the proposed method to a real data set and compare the results with the Bayesian sequential design without adaptive randomization in terms of sample sizes. The proposed method can further reduce required sample size. Copyright © 2017 John Wiley & Sons, Ltd.
EAP Service Use in a Managed Behavioral Health Care Organization: From the Employee Perspective.
Merrick, Elizabeth L; Hodgkin, Dominic; Hiatt, Deirdre; Horgan, Constance M; McCann, Bernard
2011-01-01
Contemporary employee assistance program (EAP) services are typically provided in broad-brush programs delivered by large external vendors in a network model. Yet research has not kept pace with EAP evolution, including in terms of how EAP clients themselves view services. We surveyed a random sample of EAP service users from a national provider (361 respondents). About one-third of respondents reported getting help for workplace issues. Most learned about the EAP through employer communications such as the company website. The large majority reported that the EAP helped them "a lot" or "some," suggesting they valued this benefit.
EAP Service Use in a Managed Behavioral Health Care Organization: From the Employee Perspective
Hodgkin, Dominic; Hiatt, Deirdre; Horgan, Constance M.; McCann, Bernard
2011-01-01
SUMMARY Contemporary employee assistance program (EAP) services are typically provided in broad-brush programs delivered by large external vendors in a network model. Yet research has not kept pace with EAP evolution, including in terms of how EAP clients themselves view services. We surveyed a random sample of EAP service users from a national provider (361 respondents). About one-third of respondents reported getting help for workplace issues. Most learned about the EAP through employer communications such as the company website. The large majority reported that the EAP helped them “a lot” or “some,” suggesting they valued this benefit. PMID:21966281
Clark, Rebecca E; Linville, Deanna; Rosen, Karen H
2009-04-01
Recognizing the fit between family medicine and marriage and family therapy (MFT), members of both fields have made significant advances in collaborative health research and practice. To add to this work, we surveyed a nationwide random sample of 240 family physicians (FPs) and asked about their perspectives and experiences of collaboration with MFTs. We found that FPs frequently perceive a need for their patients to receive MFT-related care, but their referral to and collaboration with MFTs were limited. Through responses to an open-ended question, we gained valuable information as to how MFTs could more effectively initiate collaboration with FPs.
Three species of Plasmodium from Canada geese, Branta canadensis
Herman, C.M.; Barrow, J.H.
1967-01-01
Studies on Canada geese at the Seney National Wildlife Refuge in northern Michigan during the past few years have uncovered at least three species of Plasmodium: P circumflexum, P. relictum, and P. vaughani. Although rarely observed in direct blood smears from the wild hosts, isodiagnosis, using primarily domestic geese as recipients, revealed a prevalence of 60 percent in random samplings of the population. P. circumflexum is the most prevalent and mixed infections have been noted. In experimental infections, induced by blood inoculation, the malaria produced by P. circumflexum produces about a 70 percent mortality in Canada geese and about a 10 percent mortality in domestic geese.
September-March survival of female northern pintails radiotagged in San Joaquin Valley, California
Fleskes, J.P.; Jarvis, R.L.; Gilmer, D.S.
2002-01-01
Studies on Canada geese at the Seney National Wildlife Refuge in northern Michigan during the past few years have uncovered at least three species of Plasmodium: P circumflexum, P. relictum, and P. vaughani. Although rarely observed in direct blood smears from the wild hosts, isodiagnosis, using primarily domestic geese as recipients, revealed a prevalence of 60 percent in random samplings of the population. P. circumflexum is the most prevalent and mixed infections have been noted. In experimental infections, induced by blood inoculation, the malaria produced by P. circumflexum produces about a 70 percent mortality in Canada geese and about a 10 percent mortality in domestic geese.
Whitford, David L; Hickey, Anne; Horgan, Frances; O'Sullivan, Bernadette; McGee, Hannah; O'Neill, Desmond
2009-01-01
Background Stroke is a major cause of mortality and morbidity with potential for improved care and prevention through general practice. A national survey was undertaken to determine current resources and needs for optimal stroke prevention and care. Methods Postal survey of random sample of general practitioners undertaken (N = 204; 46% response). Topics included practice organisation, primary prevention, acute management, secondary prevention, long-term care and rehabilitation. Results Service organisation for both primary and secondary prevention was poor. Home management of acute stroke patients was used at some stage by 50% of responders, accounting for 7.3% of all stroke patients. Being in a structured cardiovascular management scheme, a training practice, a larger practice, or a practice employing a practice nurse were associated with structures and processes likely to support stroke prevention and care. Conclusion General practices were not fulfilling their potential to provide stroke prevention and long-term management. Systems of structured stroke management in general practice are essential to comprehensive national programmes of stroke care. PMID:19402908
Mhaskar, Rahul; Djulbegovic, Benjamin; Magazin, Anja; Soares, Heloisa P; Kumar, Ambuj
2012-06-01
To assess whether the reported methodological quality of randomized controlled trials (RCTs) reflects the actual methodological quality and to evaluate the association of effect size (ES) and sample size with methodological quality. Systematic review. This is a retrospective analysis of all consecutive phase III RCTs published by eight National Cancer Institute Cooperative Groups up to 2006. Data were extracted from protocols (actual quality) and publications (reported quality) for each study. Four hundred twenty-nine RCTs met the inclusion criteria. Overall reporting of methodological quality was poor and did not reflect the actual high methodological quality of RCTs. The results showed no association between sample size and actual methodological quality of a trial. Poor reporting of allocation concealment and blinding exaggerated the ES by 6% (ratio of hazard ratio [RHR]: 0.94; 95% confidence interval [CI]: 0.88, 0.99) and 24% (RHR: 1.24; 95% CI: 1.05, 1.43), respectively. However, actual quality assessment showed no association between ES and methodological quality. The largest study to date shows that poor quality of reporting does not reflect the actual high methodological quality. Assessment of the impact of quality on the ES based on reported quality can produce misleading results. Copyright © 2012 Elsevier Inc. All rights reserved.
Nakamura, Hidenori
2017-10-01
The Great East Japan Earthquake and subsequent Fukushima nuclear accident triggered citizen dialogue on energy and environmental management in Japan. However, an international survey has shown that the willingness of Japanese citizens to participate in political and social activities has declined since the Fukushima accident. Employing an internet-based survey in four urban or nuclear power plant-hosting prefectures in Japan, this study examines the willingness to participate in random sampling deliberation on post-disaster energy and environmental policy. It focuses on the effects of political, environmental, and social attitudes towards willingness to participate in citizen dialogue. The survey shows around 40% of respondents may participate in energy and environmental deliberation. Statistical analysis reveals that environmental consciousness raises the propensity to participate in deliberation, while political obedience and social hesitation decreases the will to participate. The effect of environmental attitudes is larger than that of political and social attitudes. The survey also finds that governmental response to deliberation, i.e., information generation and disclosure based on requests from citizen dialogue, encourages participation in deliberation in a conservative prefecture, when citizen dialogue is held at the national level. Random sampling deliberation opens a new mode of environmental governance regardless of local political and social characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.
Socioeconomic status and weight control practices in British adults
Wardle, J; Griffith, J
2001-01-01
STUDY OBJECTIVE—Attitudes and practices concerning weight control in British adults were examined to test the hypothesis that variation in concern about weight and deliberate weight control might partly explain the socioeconomic status (SES) gradient in obesity. Higher SES groups were hypothesised to show more weight concern and higher levels of dieting. SETTING—Data were collected as part of the monthly Omnibus Survey of the Office of National Statistics in March 1999. PARTICIPANTS—A stratified, probability sample of 2690 households was selected by random sampling of addresses in Britain. One randomly selected person in each household was interviewed at their home. MAIN RESULTS—As predicted, higher SES men and women had higher levels of perceived overweight, monitored their weight more closely, and were more likely to be trying to lose weight. Higher SES groups also reported more restrictive dietary practices and more vigorous physical activity. CONCLUSIONS—The results are consistent with the idea that part of the protection against weight gain in higher SES groups could be a higher frequency of weight monitoring, a lower threshold for defining themselves as overweight, and a greater likelihood of deliberate efforts at weight control. Keywords: socioeconomic status; weight control; obesity PMID:11160173
An Overview of Patient Safety Climate in the VA
Hartmann, Christine W; Rosen, Amy K; Meterko, Mark; Shokeen, Priti; Zhao, Shibei; Singer, Sara; Falwell, Alyson; Gaba, David M
2008-01-01
Objective To assess variation in safety climate across VA hospitals nationally. Study Setting Data were collected from employees at 30 VA hospitals over a 6-month period using the Patient Safety Climate in Healthcare Organizations survey. Study Design We sampled 100 percent of senior managers and physicians and a random 10 percent of other employees. At 10 randomly selected hospitals, we sampled an additional 100 percent of employees working in units with intrinsically higher hazards (high-hazard units [HHUs]). Data Collection Data were collected using an anonymous survey design. Principal Findings We received 4,547 responses (49 percent response rate). The percent problematic response—lower percent reflecting higher levels of patient safety climate—ranged from 12.0–23.7 percent across hospitals (mean=17.5 percent). Differences in safety climate emerged by management level, clinician status, and workgroup. Supervisors and front-line staff reported lower levels of safety climate than senior managers; clinician responses reflected lower levels of safety climate than those of nonclinicians; and responses of employees in HHUs reflected lower levels of safety climate than those of workers in other areas. Conclusions This is the first systematic study of patient safety climate in VA hospitals. Findings indicate an overall positive safety climate across the VA, but there is room for improvement. PMID:18355257
Luce, Bryan R; Connor, Jason T; Broglio, Kristine R; Mullins, C Daniel; Ishak, K Jack; Saunders, Elijah; Davis, Barry R
2016-09-20
Bayesian and adaptive clinical trial designs offer the potential for more efficient processes that result in lower sample sizes and shorter trial durations than traditional designs. To explore the use and potential benefits of Bayesian adaptive clinical trial designs in comparative effectiveness research. Virtual execution of ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial) as if it had been done according to a Bayesian adaptive trial design. Comparative effectiveness trial of antihypertensive medications. Patient data sampled from the more than 42 000 patients enrolled in ALLHAT with publicly available data. Number of patients randomly assigned between groups, trial duration, observed numbers of events, and overall trial results and conclusions. The Bayesian adaptive approach and original design yielded similar overall trial conclusions. The Bayesian adaptive trial randomly assigned more patients to the better-performing group and would probably have ended slightly earlier. This virtual trial execution required limited resampling of ALLHAT patients for inclusion in RE-ADAPT (REsearch in ADAptive methods for Pragmatic Trials). Involvement of a data monitoring committee and other trial logistics were not considered. In a comparative effectiveness research trial, Bayesian adaptive trial designs are a feasible approach and potentially generate earlier results and allocate more patients to better-performing groups. National Heart, Lung, and Blood Institute.
NASA Astrophysics Data System (ADS)
Zhang, Jingdong; Zhu, Tao; Zheng, Hua; Kuang, Yang; Liu, Min; Huang, Wei
2017-04-01
The round trip time of the light pulse limits the maximum detectable frequency response range of vibration in phase-sensitive optical time domain reflectometry (φ-OTDR). We propose a method to break the frequency response range restriction of φ-OTDR system by modulating the light pulse interval randomly which enables a random sampling for every vibration point in a long sensing fiber. This sub-Nyquist randomized sampling method is suits for detecting sparse-wideband- frequency vibration signals. Up to MHz resonance vibration signal with over dozens of frequency components and 1.153MHz single frequency vibration signal are clearly identified for a sensing range of 9.6km with 10kHz maximum sampling rate.
78 FR 57033 - United States Standards for Condition of Food Containers
Federal Register 2010, 2011, 2012, 2013, 2014
2013-09-17
... containers during production. Stationary lot sampling is the process of randomly selecting sample units from.... * * * * * Stationary lot sampling. The process of randomly selecting sample units from a lot whose production has been... less than \\1/16\\-inch Stringy seal (excessive plastic threads showing at edge of seal 222 area...
Health indicators: eliminating bias from convenience sampling estimators.
Hedt, Bethany L; Pagano, Marcello
2011-02-28
Public health practitioners are often called upon to make inference about a health indicator for a population at large when the sole available information are data gathered from a convenience sample, such as data gathered on visitors to a clinic. These data may be of the highest quality and quite extensive, but the biases inherent in a convenience sample preclude the legitimate use of powerful inferential tools that are usually associated with a random sample. In general, we know nothing about those who do not visit the clinic beyond the fact that they do not visit the clinic. An alternative is to take a random sample of the population. However, we show that this solution would be wasteful if it excluded the use of available information. Hence, we present a simple annealing methodology that combines a relatively small, and presumably far less expensive, random sample with the convenience sample. This allows us to not only take advantage of powerful inferential tools, but also provides more accurate information than that available from just using data from the random sample alone. Copyright © 2011 John Wiley & Sons, Ltd.
Kamika, Ilunga; Mngqawa, Pamella; Rheeder, John P; Teffo, Snow L; Katerere, David R
2014-01-01
Peanut (Arachis hypogaea L.) is an important food crop in sub-Saharan Africa. In this survey, the mycological and aflatoxin contamination of peanuts collected from Kinshasa, Democratic Republic of Congo, and Pretoria, South Africa, was assessed. Twenty peanut samples were purchased randomly at informal markets in the two cities and analysed for mycoflora and aflatoxins (AFB1, AFB2, AFG1 and AFG2) using standard methods. The results indicated that 95% of the Kinshasa samples and 100% of the Pretoria samples were contaminated with aflatoxigenic fungi in the ranges 20-49,000 and 40-21,000 CFU/g, respectively. Seventy-five per cent of the Kinshasa samples and 35% of the Pretoria samples exceeded the maximum limits of AFB1 as set by The Joint FAO/WHO Expert Committee on Food Additives. Residents of both cities are at a high risk of aflatoxin exposure despite their apparent cultural, socio-economic, geographic and climatic differences. Further work needs to be done to understand the supply chains of peanut trade in informal markets of the two countries so that interventions are well targeted on a regional rather than a national level.
Lot quality assurance sampling for screening communities hyperendemic for Schistosoma mansoni.
Rabarijaona, L P; Boisier, P; Ravaoalimalala, V E; Jeanne, I; Roux, J F; Jutand, M A; Salamon, R
2003-04-01
Lot quality assurance sampling (LQAS) was evaluated for rapid low cost identification of communities where Schistosoma mansoni infection was hyperendemic in southern Madagascar. In the study area, S. mansoni infection shows very focused and heterogeneous distribution requiring multifariousness of local surveys. One sampling plan was tested in the field with schoolchildren and several others were simulated in the laboratory. Randomization and stool specimen collection were performed by voluntary teachers under direct supervision of the study staff and no significant problem occurred. As expected from Receiver Operating Characteristic (ROC) curves, all sampling plans allowed correct identification of hyperendemic communities and of most of the hypoendemic ones. Frequent misclassifications occurred for communities with intermediate prevalence and the cheapest plans had very low specificity. The study confirmed that LQAS would be a valuable tool for large scale screening in a country with scarce financial and staff resources. Involving teachers, appeared to be quite feasible and should not lower the reliability of surveys. We recommend that the national schistosomiasis control programme systematically uses LQAS for identification of communities, provided that sample sizes are adapted to the specific epidemiological patterns of S. mansoni infection in the main regions.
Adamse, Paulien; Schoss, Stefanie; Theelen, Rob M C; Hoogenboom, Ron L A P
2017-01-01
The aim of this study was to assess levels of dioxins (polychlorinated dibenzo-p-dioxins and dibenzofurans, PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs) (DL-PCBs) in food of animal origin produced in the Netherlands, including potential trends in time. Test results from about 2500 samples of animal derived food products (beef, veal, lamb, chicken, pork, deer, milk and eggs), sampled for the National Residue Monitoring Plan from 2001-2011, were evaluated. Most samples were screened with a bioassay and, if suspected, analysed by GC-HRMS. The fraction of samples which were non-compliant with European maximum levels was rather low, being below 1% for most food products, except for lamb. Exceedance of action levels was particularly observed for lamb and beef. To obtain an insight into background levels, a randomly taken part of the samples was directly analysed by GC-HRMS. In general, only minor decreases in mean PCDD/F and DL-PCB concentrations could be observed for the period 2001-2011. This may be due to a plateauing of current background levels but also to factors like the sensitivity of the analytical method.
Voineskos, Sophocles H; Coroneos, Christopher J; Ziolkowski, Natalia I; Kaur, Manraj N; Banfield, Laura; Meade, Maureen O; Chung, Kevin C; Thoma, Achilleas; Bhandari, Mohit
2016-02-01
The authors examined industry support, conflict of interest, and sample size in plastic surgery randomized controlled trials that compared surgical interventions. They hypothesized that industry-funded trials demonstrate statistically significant outcomes more often, and randomized controlled trials with small sample sizes report statistically significant results more frequently. An electronic search identified randomized controlled trials published between 2000 and 2013. Independent reviewers assessed manuscripts and performed data extraction. Funding source, conflict of interest, primary outcome direction, and sample size were examined. Chi-squared and independent-samples t tests were used in the analysis. The search identified 173 randomized controlled trials, of which 100 (58 percent) did not acknowledge funding status. A relationship between funding source and trial outcome direction was not observed. Both funding status and conflict of interest reporting improved over time. Only 24 percent (six of 25) of industry-funded randomized controlled trials reported authors to have independent control of data and manuscript contents. The mean number of patients randomized was 73 per trial (median, 43, minimum, 3, maximum, 936). Small trials were not found to be positive more often than large trials (p = 0.87). Randomized controlled trials with small sample size were common; however, this provides great opportunity for the field to engage in further collaboration and produce larger, more definitive trials. Reporting of trial funding and conflict of interest is historically poor, but it greatly improved over the study period. Underreporting at author and journal levels remains a limitation when assessing the relationship between funding source and trial outcomes. Improved reporting and manuscript control should be goals that both authors and journals can actively achieve.
Woo, Jung Hoon; Grinspan, Zachary; Shapiro, Jason; Rhee, Sang Youl
2016-01-01
The Korean National Health Insurance, which provides universal coverage for the entire Korean population, is now facing financial instability. Frequent emergency department (ED) users may represent a medically vulnerable population who could benefit from interventions that both improve care and lower costs. To understand the nature of frequent ED users in Korea, we analyzed claims data from a population-based national representative sample. We performed both bivariate and multivariable analyses to investigate the association between patient characteristics and frequent ED use (4+ ED visits in a year) using claims data of a 1% random sample of the Korean population, collected in 2009. Among 156,246 total ED users, 4,835 (3.1%) were frequent ED users. These patients accounted for 14% of 209,326 total ED visits and 17.2% of $76,253,784 total medical expenses generated from all ED visits in the 1% data sample. Frequent ED users tended to be older, male, and of lower socio-economic status compared with occasional ED users (p < 0.001 for each). Moreover, frequent ED users had longer stays in the hospital when admitted, higher probability of undergoing an operative procedure, and increased mortality. Among 8,425 primary diagnoses, alcohol-related complaints and schizophrenia showed the strongest positive correlation with the number of ED visits. Among the frequent ED users, mortality and annual outpatient department visits were significantly lower in the alcohol-related patient subgroup compared with other frequent ED users; furthermore, the rate was even lower than that for non-frequent ED users. Our findings suggest that expanding mental health and alcohol treatment programs may be a reasonable strategy to decrease the dependence of these patients on the ED. PMID:26809051