Abstract:
:A small variability of exposure in a population, for example small variance in nutrient intake, limits the power of an epidemiologic study. McKeown-Eyssen and Thomas (J Chron Dis 1985; 38:559-568) have shown that by selecting a population with larger exposure variance vs one with smaller variance, the study sample size can be reduced by a factor equal to the ratio of the smaller to larger variance. The authors show that this benefit may be even greater for exposures measured with error. When there is measurement error, the sample size requirements are greatly increased. However, the proportional reduction in sample size from selecting a population with larger variance may be even greater when there is error than when there is not. Under certain assumptions, the validity of the exposure (correlation coefficient of the mismeasured exposure with the true exposure) is enhanced in the population with larger exposure variance, which provides the additional sample size benefit. Simple equations are presented that demonstrate quantitatively the substantial benefit of selecting a population with larger exposure variance when there is moderate or large measurement error. For example, selecting a population with a 30% greater standard deviation of exposure could reduce sample size requirements by 41% when the exposure is perfectly measured, but when the exposure is poorly measured with a validity coefficient of 0.6, the savings could be 56% if a population with 30% greater standard deviation of exposure could be studied. Applications of these results as well as the limitations of the assumptions are discussed.
journal_name
J Clin Epidemioljournal_title
Journal of clinical epidemiologyauthors
White E,Kushi LH,Pepe MSdoi
10.1016/0895-4356(94)90190-2subject
Has Abstractpub_date
1994-08-01 00:00:00pages
873-80issue
8eissn
0895-4356issn
1878-5921pii
0895-4356(94)90190-2journal_volume
47pub_type
杂志文章,评审abstract::Serum hepatitis C virus (HCV) RNA, HCV genotypes and liver function tests were evaluated in a series of 189 unselected, consecutive anti-HCV positive intravenous drug users (IVDUs). Serum HCV RNA was detected in 106/189 patients. Abnormal liver function tests were associated with alcohol abuse, but not with the presen...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/s0895-4356(97)00305-3
更新日期:1998-05-01 00:00:00
abstract:OBJECTIVES:To develop a theory-led framework to inform reviewers' understanding of what, how, and why health care interventions may lead to differential effects across socioeconomic groups. STUDY DESIGN AND SETTING:A metaframework approach combined two theoretical perspectives (socioeconomic health inequalities and co...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/j.jclinepi.2018.08.008
更新日期:2018-12-01 00:00:00
abstract:OBJECTIVES:To review James Jackson's analysis of bloodletting among pneumonitis patients at the newly founded Massachusetts General Hospital, in which he implemented the numerical method advocated by Pierre-Charles-Alexandre Louis. STUDY DESIGN AND SETTING:The study sample included 34 cases of clinically diagnosed pne...
journal_title:Journal of clinical epidemiology
pub_type: 传,历史文章,杂志文章
doi:10.1016/j.jclinepi.2014.10.013
更新日期:2015-04-01 00:00:00
abstract::This study compared the utility of different health indicators in frail older people, as a component of a larger study of medical evaluations of 183 adult day care participants in five Maryland centers. Indices examined included: number of disease categories, number of active categories, number of severe categories, n...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/s0895-4356(01)00389-4
更新日期:2001-11-01 00:00:00
abstract::In 1984, a prospective cohort study, Coronary Artery Risk Development in Young Adults (CARDIA) was initiated to investigate life-style and other factors that influence, favorably and unfavorably, the evolution of coronary heart disease risk factors during young adulthood. After a year of planning and protocol developm...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/0895-4356(88)90080-7
更新日期:1988-01-01 00:00:00
abstract:BACKGROUND AND OBJECTIVE:Reference limits are widely used in anthropometry, the behavioral sciences, medicine, and clinical chemistry. They describe the distribution of a quantitative variable in a healthy population, and are often a smooth function of age or another determinant. Thus, instead of estimating reference l...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/j.jclinepi.2006.09.004
更新日期:2007-06-01 00:00:00
abstract:OBJECTIVE:Correspondence analysis (CA) is a multivariate graphical technique designed to explore the relationships among categorical variables. Epidemiologists frequently collect data on multiple categorical variables with the goal of examining associations among these variables. Nevertheless, CA appears to be an under...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/j.jclinepi.2009.08.008
更新日期:2010-06-01 00:00:00
abstract::We investigated asthma morbidity in children and adults among Registered Indians in Saskatchewan using hospitalization data for 1970-1989. In Registered Indians, significant increases were observed in the asthma hospitalization rates from 1979 to 1989 in boys and girls under 4 years, boys aged 5-14 years, and female a...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/0895-4356(95)00019-z
更新日期:1995-10-01 00:00:00
abstract:OBJECTIVE:Mendelian randomization is a popular technique for assessing and estimating the causal effects of risk factors. If genetic variants which are instrumental variables for a risk factor are shown to be additionally associated with a disease outcome, then the risk factor is a cause of the disease. However, in man...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/j.jclinepi.2015.08.001
更新日期:2016-01-01 00:00:00
abstract::The importance of using risk-adjusted mortality rates to measure quality of care is well-established. However, mortality rates may be an insensitive measure of quality for surgical patients since death is a relatively rare outcome. This study used Medicare files to identify, through chart abstraction, clinical postope...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/0895-4356(94)00165-m
更新日期:1995-05-01 00:00:00
abstract::Remaining questions relative to the measurement of health-state preferences are outlined and applications discussed. We recommend more widespread use of functional measurement to better understand preference structures. Further research should be conducted on the reliability and validity of preference values produced ...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章,评审
doi:10.1016/0895-4356(89)90011-5
更新日期:1989-01-01 00:00:00
abstract::The purpose of this study was to assess the association between the international overweight cutoffs for children and youth and coronary heart disease risk factors. The sample included 410 boys and 337 girls 9-18 years of age from the Québec Family Study. Participants were classified as normal weight or overweight usi...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/s0895-4356(02)00595-4
更新日期:2003-05-01 00:00:00
abstract::Laparoscopic cholecystectomy was introduced to Western Australia in 1991 and has become the method of choice for this procedure, although there are concerns about complications, particularly bile duct injuries. Previous studies have investigated this problem but have not confirmed the accuracy of coded information. We...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章,多中心研究
doi:10.1016/s0895-4356(99)00043-8
更新日期:1999-09-01 00:00:00
abstract::From a database of 93,077 in-patient admissions, patients assigned to catastrophic, very severe, moderately severe, and average 30-day mortality risk categories (as defined in Medicare Hospital Mortality Information, 1989 release, from the Health Care Financing Administration (HCFA] were selected for study. These admi...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/0895-4356(91)90100-n
更新日期:1991-01-01 00:00:00
abstract:BACKGROUND:Recently updated guidelines by the American College of Cardiology/American Heart Association and the European Society of Cardiology recommend at least 12 hours bed rest in patients with uncomplicated myocardial infarction. METHODS:We performed a systematic literature review and meta-analysis of randomized a...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章,meta分析,评审
doi:10.1016/s0895-4356(03)00121-5
更新日期:2003-08-01 00:00:00
abstract::Altogether, 3365 men and 3266 women who attended two cardiovascular screenings in 1974-1975 and 1977-1978, have been followed with respect to death for an average of 15 years. The mortality from coronary heart disease was lower in men who reported being of Lappish origin than in men who reported Norse origin at both s...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/s0895-4356(97)00021-8
更新日期:1997-06-01 00:00:00
abstract::This article reports on the development and validation of the Italian SF-36 Health Survey using data from seven studies in which an Italian version of the SF-36 was administered to more than 7000 subjects between 1991 and 1995. Empirical findings from a wide array of studies and diseases indicate that the performance ...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/s0895-4356(98)00094-8
更新日期:1998-11-01 00:00:00
abstract::Reliability testing was conducted on a survey instrument for a genetic epidemiological study of Parkinson's disease (PD). Information on demographics, medical history, places of residence, and occupations was collected. The instrument was administered to 11 pairs of siblings discordant for PD and then re-administered ...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/s0895-4356(00)00229-8
更新日期:2000-08-01 00:00:00
abstract:OBJECTIVE:To develop a conceptual model to describe the burden of osteoarthritis in individuals with this condition and on the broader community. STUDY DESIGN AND SETTING:Six concept mapping workshops were undertaken: three with patients (n = 26) and three with health professionals (n = 27) in Australia and Sweden. Th...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/j.jclinepi.2013.03.012
更新日期:2013-09-01 00:00:00
abstract::The uses of hypothesis in scientific medicine and in clinical medicine are broadly similar; but they differ in subtle but important logical details. The key distinction is that scientific medicine deals with broad ("public") hypotheses about entire populations; and the predominant problem of inference is statistics in...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/0895-4356(89)90028-0
更新日期:1989-01-01 00:00:00
abstract:OBJECTIVES:Interpretation of clinical research findings using the paradigm of null hypothesis significance testing has a number of limitations. These include arbitrary dichotomization of results, lack of incorporation of study power and prior probability, and the confusing use of conditional probability. This study aim...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/j.jclinepi.2017.08.016
更新日期:2017-12-01 00:00:00
abstract:OBJECTIVE:The objectives of this study were to evaluate the current state of reporting and handling of effect modification in network meta-analyses (NMAs) and perform exploratory analyses to identify variables that are potentially associated with incomplete reporting of effect modifiers in NMAs. STUDY DESIGN AND SETTI...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章,meta分析
doi:10.1016/j.jclinepi.2017.06.004
更新日期:2017-08-01 00:00:00
abstract:OBJECTIVE:When studying the effects of a non-pharmacologic intervention, the choice of a control group is often difficult. In a study on the effectiveness of increased water intake on voiding dysfunction in elderly men we used an unusual design. This article addresses the internal validty and ethics of this design. ST...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/j.jclinepi.2004.08.009
更新日期:2005-04-01 00:00:00
abstract:BACKGROUND:There is no population-based prospective study concerning the relation between serum albumin and mortality in a non-Western population, and few previous studies included the subgroup analysis stratified by serum cholesterol level. METHODS:A 13.7-year cohort study was conducted on 6,957 males and females age...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/j.jclinepi.2004.02.019
更新日期:2004-11-01 00:00:00
abstract:OBJECTIVES:To evaluate the ability of population surveys to estimate the occurrence of maternal morbidities. STUDY DESIGN AND SETTING:A literature search was conducted using MEDLINE, EMBASE, POPLINE references from relevant papers and proceedings of scientific meetings. No restrictions were made regarding language, da...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章,评审
doi:10.1016/j.jclinepi.2007.04.009
更新日期:2008-02-01 00:00:00
abstract:OBJECTIVES:To outline contemporary and novel developments for the presentation and reporting of syntheses of qualitative, implementation, and process evaluation evidence and provide recommendations for the use of reporting guidelines. STUDY DESIGN AND SETTING:An overview of reporting guidelines for qualitative, implem...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/j.jclinepi.2017.10.022
更新日期:2018-05-01 00:00:00
abstract:OBJECTIVE:Clinical trials are unlikely to ever be launched for many comparative effectiveness research (CER) questions. Inferences from hypothetical randomized trials may however be emulated with marginal structural modeling (MSM) using observational data, but success in adjusting for time-dependent confounding and sel...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/j.jclinepi.2013.01.016
更新日期:2013-08-01 00:00:00
abstract:OBJECTIVES:Recent studies suggest that rating clinical marker states (CMS) does not improve the measurement properties of the standard gamble (SG) and only slightly improves those of the feeling thermometer (FT). The poor intrarater (test-retest) reliability of CMS may explain their meager performance. Further, lack of...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章,多中心研究
doi:10.1016/j.jclinepi.2007.03.010
更新日期:2007-12-01 00:00:00
abstract::Results from pragmatic trials should reflect the comparative treatment effects encountered in patients in real-life clinical practice to guide treatment decisions. Therefore, pragmatic trials should focus on outcomes that are relevant to patients, clinical practice, and treatment choices. This sixth article in the ser...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章
doi:10.1016/j.jclinepi.2016.12.022
更新日期:2017-10-01 00:00:00
abstract:OBJECTIVE:To compare and contrast clinical epidemiology and population health perspectives on the role of health care in reducing socioeconomic disparities in health. STUDY DESIGN AND SETTING:A review of concepts outlined in selected articles on population health and clinical epidemiology and a systematic literature s...
journal_title:Journal of clinical epidemiology
pub_type: 杂志文章,评审
doi:10.1016/j.jclinepi.2004.10.020
更新日期:2005-08-01 00:00:00