Abstract：
OBJECTIVE:Optimism bias refers to unwarranted belief in the efficacy of new therapies. We assessed the impact of optimism bias on a proportion of trials that did not answer their research question successfully and explored whether poor accrual or optimism bias is responsible for inconclusive results. STUDY DESIGN:Systematic review. SETTING:Retrospective analysis of a consecutive-series phase III randomized controlled trials (RCTs) performed under the aegis of National Cancer Institute Cooperative groups. RESULTS:Three hundred fifty-nine trials (374 comparisons) enrolling 150,232 patients were analyzed. Seventy percent (262 of 374) of the trials generated conclusive results according to the statistical criteria. Investigators made definitive statements related to the treatment preference in 73% (273 of 374) of studies. Investigators' judgments and statistical inferences were concordant in 75% (279 of 374) of trials. Investigators consistently overestimated their expected treatment effects but to a significantly larger extent for inconclusive trials. The median ratio of expected and observed hazard ratio or odds ratio was 1.34 (range: 0.19-15.40) in conclusive trials compared with 1.86 (range: 1.09-12.00) in inconclusive studies (P<0.0001). Only 17% of the trials had treatment effects that matched original researchers' expectations. CONCLUSION:Formal statistical inference is sufficient to answer the research question in 75% of RCTs. The answers to the other 25% depend mostly on subjective judgments, which at times are in conflict with statistical inference. Optimism bias significantly contributes to inconclusive results.
journal_name
J Clin Epidemioljournal_title
Journal of clinical epidemiologyauthors
Djulbegovic B,Kumar A,Magazin A,Schroen AT,Soares H,Hozo I,Clarke M,Sargent D,Schell MJdoi
10.1016/j.jclinepi.2010.09.007subject
Has Abstractpub_date
2011-06-01 00:00:00pages
583-93issue
6eissn
0895-4356issn
1878-5921pii
S0895-4356(10)00317-3journal_volume
64pub_type
杂志文章,评审abstract：OBJECTIVE:Exposure to ultraviolet radiation has consistently been linked to an increased risk of melanoma. Epidemiologic studies are susceptible to measurement error, which can distort the magnitude of observed effects. Although the reliability of self-report of many sun exposure factors has been previously described i...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/j.jclinepi.2004.09.004
更新日期：2005-04-01 00:00:00
abstract：OBJECTIVE:To assess whether nominally statistically significant effects in meta-analyses of clinical trials are true and whether their magnitude is inflated. STUDY DESIGN AND SETTING:Data from the Cochrane Database of Systematic Reviews 2005 (issue 4) and 2010 (issue 1) were used. We considered meta-analyses with bina...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,评审
doi：10.1016/j.jclinepi.2010.12.012
更新日期：2011-10-01 00:00:00
abstract：OBJECTIVE:Many clinicians and decision makers want to know the combined effects of treatments that have not been evaluated in combination. It is possible to determine such treatment effects by making assumptions about the additive effects. We discuss here the prerequisites and methods of applying additivity assumptions...
journal_title：Journal of clinical epidemiology
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abstract：:The objective of our study was to assess the applicability of using estimates of within-person variance (WPV) from reproducibility studies for a correction of blood pressure values in another study to improve the accuracy of the prevalence estimation of hypertension. Data were collected from two cross-sectional popula...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/s0895-4356(00)00228-6
更新日期：2000-11-01 00:00:00
abstract：:The associations between nine domain-specific measures of health (e.g., depressive symptoms, psychological distress, mental health, physical functioning, role functioning, social functioning, bodily pain, somatic symptoms, and chronic medical morbidity) and a single-item measure for perceived overall health were studi...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/s0895-4356(97)00234-5
更新日期：1998-01-01 00:00:00
abstract：:Clinimetrics and psychometrics, two accepted methods for developing multiitem health measurement scales, have fundamentally different aims and methods that have seldom been compared and never prospectively. The purpose of this study was to determine whether these two methodologies provided comparable scales in the dev...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,多中心研究
doi：10.1016/s0895-4356(98)00148-6
更新日期：1999-02-01 00:00:00
abstract：:The effect of gender and other clinical variables on short-term and long-term cardiac mortality after a first transmural myocardial infarction (MI) was assessed in a population-based hospital register. A cohort of 1216 consecutive patients (1023 men and 193 women), 25-74 years old admitted to the only reference hospit...
journal_title：Journal of clinical epidemiology
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doi：10.1016/0895-4356(94)90016-7
更新日期：1994-02-01 00:00:00
abstract：:Mortality in relation to body mass index (BMI) was studied in 17,159 healthy Finnish women aged 25-79 followed up for a median of 12 years. Mortality from all cases was related to BMI only in non-smokers aged 25-64, among whom the mortality pattern was "U"-shaped, with a minimum in the second quintile of BMI (the refe...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/0895-4356(91)90131-r
更新日期：1991-01-01 00:00:00
abstract：:Time to revision is an important criterion describing the quality of implants in total joint surgery. Estimates of failure probabilities are required to inform a patient about the risk of suffering a reoperation. Also, regression models are used for comparing different prosthesis designs. Typically, patients dying bef...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/s0895-4356(01)00371-7
更新日期：2001-10-01 00:00:00
abstract：:This paper describes a multivariate analysis of a 3-year prospective study of the covariates of age at menopause among women who were randomly sampled from a general population. This approach avoids three problems that may account for the inconsistent results of prior studies: recall bias in retrospectively collected ...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/0895-4356(89)90044-9
更新日期：1989-01-01 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：:Individual energy expenditure (kcal/kg/day) was calculated from a detailed set of questions from the Health Promotion and Disease Prevention Supplement of the 1985 National Health Interview Survey. Responses to three single-item, self-assessment questions were compared to the energy expenditure variable to test criter...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
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更新日期：1990-01-01 00:00:00
abstract：OBJECTIVES:A key systematic review (SR) methodology is comprehensive searching. The Drug Effectiveness Review Project (DERP) SRs search US Food and Drug Administration (FDA) documents to identify unpublished evidence. This study evaluates the success of those efforts. STUDY DESIGN AND SETTING:We examined DERP reports ...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,评审
doi：10.1016/j.jclinepi.2013.05.006
更新日期：2013-10-01 00:00:00
abstract：:In a community based, prospective study to determine risk factors for falls, 465 women and 296 men 70 years and over were followed for 1 year and 507 falls were documented. A greater proportion of women (32.7%) than men (23.0%) experienced at least one fall in which there was no or minimal external contribution. Using...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/0895-4356(90)90110-b
更新日期：1990-01-01 00:00:00
abstract：:The aim was to assess relationships between increased aerobic fitness sustained over 4 years, and changes in blood pressure (SBP and DBP) and lipids. Measurements were made of BP, lipids, weight, and fitness in 1000 middle-aged men and women entering a fitness programme, and were repeated 2 and 4 years later. The 342 ...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/0895-4356(93)90052-3
更新日期：1993-02-01 00:00:00
abstract：:The objective of this study was to identify characteristics of nonrespondents and late respondents in a population-based case-control study on lung cancer conducted in the city of Turin (Italy). Information about demographic and socioeconomic variables of 634 cases and 859 controls who responded to an interview, as we...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/s0895-4356(02)00455-9
更新日期：2002-10-01 00:00:00
abstract：:More than one odds ratio estimate will often arise from a single epidemiologic study. Examples of designs where this may occur include those where there is more than one case or control group, and investigations of several risk factors as part of the same study. Various methods for presenting multiple interval estimat...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/0895-4356(89)90132-7
更新日期：1989-01-01 00:00:00
abstract：OBJECTIVE:In lifestyle intervention trials, participants of the control group often change their behavior despite the request to maintain their usual lifestyle pattern. These changes in the control group and changes in addition to the intended in the intervention group can lead to undesirable confounding effects. STUD...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/j.jclinepi.2009.10.007
更新日期：2010-08-01 00:00:00
abstract：:In this paper we propose a method and discuss the type of data required to estimate age incidence rates from population survey data. While surveys are typically designed to estimate the prevalence of a disease or medical condition, they can also be used to estimate incidence rates. A limitation of survey data, however...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
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更新日期：1989-01-01 00:00:00
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journal_title：Journal of clinical epidemiology
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更新日期：2021-01-01 00:00:00
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journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,评审
doi：10.1016/j.jclinepi.2005.09.005
更新日期：2006-04-01 00:00:00
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journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/j.jclinepi.2018.11.023
更新日期：2019-03-01 00:00:00
abstract：:Administrative databases are increasingly used for studying outcomes of medical care. Valid inferences from such data require the ability to account for disease severity and comorbid conditions. We adapted a clinical comorbidity index, designed for use with medical records, for research relying on International Classi...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/0895-4356(92)90133-8
更新日期：1992-06-01 00:00:00
abstract：OBJECTIVE:To estimate the yield from searching a range of bibliographic databases and additional sources to identify test accuracy studies for systematic reviews. STUDY DESIGN AND SETTING:We examined eight systematic reviews and their database searches: MEDLINE, EMBASE, BIOSIS, Science Citation Index, LILACS, Pascal, ...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/j.jclinepi.2007.05.013
更新日期：2008-04-01 00:00:00
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journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/j.jclinepi.2006.08.011
更新日期：2007-05-01 00:00:00
abstract：OBJECTIVES:The massive growth in the publication of meta-analyses may cause redundancy and wasted efforts. We performed a metaepidemiologic study to evaluate the extent of potential redundancy in published meta-analyses in genetic epidemiology. STUDY DESIGN AND SETTING:Using a sample of 38 index meta-analyses of genet...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,评审
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更新日期：2020-11-01 00:00:00
abstract：:Pierre Charles Alexandre Louis (1787-1872) has been the direct or indirect mentor of influential U.S. and English scientists in public health, epidemiology, medicine, and biostatistics during the 19th and 20th century. Louis was primarily a clinician, but his name has been more closely associated with the history of e...
journal_title：Journal of clinical epidemiology
pub_type： 传,历史文章,杂志文章
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更新日期：1996-12-01 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：:Plasma fibrinogen was measured in a sample of 8824 men and women aged 40-59 years participating in the Scottish Heart Health Study, and related to cardiovascular risk factors. Women had higher fibrinogen levels than men. In both sexes, multivariate analysis showed that fibrinogen was positively associated with age, sm...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/0895-4356(90)90075-z
更新日期：1990-01-01 00:00:00
abstract：BACKGROUND:Longitudinal studies estimating the association between disability and mortality in the elderly population have typically assumed disability constant through the follow-up study period. Current knowledge indicates that such assumptions may not be appropriate. Our purpose was to examine this association (disa...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/s0895-4356(03)00201-4
更新日期：2003-12-01 00:00:00
