Abstract：
OBJECTIVES:Calibration is often thought to assess the bias of a clinical prediction rule. In particular, if the rule is based on a linear logistic model, it is often assumed that an overestimation of all coefficients results in a calibration slope less than 1 and an underestimation in a slope larger than 1. STUDY DESIGN AND SETTING:We investigate the relation of the bias and the residual variation of clinical prediction rules with the typical behavior of calibration plots and calibration slopes, using some artificial examples. RESULTS:Calibration is not only sensitive to the bias of the clinical prediction rule but also to the residual variation. In some circumstances, the effects may cancel out, resulting in a misleading perfect calibration. CONCLUSION:Poor calibration is a clear indication of limited usefulness of a clinical prediction rule. However, a perfect calibration should be interpreted with care as this may happen even for a biased prediction rule.
journal_name
J Clin Epidemioljournal_title
Journal of clinical epidemiologyauthors
Vach Wdoi
10.1016/j.jclinepi.2013.06.003subject
Has Abstractpub_date
2013-11-01 00:00:00pages
1296-301issue
11eissn
0895-4356issn
1878-5921pii
S0895-4356(13)00237-0journal_volume
66pub_type
杂志文章abstract：:Occasionally, the efficacy of screening for cancer recurrence has been evaluated by means of case-control studies. However, these studies generally have not been designed and analyzed in a manner that will yield an unbiased result. The commentary shows that by adhering to the principles developed for the analysis of s...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/j.jclinepi.2010.07.013
更新日期：2011-01-01 00:00:00
abstract：:Scotland has one of the highest mortality rates from coronary heart disease for both men and women. However within Scotland there are major geographical differences in the mortality rates, exemplified by the differences between the two largest Scottish cities. Glasgow on the west has a much higher mortality rate for c...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/0895-4356(90)90033-l
更新日期：1990-01-01 00:00:00
abstract：BACKGROUND AND OBJECTIVE:There is a growing evidence base on methods to improve response rates in surveys among patients. This study aimed to determine the additional effect of two intensive follow-up procedures compared to a simple follow-up procedure. METHODS:Randomized controlled trial that compared repeated mailin...
journal_title：Journal of clinical epidemiology
pub_type： 临床试验,杂志文章,随机对照试验
doi：10.1016/j.jclinepi.2005.03.002
更新日期：2005-09-01 00:00:00
abstract：OBJECTIVES:Explicit reporting of absolute measures is important to ensure treatment effects are correctly interpreted. We examined the extent to which authors report absolute effects for patient-important outcomes in abstracts of systematic review (SR). STUDY DESIGN AND SETTING:We searched OVID MEDLINE and Cochrane Da...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,评审
doi：10.1016/j.jclinepi.2016.08.004
更新日期：2017-01-01 00:00:00
abstract：OBJECTIVE:To describe the pain decrease considered as clinically relevant when designing a trial and reporting its results. METHODS:A systematic review of the literature in MEDLINE was conducted to select randomized controlled trials (RCTs) with pain as a primary outcome. Data extracted included the definition (terms ...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,评审
doi：10.1016/j.jclinepi.2010.06.008
更新日期：2011-05-01 00:00:00
abstract：OBJECTIVE:To evaluate a self-report version of the Home Falls and Accidents Screening Tool (HOME FAST-SR). STUDY DESIGN AND SETTING:The HOME FAST-SR was designed using expert review, pretesting and piloting. Agreement of self-reported home hazard ratings and ratings by health professionals was evaluated using the kapp...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/j.jclinepi.2010.02.013
更新日期：2011-02-01 00:00:00
abstract：OBJECTIVES:To investigate whether the relationship between demographic and disease-related variables and disability is constant during the first five years of inflammatory polyarthritis (IP) and to identify the contribution from involvement of specific joint areas to overall disability. METHODS:684 patients referred t...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/s0895-4356(00)00189-x
更新日期：2000-10-01 00:00:00
abstract：:Period prevalence is frequently measured in studies based on administrative data such as that from health maintenance organizations. For example, treated prevalence and drug utilization prevalence are important measures that are typically defined in relationship to a specified time period. Often one wishes to compare ...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,评审
doi：10.1016/0895-4356(95)00573-0
更新日期：1996-04-01 00:00:00
abstract：:Seasonal plasma lipid and lipoprotein cycles were studied in 1446 hypercholesterolemic 35-59 year-old men followed for 7 years as the placebo group of the Lipid Research Clinics (LRC) Coronary Primary Prevention Trial (CPPT). Separate periodic time series were calculated for each study participant; mean parameter esti...
journal_title：Journal of clinical epidemiology
pub_type： 临床试验,杂志文章,随机对照试验
doi：10.1016/0895-4356(88)90120-5
更新日期：1988-01-01 00:00:00
abstract：OBJECTIVE:The Kaplan-Meier method may overestimate absolute mortality risk (AMR) in the presence of competing risks. Urgent heart transplantation (UHT) and ventricular assist device implantation (VADi) are important competing events in heart failure. We sought to quantify the extent of bias of the Kaplan-Meier method i...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/j.jclinepi.2018.07.006
更新日期：2018-11-01 00:00:00
abstract：:Ecological studies may reduce the problem of confounding by indication; however, these studies introduce new biases not present in individual-level analyses. To study the potential for ecological variables to reduce confounding by indication, we used a large database of admissions for ruptured cerebral aneurysms to ev...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,多中心研究
doi：10.1016/s0895-4356(00)00251-1
更新日期：2000-12-01 00:00:00
abstract：OBJECTIVE:To compare methods commonly used to derive minimal important differences and recommend a rule for defining patients as clinically improved on the low back pain-specific Roland-Morris Disability Questionnaire (RMDQ). METHODS:447 primary care low back pain consulters completed a questionnaire at consultation a...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/j.jclinepi.2005.03.018
更新日期：2006-01-01 00:00:00
abstract：OBJECTIVE:To simulate possible changes in systematic review results if rapid review methods were used. STUDY DESIGN AND SETTING:We recalculated meta-analyses for binary primary outcomes in Cochrane systematic reviews, simulating rapid review methods. We simulated searching only PubMed, excluding older articles (5, 7, ...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,meta分析
doi：10.1016/j.jclinepi.2018.12.015
更新日期：2019-05-01 00:00:00
abstract：:Recently, there has been a great deal of discussion regarding the use of administrative databases to study outcomes of medical care. A major issue in this discussion is how to classify patients in terms of characteristics such as disease-severity, comorbidities, resource needs, stability, etc. Different indices have b...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/0895-4356(94)00202-2
更新日期：1995-07-01 00:00:00
abstract：:A 110-item food frequency questionnaire was tested among 152 community controls of the Kuopio Breast Cancer Study. They completed the questionnaire twice and kept two 7-day diet records at 3-month intervals. The intraclass correlations for nutrients varied from 0.49 (thiamine with supplements) to 0.81 (lactose), and f...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/0895-4356(95)00551-x
更新日期：1996-04-01 00:00:00
abstract：:This study assesses psychometric properties of the Modified Mini-Mental State Exam (3MS) and present population norms and demographic risk factors for low 3MS scores. The subjects were 885 persons aged 65 and older who took the 3MS as part of the Stirling County Study, a population-based longitudinal study of adult re...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/s0895-4356(03)00111-2
更新日期：2003-07-01 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：BACKGROUND AND OBJECTIVE:Response bias may affect the result of surveys with <100% response rate. We applied methods commonly used in meta-analysis to ascertain the extent to which response bias affects multiwave survey results. METHODS:To test hypotheses of between-wave similarity, we used the Cochran-Armitage test f...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/j.jclinepi.2004.11.027
更新日期：2005-08-01 00:00:00
abstract：OBJECTIVES:Understanding patterns of maternity care requires knowing which women have given birth previously, but this information is typically unavailable in administrative hospital data sets. We assessed how well parity can be derived using linked historical records. STUDY DESIGN AND SETTING:Using Hospital Episode S...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/j.jclinepi.2013.10.011
更新日期：2014-05-01 00:00:00
abstract：:We have previously shown that patients with a positive family history of lung cancer did not exhibit characteristics expected if the familial association was a surrogate for a genetic mechanism which was absent in those without such a history. In this study, we examine the incidence of cancer (all sites) in two groups...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/0895-4356(91)90202-k
更新日期：1991-01-01 00:00:00
abstract：OBJECTIVE:To examine the relationships between study quality, author prestige, journal impact factors, and citation rates of trials and to examine whether journal impact factors mediated the relationships between study quality and author prestige on citation rates. STUDY DESIGN AND SETTING:We used bibliometric data fr...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/j.jclinepi.2016.01.028
更新日期：2016-07-01 00:00:00
abstract：OBJECTIVES:To determine what criteria researchers use to assess whether the estimates of effect of an intervention on a dichotomous outcome are different when obtained using different study designs. STUDY DESIGN AND SETTING:Scoping review of the literature. We included studies of dichotomous outcomes in which authors ...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,评审
doi：10.1016/j.jclinepi.2016.02.001
更新日期：2016-07-01 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：:Meta-analysis seems to have a potentially useful role in carefully selected situations where the primary literature is of good quality, heterogeneity in the response to treatment of the tested population is small and well-understood, interest centers on estimation of a specific, critical parameter of outcome, and the ...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,评审
doi：10.1016/0895-4356(94)00149-k
更新日期：1995-01-01 00:00:00
abstract：OBJECTIVE:Cases and controls should be chosen from the same base population to reduce selection bias in case-control studies. For hospital cases, we examined how inferences drawn from a case-control study can differ by choice of hospital- vs. community-based controls. STUDY DESIGN AND SETTINGS:We used data from a case...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/j.jclinepi.2009.11.006
更新日期：2010-08-01 00:00:00
abstract：OBJECTIVES:The relative contributions of genetic and environmental variables to within-household clustering of quantitative traits in household surveys are poorly characterized. We estimated shared genetic and shared environmental contributions to within-household correlation for anthropometric variables and cardiovasc...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章
doi：10.1016/j.jclinepi.2006.02.015
更新日期：2006-11-01 00:00:00
abstract：BACKGROUND AND OBJECTIVES:Clinical trials increasingly use results of diagnostic tests as surrogate outcomes. Our objective was to answer the following questions: (1) is the parameter measured by the reference standard a valid surrogate? (2) How does the tests accuracy influence the estimate of the treatment benefit on...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,评审
doi：10.1016/j.jclinepi.2005.02.024
更新日期：2005-10-01 00:00:00
abstract：OBJECTIVES:In multisite human immunodeficiency virus (HIV) observational cohorts, clustering of observations often occurs within sites. Ignoring clustering may lead to "Simpson's paradox" (SP) where the trend observed in the aggregated data is reversed when the groups are separated. This study aimed to investigate the ...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,多中心研究
doi：10.1016/j.jclinepi.2016.01.030
更新日期：2016-08-01 00:00:00
abstract：OBJECTIVES:To assess whether the reported trial characteristics are associated with treatment effects on all-cause mortality within critical care medicine. STUDY DESIGN AND SETTING:We identified all eligible randomized controlled trials (RCTs) from Cochrane Reviews on patients with sepsis, septic shock, and cardiogeni...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,评审
doi：10.1016/j.jclinepi.2013.05.016
更新日期：2013-11-01 00:00:00
abstract：OBJECTIVES:The decision to make protocols of phase III randomized controlled trials (RCTs) publicly accessible by leading journals was a landmark event in clinical trial reporting. Here, we compared primary outcomes defined in protocols with those in publications describing the trials and in trial registration. STUDY ...
journal_title：Journal of clinical epidemiology
pub_type： 杂志文章,评审
doi：10.1016/j.jclinepi.2017.07.010
更新日期：2017-11-01 00:00:00
