摘要:

AbstractCriteria are given for the choice of scale prior to estimation of repeatability. Recommendations of Bland and Altman should then be used for expressing repeatability and agreement of methods of measurement on the same scale. Repeatability of measurements on different scales should be compared using the appropriate ratio of variances, or intraclass correlation coefficient. A reference range for diagnosis requires a high ratio of between‐subject variation to total variation. The index of separation between diseased and healthy subjects should be used whenever possible. Changes within patients should be compared with reference change ranges, and not against the diagnostic rang

ISSN:0277-6715    

DOI:10.1002/sim.4780090402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractDespite recommendations to the contrary, medical researchers still routinely use the Yates‐corrected chisquare statistic in analyses of 2 × 2 contingency tables. Research has shown that these ‘corrected’ statistics are overly conservative and that the conventional Pearson chi‐square generally provides adequate control over type I error probabilities. This paper makes a straightforward argument against use of Yates's correction for continuity and Fisher's exact probabil

ISSN:0277-6715    

DOI:10.1002/sim.4780090403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

ISSN:0277-6715    

DOI:10.1002/sim.4780090404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

ISSN:0277-6715    

DOI:10.1002/sim.4780090405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

ISSN:0277-6715    

DOI:10.1002/sim.4780090406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

ISSN:0277-6715    

DOI:10.1002/sim.4780090407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

ISSN:0277-6715    

DOI:10.1002/sim.4780090408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

ISSN:0277-6715    

DOI:10.1002/sim.4780090409

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractMany studies over the last 20 years have used logistic regression to model the relationship between the risk of developing coronary heart disease (CHD) and the levels of risk factors such as high blood pressure, high serum cholesterol, and cigarette smoking. Subsequently, several investigators have proposed the use of some of the published estimated logistic risk functions to predict risk in new populations. Because of great variation in definition of event, duration of follow‐up, population characteristics, definition of risk variables, and selection of other variables in the logistic functions, direct use of such established functions would generally not have validity for the prediction of absolute risk levels. A review of fifteen of these studies indicates on the one hand generally similar results in direction and order of magnitude of effects of the major risk factors, confirming the importance of these risk factors of CHD. On the other hand the reviews indicate sufficient variation to suggest that extrapolation to new populations even to predict relative risk is not justifie

ISSN:0277-6715    

DOI:10.1002/sim.4780090410

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractI assume the survival function of treated cancer patients to be a mixture of two subpopulations, withcequal to the proportion who will die of other causes, and 1 —cthe proportion who will die of their disease. Using census data, I estimate the parameters of the survival distribution of those patients dying of other causes, and then use follow‐up data to determine the maximum likelihood estimates of the proportion constantcand the parameters of the survival function of those dying of their disease. I illustrate the methodology using data from a prospective clinical trial in breast can

ISSN:0277-6715    

DOI:10.1002/sim.4780090411

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY