Journal of clinical epidemiology
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To summarize the findings of methodological studies on the RAND/University of California Los Angeles (RAND/UCLA) appropriateness method, which was developed to assess if variation in the use of surgical procedures is because of overuse and/or underuse. ⋯ Our findings support use of the appropriateness method to assess variation in the rates of the procedures studied by identifying overuse and underuse. Further methodological research should be conducted as appropriateness criteria are developed and implemented for a broader range of procedures.
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Simple guidelines for calculating efficient sample sizes in cluster randomized trials with unknown intraclass correlation (ICC) and varying cluster sizes. ⋯ Efficient sample sizes for cluster randomized trials are easily computed, provided the cost per cluster and cost per person are specified.
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This study highlights the serious consequences of ignoring reverse causality bias in studies on compensation-related factors and health outcomes and demonstrates a technique for resolving this problem of observational data. ⋯ To avert biased policy and judicial decisions that might inadvertently disadvantage people with compensable injuries, there is an urgent need for researchers to address reverse causality bias in studies on compensation-related factors and health.
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Multicenter Study Comparative Study
Urgent readmission rates can be used to infer differences in avoidable readmission rates between hospitals.
Most of the urgent readmissions are unavoidable. This study developed a method that used observed urgent readmission rates to compare the latent avoidable readmission rates between the two hospitals. ⋯ Urgent readmission rates can be used to estimate the probability that avoidable readmission rates differ significantly between the two hospitals. The probability that avoidable readmission rates differ significantly between hospitals is small even when significant differences in urgent 30-day readmission rates exist. Our results show that 30-day urgent readmission rates should be used very cautiously to compare hospital quality of care.
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Studies measuring interobserver agreement (reliability) are common in clinical practice, yet discussion of appropriate sample size estimation techniques is minimal as compared with clinical trials. The authors propose a sample size estimation technique to achieve a prespecified lower and upper limit for a confidence interval for the κ coefficient in studies of interobserver agreement. ⋯ This method should be useful in the planning stages of an interobserver agreement study in which the investigator would like to obtain a prespecified level of precision in the estimation of κ. An R software package (R Foundation for Statistical Computing, Vienna, Austria), kappaSize is also provided that implements this method.