Journal of clinical epidemiology
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To propose and test a simple instrument based on seven criteria of study design to distinguish effectiveness (pragmatic) from efficacy (explanatory) trials. ⋯ When applied in a standardized manner, our proposed criteria can provide a valid and simple tool to distinguish effectiveness from efficacy studies. The applicability of systematic reviews can improve when analysts place more emphasis on the generalizability of included studies. In addition, clinicians can also use our criteria to determine the external validity of individual studies, given an appropriate population of interest.
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To illustrate the effects of different methods for handling missing data--complete case analysis, missing-indicator method, single imputation of unconditional and conditional mean, and multiple imputation (MI)--in the context of multivariable diagnostic research aiming to identify potential predictors (test results) that independently contribute to the prediction of disease presence or absence. ⋯ In multivariable diagnostic research complete case analysis and the use of the missing-indicator method should be avoided, even when data are missing completely at random. MI methods are known to be superior to single imputation methods. For our example study, the single imputation methods performed equally well, but this was most likely because of the low overall number of missing values.
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To assess the effect of publication bias and country effect on the results and conclusion of a systematic review of wrist P6 acupoint stimulation for the prevention of postoperative nausea and vomiting. ⋯ Publication bias affects the published estimate of postoperative nausea, not vomiting.
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To determine empirically chance agreement between different clinicians evaluating physical examination findings in children with acute abdominal pain. ⋯ Expected chance agreement, as calculated from the kappa statistic, is a reasonable reflection of empirically observed chance agreement between clinicians.
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To evaluate the accuracy of Ontario administrative health data for identifying intensive care unit (ICU) patients. ⋯ Administrative databases can be used to identify ICU patients, but no single strategy simultaneously provided high sensitivity, specificity, and PPV. Researchers should consider the study purpose when selecting a strategy for health services research on ICU patients.