Journal of clinical epidemiology
-
Review Meta Analysis
A systematic review finds that methodological quality is better than its reputation but can be improved in physiotherapy trials in childhood cerebral palsy.
To identify critical issues in performing randomized controlled trials (RCTs) on complex interventions such as physiotherapy in multifaceted disabilities like cerebral palsy (CP); to systematically assess how well trials handled patient characteristics, key components of complex interventions, and outcome assessments; to make suggestions for improving the effectiveness of physiotherapy research. ⋯ We found good to fair methodological quality in a considerable number of RCTs on physiotherapy in CP children. Nevertheless, improvement is indicated for certain areas in design and performance of future studies. This review shows that informative RCTs on complex interventions for multifaceted disabilities are feasible.
-
To evaluate the methodological robustness of patient-reported outcomes (PROs) evaluation in complementary and alternative medicine (CAM) randomized controlled trials (RCTs) in oncology. ⋯ To facilitate the interpretation of results from such CAM RCTs, investigators are encouraged to pay greater attention to key methodological issues as identified in this study.
-
Controlled trials that use randomized allocation are the best tool to control for bias and confounding in trials testing clinical interventions. Investigators must be sure to include information that is required by the reader to judge the validity and implications of the findings in the reports of these trials. In part, complete reporting of trials will allow clinicians to modify their clinical practice to reflect current evidence toward the improvement of clinical outcomes. ⋯ We expect that these recommendations will lead to more complete and accurate reporting of herbal trials. We wrote this explanatory document to outline the rationale for each recommendation and to assist authors in using them by providing the CONSORT items and the associated elaboration, together with examples of good reporting and empirical evidence, where available, for each. These recommendations for the reporting of herbal medicinal products presented here are open to revision as more evidence accumulates and critical comments are collected.
-
Errors in the electronic search strategy of a systematic review may undermine the integrity of the evidence base used in the review. We studied the frequency and types of errors in reviews published by the Cochrane Collaboration. ⋯ When the MEDLINE search strategy used in a systematic review is reported in enough detail to allow assessment, errors are commonly revealed. Additional peer review steps are needed to ensure search quality and freedom from errors.
-
In most situations, simple techniques for handling missing data (such as complete case analysis, overall mean imputation, and the missing-indicator method) produce biased results, whereas imputation techniques yield valid results without complicating the analysis once the imputations are carried out. Imputation techniques are based on the idea that any subject in a study sample can be replaced by a new randomly chosen subject from the same source population. Imputation of missing data on a variable is replacing that missing by a value that is drawn from an estimate of the distribution of this variable. ⋯ But single imputation results in too small estimated standard errors, whereas multiple imputation results in correctly estimated standard errors and confidence intervals. In this article we explain why all this is the case, and use a simple simulation study to demonstrate our explanations. We also explain and illustrate why two frequently used methods to handle missing data, i.e., overall mean imputation and the missing-indicator method, almost always result in biased estimates.