Journal of clinical epidemiology
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Meta Analysis Comparative Study
Adjustment for compliance behavior in trials of epidural analgesia in labor using instrumental variable meta-analysis.
Intention-to-treat (ITT) analysis of randomized controlled trials (RCTs) may cause bias when compliance is poor. Noncompliance describes failure to comply with allocation in the intervention arm, and contamination describes uptake of the intervention in the control arm. Instrumental variable (IV) analysis can be applied in addition to the primary ITT analysis to estimate the causal effect adjusted for noncompliance and contamination, assuming that noncompliers would have had the same treatment benefit as compliers. We aimed to compare ITT and IV meta-analysis of the association between epidural analgesia in labor and cesarean section. ⋯ ITT meta-analysis underestimates the effect of receiving epidural analgesia in labor on cesarean section compared with IV meta-analysis.
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To identify factors associated with the implementability of clinical practice guidelines (CPGs) and to determine what characteristics improve their uptake. ⋯ Our work represents a comprehensive and interdisciplinary effort toward better understanding, which attributes of guidelines have the potential to improve uptake in clinical practice. We also created codebooks and narratives of key concepts, which can be used to create tools for developing better guidelines to promote better care.
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Comparative Study
Comparison of noninferiority margins reported in protocols and publications showed incomplete and inconsistent reporting.
To compare noninferiority margins defined in study protocols and trial registry records with margins reported in subsequent publications. ⋯ The reporting of noninferiority margins was incomplete and inconsistent with study protocols in a substantial proportion of published trials, and margins were rarely reported in trial registries.
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We sought to determine whether producers or users of systematic reviews using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach or a close variation give the same meanings to terms intended to convey uncertainty about treatment effects when interpreting grades for the quality or strength of evidence. ⋯ GRADE is, in general, a suitable method to convey uncertainties for systematic review producers to users. The wide ranges of likelihoods associated with GRADE terms suggest that current definitions of levels of QOE that rely exclusively on qualitative certainty expressions should be augmented by numerical predictions once such data are available.
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Multi-item questionnaires are frequently used to measure outcomes in randomized controlled trials (RCTs) in patients with sciatica. Knowing the minimaly important change (MIC) values for these instruments will facilitate interpretation of change scores. MIC values have been shown to be dependent on baseline values. The question is whether they also depend on the type of intervention. To estimate the MIC of the Roland Morris Disability Questionnaire (modified 23 item version) (RMDQ) and of intensity of leg pain measured by a Visual Analogue Scale (VAS) in patients with sciatica and to assess to what extent MIC values depend on type of intervention and on baseline values. ⋯ The MIC values of the RMDQ-23 and VAS leg pain were found to be highly dependent on their baseline values, although the type of intervention appeared to influence the MIC value only slightly.