Methods for the Analysis of Pretest-Posttest Binary Outcomes from Cluster Randomization Trials

In this thesis we investigate methods for assessing the intervention effect in completely randomized, cluster randomization trials where participants are measured prior to random assignment and again after completion of the intervention, i.e. a pretest-posttest design. Attention is further limited to binary outcomes. We compare the performance of six test statistics used to test the intervention effect. Test statistics are obtained from cluster-specific and population-averaged extensions of logistic regression. A simulation study is used to estimate type I error and power for the test statistics. In addition, we examine the effect on power of correctly assuming a common pretest-posttest association. Cluster-specific models yielded satisfactory 5% type I error rates while a longitudinal approach yielded the lowest power. Assumptions about the pretest-posttest association had little effect on power. Data from a school-based randomized trial are used to illustrate results

Effects of dance on cognitive function among older adults: a protocol for systematic review and meta-analysis

Abstract Background Cognitive impairment is characterized by problems in thinking, memory, language, and judgment that are greater than cognitive changes in normal aging. Considering the unprecedented growth of the older adult population and the projected increase in the prevalence of cognitive impairment, it is imperative to find effective strategies to improve or maintain cognitive function in older adults. The objective of this review is to summarize the effects of dance versus any other control group on cognitive function, physical function, adverse events, and quality of life in older adults. Method We will search the following databases MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) to identify the randomized controlled trials (RCTs) evaluating the effects of dance on cognitive function among older adults. Also, we will search http://apps.who.int/trialsearch, clinicaltrials.gov and conference abstracts to identify ongoing and unpublished studies. There will be no restrictions on language, date, or journal of publication. Reviewers will independently and in duplicate screen for eligible studies using pre-defined criteria. Data extraction from eligible studies will be performed independently and in duplicate. The Cochrane risk of bias tool will be used to assess the risk of bias of studies. Our primary outcome of interest is cognitive function, more specifically the executive function domain. We will include other domains as well such as processing speed and reaction time. Secondary outcomes of interest are physical function. The secondary outcomes also include adverse events including falls and quality of life. We will use Review Manager (RevMan 5.3) to pool the effect of dance for each outcome where possible. Results will be presented as relative risks along with 95% confidence intervals for dichotomous outcomes and as mean differences, or standardized mean differences along with 95% confidence intervals, for continuous outcomes. We will assess the certainty of the evidence using the GRADE approach and present findings in a Summary of Findings table. Discussion This systematic review, to our best knowledge the first-ever, will synthesize the available evidence on the effects of dance on cognitive function among older people. Systematic review registration PROSPERO CRD4201705713

Additional file 1: of Effects of dance on cognitive function among older adults: a protocol for systematic review and meta-analysis

PRISMA-P 2015 Checklist. This file contains Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) 2015 checklist. (DOCX 30 kb

Additional file 2: of Effects of dance on cognitive function among older adults: a protocol for systematic review and meta-analysis

Proposed search strategy (or strategies) and terms. This file contains proposed search strategy for MEDLINE in OVID interface. (DOCX 12 kb