Dataset Information

The use and abuse of multiple outcomes in randomized controlled depression trials.

ABSTRACT:

Objective

Multiple outcomes are commonly analyzed in randomized trials. Interpretation of the results of trials with many outcomes is not always straightforward. We characterize the prevalence and factors associated with multiple outcomes in reports of clinical trials of depression, methods used to account for these outcomes, and concordance between published analyses and original protocol specifications.

Methods

A PubMed search for randomized controlled depression trials that included multiple outcomes published between January 2007 and October 2008 in 6 medical journals. Original study protocols were reviewed where available. Parallel data collection by 2 abstractors was used to determine trial registration information, the number of outcomes, and analytical method.

Results

Of the 55 included trials, nearly half of the papers reported more than 1 primary outcome, while almost all (90.9%, n = 50) reported more than 2 combined primary or secondary outcomes. Relatively few of the studies (5.8%, n = 3) adjusted for multiple outcomes. While most studies had published protocols in clinical trial registries (76.4%, n = 42), many did not specify outcomes in the protocol (n = 11) and a number had discrepancies with the published report.

Conclusions

Multiple outcomes are prevalent in randomized controlled depression trials and appropriate statistical analyses to account for these methods are rarely used. Not all studies filed protocols, and there were discrepancies between these protocols and published reports. These issues complicate interpretability of trial results, and in some cases may lead to spurious conclusions. Promulgation of guidelines to improve analysis and reporting of multiple outcomes is warranted.

SUBMITTER: Tyler KM

PROVIDER: S-EPMC3071542 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The use and abuse of multiple outcomes in randomized controlled depression trials.

Tyler Kristin M KM Normand Sharon-Lise T SL Horton Nicholas J NJ

Contemporary clinical trials 20101223 2

<h4>Objective</h4>Multiple outcomes are commonly analyzed in randomized trials. Interpretation of the results of trials with many outcomes is not always straightforward. We characterize the prevalence and factors associated with multiple outcomes in reports of clinical trials of depression, methods used to account for these outcomes, and concordance between published analyses and original protocol specifications.<h4>Methods</h4>A PubMed search for randomized controlled depression trials that inc ...[more]

PMID: 21185405

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Project description:BackgroundMultiple primary outcomes are commonly used in randomized controlled trials (RCTs) of Chinese herbal medicine (CHM). Analysis and interpretation of the results of CHM RCTs with many outcomes are not clear. No previous studies have systematically assessed the use of multiple primary outcomes in this area. This study aimed to assess the reporting of multiple primary outcomes and the statistical methods used to adjust multiplicity in RCTs of CHM.MethodsSearch for RCTs of CHM published in English between January 2010 and December 2019 in MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) was undertaken. We randomly selected 20% of the included RCTs as the analyzing sample of this study. The number of multiple primary outcomes, the methods used to adjust the multiplicity in statistical analysis and sample size estimate, and the trial information were collected. For RCTs that adopted multiple primary outcomes without the multiplicity adjustment, we used Bonferroni correction to adjust.Results227 CHM RCTs were included in our study. 92 (40.5%) failed to report what their primary outcome was. Of 135 (59.5%) RCTs that reported primary outcome, 93 (68.9%) reported one and 42 (31.1%) reported more than one primary outcome (range 2-5). Of 42 RCTs that reported multiple primary outcomes, only 5 adjusted for multiple outcomes. If multiplicity had been accounted for using Bonferroni correction, 10 (37.0%) RCTs that reported a significant result had demonstrated a nonsignificant result, giving the adjusted P value. Only one of the 42 RCTs calculated sample size based on multiple primary outcomes. Adopting multiple primary outcomes showed a slow growth trend with the publication year. The proportion of primary outcome reported explicitly in RCTs was different in terms of the nationality of the first author (P=0.004), in which mainland China has the lowest proportion (55.8%). The highest percentage of the studies with primary outcome reporting explicitation was mental and behavioural disorders (83.3%), and the most frequently adopting multiple primary outcomes were studies on the disease of the nervous system (66.7%). The percentage of reporting primary outcome explicitly was associated with sample size (P < 0.001); for the percentage of RCTs adopting multiple primary outcomes, there was no statistically significant difference (P=0.739).ConclusionsMultiple primary outcomes are prevalent in CHM RCTs. However, appropriate methods are not usually taken in most of the analyses to safeguard the inferences against multiplicity. Sample size estimation based on multiple primary outcomes is still lacking. These issues complicate the interpretability of trial results and can lead to spurious conclusions. Guidelines to improve analyzing and reporting for multiple primary outcomes in CHM RCTs are warranted.

Dataset Information

The use and abuse of multiple outcomes in randomized controlled depression trials.

Objective

Methods

Results

Conclusions

Publications

The use and abuse of multiple outcomes in randomized controlled depression trials.

Similar Datasets

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