Assessing the quality of evidence for preterm labor tocolytic trials.
OBJECTIVE
To assess the quality of tocolysis randomized controlled trials (RCTs) and to determine trial factors contributing to better quality evidence.


METHODS
The Cochrane Central Register of Controlled Trials, MEDLINE, MEDLINE In-Process, EMBASE and CINAHL were searched for terms "preterm labor," "tocolytic" or "obstetric labor, premature" up to 1 August 2009.Data regarding study design, characteristics, number of participants and outcomes reported were extracted by at least two review authors. Study quality was assigned using the Cochrane Collaboration Handbook methodology and categories. Trends for quality over time, the impact of study size and the individual drugs compared were analyzed for impact on overall quality of trials.


RESULTS
Of the 3197 titles initially identified, 89 RCTs of tocolytic therapy were reviewed. Of the six quality areas, 10 (11.2%) trials satisfied all areas, while only one trial (1.1%) met one area. The mean number of adequate areas was 4.1 ± 1.2. Overall, 52 (58.4%) of the trials achieved high-quality categorization. Controlling for multiple trial factors, the trial continent and decade were significant predictors of overall trial quality.


CONCLUSIONS
The majority of tocolysis RCTs are of high quality. Larger trials, more recent trials and placebo-controlled trials were associated with higher quality scores.
Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis, IN, USA. dahaas@iupui.edu
David M
DM
Haas
Page
P
Kirkpatrick
Jennifer J
JJ
McIntosh
Deborah M
DM
Caldwell
D000465:Algorithms; D005260:Female; D006801:Humans; D007752:Obstetric Labor, Premature / Q000188:drug therapy* / Q000453:epidemiology; D011247:Pregnancy; D011785:Quality Assurance, Health Care; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data*; D012107:Research Design; D015145:Tocolysis / Q000379:methods / Q000706:statistics & numerical data*; D015149:Tocolytic Agents / Q000627:therapeutic use*
D015149:Tocolytic Agents