Quality and retrieval of obstetrical anaesthesia randomized controlled trials

Abstract

Purpose: Randomized controlled trials (RCTs) are suitable for meta-analysis and systematic reviews provided they are of high quality and are easy to retrieve. We determined these attributes of RCTs in obstetrical anaesthesia in a sample of available journals that are indexed in MEDLINE.

Source: Randomized controlled trials published between January 1985 and December 1994 in seven anaesthetic and three obstetric journals were identified by a MEDLINE search, and by handsearch of the same journals. Each RCT was assigned a quality score by a blinded rater using a reliable and validated scaled. The quality of each RCT was described and compared over time and by journal. The comparative yield of MEDLINE and hand-search was evaluated.

Principal findings: Three hundred and forty RCTs were retrieved by MEDLINE and handsearch. Two hundred and twenty seven (65%) were identified by the MEDLINE search and 333 by the handsearch (98%). The median quality score was 3/5. There was no difference in score over time. Anesthesiology had the highest median score, Anaesthesia had the lowest (P < 0.05).

Conclusions: Care must be taken when reviewing obstetrical anaesthesia research. Strategies in addition to a MEDLINE search must be used to identify RCTs since more than one third were missed using MEDLINE alone. Poor quality RCTs are more likely to be biased in favour of a new treatment. Therefore, to increase the validity of reviews sensitivity analyses based on quality should be done.