Quality and retrieval of obstetrical anaesthesia randomized controlled trials

Abstract

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.

A systematic review of trends in the methodological quality of randomized controlled trials in various research fields

“…In Table 1 we present the available data from the studies that compared the methodological quality of RCTs in various research fields [3e37; Table is available on the journal's website at www.jclinepi.com]. The included studies reported on the methodological changes that were performed during the years in the RCTs of various biomedical fields, including rheumatology [10, 14,15,33,36], gastroenterologyehepatology [12, 23,24], orthopedics [6,9,17], anesthesiology [19,20,27], surgery [13,32], public health/ health services [29,30], intensive care [16,18] [26], psychiatry [25], radiology [35], complementary medicine [22], and general practice [31]. One study [34] examined meta-analyses conducted on the fields of gastroenterology, cardiology, obstetrics, and smoking cessation.…”

“…The items included in these scales and the relative importance assigned to each of them varied considerably. In seven studies [9, 14,18,22,23,25,27] 13,15,16,18,22,32,33]), and intention-to-treat analysis (assessed in 11 studies [3,4,6e10,14,15,18,24]). Trial design, statistical analysis, report of adverse events, baseline comparability between groups, outcome specification, eligibility criteria were evaluated in a fewer number of studies.…”

“…It is interesting that three [23,25,27] out of nine studies not showing statistically significant changes in the overall quality score assessed the overall methodological quality of RCTs using the Jadad scale, which is a quality scale incorporating items referring to blinding, randomization, and handling of losses to follow-up. As other important quality indicators were not included in the quality score calculated in these studies, possible methodological improvements of RCTs might have been missed.…”

Reviews assessing the quality or the reporting of randomized controlled trials are increasing over time but raised questions about how quality is assessed

“…For the PubMed search, there was no MeSH term corresponding to articles assessing the quality of RCTs; thus all articles published in English between January 1, 1987 and March 7, 2007 were searched using 55 terms around the idea of quality in the title. No limits were used because some articles in PubMed may be misclassified [6,7]. For the Cochrane search, we searched the Cochrane Methodology Register, part of the Cochrane Library, (issue 1, 2007) using the following indexing terms: ''relationship to trial quality,'' ''scales and checklists,'' ''checklists and guidelines,'' ''critical appraisal,'' ''bias in trials.''…”

Anaesthesia and evidence‐based medicine

“…Different units in a myriad of studies use all sorts of different analgesic regimens; policies for infusing oxytocics vary; obstetrician and midwife bias is inevitable [87]. Perhaps for these reasons, and because there are many trials of poor quality [88], studies asking apparently the same question find different or conflicting answers. McGrady concluded that the effect of 'extradurals on outcome of labour is overshadowed by that of obstetric practice', a statement that can be generalised to much of anaesthesia.…”