Monika Mierzwinski-Urban

THE EFFECT OF ENGLISH-LANGUAGE RESTRICTION ON SYSTEMATIC REVIEW-BASED META-ANALYSES: A SYSTEMATIC REVIEW OF EMPIRICAL STUDIES

OBJECTIVES The English language is generally perceived to be the universal language of science. However, the exclusive reliance on English-language studies may not represent all of the evidence. Excluding languages other than English (LOE) may introduce a language bias and lead to erroneous conclusions. STUDY DESIGN AND SETTING We conducted a comprehensive literature search using bibliographic databases and grey literature sources. Studies were eligible for inclusion if they measured the effect of excluding randomized controlled trials (RCTs) reported in LOE from systematic review-based meta-analyses (SR/MA) for one or more outcomes. RESULTS None of the included studies found major differences between summary treatment effects in English-language restricted meta-analyses and LOE-inclusive meta-analyses. Findings differed about the methodological and reporting quality of trials reported in LOE. The precision of pooled estimates improved with the inclusion of LOE trials. CONCLUSIONS Overall, we found no evidence of a systematic bias from the use of language restrictions in systematic review-based meta-analyses in conventional medicine. Further research is needed to determine the impact of language restriction on systematic reviews in particular fields of medicine.

Preoperative Skin Antiseptic Preparations for Preventing Surgical Site Infections: A Systematic Review

OBJECTIVE To evaluate the clinical effectiveness of preoperative skin antiseptic preparations and application techniques for the prevention of surgical site infections (SSIs). DESIGN Systematic review of the literature using Medline, EMBASE, and other databases, for the period January 2001 to June 2011. METHODS Comparative studies (including randomized and nonrandomized trials) of preoperative skin antisepsis preparations and application techniques were included. Two researchers reviewed each study and extracted data using standardized tables developed before the study. Studies were reviewed for their methodological quality and clinical findings. RESULTS Twenty studies (n = 9,520 patients) were included in the review. The results indicated that presurgical antiseptic showering is effective for reducing skin flora and may reduce SSI rates. Given the heterogeneity of the studies and the results, conclusions about which antiseptic is more effective at reducing SSIs cannot be drawn. CONCLUSIONS The evidence suggests that preoperative antiseptic showers reduce bacterial colonization and may be effective at preventing SSIs. The antiseptic application method is inconsequential, and data are lacking to suggest which antiseptic solution is the most effective. Disinfectant products are often mixed with alcohol or water, which makes it difficult to form overall conclusions regarding an active ingredient. Large, well-conducted randomized controlled trials with consistent protocols comparing agents in the same bases are needed to provide unequivocal evidence on the effectiveness of one antiseptic preparation over another for the prevention of SSIs.

A pragmatic critical appraisal instrument for search filters: introducing the CADTH CAI

OBJECTIVE To identify or develop a critical appraisal instrument (CAI) to aid in the selection of search filters for use in systematic review searching. The CAI is to be used by experienced searchers without specialized training in statistics or search filter design. METHODS Through extensive searching and consultation, one candidate instrument was identified. Through expert consultation and several rounds of testing, the instrument was extensively revised to become the Canadian Agency for Drugs and Technologies in Health (CADTH) CAI. RESULTS The CADTH CAI consists of ten questions and can be applied by experienced searchers with a moderate knowledge of search filter methodology. CONCLUSION The CADTH CAI provides experienced searchers with a means of selecting the search filter that is most methodologically sound.