Lynn Whitener

How reviews covered the unfolding scientific story of gabapentin for bipolar disorder

BACKGROUND Despite the lack of randomized controlled trials (RCTs), gabapentin use increased rapidly in the 1990s for mental health conditions. Subsequent RCTs did not demonstrate efficacy for bipolar disorder (BD). We examined the characteristics of review articles to determine their potential role in the growth of gabapentin for BD. METHODS We searched MEDLINE, the International Pharmaceutical Abstracts and LexisNexis for review articles or commentaries examining the role of gabapentin for BD. Electronic searches were supplemented by manual searches of reference lists. Articles were abstracted for the types of evidence cited, source of evidence, the proportion of available RCTs cited and narrative blurbs discussing the role of gabapentin for BD. Review articles were classified as narrative versus systematic and positive, neutral or negative regarding the role of gabapentin in BD. RESULTS We included 27 review articles published between 1998 and 2008, but no commentaries met eligibility criteria. Most did not describe potential conflicts of interest or a funding source, and the 3 systematic reviews were of low quality. The 11 reviews published prior to the first RCT of gabapentin for BD cited uncontrolled trials or case series (n=9), basic science (n=6), chart reviews (n=3) or unpublished RCTs (n=2). Six recommended gabapentin, 3 were neutral and 2 were negative. The 16 articles published after the first gabapentin RCT continued to cite uncontrolled trials and basic science; only 5 cited all the available RCTs. However, more of these reviews (n=10) reached negative conclusions about the role of gabapentin for BD. CONCLUSIONS Narrative and low-quality systematic reviews, principally those published prior to RCTs, may have contributed to the growth of gabapentin use for BD. High-quality systematic reviews are needed to inform clinicians and policymakers about the effectiveness of new treatments.

Strategies in assessing the need for updating evidence‐based guidelines for six clinical topics: an exploration of two search methodologies

BACKGROUND Because of the expense of updating practice guidelines, recent attention has focused on approaches that can reliably assess any updating required. Shekelle et al. (Journal of the American Medical Association 2001, 286, 1461-7) proposed using limited literature searches with expert involvement to reduce resources used in assessing whether a guideline needs updating. OBJECTIVES This study compared Shekelles method and the traditional systematic review method regarding comprehensiveness and effort. METHODS Two research teams translated critical key questions on screening test treatments and outcomes to Medical Subjects Headings (MeSH) and search strategies. They refined Shekelles method over three iterations, seeking greater efficiency. Using both methods independently, teams assessed the need to update six topics from the 1996 Guide to Clinical Preventive Services (US Preventive Services Task Force). Outcomes included completeness of study identification, importance of missed studies and effort involved. RESULTS The revised review approach produced fewer citations than the traditional approach and saved time, identifying fewer eligible studies than the traditional approach. None of the studies missed was rated important by the experts consulted. CONCLUSIONS The revised review approach provides an acceptable method for judging whether a guideline requires updating. Librarians were an integral part of the research process that streamlined the searches.