Systematic Reviews and Meta-Analysis in Spine Surgery—How Good Are They in Methodological Quality? A Systematic Review

Abstract
Study Design: Systematic review.
Objectives: To assess the methodological quality of systematic reviews and meta-analyses in spine surgery over the past 2 decades. Materials and Methods: We conducted independent and in duplicate systematic review of the published systematic reviews and meta-analyses between 2000 and 2019 from PubMed Central and Cochrane Database pertaining to spine surgery involving surgical intervention. We searched bibliographies to identify additional relevant studies. Methodological quality was evaluated
with AMSTAR score and graded with AMSTAR 2 criteria.
Results: A total of 96 reviews met the eligibility criteria, with mean AMSTAR score of 7.51 (SD ¼ 1.98). Based on AMSTAR 2
criteria, 13.5% (n ¼ 13) and 18.7% (n ¼ 18) of the studies had high and moderate level of confidence of results, respectively, without any critical flaws. A total of 29.1% (n ¼ 28) of the studies had at least 1 critical flaw and 38.5% (n ¼ 37) of the studies had more than 1 critical flaw, so that their results have low and critically low confidence, respectively. Failure to analyze the conflict of interest of authors of primary studies included in review and lack of list of excluded studies with justification were the most common critical flaw. Regression analysis demonstrated that studies with funding and studies published in recent years were significantly associated with higher methodological quality. Conclusion: Despite improvement in methodological quality of systematic reviews and meta-analyses in spine surgery in current decade, a substantial proportion continue to show critical flaws. With increasing number of review articles in spine surgery,
stringent measures must be taken to adhere to methodological quality by following PRISMA and AMSTAR guidelines to attain higher standards of evidence in published literature.