A systematic review of randomized controlled trials and reviews in the management of ventral hernias.

Background: The literature supporting ventral hernia management is growing; however, it is unclear whether the quality of work is improving. We hypothesize that the quality of clinical ventral hernia research has improved over the past 2.5 decades.

Methods: A review of MEDLINE, Scopus, and Cochrane databases was conducted for all ventral hernia studies from January 1, 1980 to May 1, 2015. Relevant abstracts were assigned a level according to the Oxford Center for Evidence-Based Medicine. Reviews, and meta-analyses were graded using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Checklist and randomized controlled trials (RCTs) using the Consolidated Standards of Reporting Trials (CONSORT) checklist. Studies that did not fulfill at least 70% of the elements for the PRISMA (19/27) or CONSORT (26/37) checklists were considered to contain substantial methodological flaws.

Results: Of 12,431 citations, 1336 met criteria for quality evaluation. Level 1 studies were sparse (n = 104, 7.8%), and most were level 2 or 3 (n = 463, 34.7%) or 4 (n = 769, 57.6%). Of the level 1 studies, 37 (35.6%) were RCTs, 61(58.7%) were reviews and/or meta-analyses, and 6 (5.8%) were consensus statements. Most RCTs and reviews and/or meta-analyses contained substantial methodological flaws (75.7%, 75.8%). Critical areas of weakness in RCTs were explaining losses and exclusions after randomization and/or allocation and reporting determination of sample size. For reviews and/or meta-analyses, areas of weakness were presenting an electronic search strategy and providing an assessment of risk of bias before pooling data. Linear regressions of PRISMA and CONSORT scores demonstrated improvement over time (PRISMA slope 0.95, R(2) = 0.24; CONSORT slope 0.34, R(2) = 0.08).

Conclusions: Although the quality of literature guiding ventral hernia management has improved over time, there is room for improvement.