The Value of Systematic Reviews and Meta-Analyses in Surgery

Abstract

<b><i>Background:</i></b> Systematic reviews and meta-analyses are generally regarded as sitting atop the hierarchy of clinical evidence. The unbiased summary of current evidence that a systematic review provides, along with the increased statistical power from larger numbers of patients, is invaluable in guiding clinical decision-making and development of practice guidelines. Surgical specialties have historically lagged behind other areas of medicine in the application of evidence-based medicine, perhaps due to the unique challenges faced in the conduct of surgical clinical trials. These challenges extend to the conduct of systematic reviews, due to issues with the quality and heterogeneity of the underlying literature. <b><i>Summary:</i></b> Recent years have seen an improvement in the quality of randomized controlled trials in surgical topics and an explosion in the publication of systematic reviews. This review explores recent trends in systematic reviews in surgery and discussed some of the aspects in conducting and interpreting reviews that are unique to surgical topics, including blinding, surgical heterogeneity and learning curves, patient and clinician preference, and industry involvement. <b><i>Key Messages:</i></b> Clinical trials, and therefore systematic reviews, of surgical interventions pose unique challenges which are important to consider when conducting them or applying the findings to clinical practice. Despite the challenges, systematic reviews still represent the best level of evidence for development of surgical practice guidelines.

Reconstruction techniques of the orbit after Brown class III maxillectomy: A systematic review

“…The first lies in the inclusion of case series with low level of evidence 50 . However, in the field of surgery, observational studies can provide valuable information regarding the benefits and risks of certain procedures when double‐blind surgical trials are not possible 51 . Secondly, there was substantial heterogeneity in the methods used regarding the assessment of the functional and aesthetic parameters, almost with subjective clinical methods of measurements.…”

“…50 However, in the field of surgery, observational studies can provide valuable information regarding the benefits and risks of certain procedures when doubleblind surgical trials are not possible. 51 Secondly, there was substantial heterogeneity in the methods used regarding the assessment of the functional and aesthetic parameters, almost with subjective clinical methods of measurements. Finally, the ophthalmological functional and aesthetic parameters were assessed only based on the reconstruction techniques.…”

Glycemic Control in the era of bariatric surgery: A systematic review and meta-analysis of published studies on the Saudi-Arabian population

“…“+” indicates that the study met all quality criteria and had a low risk of bias, “?” means that there were one or more ambiguous quality criteria, and “-” indicates that there were a few quality criteria, and the study had a high risk of bias. [ 13 ]…”

A commentary on “Meta-research studies in surgery: a field that should be encouraged to assess and improve the quality of surgical evidence”

“…Dr Glass (Gene V. Glass) developed this quantitative research synthesis technique in 1975, and it has now become an essential part of the research armamentarium. Nevertheless, conducting systematic reviews and meta-analyses of surgical interventions comes with unique challenges and considerations, which would impact the validity and applicability of the results 2 . For example, studies with heterogeneous populations can result in unexplained heterogeneity in meta-analyses, further raising doubts about the reliability of the reviews.…”