A comprehensive appraisal of meta-analyses focusing on nonsurgical treatments aimed at decreasing perioperative mortality or major cardiac complications

Abstract

Purpose: Millions of patients worldwide who undergo surgical procedures face significant morbidity and mortality risks. Several systematic reviews have been performed on ancillary treatments aimed at improving surgical outcomes, but their features and scholarly impact are unclear. We describe characteristics of meta-analyses on ancillary treatments aimed at improving surgical outcomes and explore factors associated with scholarly citations.

Methods: Systematic reviews published up to 2008 were searched without language restrictions in MEDLINE/PubMed. Reviews focusing on nonsurgical treatments aimed at decreasing mortality or major cardiac complications were included. Associations between content, quality, and bibliometric details and scholarly citations in several indexes were systematically appraised.

Results: From 2,239 citations, 84 systematic reviews were identified. Patients most commonly underwent cardiovascular surgery (40.2%), and were tested for cardiovascular drugs (25.8%), with placebo acting as control (38.1%). Internal validity appeared largely robust, as most (50.5%) reviews were at low risk of bias. Normalized yearly citations for the included reviews ranged between 5.6 in Google Scholar and 4.3 in Web of Science. Multivariable analysis showed that citations were significantly and positively associated with number of authors, North American corresponding author, number of studies included, number of patients included, noncardiothoracic surgical scope, explicit funding, and lack of competing interests (all p < 0.05).

Conclusions: Systematic reviews currently represent a key element in defining state of the art ancillary treatments of patients undergoing surgery. However, the citation success of available meta-analyses is not significantly associated with prognostically relevant findings or quality features.