Differences in reported outcomes in industry-funded vs nonfunded studies assessing thromboprophylaxis after total joint arthroplasty

Abstract

Background: There are numerous studies discussing thromboprophylaxis after total joint arthroplasty (TJA), with varying conclusions. Patient inclusion criteria may be different for each study, which may lead to selection bias and misrepresentation of data. This study aimed to investigate if industry funding impacted patient demographics and overall reported outcomes of studies analyzing venous thromboembolism (VTE) prevention after TJA. Methods: Electronic searches were completed using Ovid, PubMed, and Embase databases. Studies were included if (1) they are published in the English language between 2000 and 2016; (2) they included patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA); and (3) they evaluated prevention and control of postoperative VTE with at least one of the following thromboprophylactic agents: aspirin, enoxaparin, dalteparin, dabigatran, apixaban, rivaroxaban, dabigatran, ximelagatran, fondaparinux, or coumadin. Data were extracted and analyzed via mixed-effect logistic regression. Results: Fifty-seven studies were included; 29 were industry funded, and 28, nonfunded. There were no significant differences between patient's age, body mass index, or revision exclusions between funded and nonfunded studies. Funded studies reported less pulmonary embolisms, fewer events of major bleeding, and significantly less 90-day mortality compared with nonfunded studies. Conclusion: Industry-funded studies reported less pulmonary embolisms, major bleeding, and mortality compared with nonfunded studies. Detailed demographic data were missing from the literature, and we were unable to demonstrate the cause of different reported outcomes between industry-funded and nonfunded studies. Further investigations should be aimed toward understanding how funded studies report less adverse outcomes in analyzing VTE after TJA.