부산대학교 도서관

Although medical devices (MDs) and surgery have been part of medicine since its start, the methods for their study in epidemiology have not kept pace with the developments in pharmacoepidemiology. The recent increased attention from society to the potential harms of unsafe implants has led to improved legislation that call for a much closer evaluation of MDs. However, the evaluation of MDs and surgery presents unique caveats and challenges, such as the ascertainment of the indication of the surgery or how to include surgeon characteristics in the analysis, that can greatly influence outcomes. To advance research on how one can overcome these challenges, I tested several methods. I used Propensity Score (PS) methods, namely PS matching, stratifications and inverse probability weighting (IPW); and Instrumental Variables (IVs), based on surgeon and hospital preference in the study of the effectiveness and safety of partial vs total knee replacement and evaluated them by comparing observational results to those from a randomised controlled trial. I applied the target trial framework to the study of the timing of tracheostomy in patients with COVID-19. I further studied the safety of knee replacements using the self-controlled case series method. I studied the potential heterogeneity by subgroups (on high-risk patients, by gender, by age, and by deprivation) on the safety and effectiveness of knee replacements. I explored the effect of surgical volume on knee replacement outcomes. I finally used simulation studies to examine the flaws and challenges of preference-based IV. I found that PS stratification and IPW may be able to minimise confounding and bias in the study of partial vs total knee replacement, provided that the study is carefully designed to consider both patient and surgeon characteristics. I also showed how preference-based IVs may not be fit for purpose for this use case. Future research is needed to examine whether my findings are generalisable to other settings and whether other IVs can be used safely in MD and surgical research.