Validation study of a pooled electronic healthcare database: the effect of obesity on the revision rate of total knee arthroplasty.

The objective of this study was to validate the use of a software platform (Explorys, Inc., Cleveland, OH) by determining whether the association observed between obesity and revision of total knee arthroplasty (TKA) was obtained within this database. Risk of revision in cohorts with a BMI > 30, as well as cohorts with a BMI between 30-35, 35-40 and >40 was compared to patients with a BMI between 18 and 30 (relative risk, RR). Risk in men versus women was examined. From this database, 70,070 patients were identified that had undergone a TKA. Risk of revision increased as a function of BMI; RR achieved significance in the following cohorts: all patients with a BMI > 30, all patients with a BMI > 40, men with a BMI > 30 and men with a BMI > 40. All other subgroups showed increased RR but did not reach significance. In obese patients, RR was greater in men than in women, and the effect was significant in all groups examined except patients with a BMI between 35 and 40. Data from this study contribute to the process of demonstrating the Explorys software platform is a valid and useful method to investigate associations across large populations.