The Combination of Depression and Obesity Is Associated With Increased Incidence of Subsequent Total Knee Arthroplasty

Objective. To compare the incidence of total knee arthroplasty (TKA) within the first 5 years after knee osteoarthritis (OA) diagnoses between matched groups of individuals with or without comorbid diagnoses of obesity and/or depression. We hypothesized that the greatest incidence of TKA within 5 years of OA diagnosis would be in the cohort of individuals with combined obesity and depression. Methods. The PearlDiver Mariner Ortho157 database was used to identify 4 cohorts of individuals with knee OA based on diagnosis codes that were matched by age, sex, and the Charlson Comorbidity Index: those without diagnoses associated with depression or obesity (Control), those with obesity but not depression (Obesity), those with depression but not obesity (Depression), and those with diagnoses of both obesity and depression (Depression + Obesity). The incidence of subsequent TKA within the first 5 years after the index OA diagnosis were compared between the 4 matched cohorts. Results. Each cohort comprised 274,403 unique individuals (180,563 females, 93,840 males; mean age = 55 [SD 7] years). The incidence of TKA was greatest for the Depression + Obesity group (11.9%) when compared to the Control group (8.3%, P < 0.001; risk ratios [RR] 1.43, 95% CI 1.41-1.45, P < 0.001), Obesity group (10.2%, P < 0.001; RR 1.13, 95% CI 1.11-1.14, P < 0.001), or Depression group (7.8%, P < 0.001; RR 1.53, 95% CI 1.50-1.55, P < 0.001). Conclusion. The incidence of subsequent TKA was greatest for those with the combination of obesity and depression when compared to the control group and those with an individual diagnosis of obesity or depression.