The Combination of Depression and Obesity was Associated with Increased Incidence of Subsequent Total Knee Arthroplasty.

Objective: Compare the incidence of total knee arthroplasty (TKA) within the first 5 years after knee 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 four cohorts of individuals with knee OA based on diagnosis codes that were matched by age, sex, and Charlson Comorbidity Index: a group 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 four matched cohorts.

Results: Each cohort was comprised of 274,403 unique individuals (180,563 females, 93,840 males; age=55±7 y). The incidence of TKA was greatest for the Depression+Obesity group (11.9%) when compared to the Control group (8.3%, p<0.0001, RR=1.43 [95%CI:1.41,1.45]), the Obesity group (10.2%, p<0.0001, RR=1.13 [95%CI:1.11,1.14], p<0.0001) or Depression (7.8%, p<0.0001, RR=1.53 [95%CI:1.50,1.55], p<0.0001).

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 individual diagnosis of obesity or depression.