Risk factors for early revision after primary total hip arthroplasty in Medicare patients.

BACKGROUND: Patient, surgeon, health system, and device factors are all known to influence outcomes in THA. However, patient-related factors associated with an increased risk of early failure are poorly understood, particularly in elderly patients. QUESTIONS/PURPOSES: We identified specific demographic and clinical characteristics associated with increased risk of early revision in Medicare patients with THA.
METHODS: The Medicare 5% national sample administrative database was used to calculate the relative risk of revision within 12 months following primary THA as a function of baseline medical comorbidities in 56,030 Medicare patients who underwent primary THA between 1998 and 2010. The impact of 29 comorbid conditions on risk of early revision was examined using Cox regression, controlling for age, sex, race, US Census region, socioeconomic status, and all other baseline comorbidities.
RESULTS: Depression, rheumatologic disease, psychoses, renal disease, chronic urinary tract infection, and congestive heart failure were associated with revision THA within 12 months of the index arthroplasty (p ≤ 0.038 for all comparisons; risk factors listed in order of significance).
CONCLUSIONS: This information is important when counseling elderly patients with THA regarding the risk of early failure and for risk stratifying publicly reported outcomes in Medicare patients with THA.