Preoperative Patient Functional Status Is an Independent Predictor of Outcomes After Primary Total Hip Arthroplasty.

This study was designed to determine whether preoperative functional status of patients with osteoarthritis predicts outcomes after primary total hip arthroplasty. The American College of Surgeons National Surgical Quality Improvement Program database was queried for records of patients who underwent primary total hip arthroplasty for a principal diagnosis of osteoarthritis from 2009 to 2013 (N=43,179). Patients were categorized as dependent or independent according to their preoperative functional status. The groups were compared regarding several potential confounders using Student's t and chi-square tests. Logistic and Poisson regression models (inclusion threshold of P<.1) were used to assess the associations of functional status with outcomes. The alpha level was set at 0.05. Compared with independent patients, dependent patients were likely to be older (mean, 70 vs 66 years, P<.01) and to have more preoperative comorbidities. After controlling for potential confounders, preoperative dependent functional status was predictive of major complications (odds ratio, 2.34; 95% confidence interval, 1.67-3.28), nonroutine discharge (odds ratio, 2.80; 95% confidence interval, 2.35-3.34), and longer hospital stay (incidence risk ratio, 1.19; 95% confidence interval, 1.12-1.27). Rates of unplanned reoperation were similar between groups on multivariate analysis. Compared with preoperative independent functional status, preoperative dependent functional status was independently associated with worse outcomes after primary total hip arthroplasty for osteoarthritis. [Orthopedics. 201x; xx(x):xx-xx.].