The Effects of Rheumatoid Arthritis on In-Hospital Lengths of Stay, Complications, and Costs following Primary Total Hip Arthroplasty: A Matched-Control Study

Abstract

Studies investigating the relationship of rheumatoid arthritis (RA) in patients undergoing primary total hip arthroplasty (THA) are limited. Therefore, the purpose of this study was to analyze whether RA patients undergoing primary THA have higher rates of: (1) in-hospital lengths of stay (LOS), (2) medical complications, (3) implant-related complications, and (4) costs of care. A query using an administrative claims database was performed identifying patients who underwent primary THA with RA, whereas patients without RA served as controls. Study group patients were matched to controls in a 1:5 ratio by age, sex, and medical comorbidities. The query yielded 518,927 patients with (n = 86,507) and without (n = 432,420) RA undergoing primary THA. A p-value of less than 0.002 was considered statistically significant. Patients with RA were found to have significantly longer in-hospital LOS (4 vs. 3 days, p < 0.0001). Additionally, RA patients had significantly higher incidence and odds (odds ratio [OR]) of medical (6.39 vs. 1.18%; OR: 5.71, p < 0.0001) and implant-related complications (7.45 vs. 3.35%; OR: 2.32, p < 0.0001) compared with patients without RA. Furthermore, RA patients were found to have significantly higher day of surgery ($12,422.19 vs. $12,103.08, p < 0.0001) and total global 90-day episode of care costs ($16,560.40 vs. $15,167.67, p < 0.0001). This study of 518,927 patients demonstrates patients with RA undergoing primary THA have significantly longer in-hospital LOS, in addition to higher rates of complications and costs. The study is informative as orthopaedists can adequately counsel and educate RA patients of the potential complications which may occur following their procedure.