Trends in discharge to institutional post-acute care after total joint arthroplasty in the United States and Canada

Background — Recent payment reforms in the United States have been credited with reducing the use of institutional post-acute care (PAC) after total knee arthroplasty (TKA) and total hip arthroplasty (THA). This dual-country study of Canada and the United States compares longitudinal trends in discharge to institutional PAC after primary TKA or THA.

Methods — We conducted serial cross-sectional analyses to compare discharge to institutional PAC trends among adults aged ≥ 66 years undergoing primary TKA or THA in the United States and Canada from 2013 to 2019. Patient-level data were obtained from population-based Medicare claims in the United States and analogous datasets in Ontario. Discharge trends were assessed using standardized differences and linear regression models to evaluate relative changes over time.

Results — Patients receiving TKA (2,308,001) and THA (1,234,149) in the United States and Ontario (106,721 and 53,371, respectively) were similar in age (73–74 years) and sex (~60% female). The absolute reduction in institutional PAC discharge over time for TKA was greater in the United States (slope = −3.59) than in Canada (slope = −0.53) (p < 0.0001), but relative reductions (slope = −8.78 in the United States, slope = −6.99 in Canada) were statistically similar (p = 0.08). THA showed a similar trend of absolute reductions; however, the relative reduction trend in the United States (slope = −9.98) was steeper than in Canada (slope = −6.46) (p = 0.0009).

Conclusions — The US payment reforms from 2013 to 2019 were associated with a greater impact on reducing institutional PAC utilization for THA than for TKA.