Frailty and associated healthcare expenditures among patients undergoing total hip and knee arthroplasty.

Background: Major joint surgery is one of the largest components of Medicare spending in the US and the most frequent major procedure performed in older adults. Increasing age is associated with increasing prevalence of frailty, but the influence of frailty on healthcare expenditures following arthroplasty has yet to be adequately explored.

Objective: To explore the association between frailty and healthcare expenditures in the year following total hip and knee arthroplasties.

Design: Retrospective cohort study SETTING: United States population PARTICIPANTS: Medicare beneficiaries 65 and older undergoing total knee or hip arthroplasty (n = 1,152,872) from 2017 through 2018.

Measurements: Claims-based frailty index (exposure), total 1-year Medicare expenditures broken down by category (primary outcome), in-hospital complications, length of stay, discharge destination, readmission and mortality (secondary outcomes).

Results: Among 435,496 patients who underwent hip (37.8 %) and 717,376 patients who underwent knee arthroplasty (62.2 %), the mean age was 73.7 years and 19.2 % were classified as frail. Median total expenditures in US dollars at one year were higher in those with frailty ($247,503; IQR [$169,400-$391,176]) relative to the prefrail ($179,379 [$127,396-$265,039]) and robust ($130,314 [$85,438-$199,605]) groups. Total expenditures included the index surgical admission, rehospitalization, skilled nursing care, and outpatient care, all of which were higher with increasing frailty. However, the surgical procedure accounted for less than a third of the total 1-year healthcare costs and was the category with the lowest degree of variation between patients. Frailty was also associated with longer lengths of stay, higher risks of complications, readmission, and mortality and lower likelihood of being discharged home after the procedure.

Conclusions: Among older adults undergoing total hip and knee arthroplasty, frailty is associated with higher healthcare expenditures, predominantly driven by longitudinal care during the year following the procedure. More research is needed to test interventions to improve outcomes and reduce cost in this high-risk population.