Long‐term health‐related quality of life of total hip arthroplasty patients and cost‐effectiveness analysis in the Japanese universal health insurance system

Abstract

AbstractAimTotal hip arthroplasty can effectively improve patients' motility with end‐stage osteoarthritis. This study aimed to: (1) compare gradual changes in utility values with total hip arthroplasty and estimated values without; (2) evaluate total hip arthroplasty cost‐effectiveness; and (3) evaluate cost‐effectiveness by age, diagnosis, and comorbidity.MethodsPatients who underwent total hip arthroplasty between January 2008 and December 2009 were included. Patients completed the EuroQol preoperatively and at 1, 3, 5 and 7 years postoperatively. To derive the quality‐adjusted life years gained, a utility score was obtained from the EuroQol item scores and combined with 7 years, and estimates were obtained by discounting the postoperative 1‐year utility value at an annual rate of 2%–4%. Mixed‐effects regression models were used to compare the estimated and the measured utility values.ResultsMean total cost was 1,921,849 yen, and quality‐adjusted life years gain score was 1.746 with per cost as 1,100,715 yen. Compared with actual measurements, the estimated values from 1 to 7 years post‐surgery differed significantly, and interaction was observed. Regarding age, the older the patient, the higher the cost per quality‐adjusted life years. Patients with lower preoperative physical function had higher quality‐adjusted life years gains, while the cost per quality‐adjusted life years was lower.ConclusionsTotal hip arthroplasty was cost‐effective. Compared with actual measurements, the estimated utility values from 1 to 7 years post‐surgery significantly differed. Even among older patients and those with impaired preoperative physical functions, its cost was lower than patients' willingness to pay in Japan.