Three-year follow-up study of health related QOL and lifestyle indicators for Japanese patients after total hip arthroplasty.

BACKGROUND: In non-Western countries including Japan, activities requiring deep flexion of the hip joint, such as seiza (kneeling with calves tucked under the thighs and buttocks resting on the heels) and using squat toilets are commonly practiced. The purpose of this study was to assess longitudinal changes in traditional health-related quality of life measures and measures of physical functions associated with lifestyle for Japanese patients pre-surgery and after total hip arthroplasty.

METHODS: Consecutive primary total hip arthroplasty patients between July 2003 and November 2006 were eligible. Patients were measured preoperatively and at 6 weeks, 1 year and 3 years postoperatively. Patients completed the EuroQol 5D, the Western Ontario and McMaster Universities Osteoarthritis Index and items related to Japanese lifestyle activities such as squatting. Changes in these scale scores across the four time points were tested, and we examined predictive factors of EuroQol 5D score at 3-year follow-up using multiple linear regression.

RESULTS: Of 1103 eligible patients, 576 completed questionnaires at all four time points. By 6 weeks post-surgery, reductions in pain and improvements in physical function and stiffness became highly significant, and improvements continued to 3 years postoperative. In contrast, improvements were far more limited for items related to Japanese lifestyle functions such as seiza and use of a Japanese squat toilet, even 3 years after surgery. Predictive factors of EQ5D at 3-year post THA were WOMAC pain and physical function, seiza, age and comorbidity measured at 3-year post THA.

CONCLUSION: The rate of improvement in QOL requiring deep flexion of the hip joint was much slower than that in QOL related to Western lifestyle. Our study suggests a need for lifestyle modification for THA patients in the other countries where kneeling and squatting are commonly performed.