[1] Kyoto Univ, Grad Sch Med & Publ Hlth, Dept Epidemiol & Hlth Care Res, Sakyo Ku, Kyoto 6068501, Japan
[2] Inst Hlth Outcomes & Proc Evaluat Res, Tokyo, Japan
[3] Fukushima Med Univ, Dept Orthopaed Surg, Fukushima, Japan
[4] Univ Tokyo, Grad Sch Med, Tokyo, Japan