Health Policy 69 (2004) 179–187 Association of hospital resource use with comorbidity status and patient age among hip fracture patients in Japan Tatsuro Ishizaki ∗ , Yuichi Imanaka, Eunhwan Oh, Kazuaki Kuwabara, Masahiro Hirose, Kenshi Hayashida, Yoshiaki Harada Department of Healthcare Economics and Quality Management, School of Public Health, Kyoto University Graduate School of Medicine, Yoshida Konoe-cho, Sakyo-ku, Kyoto 606-8501 Japan Accepted 8 December 2003 Abstract Objectives: This study examined the association of resource use with comorbidity status and patient age among hip fracture patients who underwent surgical treatment. Design: We used a database from the Voluntary Hospitals of Japan Quality Indi- cator Project that involved 10 privately owned leading teaching hospitals in Japan. Setting: Four of these hospitals in Japan. Participants: We selected 778 operable hip fracture patients aged 65 or older who were admitted to these hospitals between January 1996 and August 2000 (mean age: 80.3 ± 7.3 years). Measurements: A linear mixed model was performed to iden- tify factors associated with the resource use, such as total length of stay (LOS), LOS before surgery, LOS after surgery, total hospital charges, charges for diagnostic examinations, charges for surgery, and length of theater time, among operable hip fracture patients. Results: The mean LOS was 45.9 days, and the mean total hospital charges were US$14,495.0. Results from linear mixed models revealed that higher age was significantly associated with shorter length of theater time (P < 0.01), and that the presence of comorbidity among hip fracture patients was significantly associated with longer total LOS (P < 0.01), longer LOS after surgery (P < 0.001), higher charges for diagnostic examinations (P < 0.001), and shorter length of theater time (P < 0.01). Conclusion: These results suggest that the presence of comorbidity among operable hip fracture patients re- quires greater resource use during their hospital stay, but higher age is not significantly associated with greater resource use at all. © 2004 Elsevier Ireland Ltd. All rights reserved. Keywords: Hip fracture; Comorbidity; Length of stay; Cost; Japan 1. Introduction It is often said that total health expenditures in- crease with age among older patients. Some studies ∗ Corresponding author. Tel.: +81 75 753 4454; fax: +81 75 753 4455. E-mail address: tatsuro@pbh.med.kyoto-u.ac.jp (T. Ishizaki). have failed to identify any association between ad- vanced age and higher health expenditure [1], while others identified just such an association [2–4]. On the other hand, some studies revealed that comorbid- ity status rather than age was significantly associated with higher costs in acute care settings [1,5]. Since we consider that inconsistency among these results may be caused by differences in required treatment among 0168-8510/$ – see front matter © 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.healthpol.2003.12.018