Impact of behavioral health comorbidities on health care costs among Japanese cancer patients

Abstract Background Little is known about how behavioral health (BH) conditions affect health care costs of cancer patients in Japan. Objective The purpose of this study is to evaluate the magnitude of general medical claims expenditures for individuals with cancer who use or do not use BH services in Japan. Methods The study used a health insurance claims database for over 3 million enrollees in Japan. All health plan enrollees (18 years or older) who had tumors without metastasis or metastatic solid tumors defined by the Charlson Comorbidity Index were included in the study (n=20,260). Measurements included total claims expenditures for BH and medical services. Results The proportion of enrollees using BH services was 12.8%. BH service users accounted for 17.7% of total health service spending. Mean annual cost of total health care services were 1.5 times higher in BH users than those with no BH use, while the median was 1.8 times higher. Mean annual medical cost alone for BH users was 1.3 times higher than that for non-BH users, while the median was 1.5 times higher. Conclusions The findings suggest the importance for the Japanese medical system to address BH needs of cancer patients and introduce fiscal efficiencies to cancer care. Strategic implementation of effective integrated care services for cancer patients should be considered in Japan.