Estimates of annual medical costs of work-related low back pain in Japan.

Little is reported regarding economic burden of work-related low back pain except for the United States. In the present study, annual medical cost of work-related low back pain in Japan was calculated based on the treatment fee per day, a total of days of treatment received for low-back pain of all causes, employment rates, and an estimated number of work-related low-back cases. The analysis indicated that, in 2011, the total annual medical cost for work-related low back pain was 82.14 billion yen, consisting of 26.48 and 55.66 billion yen for inpatients and outpatients, respectively. As well as for 2011, the costs were also estimated for 2008, 2005, and 2002. Whereas the total medical costs of work-related low back pain monotonically increased during 2002-2011, the costs for spine disorder (including spondylosis) have also increased in recent years. Work-related low back pain entails a considerable economic burden to Japanese society.