Estimated number of spine surgeries and related deaths in Japan from 2014 to 2020.

BACKGROUND:The total number of spine surgeries per year and their related deaths in Japan has not been adequately estimated in the literature. METHODS:We retrospectively reviewed the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) between April 2014 to March 2021, which covers 99.9 % of health insurance claim receipts by general practitioners. The annual number of surgeries was counted using K codes, a procedure classification unique to Japan, and classified into the following six categories; percutaneous vertebroplasty, endoscopic surgery, open discectomy, laminoplasty/laminectomy, instrumentation surgery, and others. The data distribution was also summarized by sex and age. Additionally, by reviewing DPC database-related papers for evaluation of the mortality rate after spine surgery in Japan, the number of spine surgery-related deaths was calculated. RESULTS:The NDB showed that the number of spine surgeries analyzed in this study increased from 170,081 in 2014 to 193,903 in 2019, with a slight decrease in 2020. The ratio of instrumentation surgery increased from 33.0 % in 2014 to 37.9 % in 2020. The rate of patients aged 75 or older increased 31.6 % to 39.6 %. Combining these findings with DPC data showing a mortality rate of 0.1 % to 0.4 % revealed that the estimated number of deaths related to spine surgery in Japan ranged from 200 to 800 per year. CONCLUSIONS:Approximately 200,000 spine surgeries and 200 to 800 spine surgery-related inpatient deaths were estimated to have occurred in Japan around 2020.