Annual dialysis data report 2021, Japanese Society for Dialysis Therapy (JSDT) renal data registry

The annual survey of the Japanese Society for Dialysis Therapy (JSDT) Renal Data Registry (JRDR) at the end of 2021 was conducted at 4508 facilities, of which 4454 facilities (98.8%) returned the facility questionnaire and 4251 (94.3%) returned the patient questionnaire, giving response rates as high as those in previous years. The number of dialysis patients in Japan has been increasing year by year, reaching 349,700 as of the end of 2021 or 2786 patients per million population according to the results of the facility survey. The mean age of patients based on the patient survey was 69.67 years, with the most common primary disease being diabetic nephropathy (39.6%), followed by chronic glomerulonephritis (24.6%) and nephrosclerosis (12.8%). The number of incident dialysis patients in 2021 based on the facility survey was 40,511, a decrease of 233 patients from 2020. The mean age of incident dialysis patients based on the patient survey was 71.09 years, with diabetic nephropathy being the most common primary disease with a frequency of 40.2%, 0.5% points less than the previous year. Nephrosclerosis (18.2%) was the second most common primary disease, surpassing chronic glomerulonephritis (14.2%) as in the previous year. The annual number of deceased patients in 2021 based on the facility survey was 36,156, with an annual crude mortality rate of 10.4%. The leading causes of death, in descending order, were heart failure (22.4%), infection (22.0%), and malignancy (8.4%), with similar rates as the previous year. The number of patients on hemodiafiltration (HDF) has increased rapidly since 2012, reaching 176,601 according to the facility survey at the end of 2021, accounting for 50.5% of all maintenance dialysis patients. The number of patients on peritoneal dialysis (PD) was 10,501 and has been increasing since 2017. Of the PD patients, 20.3% were on combination therapy with hemodialysis (HD) or HDF, and this proportion has remained almost constant. The number of patients on home HD as of the end of 2021 was 748, a decrease of 3 patients from the end of 2020. In 2021, the facility survey items included disaster preparedness, in addition to items from the previous year, including coronavirus disease 2019 (COVID-19), malignancy, and history of kidney donation for living donor kidney transplantation. These data provide basic information on individual diseases and patients, and the results are expected to be used to propose more effective routine clinical management patterns. Trial registration The JRDR was approved by the Japanese Society for Dialysis Therapy ethics committee. It was registered in the University Hospital Medical Information Network (UMIN) Clinical Trials Registry on September 10, 2020 and in the UMIN clinical trials registration system (UMIN000018641).