Overview of regular dialysis treatment in Japan (as of 31 December 2008)

A nationwide statistical survey of 4124 dialysis facilities was conducted at the end of 2008 and 4081 facilities (99.0%) responded. The number of patients undergoing dialysis at the end of 2008 was determined to be 283 421, an increase of 8179 patients (3.0%) compared with that at the end of 2007. The number of dialysis patients per million at the end of 2008 was 2220. The crude death rate of dialysis patients from the end of 2007 to the end of 2008 was 9.8%. The mean age of the new patients begun on dialysis was 67.2 years and the mean age of the entire dialysis patient population was 65.3 years. For the primary diseases of the new patients begun on dialysis, the percentages of patients with diabetic nephropathy and chronic glomerulonephritis were 43.3% and 22.8%, respectively. Among the facilities that measured bacterial count in the dialysate solution in 2008, 52.0% of facilities ensured that a minimum dialysate solution volume of 10 mL was sampled. Among the patients treated by facility dialysis, 95.4% of patients were treated three times a week, and the average time required for one treatment was 3.92 ± 0.53 (SD) h. The average amounts of blood flow and dialysate solution flow were 197 ± 31 and 487 ± 33 mL/min, respectively. The number of patients using a polysulfone membrane dialyzer was the largest 50.7%) and the average membrane area was 1.63 ± 0.35 m². According to the classification of dialyzers by function, the number of patients using a type IV dialyzer was the largest (80.3%).The average concentrations of each electrolyte before treatment in patients treated with blood purification by extracorporeal circulation were 138.8 ± 3.3 mEq/L for serum sodium, 4.96 ± 0.81 mEq/L for serum potassium, 102.1 ± 3.1 mEq/L for serum chloride, and 20.7 ± 3.0 mEq/L for HCO₃^-; the average serum pH was 7.35 ± 0.05. Regarding the type of vascular access in patients treated by facility dialysis, in 89.7% of patients an arteriovenous fistula was used and in 7.1% an arteriovenous graft was used. The percentage of hepatitis C virus (HCV)- positive patients who were HCV-negative in 2007 was 1.04%; the percentage is particularly high in patients with a period of dialysis of 20 years or longer. The risk of becoming HCV-positive was high in patients with low serum creatinine, serum albumin, and serum total cholesterol levels, and/or a low body mass index before beginning dialysis.