The CANUSA Trial Reference Churchill DN. Implications of the Canada–USA (CANUSA) study of the adequacy of dialysis on peritoneal dialysis schedule Nephrol Dial Transplant.1998;13 (Suppl. 6):158–163.

Background The study of peritoneal dialysis has increased the importance of removing small molecular weight solutes and improved patient survival.

Aim To study the adequacy of dialysis on peritoneal dialysis schedule 2. To study the peritoneal membrane transport and patient survival 3. To study the renal function and nutrition at initiation of dialysis.

Method Design: The CANUSA trial was a multicentre, open-labeled trial. Study population: 680 new CAPD or continuous cycle peritoneal dialysis (CCPD) patients were enrolled in this trial. Treatment regimen: The adequacy of dialysis was estimated by measurement of the Kt/V for urea and the total creatinine clearance (CrCl) per week. The nutritional status estimates like serum albumin concentration, subjective global assessment, protein catabolic rate normalized to standardized body weight and percentage lean body mass were obtained at the same intervals as those for adequacy.

Result The relative risk (RR) of death was increased with a increased age, dialysis in the USA, insulin-dependent diabetes mellitus, history of cardiovascular disease, lower serum albumin concentration, and worse nutritional status according to SGA and %LBM. The relative risk of death was increased by 6% for a 0.1 increase in the Kt/V and 7% for a 51/1.73 m2 increase in the CrCl. Lower residual renal function at initiation of dialysis was associated with a worst nutritional status, which was further associated with a reduced possibility of survival. The probability of 2-year survival was 79% for those with lower transport while only 71% for those with high transport. The RR of death was 2.18 for high transporters in comparison to the low transporters.

Conclusion The three CANUSA studies have reviewed the adequacy of dialysis, association between the residual renal function at initiation and nutritional status and the association between the peritoneal membrane transport and both techniques and patient survival. They suggest that the increased clearance of urea and creatinine were associated with reduced RR of death. The early initiation of the dialysis is associated with better initial nutritional status and consequently better survival rates. The CANUSA study has shown that the higher than average transport is associated with elevated RR of death. The CANUSA trial suggest that the increased clearance of urea and creatinine were associated with reduced relative risk of death. It also shown that the higher than average transport is associated with elevated relative risk of death.