Adequacy of dialysis and nutrition in continuous peritoneal dialysis: association with clinical outcomes. Canada-USA (CANUSA) Peritoneal Dialysis Study Group.
The objective of the study presented here was to evaluate the relationship of adequacy of dialysis and nutritional status to mortality, technique failure, and morbidity. This was a prospective cohort study of consecutive patients commencing continuous peritoneal dialysis in 14 centers in Canada and the United States. Between September 1, 1990 and December 31, 1992, 680 patients were enrolled. Follow-up was terminated December 31, 1993. There were 90 deaths, 137 transplants, and 118 technique failures. Fifteen withdrew from dialysis. Analysis of the patient and technique survival used the Cox proportional hazards model with adequacy of dialysis and nutritional status as time-dependent covariates. The relative risk (RR) of death increased with increased age, insulin-dependent diabetes mellitus, cardiovascular disease, decreased serum albumin concentration and worsened nutritional status (subjective global assessment and percentage lean body mass). A decrease of 0.1 unit Kt/V per week was associated with a 5% increase in the RR of death; a decrease of 5 L/1.73 m2 creatinine clearance (CCr) per week was associated with a 7% increase in the RR of death. The RR of technique failure was increased with decreased albumin concentration and decreased CCr. Hospitalization was increased with decreased serum albumin concentration, worsened nutrition according to subjective global assessment and decreased CCr. A weekly Kt/V of 2.1 and a weekly CCr of 70 L/1.73 m2 were each associated with an expected 2-yr survival of 78%.