The effects of comorbid conditions on the outcomes of patients undergoing peritoneal dialysis.

Purpose: Dialysis patients frequently have comorbid conditions. We examined the effects of age and comorbid conditions on technique failure (i.e., transfer to hemodialysis), death, hospital costs, and kidney transplantation in patients treated with peritoneal dialysis.

Methods: We studied 97 patients who began peritoneal dialysis from January 1, 1993, to December 31, 1998, at the University of Pittsburgh outpatient dialysis unit. Demographic characteristics, comorbid conditions, and outcomes were determined by reviewing the Medical Archival Retrieval System database and outpatient records. Because the comorbidity (Charlson) score was colinear with age, we used a modified version of the score without an age component. Low, moderate, and high comorbidity groups were defined based on the 33rd and 66th percentiles of the comorbidity score.

Results: In multivariate-adjusted models, each decade increase in age was associated with an increased risk of death (hazard ratio [HR] = 1.7; 95% confidence interval [CI]: 1.1 to 2.5) and technique failure (HR = 1.5; 95% CI: 1.0 to 2.3). High (versus low) comorbidity was associated with an increased risk of death or technique failure (HR = 3.5; 95% CI: 1.0 to 12) and significantly higher average inpatient costs. There were no differences in age or comorbidity score between patients who transferred to hemodialysis and those who died.

Conclusion: Patients who are older and more ill have a greater risk of death and of transfer to hemodialysis from peritoneal dialysis.