The pattern of choosing dialysis modality and related mortality outcomes in Korea: a national population-based study

BACKGROUND/AIMS Since comorbidities are major determinants of modality choice, and also interact with dialysis modality on mortality outcomes, we examined the pattern of modality choice according to comorbidities and then evaluated how such choices affected mortality in incident dialysis patients. METHODS We analyzed 32,280 incident dialysis patients in Korea. Patterns in initial dialysis choice were assessed by multivariate logistic regression analyses. Multivariate Poisson regression analyses were performed to evaluate the effects of interactions between comorbidities and dialysis modality on mortality and to quantify these interactions using the synergy factor. RESULTS Prior histories of myocardial infarction (p = 0.031), diabetes (p = 0.001), and congestive heart failure (p = 0.003) were independent factors favoring the initiation with peritoneal dialysis (PD), but were associated with increased mortality with PD. In contrast, a history of cerebrovascular disease and 1-year increase in age favored initiation with hemodialysis (HD) and were related to a survival benefit with HD (p < 0.001, both). While favoring initiation with HD, having Medical Aid (p = 0.001) and male gender (p = 0.047) were related to increased mortality with HD. Furthermore, although the severity of comorbidities did not inf luence dialysis modality choice, mortality in incident PD patients was significantly higher compared to that in HD patients as the severity of comorbidities increased (p for trend < 0.001). CONCLUSIONS Some comorbidities exerted independent effects on initial choice of dialysis modality, but this choice did not always lead to the best results. Further analyses of the pattern of choosing dialysis modality according to baseline comorbid conditions and related consequent mortality outcomes are needed.