Changes in mortality hazard of the Korean long-term dialysis population: The dependencies of time and modality switch

Abstract

Background: Many studies have compared patient survival outcome between hemodialysis (HD) and peritoneal dialysis (PD); however, time-varying risks of dialysis modality have been rarely investigated. This study aimed to investigate dialysis modality switch and its association with the survival outcome in the Korean population. Methods: Data from the Korean Society of Nephrology were used. A total of 21,840 incident dialysis patients who started dialysis in or after 2000 were analyzed. For the survival analysis, both proportional and non-proportional hazard assumptions were applied. For the modality switch, time-varying covariate Cox regression was applied. Results: During the median follow-up of 8 years, PD group showed increased adjusted hazard ratio (HR) of 1.248 (95% CI 1.071–1.454, p = 0.004) for mortality. Interaction of PD status with female sex was significant with an HR of 1.080 (95% CI 1.000–1.165, p = 0.050). Dialysis modality switch was associated with increased HR of 1.094 (95% CI 1.015–1.180, p = 0.019), albeit switch from PD to HD did not show significant HR until 6 years. Interestingly, time-varying risk analysis showed a decreased HR of PD after 10 years in the non-switcher group, which was consistent in patients with high traditional risk factors (with diabetes, elderly). Conclusions: PD was associated with increased HR of mortality in the first 8 years, then it was associated with decreased HR of mortality after 10 years. Dialysis modality switch was associated with increased mortality risk, but switch from PD to HD within 6 years did not show significant hazard of mortality.

A prospective, randomized, multicenter, open‐label trial comparing survival in subjects receiving peritoneal dialysis or conventional in‐center hemodialysis

“…Other studies that included 23,718 US patients and 12,095 Danish patients reported that patients treated with PD had better survival than those treated with HD [16,21]. However, analyses of data from the Korean Society of Nephrology Registry and the Australia and New Zealand Dialysis and Transplant Registry found that mortality was higher on PD than on HD [17,22]. Potential explanations for these inconsistencies include patient selection bias, differences in study design, methods used for statistical analysis, confounding variables adjusted for, and the impact of switching dialysis modality.…”

“…The other trial was terminated prematurely as a result of poor recruitment and patient adherence, with only 38 patients randomized over 3 years [14]. Most of the other studies comparing patient survival between PD and HD have been observational with inconsistent findings [15][16][17].…”

The effect of dialysis modality on annual mortality: A prospective cohort study

“…Liem et al 31 concluded that the survival advantage of PD over HD decreased over time, with age, and in presence of diabetes as a primary disease 31 . Thus, dialysis modality conversion has remained subject to consideration; nly a few studies have investigated it 32 , 33 . In addition, the results should be cautiously interpreted because there were reasons for switching between modalities, such as clinical indications that precluded HD, peritonitis, and/or encapsulating peritoneal sclerosis.…”

The Effect of Dialysis Modality on Annual Mortality: a Prospective Cohort Study

“…30 Thus, dialysis modality conversion has remained subject to consideration, and only a few studies have investigated it. 31,32 In addition, we need to interpret the results with caution because there were reasons to switch modalities, such as clinical indications that precluded HD, peritonitis, and/or encapsulating peritoneal sclerosis.…”