Recent peritonitis associates with mortality among patients treated with peritoneal dialysis

Abstract

Peritonitis is a major complication of peritoneal dialysis, but the relationship between peritonitis and mortality among these patients is not well understood. In this case-crossover study, we included the 1316 patients who received peritoneal dialysis in Australia and New Zealand from May 2004 through December 2009 and either died on peritoneal dialysis or within 30 days of transfer to hemodialysis. Each patient served as his or her own control. The mean age was 70 years, and the mean time receiving peritoneal dialysis was 3 years. In total, there were 1446 reported episodes of peritonitis with 27% of patients having ≥ 2 episodes. Compared with the rest of the year, there were significantly increased odds of peritonitis during the 120 days before death, although the magnitude of this association was much greater during the 30 days before death. Compared with a 30-day window 6 months before death, the odds for peritonitis was six-fold higher during the 30 days immediately before death (odds ratio, 6.2; 95% confidence interval, 4.4-8.7). In conclusion, peritonitis significantly associates with mortality in peritoneal dialysis patients. The increased odds extend up to 120 days after an episode of peritonitis but the magnitude is greater during the initial 30 days.

Figure 1.

Days between peritonitis episode and death.

Figure 2.

Odds of peritonitis immediately before death compared with the preceding 12 months using different periods of time. (A) Odds of peritonitis in different 5-day periods before death compared with all other preceding 5-day periods in the year before death. (B) Odds of peritonitis in different 7-day periods before death compared with all other preceding 7-day periods in the year before death. (C) Odds of peritonitis in different 30-day periods before death compared with all other preceding 30-day periods in the year before death.

Figure 3.

Odds of peritonitis in the 30-day period before death compared with all other preceding 30-day periods in the preceding year, from difference causes of death. (A) Odds of peritonitis in different 30-day periods before death from vascular disease compared with all other preceding 30-day periods in the year before death (n=733). (B) Odds of peritonitis in different 30-day periods before death from infection compared with all other preceding 30-day periods in the year before death (n=115). (C) Odds of peritonitis in different 30-day periods before death from withdrawal from dialysis compared with all other preceding 30-day periods in the year before death (n=174).

Figure 4.

Case-crossover method in which individual patients serve as their own controls. The odds of peritonitis occurring within the case window (period immediately before death), which can be of varying lengths, is compared with a control window (period remote from death, as shown 6 months prior in this figure) of equal duration.