Effect of initial peritoneal dialysis prescription on clinical outcomes of Japanese peritoneal dialysis patients: a cohort study

This multicenter prospective cohort study is the first to investigate the association between different initial PD regimens and clinical and patient-reported outcomes in Japanese PD patients. No significant differences were found in HD conversion, mortality, HD conversion or mortality, incidence of peritonitis, hospitalization, and PROs between initial PD volumes ≤4 L/day and >4 L/day. did. Interestingly, during the first 2 years of PD, the >4 L/day group had approximately twice as much PD as the <4 L/day group, but there were no differences in various clinical outcomes. It was.

Two randomized controlled trials have shown that there is no survival benefit in aiming for high dialysis efficiency in PD patients.^14,15IncrPD is currently attracting attention in PD treatment. In the 2000s, there were several reports on incrPD, mainly from Italy, but these were single-arm studies with small numbers of patients.^16,17,18. However, in recent years, large-scale clinical studies comparing incrPD and standard PD (or full-dose PD) have been conducted around the world. Since 2016, one clinical study on incrPD has been conducted in the United States.¹⁹England²⁰,Portugal^{twenty one}two studies each were conducted in Italy^{twenty two,twenty three},Canada^{twenty four,twenty five},South Korea^9,26three studies were conducted in Australia^27,28,295 cases in China^{30,31,32,33,34}. Of these 17 studies, 13 were conducted at a single center (11 were single-center retrospective cohort studies, 1 was a single-center randomized controlled trial, and 1 was a single-center randomized controlled trial). Cross-sectional studies), four studies were conducted using registries. data. The single-center retrospective cohort study included a minimum of 87 patients and a maximum of 1,315 patients, which was significantly higher than previous observational studies. The definitions of incrPD and standard PD varied between studies. To separate incrPD from standard PD, nine studies applied the number of exchanges per day, one study applied the number of exchanges per week, and five studies applied the PD amount per day. , two studies applied PD doses per week. These studies compared patient survival, technical survival, peritonitis, hospitalization, RKF, and quality of life as outcomes.

13 studies investigated patient survival rates^{9,19,20,twenty one,twenty two,twenty three,26,28,29,31,32,33,34}three of which showed a survival benefit over incrPD (one of which showed a survival benefit of up to 6 years)^{twenty one,32,33}Nine studies showed no difference between the two groups^{9,19,20,twenty two,twenty three,26,28,29,31}and one study reported that standard PD had a survival benefit.³⁴. Although there was no significant difference in patient survival between the two groups in this study, the unadjusted HR for death was higher in patients with PD volume ≤ 4 L/day. However, this means that patients with an average PD volume of 4 L/day or less are 6 years older than those with a PD volume of >4 L/day, and are particularly susceptible to cardiovascular and cerebrovascular disease complications. This may be due to the heavy burden of Taking all this into account, a higher degree of frailty is likely, especially given that the difference in mortality between the groups was not significant after adjusting for other factors.

Survival of the technique has been previously investigated in 12 studies^{9,19,20,twenty one,twenty three,26,28,29,30,31,32,33}three studies showed superiority of incrPD (one of which showed superior technical survival in the low PD intensity group)^{20,twenty one,28}and nine studies showing no difference between the two groups.^{9,19,twenty three,26,29,30,31,32,33}. Surprisingly, no studies reported that incrPD was inferior to standard PD in terms of technical survival. However, the definition of technical survival varies between studies, making it difficult to directly compare them. Furthermore, it is already known that there is great heterogeneity in the definition of technical survival across clinical studies.³⁵suggesting the need for international unification of definitions. In the present study, as in many other studies, no significant difference in the transition to HD was observed between the two groups.

Of the 13 studies that compared the incidence of peritonitis^{9,20,twenty one,twenty two,twenty three,26,27,28,29,30,31,32,33}six studies showed an advantage for incrPD (one of which showed longer nominally peritonitis-free survival)^{twenty three,26,28,29,31,33}In these six studies, peritonitis rates ranged from 0.06 to 0.23 episodes/patient/year in incrPD patients, compared with 0.14 to 0.32 episodes/patient/year in standard PD patients. Meanwhile, seven studies found no difference between the two groups.^{9,20,twenty one,twenty two,27,30,32}. Theoretically, starting PD with fewer daily changes could be expected to reduce the incidence of peritonitis due to the reduced risk of contamination. However, some studies that reduced the number of exchanges did not show any benefit regarding peritonitis. In the present study, the HR for the association between PD volume ≤4 L/day and peritonitis was consistently low in different adjusted models, although no significant differences were observed, and the incidence rates in both groups reached new values. I found out that it is lower. ISPD Guidelines Target³⁶.

Six studies examining hospitalization^{19,twenty one,twenty two,twenty three,26,29}three studies have shown the benefits of incrPD^{twenty one,twenty two,twenty three} and three studies showed no difference between the two groups^19,26,29. However, the definition of a hospitalization event also varied between studies, with one study comparing hospitalization-free survival and another comparing hospitalization rates. In our study, there was no difference in the first hospitalization rate between the two groups, but the rate was higher in our study compared with previous studies. The reason for this observation is not clear, but it may be related to the older age of the patients in our study and the differences in admission criteria.

Preservation of RKF is of great concern to medical professionals managing PD patients. 12 of 17 studies investigated long-term changes in RKF with incrPD and standard PD^{9,19,20,twenty two,twenty three,26,27,29,30,31,32,33}. 4 of them showed superiority of incrPD^{9,twenty two,32,33}the remaining eight studies reported no difference between the two groups.^{19,20,twenty three,26,27,29,30,31}. We were unable to include RKF in the analysis due to a large amount of missing data regarding RKF.

Narjayan et al. Report on the impact of incrPD on QOL¹⁹. They evaluated QOL separately for APD and CAPD patients and reported the superiority of incrPD only in CAPD patients. Their results suggest that increasing the number of manual bag changes impacts quality of life. In our study, we investigated the relationship between PD amount and QOL, but no significant difference was found between the two groups.

The current study has several limitations. First, it is an observational study, with a relatively small sample size and residual confounders (e.g., activities of daily living, socioeconomic factors, mental status, reasons for choosing PD, and other unmeasured confounders). ) could not be excluded. Therefore, this study lacks statistical power and therefore caution should be taken when attempting to generalize the results of this study. However, the number of patients was larger than in some previously reported single-center retrospective cohort studies, and it is noteworthy that this study was conducted prospectively in a multicenter facility. Additionally, we collected several potential confounder variables for consideration and performed the analysis taking them into account. Second, changes in RKF, which have a significant impact on the prognosis of PD patients, could not be compared due to a large number of missing data. It is well known that RKF is an important factor influencing the survival of PD patients. However, we showed that the 24-hour urine output, which reflects RKF, was similar in the two groups. Large randomized controlled trials comparing defined outcome measures are needed to resolve confounding bias and clarify causal relationships. Third, an important limitation of the study is that it is not clear why the lower PD regimen was chosen for the patients. Finally, no data are provided regarding residence time, an important factor that can influence the removal of solutes and excess water.

In conclusion, this study shows that patients with PD volumes ≤4 L/day have similar survival rates, conversion to HD, hospitalization, and peritonitis as those with PD volumes >4 L/day and those receiving dialysis. It has been shown that this results in the following results. . Furthermore, patients with PD volumes ≤4 L/day may have lower healthcare costs compared to patients with PD volumes >4 L/day.