Predicting transfer to haemodialysis using the peritoneal dialysis surprise question.

Background: People on peritoneal dialysis (PD) at risk of transfer to haemodialysis (HD) need support to remain on PD or ensure a safe transition to HD. Simple point-of-care risk stratification tools are needed to direct limited dialysis centre resources. In this study, we evaluated the utility of collecting clinicians' identification of patients at high risk of transfer to HD using a single point of care question.

Methods: In this prospective observational study, we included 1275 patients undergoing PD in 35 home dialysis programmes. We modified the palliative care 'surprise question' (SQ) by asking the registered nurse and treating nephrologist: 'Would you be surprised if this patient transferred to HD in the next six months?' A 'yes' or 'no' answer indicated low and high risk, respectively. We subsequently followed patient outcomes for 6 months. Cox regression model estimated the hazard ratio (HR) of transfer to HD.

Results: Patients' mean age was 59 ± 16 years, 41% were female and the median PD vintage was 20 months (interquartile range: 9-40). Responses were received from nurses for 1123 patients, indicating 169 (15%) as high risk and 954 (85%) as low risk. Over the next 6 months, transfer to HD occurred in 18 (11%) versus 29 (3%) of the high and low-risk groups, respectively (HR: 3.92, 95% confidence interval (CI): 2.17-7.05). Nephrologist responses were obtained for 692 patients, with 118 (17%) and 574 (83%) identified as high and low risk, respectively. Transfer to HD was observed in 14 (12%) of the high-risk group and 14 (2%) of the low-risk group (HR: 5.56, 95% CI: 2.65-11.67). Patients in the high-risk group experienced higher rates of death and hospitalisation than low-risk patients, with peritonitis events being similar between the two groups.

Conclusions: The PDSQ is a simple point of care tool that can help identify patients at high risk of transfer to HD and other poor clinical outcomes.