Supplementary Material for: Higher Ultrafiltration Rate Is Associated with Longer Dialysis Recovery Time in Patients Undergoing Conventional Hemodialysis

Background: Increased mortality and morbidity are reported in association with high ultrafiltration rate (UFR) and with long dialysis recovery time (DRT). We studied the association between UFR and DRT. Methods: This is a cross-sectional, observational study was conducted. Patients on thrice-weekly hemodialysis (HD) with self-reported DRT between August and December 2014 were included. We examined the association of 30-day average UFR with recovery time. Results: The total number of patients included in this study was 2,689. DRT in categories of immediate recovery, >0-≤2, >2-≤6, >6-≤12, and >12 h, were reported in 27, 28, 17, 9, and 20% of the patients respectively. In multivariable analysis, longer DRT was associated with female gender, non-black race, higher body weight, lower serum albumin, chronic heart failure, cerebrovascular disease, missed dialysis sessions, higher pre-dialysis systolic blood pressure, and larger UF volume. Compared to UFR of <10, UFR ≥13 mL/kg/h was associated with longer DRT, OR of 1.16 (95% CI 0.99-1.36), and 1.28 (95% CI 1.06-1.54) in the unadjusted and the adjusted analyses respectively. Intradialytic hypotension was also associated with longer DRT in the unadjusted (per 10% higher frequency, OR 1.04 [95% CI 1.01-1.07]) and adjusted analyses (OR 1.03 [95% CI 1.00-1.07]). Conclusion:Long recovery time is common after HD. Rapid fluid removal is associated with longer DRT.