Residual urine volume and quality of life in maintenance hemodialysis

Abstract Background Residual urine volume in patients undergoing hemodialysis is closely linked to fluid balance and clinical outcomes. However, its association with quality of life (QOL), an important patient-centered outcome, has not been well characterized across a broad quantitative range. In this study, we aimed to evaluate the association between residual urine volume and QOL in patients undergoing hemodialysis. Methods This cross-sectional study included 99 patients undergoing hemodialysis at a single center. Twenty-four-hour residual urine volume collected on a non-dialysis day was used as the exposure variable and categorized into three groups: 0 mL/day, 1–520 mL/day, and > 520 mL/day. QOL was assessed using the EQ-5D-5L index and dichotomized at the median value (0.82). Logistic regression with Firth’s penalized likelihood method was performed to examine the association after adjustment for demographic, clinical, dialysis-related, and laboratory variables. Restricted cubic spline models were applied to assess potential nonlinearity. Results The proportion of patients with good QOL increased across residual urine volume categories. In multivariable analysis, residual urine volume > 520 mL/day was independently associated with higher odds of good QOL compared with 0 mL/day (adjusted odds ratio 5.40; 95% confidence interval 1.23–27.09). Spline analysis demonstrated a generally increasing trend in the likelihood of good QOL with higher residual urine volume, without significant nonlinearity. Conclusions Higher residual urine volume was independently associated with better QOL in patients undergoing hemodialysis. Strategies aimed at maintaining residual urine volume may support improved patient-centered outcomes.