Background Kt/V has been used as a standard for determining dialysis adequacy. Studies comparing Kt/V calculated by ultraviolet (UV) absorbance-based online clearance monitoring (OCM) with other methods are scanty. The study aims to assess agreement between OCM and other methods of Kt/V estimation and to evaluate the impact of gender on estimating Kt/V by different methods. Materials and Methods This was a cross-sectional study including 50 patients with end-stage renal disease (ESRD) undergoing maintenance hemodialysis (HD) on a B Braun Dialog HD machine integrated with Adimea technology with a 1.4 m 2 dialyzer. Kt/V was calculated by three methods, namely, Daugirdas formula, nomogram method, and OCM by UV absorbance. Results The mean age was 56 ± 11.78 years, with 68% being males. The mean Kt/V values estimated by OCM, Daugirdas formula, and nomogram were 1.43, 1.29, and 1.26, respectively. Kt/V measured by OCM (UV absorbance) was significantly higher compared to the other two blood-based methods. However, agreement analysis using Bland-Altman plots demonstrated the presence of systematic bias between OCM Kt/V and Daugirdas Kt/V. The observed differences between OCM Kt/V and other methods likely reflect methodological variations rather than any definitive differences in delivered dialysis dose. Linear regression analysis demonstrated that females and males with lower body weight had significantly higher Kt/V. Although visual inspection of Bland-Altman plots also suggested a possible trend, regression analysis did not demonstrate statistically significant proportional bias. Conclusion OCM Kt/V by UV absorbance overestimates Kt/V compared with other methods, with moderate agreement, limiting its clinical interchangeability.
Prothasis et al. (Tue,) studied this question.