Development of a nomogram for identifying prevalent medication discrepancy in maintenance hemodialysis patients: a...

Medication discrepancy reflects an observed mismatch between a prescribed medication regimen and actual medication use and is conceptually distinct from medication nonadherence or medication error. We estimated the prevalence of medication discrepancy in maintenance hemodialysis (MHD) patients and developed a development-stage nomogram for identifying prevalent medication discrepancy.

This multicenter cross-sectional study included 328 MHD patients from four tertiary-hospital hemodialysis centers in Guangdong Province, China, between December 2022 and May 2023. Medication discrepancy was ascertained with an order-referenced medication-reconciliation process based on the modified Medication Discrepancy Tool. The primary model included three predictor domains with complete data: residential area, monthly income, and the Beliefs about Medicines Questionnaire (BMQ) total score, represented by five model parameters after categorical coding and spline transformation. BMQ was modeled continuously with a three-knot restricted cubic spline. Model performance was evaluated using 1,000-resample bootstrap optimism correction and leave-one-center-out internal-external validation.

Medication discrepancy was identified in 256 of 328 participants (78.05%). BMQ showed an overall nonlinear association with prevalent medication discrepancy (global P < 0.001; test for nonlinearity P = 0.011). In the primary model, urban residence had an odds ratio (OR) of 1.93 (95% CI 0.99-3.75; P = 0.053) versus rural residence, while monthly income >5,000 CNY had an OR of 0.33 (95% CI 0.15-0.73; P = 0.006) versus <3,000 CNY. The apparent AUC was 0.723 (95% CI 0.663-0.783) and the bootstrap optimism-corrected AUC was 0.701. Leave-one-center-out validation yielded a pooled AUC of 0.601, Brier score of 0.180, calibration intercept of 0.722, and calibration slope of 0.362, with substantial heterogeneity across centers.

The three-domain nomogram showed moderate apparent discrimination but substantially attenuated and heterogeneous cross-center performance. It should be regarded as a development-stage identification model for prevalent medication discrepancy and requires independent external validation, and potentially recalibration, before clinical use.