The difference in moderate/severe pruritus prevalence between Clusters 2 and 1 was statistically significant after Bonferroni correction ( p < 0.001), while the difference between Clusters 2 and 3 approached significance ( p = 0.057).
When analyzing 5D-IS scores as a continuous variable, a positive trend was observed between serum iron levels and pruritus severity (β = 0.44, 95% CI -0.06 to 0.94, p = 0.081 in the crude model; β = 0.53, 95% CI 0.01 to 1.04, p = 0.045 after demographic adjustment; β = 0.49, 95% CI -0.05 to 1.03, p = 0.077 in the fully adjusted model), although statistical significance was not consistently maintained across all models (Table 2 ).