Phosphorus management behaviors in elderly patients with chronic kidney disease: a comparison between pre-dialysis and hemodialysis stages

Dietary recommendations, phosphorus management strategies, and monitoring requirements differ substantially between pre-dialysis and hemodialysis stages. This study aimed to determine preventive, self-regulatory and dietary practices for phosphorus management in pre-dialysis and hemodialysis elderly patients. A cross-sectional analytical study was conducted among 91(30 pre-dialysis patients and 61 maintenance hemodialysis) elderly Egyptian CKD patients, age ≥ 65 years) at Cairo University Hospitals. A culturally adapted questionnaire assessed preventive and self-regulatory phosphorus management practices (10 items), dietary practices (17 items), and binder proper use (4 items). Percent scores were calculated using modified Bloom's cut-off points (≥ 60% = adequate). Weekly phosphorus intake was quantified using Egyptian food composition tables. The dialysis group showed significantly better self-regulatory practices. They had significantly higher median percent score at 71 (IQR: 57–86) compared to 57 (IQR: 43–71) in the pre-dialysis group (p = 0.007), significant higher rates of phosphorus laboratory monitoring (72.1% vs. 43.3%, p = 0.008, significantly more common action taken in response to elevated phosphorus levels (86.9% vs. 66.7%, p = 0.023) and they were significantly less likely to report taking phosphate binders on an empty stomach (10% vs. 40%, p = 0.013). Multiple linear regression analysis revealed that age and dialysis status predicted the self-regulatory engagement scores. Higher age was associated with lower engagement scores (B = – 0.724, 95% CI: –1.268 to –0.181; p = .010) while dialysis scored approximately 10 percentage points more than pre-dialysis patients (B = 10.214, 95% CI: 3.390 to 17.038; p = .004). No statistically significant differences were observed between groups regarding feeding and preventive practices, P > 0.05. Laboratory phosphorus level showed an inverse relationship with feeding practice score with borderline significance (r = -0.260, p value 0.056). However, no demographic or clinical factors were found to be significantly correlated with the feeding practices score or with the combined preventive and self-regulatory practices score. Dietary adherence was high across all elderly CKD stages. Pre-dialysis elderly patients showed significantly limited engagement in self-regulatory practices, laboratory results monitoring and lower binder compliance compared to age matched dialysis patients. Elderly pre- dialysis patients require more system support not just an education.