Agreement between renal prescribing references and determination of prescribing appropriateness in hospitalized patients with chronic kidney disease.

Background: Chronic kidney disease (CKD) is a risk factor for adverse drug events. The clinical significance of discordance between renal prescribing references is unknown.

Aim: We determined the prevalence of potentially inappropriate prescribing (PIP) in CKD, measured agreement between two prescribing references, and assessed potential for harm consequent to PIP.

Design: Single-centre observational study.

Methods: A random sample of hospitalized patients with CKD were grouped according to baseline CKD stage (3, 4, or 5). Prescriptions requiring caution in CKD were referenced against the Renal Drug Handbook (RDH) and British National Formulary (BNF) to identify PIP (non-compliance with recommendations). Inter-reference agreement was measured using percentage agreement and Kappa coefficient. Potential for harm consequent to PIP was assessed by physicians and pharmacists using a validated scale. One-year mortality was compared between patients with or without PIP during admission.

Results: Among 119 patients (median age 73 years, 50% male), 136 cases of PIP were identified in 78 (65.5%) patients. PIP prevalence, per patient, was 64.7% using the BNF and 28.6% using the RDH (fair agreement, Kappa 0.33, P <  0.001). The majority (63.2%) of PIP cases detected exclusively by the BNF carried minimal or no potential for harm. PIP was not significantly associated with one-year mortality (34.7% vs. 21.1%, P = 0.14).

Conclusions: PIP was common in hospitalized patients with CKD. Substantial discordance between renal prescribing references was apparent. The development of universally-adopted, evidence-based, prescribing guidelines for CKD might optimize medications safety in this vulnerable group.