Healthcare resource utilisation and cost associated with elevated potassium levels: a Danish population-based cohort study

OBJECTIVES: To investigate healthcare costs associated with hyperkalaemia (HK) among patients with chronic kidney disease (CKD), heart failure (HF) or diabetes. DESIGN: Before–after cohort study of patients with HK and matched patients without HK. SETTING: Population-based databases covering primary and secondary care for the entire of Northern Denmark. PARTICIPANTS: Patients with a first incident record of CKD (n=78 372), HF (n=14 233) or diabetes (n=37 479) during 2005–2011. Among all patients experiencing a first HK event (potassium level >5.0 mmol/L), healthcare costs were compared during 6 months before and 6 months after the HK event. The same cost assessment was conducted 6 months before and after a matched index date in a comparison cohort of patients without HK. PRIMARY AND SECONDARY OUTCOME MEASURES: Mean costs of hospital care, general practice and dispensed drugs converted to 2018 Euros. RESULTS: Overall, 17 747 (23%) CKD patients, 5141 (36%) HF patients and 4183 (11%) diabetes patients with a first HK event were identified. More than 40% of all HK patients across the patient groups had subsequent HK events with successively shorter times between the events. In CKD patients, overall mean costs were €5518 higher 6 months after versus before first HK, while €441 higher in matched CKD patients without HK, yielding HK-associated costs of €5077. Corresponding costs associated with a HK event were €6018 in HF patients, and €4862 in diabetes patients. CONCLUSIONS: Among CKD, HF and diabetes patients, an incident HK event was common, and a large proportion of the patients experienced recurrent HK events. Substantial increase in healthcare costs associated with a HK event was observed in the HK patients compared with non-HK patients. These results are important to better understand the potential economic impact of HK among high-risk comorbid patients in a real-wold setting and help inform decision-making for clinicians and healthcare providers.