Epidemiology and health outcomes associated with hyperkalemia in a primary care setting in England.

Background: Real-world incidence, clinical consequences, and healthcare resource utilization (HRU) of hyperkalemia (HK) remain poorly characterized, particularly in patients with specific comorbidities.

Methods: Data from the Clinical Practice Research Datalink and Hospital Episode Statistics databases were analyzed to determine incidence of an index HK event, subsequent clinical outcomes, and HRU in the English population. Factors associated with index HK in a primary care setting were also identified for those with an index HK event during the study period (2009-2013) and matched controls.

Results: The overall incidence rate of an index HK event was 2.9 per 100 person-years. Use of renin-angiotensin-aldosterone system inhibitors was strongly associated with HK (odds ratio, 13.6-15.9). Few patients (5.8%) had serum potassium (K) retested ≤ 14 days following the index event; among those retested, 32% had HK. Following an index HK event, all-cause hospitalization, HK recurrence, and kidney function decline were the most common outcomes (incidence rates per 100 person-years: 14.1, 8.1, and 6.7, respectively), with higher rates in those with comorbidities or K > 6.0 mmol/L. Mortality and arrhythmia rates were higher among those with K > 6.0 mmol/L. Older age, comorbid diabetes mellitus, and mineralocorticoid receptor antagonist use were associated with HK recurrence. Relatively few patients received testing or prescriptions to treat HK following an event.

Conclusions: Severe index HK events were associated with adverse outcomes, including arrhythmia and mortality. Despite this, retesting following an index event was uncommon, and incidence of recurrence was much higher than that of the index event.