How common is hyperkalaemia? A systematic review and meta-analysis of the prevalence and incidence of hyperkalaemia reported in observational studies.

Background: The prevalence and incidence of hyperkalaemia, a potassium abnormality that can potentially have life-threatening consequences, are unclear.

Methods: The objective was to provide the most comprehensive overview of the epidemiology of hyperkalaemia to date within the general population, across different continents, in different healthcare settings and within pre-specified subgroups. Embase and MEDLINE were searched from database inception to 2 February 2021 using the Ovid SP platform. Relevant congress proceedings from 2018 to 2020 were also reviewed for inclusion. There was no language constraint applied. Observational studies from any time period and language reporting prevalence or incidence of hyperkalaemia within both adult and paediatric populations. Four investigators independently screened abstracts and assessed study quality of those meeting the pre-determined inclusion/exclusion criteria. Data extraction was conducted by the lead author with oversight from the senior author and data were pooled using a random-effects model. The measures assessed were the prevalence and incidence of hyperkalaemia. Prevalence was reported as a percentage, whilst incidence was reported as the rate per 100 person years.

Results: In total, 542 articles were included from an initial search of 14 112 articles. Across all adult studies, we report a prevalence of hyperkalaemia (by any definition/threshold) of 6.3% [95% confidence interval (CI): 5.8-6.8%], with an incidence of hyperkalaemia in the adult population of 2.8 (2.3-3.3) cases per 100 person years. Prevalence within the general population was 1.3% (1.0-1.8%), whilst incidence was 0.4 (0.2-0.8) cases per 100 person years. There was a variation by sex with a prevalence of 6.3% (4.9-8.0%) in males and 5.1% (4.0-6.6%) in females. Prevalence also varied according to the definition/threshold of hyperkalaemia used: >5 mmol/L-8.0% (7.2-8.9), ≥5.5 mmol/L-5.9% (3.5-10.0) and ≥6.0 mmol/L-1.0% (0.8-1.4); hyperkalaemia (by any definition/threshold) was highest amongst patients with end-stage kidney disease (21.5%; 18.3-25.3), kidney transplant patients (21.8%; 16.1-29.5) and patients with acute kidney injury (24.3%; 19.3-30.7).

Conclusions: This novel review provides a comprehensive and valuable resource on the prevalence and incidence of hyperkalaemia to better inform clinicians, healthcare providers and health policy makers on the burden of hyperkalaemia across different healthcare settings, patient populations and continents.