Hypertension and primary aldosteronism diagnosis in hospitalized patients: an observation from public hospitals in Victoria, Australia

Current efforts of increasing diagnosis of primary aldosteronism (PA), a potentially curable but under-diagnosed form of hypertension, have been limited to primary care and specialist clinics, leaving out additional opportunities within healthcare. This study estimated hypertension and PA diagnosis rates during hospital admission. Public hospital admissions in Victoria, Australia, between 2007/8 and 2018/19 from patients aged ≥ 15years were retrospectively analysed to estimate rates of hypertension as principal diagnosis and PA as principal and secondary diagnosis to hypertension. There were 27,749,684 admissions identified in the period, with 53.2% females and 68.2% aged ≥ 50years. Nine in 10,000 had a principal diagnosis of hypertension and 51 hypertensive patients also had PA (0.21%, 95% confidence interval 0.15%-0.26%). Principal diagnosis of PA occurred in 0.31/10,000 admissions, with higher diagnosis among males than females (0.34/10,000 vs. 0.29/10,000 admissions; p-value = 0.019) and highest amongst patients aged 50-59years (0.63/10,000 admissions) compared with 0.23/10,000 and 0.07/10,000 amongst those aged < 40years and ≥ 70years, respectively. Under 1% of patients admitted into hospital had a principal diagnosis of hypertension. Although this number is small, the presentations offer an opportunity for clinicians to test patients for PA. The proportion of hypertensive patients diagnosed with PA during admission was lower than the estimated 15% prevalence among hypertensive individuals, however this also highlights that PA diagnosis can occur in this setting. Future research should explore barriers and facilitators to PA diagnosis when patients are admitted to hospital with hypertension, and develop strategies to support timely diagnosis in this setting.