Prevalence of inpatient blood pressure elevations in Australian hospitalised patients and analysis of associated factors.

Background: Hypertension is a significant cardiovascular risk factor. While community hypertension is well studied, inpatient hypertension remains poorly understood with limited epidemiological data in Australian cohorts. We therefore investigated the prevalence and factors associated with inpatient systolic blood pressure (SBP) elevations, defined as SBP ≥140 mmHg using Australian data.

Methods: We conducted a retrospective cohort study on non-cardiac inpatients aged ≥65 admitted to general medical wards at Flinders Medical Centre, Adelaide (January-April in 2022-2024). Blood pressure recordings during hospital stay were extracted from electronic medical records. The primary endpoint was ≥10 SBP readings ≥140 mmHg, with secondary endpoints being at least one, two or three readings ≥140 mmHg.

Results: Among 753 eligible patients, 94.2% had at least one, 89.4% two, 85.7% three and 65.2% 10 SBP readings ≥140 mmHg. Independent factors positively associated with ≥10 elevations included age (years) (OR = 1.022, CI 1.00-1.04, P = 0.033), number of comorbidities (OR = 1.203, CI 1.06-1.35, P = 0.0026), length of stay (days) (OR = 1.041, CI 1.02-1.07, P = 0.002), antihypertensive use prior to admission (OR = 1.95, CI 1.26-3.02, P = 0.003) and use of calcium channel blockers (OR = 2.55, 1.53-4.25, P < 0.001). Whereas beta-blocker use (OR 0.593, CI 0.38-0.92, P = 0.020), history of coronary artery disease (OR = 0.59, CI 0.38-0.90, P = 0.015), chronic obstructive lung disease (OR = 0.46, CI 0.39-0.69, P < 0.001) and heart failure (OR = 0.43, CI 0.27-0.7, P < 0.001) were negatively associated.

Conclusions: This study provides first evidence of the epidemiology of inpatient SBP elevations in Australian inpatients and the associated factors. Further research should determine the clinical significance of these elevations and the impact of blood-pressure-lowering strategies in hospital settings.