Feasibility, reliability and safety of self-assessed orthostatic blood pressure at home

Abstract

Background: A postural blood pressure assessment is required to diagnose Orthostatic Hypotension. With increasing remote consultations, alternative methods of performing postural blood pressure assessment are required. Objective: Determine whether postural blood pressure measurement at home, without a clinician, is reliable, feasible and safe. Design: Service improvement project within a falls and syncope service in Northeast England. Subjects: Eligibility criteria: aged ≥60 years; postural blood pressure measurement is indicated and is physically and cognitively able to perform. Exclusion criteria: nursing home residents, attending clinic in person. Methods: Postural blood pressure measurements were performed in patients' homes under clinical observation. Patient-led assessments were performed independent of the clinician, following written guidance. This was followed by a clinical-led assessment after 10-minute supine rest. Outcomes: Agreement between patient and clinician derived postural blood pressure values and diagnosis of Orthostatic Hypotension; intervention safety, feasibility and acceptability. Results: Twenty-eight patients were eligible and 25 participated (mean age 75, median Clinical Frailty Score five). There was 95% agreement (Cohen's kappa 0.90 (0.70, 1.00)) between patient and clinician derived readings to diagnose orthostatic hypotension. Postural systolic blood pressure drop correlated strongly (r = 0.80), with patient derived readings overestimating by 1 (-6, 3) mmHg. Limits of agreement, determined via Bland Altman analysis, were +17 and -20 mmHg, greater than pre-determined maximum clinically important difference (±5 mmHg). Twenty participants performed valid postural blood pressure assessments without clinical assistance. Conclusions: Patient-led postural blood pressure assessment at home is a reliable, safe and acceptable method for diagnosing Orthostatic Hypotension.