Interpreting home blood pressure monitoring (HBPM) results in patients with suspected hypertension involves using validated devices, standardised measurement techniques, and specific diagnostic thresholds. Patients should be advised to measure their blood pressure in a relaxed, seated position with the arm supported, using an appropriately sized cuff, and to take multiple readings over several days to obtain an average value NICE NG136.
HBPM is recommended as a confirmatory test when clinic blood pressure readings are elevated (140/90 mmHg or higher) but ambulatory blood pressure monitoring (ABPM) is unsuitable or not tolerated NICE NG136. The diagnostic threshold for hypertension using HBPM is generally 135/85 mmHg or higher, which is 5 mmHg lower than clinic thresholds, reflecting the lower white-coat effect in home settings NICE NG136.
When interpreting HBPM results, clinicians should consider the average of multiple readings taken during the patient’s usual waking hours, ideally over at least 3 to 7 days, excluding the first day’s measurements to improve accuracy NICE NG136. Consistency in measurement conditions is important to reduce variability NICE NG136.
HBPM can also help identify white-coat hypertension (elevated clinic but normal home readings) and masked hypertension (normal clinic but elevated home readings), which have implications for cardiovascular risk and management NICE NG136.
Recent literature supports these practices and emphasises the importance of device validation and patient training to ensure reliable HBPM data Dadlani et al. 2019. Furthermore, standards for ambulatory and home monitoring highlight the need for averaging multiple readings and considering patient-specific factors such as pulse irregularities, which may require manual measurement techniques or specialist referral Omboni et al. 2024.
In summary, HBPM results should be interpreted using validated devices, standardised protocols, and diagnostic thresholds of ≥135/85 mmHg averaged over multiple days, with attention to identifying white-coat or masked hypertension. This approach aligns with NICE guidelines and is supported by recent evidence on monitoring standards and clinical utility NICE NG136; Dadlani et al. 2019; Omboni et al. 2024.
Key References
- NG136 - Hypertension in adults: diagnosis and management
- (Dadlani et al., 2019): Ambulatory blood pressure monitoring in clinical practice.
- (Basalely et al., 2023): Ambulatory Blood Pressure Monitoring in Pediatrics, an Update on Interpretation and Classification of Hypertension Phenotypes.
- (Omboni et al., 2024): Standards for the Implementation, Analysis, Interpretation, and Reporting of 24-hour Ambulatory Blood Pressure Monitoring Recommendations of the Italian Society of Hypertension.