Home blood pressure measurement as a screening tool for hypertension in a web-based worksite health promotion programme

BACKGROUND: Guidelines on home blood pressure measurement (HBPM) recommend taking at least 12 measurements. For screening purposes, however, it is preferred to reduce this number. We therefore derived and validated cut-off values to determine hypertension status after the first duplicate reading of a HBPM series in a web-based worksite health promotion programme. METHOD: Nine hundred forty-five employees were included in the derivation and 528 in the validation cohort, which was divided into a normal (n = 297) and increased cardiometabolic risk subgroup (n = 231), and a subgroup with a history of hypertension (n = 98). Six duplicate home measurements were collected during three consecutive days. Systolic and diastolic readings at the first duplicate measurement were used as predictors for hypertension in a multivariate logistic model. Cut-off values were determined using receiver operating characteristics analysis. RESULTS: Upper (≥ 150 or ≥ 95 mmHg) and lower limit (<135 and <80 mmHg) cut-off values were derived to confirm or reject presence of hypertension after one duplicate reading. The area under the curve was 0.94 (standard error 0.01, 95% confidence interval 0.93-0.95). In 62.5% of participants, hypertension status was determined, with 1.1% false positive and 4.7% false negatives. Performance was similar in participants with high and low cardiometabolic risk, but worse in participants with a history of hypertension (10.4% false negatives). CONCLUSION: One duplicate home reading is sufficient to accurately assess hypertension status in 62.5% of participants, leaving 37.5% in which the whole HBPM series needs to be completed. HBPM can thus be reliably used as screening tool for hypertension in a working population.