High Prevalence of Hypertension in a Danish Population Telemedical Home Measurement of Blood Pressure in Citizens Aged 55-64 Years in Holstebro County.

Background: Home blood pressure (HBP) is prognostically superior to office BP (OBP) and similar to ambulatory BP measurements. We determined the prevalence of hypertension using HBP with telemedical data transmission in the municipality of Holstebro, Denmark (57,000 citizens).

Methods: Using the Civil Registration System, we invited citizens aged 55-64 years to have their OBP and HBP measured using telemedical data transmission. Elevated OBP was defined as ≥140/90mm Hg. HBP was measured 3 times daily on 3 consecutive days with 3 measurements on each occasion. HBP was the mean of all measurements on day 1 and 3, and hypertension was defined as ≥135/85mm Hg.

Results: We included 3,102 citizens who had performed at least 12 HBP measurements during day 2 and 3. Group 1: (n = 1,464, 47%) had both normal OBP and HBP. Group 2: (n = 838, 27%) had both elevated OBP and HBP indicating persistent hypertension. Group 3: (n = 560, 18%) had elevated OBP and normal HBP indicating white coat hypertension (WCH). Group 4: (n = 240, 8%) had normal OBP and elevated HBP indicating masked hypertension (MH). Thus, 1,078 (35%, groups 2 and 4) were untreated or insufficiently treated. Awareness of hypertension was registered in 950 patients (31%) and of these 49% had a normal HBP.

Conclusions: This is the first large-scale study to eliminate completely reporting bias by using telemedical transmission of BP data. One third of citizens in the age group 55-64 years had an abnormally high HBP, and one fourth either had WCH or MH.

Clinical Trials Registration: ClinicalTrials.gov identification number: NCT02355392.