High blood pressure in the emergency department as an opportunistic screening tool for detection of hypertension.

Hypertension is the most preventable cause of morbidity and mortality, but many individuals are underdiagnosed and lack treatment control. High blood pressure (BP) in the emergency department (ED) is commonly observed, but mostly used for short-term evaluation. We aimed to study the usefulness of high BP in the ED as a screening tool for undiagnosed hypertension. We used the electronic medical record system to identify all patients that had attended the ED at a university hospital from 2018-01-01 to 2018-03-31 and from 2018-07-01 to 2018-09-30 with an obtained systolic BP ≥ 160 and/or diastolic BP ≥ 100 mmHg measured at the ED. We excluded patients with previously diagnosed hypertension and patients on BP-lowering medication. All patients identified where contacted two years after attending the ED, with a letter of consent and a questionnaire regarding diagnosis of hypertension and current medication. 5424 patients attended the ED during the 6-months-period. 271 patients met the inclusion criteria and were asked to participate. 167 individuals (62%) agreed to participate and responded to the questionnaire. Mean age of participants were 63.1 years and 51% were women. 134 patients (80%) had measured their BP after the ED-visit, and 48 (36%) of those had been diagnosed with hypertension. 96% of patients diagnosed with hypertension were on BP-lowering medication. To follow-up BP ≥ 160/100 mmHg after an ED visit can reveal undiagnosed hypertension in one third of the patients. Given the amount of undiagnosed hypertension, an ED-measured BP might provide an important tool to detect and start treatment of hypertension.