Background and objectives
Ambulatory blood pressure monitoring (ABPM) has been used at Ullevål University Hospital (UUS) regularly since 1990. This study aimed to look at the reasons for referral for ABPM, blood pressure at the time of referral (casual blood pressure, CBP), and the differences between CBP and ABP.
Material and methods
Information was collected from 498 randomly selected ABPM registrations at the hypertension clinic at UUS from 1998-2000. Patients were grouped according to gender, age, causes of referral, and duration of hypertension based on information in referral forms. Casual blood pressure, diabetes and antihypertensive treatment were registered. We calculated white coat effect, white coat hypertension and dipping patterns.
Reasons for referral for ABPM included diagnosing actual hypertension, white- coat hypertension, resistant hypertension, hypotensive episodes and pointing out lack of blood pressure control. The CBP was 166.3 ± 22.4/98.8 ± 10.9 mmHg. ABP values were significantly lower than CBP, 138.6 ± 16.1/ 83.1 ± 11.0 mmHg for 24- hour ABP. There was a significant white coat effect with no gender differences. A close relationship was observed between conventionally measured white coat effect and age.
The information provided in the referral forms was highly insufficient with blood pressure measurement lacking in almost 25 %. Information regarding diabetes, treatment and duration of hypertension was also deficient. This gives room for improvement when writing referral forms for ABPM. CBP was significantly higher than ABP, indicating a white coat effect, which is of clinical importance.