[IMPLEMENTING AMBULATORY BLOOD PRESSURE MONITORING (ABPM) IN THE PRIMARY CLINIC]

Hypertension (HTN) is the leading reversible risk factor for cardiovascular morbidity and all-cause mortality. Screening is currently based on office blood pressure measurement (OBPM) - a method that is neither sensitive nor specific in detecting true HTN. Home blood pressure monitoring, which is often used to confirm and follow-up the diagnosis of HTN, is limited in its ability to detect certain blood pressure (BP) patterns that are harmful, and not covered by Israeli health insurers. Over the last two decades, the alternative and gold standard - 24 hours ambulatory blood pressure monitoring (ABPM) has become cheap and easy to use, but it is virtually nonexistent in primary care clinics.

This research aims to assess the clinical and distributional benefits of operating an ABPM in the primary clinic, without utilising any additional external resources besides the ABPM monitor, which was borrowed for this purpose from the regional Israeli Defense Force's Medical Corps (IDFMC) health-care center. All service-members in a medium sized Israeli Air Force (IAF) airbase were screened for HTN using OBPM. Inclusion criteria were BP over 130/85 at least once during the past two years or a personal or family history of HTN. Exclusion criteria were any antihypertensive medication taken over the past 6 months, renal dysfunction or secondary HTN.

A total of 2167 patients were screened, of whom 64 (2.9%) met selection criteria. Of these, 56 (87.5%) responded to our invitation and performed full OBPM on three separate occasions. During an 8 weeks long lease 46 of 47 (96.4%) available slots were utilized - 2.19 times more efficient than the regional clinic average utilization rate. Of 18 patients who have been diagnosed with HTN in the past, 13 (72.2%) met the criteria on OBPM but only 6 (46.1%) of these were confirmed as having HTN on ABPM. The positive predictive value (PPV) of abnormally high BP on OBPM for the diagnosis of HTN on ABPM averaged 41.3%. The negative predictive value (NPV) of normal OBPM was 80% and 83.4%, for patients diagnosed in the past with HTN or having risk factors (obesity and family history), respectively.

The therapeutic, prognostic and economic implications of the diagnosis of HTN necessitate the utilization of an accurate diagnostic tool. Recent advancements, making ABPM affordable and easy to use, combined with the immediate and dramatic clinical implications witnessed when ABPM was used in our clinic, necessitate a closer look at the need to make ABPM available at the primary clinic.