Direct access ambulatory BP monitoring--the Edinburgh experience

The use of electronic measurement of blood pressure and, in particular, ambulatory blood pressure monitoring offers the opportunity to determine which patients with apparent hypertension have truly sustained elevation of their blood pressure levels. Given the high prevalence of hypertension and the even larger number of individuals who appear to be hypertensive but may not be so, it is difficult to deliver ambulatory blood pressure monitoring to all individuals who might benefit from it. In Edinburgh, Scotland, we have piloted a system of direct access ambulatory blood pressure monitoring whereby physicians in primary care can request of the hospital service, an ambulatory monitor on their patient without the patients attending a formal hospital clinic. In the 7 years since the service was first instituted, almost 6,000 monitors have been performed with referrals running at approximately 100 per month in recent times. The present study was set up to assess the impact of the ambulatory monitor result on clinical decision making in primary care. The referral form invited primary care physicians to indicate their planned management if an ambulatory monitor had not been available and we thereafter audited patient records to determine what ultimately happened following the advice given on the basis of the ambulatory monitoring record.A random sample of results was obtained on untreated patients and approximately 500 were analysed. It was clear that if the advice to the primary care physician based upon the ABPM was not to treat, that this was largely followed with some 94% of patients not receiving treatment within 3 months of the monitor. If, however, the advice given was to start treatment, this was less reliably followed and in only 76% of patients treatment was started within 3 months. At the time of the audit this figure had increased to 82%. Primary care physicians had indicated that they would have treated 60% of the individuals referred and in reality only treated 40%. The potential saving in drug costs from the reduction by 20% of those treated would have significant impact on health care budgets.