The impact of implementing national hypertension guidelines on prevalence and workload in primary care: a population-based survey of older people.

Recently revised UK and US hypertension guidelines have reduced thresholds for both diagnosis and treatment and differ in their recommendations. We have used data from a random, stratified community-based sample of 4784 people aged 65 years and over to compare the prevalence of treatable hypertension and the potential impact on patients and primary care from using current guidelines. BHS, NICE and JNC7 guidelines were applied to blood pressures obtained from primary care medical records (94%) or measured at a screening clinic (6%). Risk factors were obtained by questionnaire and from medical records, supplemented by epidemiological data. Workload was estimated for a representative practice population of 10 000 patients. Blood pressures were obtained on 4514 patients (94%). Prevalence of treatable hypertension was over 67%. Compared to BHS4, prevalence estimates using NICE guidelines were comparable for men but significantly lower for women (P<0.05). They were significantly higher using JNC7 compared with BHS4 and NICE guidance (P<0.05). A general practice of 10 000 patients could expect 1287 older hypertensive patients using BHS4 guidelines and 1231 patients using NICE guidelines. Under BHS4, an extra 94 patients will require annual, rather than 5-yearly review compared with that using the previous guideline. In conclusion, implementation of BHS4 guidelines, with their revised thresholds for diagnosis, will not add materially to the prevalence of treatable hypertension compared to previous BHS3 guidelines but will have a major impact on practice workload. Use of NICE guidelines in preference to BHS4 will result in GPs treating fewer patients and reviewing untreated patients less often.