The management of hypertension in the elderly by general practitioners in Merseyside: the rule of halves revisited.

BACKGROUND: Treatment of hypertension in the elderly significantly reduces cardiovascular events and confers greater absolute benefit compared with treating younger adults. However, this group has been undertreated in the past. AIM: To perform a reliable and valid multipractice audit of the current management of elderly hypertensive patients.
METHOD: An observational study conducted as multiple standardized audits in general practices. The notes of 6139 patients aged 65 years or over from 76 general practices in Merseyside were examined to determine the percentage of elderly patients who had their blood pressure recorded. The percentages of hypertensive patients who were diagnosed, treated, and controlled was also recorded.
RESULTS: Eighty-one per cent of the sample had their blood pressure recorded. Fifty-three per cent of patients over the age of 65 were identified as hypertensive; 64% of hypertensive patients are receiving antihypertensive medication and 54% of treated hypertensive patients can be considered controlled. However, very small changes in the criteria used to define blood pressure control have dramatic effects on the results. Digit preference and the number of available blood pressure recordings also significantly affect the results.
CONCLUSION: The management of hypertension in the elderly by Merseyside general practitioners (GPs) gives better results than predicted by the 'rule of halves'. Elderly hypertensive patients are more likely to be detected and treated, but only half achieve control to 160/90. The results are particularly sensitive to the degree of digit preference, the number of available recordings, and to the precise definition used for control.