Interpractice variation in prevalence of hypertension is due to inadequate detection

Editor—An interpractice audit of the diagnosis and management of hypertension in primary care found that hypertension remained uncontrolled in over three fifths of hypertensive patients despite the implementation of an intensive audit; this is disappointing.1 Another common deficiency in the management of hypertension—the failure of health care services to detect and diagnose the condition—was not, however, addressed.

Data from table 1 in the paper can be used to calculate the crude prevalence of hypertension in individual practices. This varied between 1.61% and 5.01% (mean 3.2%) during phase 1 of the study, which suggests that the detection of hypertension varied widely. This is confirmed by data from the MEDICS (morbidity and epidemiology data interchange and comparison scheme) project in Northumberland. Prevalence data for common chronic diseases have been collected from computerised records at 33 practices covering a population of 200 000 people. In March 1995 the crude prevalence of recorded hypertension in adults (aged >15) varied from 3.0% to 13.2% (mean 6.7%)—from 2.6% to 10.9% (mean 5.5 %) in men and 3.4% to 15.6% (mean 7.9%) in women. This variation persisted when data were indirectly standardised for age and expressed as standardised morbidity ratios.

MEDICS practices should probably be better than most at detecting and recording hypertension because they are all computerised, provide data on the prevalence of hypertension for the health promotion banding scheme, and participate in a project collecting morbidity data. They are also situated in a district …