Risk-adjusted versus overall blood pressure control rate for identifying the need for intensified cardiovascular risk reduction: lessons from a cross-sectional study

OBJECTIVE: To compare a cardiovascular risk (CVR)-adjusted with the traditional blood pressure (BP) control rate for assessing BP control and consequent target populations for intensified treatment.

METHODS: Model calculation using cross-sectional data retrieved from 89 German general practices; a random sample of 3355 patients with known hypertension was consecutively enrolled by their general practitioners. Cardiovascular history and risk factors were documented. In addition to the traditional control rate (fixed BP target <140/90), we calculated CVR-adjusted control rates, stratifying analyses according to three CVR categories and their corresponding BP targets on the basis of the European Cardiovascular Society's SCORE tables: (1) very high CVR, owing to manifest cardiovascular disease (CVD), BP target <130/80; (2) high CVR, BP target <140/90; and (3) low CVR, BP target <160/100 mmHg.

RESULTS: Traditional vs. CVR-adjusted BP control rates were 55.1 vs. 14.9% (manifest CVD, kappa 0.27), 36.7 vs. 35.8% (high CVR, kappa 0.98), 52.6 vs. 88.5% (low CVR, kappa 0.25), and 45.8 vs. 46.5% (overall, kappa 0.61). Among the study patients, 19.2% switched from 'controlled' to 'uncontrolled' or vice versa depending on the criterion applied.

CONCLUSIONS: Compared with the traditional BP control rate, the CVR-adjusted approach identifies a substantially different - although overall similarly large - target group for intensified cardiovascular risk reduction. Using CVR-adjusted BP control rates in surveys describing hypertension management could help to focus attention and resources on reducing CVR in patients who are likely to benefit from additional treatment efforts.