Quality management of hypertension in primary care: Do physicians treat patients' blood pressure level or cardiovascular risk?

Background: The risk of cardiovascular disease in patients with hypertension is determined not only by the level of blood pressure but also by the presence of target organ damage and other risk factors. Numerous guidelines for management of hypertension emphasise the importance of using stratification for total cardiovascular risk in clinical decision making. Aim: We investigated if primary care physicians consider individual cardiovascular risk, in addition to blood pressure level, when they select a treatment strategy. Secondarily, we evaluated physicians' performance in clinical management and pharmacological treatment of hypertension, to determine predictors of control and intensity of treatment. Methods: A cross-sectional study was conducted in an academic health maintenance organisation (HMO). A sample of 1200 records of patients with hypertension was examined to evaluate potential predictors of poorly controlled hypertension (≥160-95 mmHg) as well as predictors of change in the systolic and diastolic blood pressure (SBP and DBP respectively). Stages and groups risk stratification was used as reported by the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC VI). Results: A total of 922 hypertensive patients were included. Patient mean (± standard deviation (SD)) age was 59.5 (±15.6) years, 56.8% women, and average follow-up was 42.86 (±22.7) months, with 3.42 (±4.7) visits per year. The percentage of patients with well-controlled hypertension (< 140-90 mmHg) was 53.5%, and with poorly controlled hypertension, was 18.2%. The mean SBP and DBP at the initial visit was 155 ± 20 mmHg and 98.9 ± 40.6 mmHg respectively. There was a statistically significant gradient between control rates across stages (62.2%, 53.1% and 39.1% for stages 1, 2 and 3, respectively (P= 0.001)). There was no difference when control rates were compared across risk groups (58.6%; 51.3% and 54.4% for groups A, B and C respectively (P = 0.83)). There was a statistically significant difference between intensity of treatment according to stages, the higher the stage the more intensive the treatment (P≤ 0.05). No difference was found across risk groups adjusted by stage. The initial stage and the time of follow-up in months were the only predictors of intensity of treatment in the multivariate analysis: the higher the initial stage (odds ratio (OR) = 1.97, 95% confidence interval (CI) = 1.6-2.4), and the longer the follow-up (OR = 1.02, 95% CI= 1.01-1.02), the higher the intensity of treatment. Conclusion: Although blood pressure was reduced as a consequence of more intensive treatment in those patients with higher level of initial blood pressure, the fact that risks were not related to intensity of treatment emphasise that physicians did not consider patients' overall risk stratification when adopting a more aggressive approach in hypertension clinical management. Primary care physicians need to incorporate patients' risk profile to improve the quality of care of the hypertensive population. Better management of pharmacological therapy will be required to overcome dinical inertia.