When should hypertension be treated? The different perspectives of Canadian family physicians and patients

Background: Hypertension guidelines from different organizations often spec ify different treatment thresholds, and none explicitly state how these thr esholds were chosen. This study was undertaken to determine the treatment t hresholds of family physicians and hypertensive patients for mild, uncompli cated essential hypertension. A subject's treatment threshold can be determ ined by eliciting the minimum reduction in cardiovascular risk that he or s he feels outweighs the inconvenience, costs and side effects of antihyperte nsive therapy (the minimal clinically important difference [MCID]). Methods: The study subjects consisted of a random sample of family physicia ns and a consecutive sample of hypertensive patients without overt cardiova scular disease from Ottawa and Edmonton. To determine participants' MCIDs, we used a survey employing hypothetical scenarios teach depicting a differe nt baseline cardiovascular risk) and a probability trade-off tool. Results: Of 94 family physicians and 146 patients approached for the study, 72 and 74 participated respectively. There was marked variability in the M CIDs of both groups. In general, patients were less likely to want antihype rtensive therapy than physicians, particularly when baseline cardiovascular risks were low: 49% v. 64% (p = 0.06), 68% v. 92% (p < 0.001) and 86% v. 1 00% (p = 0.001) for 5-year cardiovascular risks of 2%, 5% and 10% respectiv ely. Moreover, patients expressed larger MCIDs (i.e., wanted greater benefi ts before accepting therapy) than physicians. However, a subgroup of patien ts (15% to 26%, depending on the scenario) wanted treatment even if there w as no anticipated benefit. Multivariate analysis showed that no sociodemogr aphic factors strongly predicted the MCIDs of either group. Interpretation: Guidelines that set treatment thresholds on the basis of ph ysician or expert opinion may nor accurately reflect the preferences of hyp ertensive patients. There is a need for patient decision aids and attention to patient preferences when initiation of antihypertensive therapy is cons idered for the prevention of cardiovascular disease. Further research is ne eded to define treatment thresholds for other chronic conditions and in oth er groups.