Antihypertensive use pattern of medicated hypertensive patients followed at Primary Care Health Centers of the Lisbon Health Region

Trabalho Final de Mestrado Integrado, Ciências Farmacêuticas, Universidade de Lisboa, Faculdade de Farmácia, 2014Introduction: Hypertension (HTN) is a risk factor which is in the basis of Cardiovascular Diseases (CVD) occurrence. The low proportion of controlled hypertensive patients supports the need of a better understanding of current antihypertensive (aHT) treatments strategies. Clinical inertia is recognized as a barrier to a good management of aHT therapy. The aim of the study was to describe aHT use pattern in Lisbon Health Region (LHR) population and to characterize aHT therapeutic change and associated factors. Issues like BP control and medication adherence were also described. Methods: DIMATCH-HTA is an observational population-base cohort study. Hypertensive medicated patients followed at Primary Care Health Centers (PHCC) of the LHR were stratified in two different cohorts, according to their status as immigrants from Portuguese Speaking African countries or native. Participants were followed-up during 12 months with face-to-face interviews each 6 month and phone interviews at 3 and 9 months. Socio- demographic characteristics and data about hypertension, such as time since the diagnosis, comorbidities and lipid disorders, were collected. Self-report of aHT medication was also collected at each face-to-face or telephone interview. Between-group comparisons were performed using Chi-square for qualitative measures or Student's t-test, Mann-Whitney test, Kruskal-Wallis test or one-way analysis of variance (ANOVA) for quantitative variables. To study the predictors of therapeutic change over time, bivariate and multivariate analysis for correlated data were performed. Results: A total of 223 (76.6%) participants took more than one aHT drug. The most frequently used aHT class was diuretics, being the majority part of them used in polytherapy. Angiotensin receptor antagonists was the second most used class, followed by calcium- channel blockers, angiotensin-converting-enzyme inhibitor and, finally, beta-blockers. Renin- angiotensin axis inhibitor agents combined with diuretics were the most frequent regimens used. Regarding therapeutic changes, 209 (71.8%) participants did not change their aHT therapy over time. Time since diagnosis was identified as a factor significantly inductor of changes in therapy (OR=1.02) as well as the presence of diabetes (OR=1.97) and high cholesterol (OR=1.88). Medical visits during follow-up (OR=2.49) and systolic blood pressure (SBP) in the previous study moment (OR=1.03) were also significantly associated to therapeutic changes over time. In a multivariate analysis, medical visits and SBP in previous moment were independent risk factors for therapeutic changes (OR (medical visit) = 2.29; OR (SBP in previous moment) = 1.03). Participants who didn't change their aHT therapy over time had significantly lower mean SBP than participants who changed aHT therapy (0 M: p value 0.001; 6 M: p valu