Trends in baseline characteristics of hypertensive patients on Angiotensin-converting enzyme inhibitors compared to other antihypertensive medications

Abstract

Background and objective: Observational studies are considered more appropriate in the assessment of comparative effectiveness in the general population. We aimed to explore the trends in differences in baseline characteristics in terms of age, sex, blood pressure, body mass index, smoking and diabetes between users of Angiotensin-converting enzyme inhibitors and other antihypertensive drug classes in observational studies since the launch of Angiotensin-converting enzyme inhibitors. Methods: We reviewed observational studies that compared Angiotensin-converting enzyme inhibitors with mono-therapies of calcium channel blockers, beta-blockers and diuretics in primary care treatment of hypertensive patients. Electronic search of studies in Medline and Embase were performed up until to June 2014. Randomized control trials, non-antihypertensive, non-comparative or combined antihypertensive drug classes observational studies and studies with participants <100 patients were excluded. Results: A total of 28 studies were included in the review. There was a declining trend in the mean difference in baseline systolic and diastolic blood pressure over time but no clear pattern was observed for the difference in proportion of male sex, diabetes and smoking or the difference in mean age and body mass index . Conclusion: Findings from this study suggest a downward trend in the differences in mean systolic and diastolic blood pressure of angiotensin-converting enzyme inhibitors users compared to diuretics and beta-blockers users and no clear pattern in other baseline variables.