Orthostatic hypotension and health outcomes: an umbrella review of observational studies

Purpose: Orthostatic hypotension (OH) is associated with older age and many negative clinical outcomes in geriatric practice. We aimed to capture the breadth of outcomes that have been associated with the presence of OH and systematically assess the quality, strength and credibility of these associations using an umbrella review with integrated meta-analyses. Methods: We systematically searched several major databases from their commencements through to 16th May 2019 for meta-analyses of observational studies of OH and any health-related outcome. We used these metrics to categorize the strength of evidence of significant outcomes (p < 0.05) from class I (convincing) to class IV (weak), according to the pre-established criteria. Results: From 975 abstracts, seven meta-analyses of 12 outcomes were included. For each outcome, the median number of studies was four, and the median number of participants was 46,493, with a median of 3630 incident cases. There was suggestive (class III) evidence that OH was associated with significantly higher risk of coronary heart disease (HR = 1.32, 95% CI 1.12–1.56), stroke (HR = 1.22, 95% CI 1.08–1.38), congestive heart failure (HR = 1.30, 95% CI 1.09–1.55), all-cause mortality (RR = 1.50, 95% CI 1.24–1.81), falls (OR = 1.84, 95% CI 1.39–2.44), and dementia (HR = 1.22, 95% CI 1.11–1.35). Conclusion: The current evidence base indicates that OH is significantly associated with a range of adverse cardiovascular, cognitive, and mortality outcomes in older people, although the strength of this evidence remains only suggestive. Further research in larger samples and with lower risk of bias is required to build a fuller picture of the impact of OH on health.