Risk factors for hypertensive crisis in adult patients: a systematic review protocol.

Objective: The objective of this review is to conduct comprehensive appraisal and synthesis of evidence on risk factors for hypertensive crisis and, specifically, hypertensive emergencies among adult patients with hypertension.

Introduction: Hypertensive crisis is the most extreme form of poorly controlled hypertension that may lead to acute target organ damage (hypertensive emergency). Hypertensive crisis is associated with increased mortality, high utilization of health care and escalated healthcare costs.

Inclusion criteria: This review will include epidemiological studies with participants over 18 years old with diagnosis of hypertension. The review will exclude pediatric, pregnant and postpartum patients. The review will consider studies that explore risk factors for hypertensive crisis, defined as an acute elevation of blood pressure equal or above 180/110 mmHg.

Methods: The search strategy aims to find both published and unpublished studies. The databases to be searched will include MEDLINE (Ovid), Embase, Cochrane Database of Systematic Reviews and Web of Science. Following the search, all identified studies will be screened against the inclusion criteria. Selected studies will be critically appraised for methodological quality. Data on exposures and outcomes will be extracted from papers included in the review. Quantitative data, where possible, will be pooled in meta-analysis. Effect sizes expressed as odds ratio and their 95% confidence intervals will be calculated. Heterogeneity of studies will be assessed statistically. Subgroup analysis to determine the association of risk factors with hypertensive emergencies will be conducted, if possible. Where statistical pooling is not possible, the findings will be presented in a narrative form.

Systematic review registration number: PROSPERO CRD42019140093.