Sociodemographic and health-related differences in undiagnosed hypertension in the Health Survey for England 2015-2019

Background Hypertension is a leading cause of morbidity and mortality worldwide, yet a substantial proportion of cases are undiagnosed. Understanding the scale of undiagnosed hypertension and identifying groups most at risk is important to inform approaches to detection. Methods We used data from the 2015 to 2019 Health Survey for England, an annual, cross-sectional, nationally representative survey. Undiagnosed hypertension was defined by a measured blood pressure of 140/90mmHg or above but no history of diagnosis. Age-adjusted prevalence of undiagnosed hypertension was estimated across sociodemographic and health-related characteristics. To assess the independent association between undiagnosed hypertension and each characteristic, we fitted a logistic regression model adjusted for sociodemographic factors. Findings An estimated 30.7% (29.0-32.4%) of men and 27.6% (26.1-29.1%) of women with hypertension were undiagnosed. Younger age, lower Body Mass Index, and better self-reported general health were associated with an increased likelihood of hypertension being undiagnosed for men and women. Living in rural areas and in regions outside of London and the East of England were also associated with an increased likelihood of hypertension being undiagnosed for men, as were being married or in a civil partnership and having higher educational qualifications for women. Interpretation Hypertension is commonly undiagnosed, and some of the groups less at risk of hypertension are most likely to be undiagnosed. Given the high lifetime risk of hypertension and its strong links with morbidity and mortality, our findings suggest a need for greater awareness of the potential for undiagnosed hypertension, including among those typically considered ‘low risk’.