Delayed Hypertension Diagnosis and Its Association With Cardiovascular Treatment and Outcomes

Hypertension is a major risk factor for cardiovascular disease, yet delays in diagnosis may limit timely treatment initiation and increase cardiovascular risk.

To examine the timing of clinical hypertension diagnosis, its association with antihypertensive medication prescribing, and its association with long-term cardiovascular outcomes.

This retrospective cohort study analyzed electronic health record (EHR) data from an integrated health care system. Adults aged 18 to 85 years with at least 2 outpatient blood pressure (BP) readings of 140/90 mm Hg or more recorded at least 30 days apart from January 1, 2010, to December 31, 2021, were included (meeting BP-based criteria for hypertension as recorded in the EHR; ie, a "computed hypertension diagnosis"). Data were analyzed from January to November 2023.

The timing of clinical hypertension diagnosis (the formal recorded diagnosis by a clinician) relative to the second elevated BP measurement was categorized as (1) preexisting diagnosis; (2) diagnosed between the first and second BP elevations (reference group); (3) diagnosed after the second BP elevation, subdivided into 1 to 90 days, 91 to 365 days, or more than 365 days after the second BP elevation; and (4) no recorded diagnosis.

The primary outcome was antihypertensive medication prescription within 30 days of diagnosis. The secondary outcome was the 5-year composite risk of myocardial infarction, ischemic stroke, or heart failure hospitalization. A multivariable Cox proportional hazards regression model estimated hazard ratios (HRs) for cardiovascular outcomes, adjusting for demographics, BP, and comorbidities.

Among 311 743 patients with a computed hypertension diagnosis, 14.6% received a diagnosis after the second BP elevation (mean [SD] age 57.9 [13.1] years; 53.3% women; 69.6% non-Hispanic White, 24.9% non-Hispanic Black, 2.4% Hispanic or Latino, and 1.7% non-Hispanic Asian). Delayed diagnosis was associated with lower antihypertensive medication prescription rates (30.6% vs 75.2%; P < .001) and increased cardiovascular risk over 5 years (delay of 1-90 days: HR, 1.04 [95% CI, 0.95-1.13]; delay of 91-365 days: HR, 1.11 [95% CI, 1.04-1.19]; and delay of >365 days: HR, 1.29 [95% CI, 1.23-1.36]). Greater delay in clinical diagnosis of hypertension was associated with younger age (45-64 years: median delay, 17.5 months [IQR, 6.1-34.6 months] vs ≥75 years: median delay, 13.4 months [IQR, 4.7-28.2 months]; P < .001), female sex (median delay, 16.6 months [IQR, 5.8-33.7 months] vs male sex: median delay, 16.1 months [IQR, 5.7-33.1 months]; P < .001), and non-Hispanic Asian or non-Hispanic Black race (non-Hispanic Asian: median delay, 18.5 months [IQR, 6.9-34.0 months]; non-Hispanic Black: median delay, 17.2 months [IQR, 5.8-34.9 months]; vs non-Hispanic White: median delay, 16.3 months [IQR, 5.9-33.3 months]).

This study suggests that delays in hypertension diagnosis were common and significantly associated with delays in treatment initiation and adverse cardiovascular outcomes, underscoring the need for earlier identification and intervention.