Delayed Hypertension Diagnosis and Its Association With Cardiovascular Treatment and Outcomes.

Importance: Hypertension is a major risk factor for cardiovascular disease, yet delays in diagnosis may limit timely treatment initiation and increase cardiovascular risk. Objectives: To examine the timing of clinical hypertension diagnosis, its association with antihypertensive medication prescribing, and its association with long-term cardiovascular outcomes. Design, Setting, and Participants: 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. Exposures: 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. Main Outcomes and Measures: 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. Results: 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]). Conclusions and Relevance: 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.