Progression of White Coat Hypertension to Sustained Hypertension in a Large Primary Care Cohort of Older Adults

Objective: White Coat Hypertension (WCH) is defined as high clinic blood pressure (BP) with normal home or ambulatory BP, with an estimated prevalence of 13% (10% - 50%), increasing in older age. Untreated WCH is associated with progression to sustained hypertension (∼42%), increased cardiovascular events and target-organ damage. However, the clinical implications of WCH are less well understood in older populations. We aimed to quantify the cumulative incidence and timing of progression from WCH to sustained hypertension in a representative cohort of older people aged >=60. Design and method: We identified individuals aged >=60 years with WCH recorded in a large longitudinal primary care electronic health record database (01/01/2010 - 01/12/2024; >9 million patient records). Follow-up accrued from WCH index date until sustained hypertension was recorded or censoring at end of observation. Progression was summarised as: (1) ever progressed during observed follow-up (a function of both underlying risk and available follow-up time); (2) crude cumulative proportions at 1, 3 and 5 years (events by time <=t divided by the baseline cohort size); and (3) Kaplan-Meier cumulative incidence (1-survival) at the same horizons to account for right censoring, recognising that crude proportions can underestimate longer-term risk when follow-up is incomplete. Results: 60,128 WCH patients; mean age 71 years (60–102), 38% female. 30,374 (50.5%) progressed to sustained hypertension during the observed follow-up period. Crude progression proportions were 19.0% (11,407) at 1 year, 32.8% (19,709) at 3 years, and 39.7% (23,892) at 5 years. Kaplan-Meier cumulative incidence was 19.38% at 1 year (95% confidence interval 19.06–19.70), 34.77% at 3 years (34.38–35.17), and 43.53% at 5 years (43.10–43.95), exceeding crude estimates at later time points consistent with censoring adjustment. Conclusions: In this large real-world cohort of older adults with recorded white coat hypertension, approximately half progressed to sustained hypertension during follow-up, with censoring-adjusted risk exceeding 40% by five years. These findings underscore that WCH frequently represents an early, high-risk phenotype warranting structured surveillance and timely escalation of out-of-office BP monitoring and preventive care into later life.