Abstract 2459: The VA Electronic Health Record Controls Hypertension and Eliminates Differences due to Age - A Large Multiyear Multicenter Analysis Displaying Seasonal Variation
Background: “Hypertensives Returning to Normal” (HRN) monitors hypertension control throughout the VA. The VA Health Data Repository (HDR) is aggregated from the Electronic Health Record (EHR) in use at all VA facilities and contains > 1.3 billion vitals.
Methods: VA hospitals in 15 cities included 1,272,074 patients with 23,399,736 blood pressure (BP) records. Hypertensive patients had lowest BP on each of 3 separate days >140 Systolic or >90 Diastolic. Normal BP was ≤140 and ≤90. Seasonal variation was the difference in % HRN in winter and summer. Age and weight were assessed for yearly improvement and seasonal changes.
Results: There were 522,264 hypertensive patients analyzed for HRN. The average HRN increase was 2.3% ± 0.01 per year (p <0.0001). Each city had a HRN worse in winter than summer (8.2% ± 0.01, p<0.0001). Seasonal variation did not correlate with latitude. In Jan 2000, patients <55 years old were easier to control than those 55 – 70, or those >70 (53.8%, 45.0%, 41% respectively p<0.001). Patients >80 were identical to those >70. After national hypertensive reminders were introduced, all age groups became equally controlled by Dec 2007 (63.0, 63.9, and 64.8 % respectively p=NS). All age groups had similar seasonal variation. Weight increased (1.8 ± 0.34 pounds p<0.001) each winter.
Conclusions: In all cities fewer hypertensives return to normal in winter than in summer. Hypertension patients may require increased anti-hypertensive intervention during winter months. A common approach to hypertensive control using the EHR reminders eliminates differences in control due to age. While not necessarily causal, weight increased each winter along with BP.