Ashton CM (Houston VA)
for_the_Houston_VA_ALLHAT_Implementation_Group (Houston VA)
Our project focused on the implementation of the results of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). ALLHAT, published 12/18/02, showed that thiazide-based antihypertensive regimens are superior in terms of cost-effectiveness to other regimens. Despite the indubitable applicability of ALLHAT’s findings, implementation into routine clinical practice has been insubstantial. This 1/1/04-6/30/04 planning project developed and tested an exportable implementation model for the ALLHAT finding that thiazide-based antihypertensive regimens are the treatment of choice for most patients with hypertension.
The implementation plan was based on Rogers’ “Diffusion of Innovations Model.” The communicators of the innovation (also the project’ proposers) were the doctors and nurses of the Houston VAMC General Medicine Section (GMS), a unique group of clinicians, educators, and researchers that together with its roughly 6,000 primary care patients constitute what the Institute of Medicine calls a microsystem of care. Working on teams aligned with the Rogers model, GMS members attempted to accelerate the diffusion of ALLHAT’s findings by devising tangible products (e.g., pocket medication algorithms), conducting functions (e.g., analysis of prescribing patterns), and interacting with key parties (e.g. Pharmacy Service). Houston VA PrimeCare patients (N roughly 40,000) served as nonrandomized concurrent controls.
The implementation period was 11/14/03-9/30/04. Data from the quarter ending 9/30/04 are not yet available from the VISN 16 CPRS warehouse. Teams devoted over 2131 person-hours to designing and testing the multifaceted implementation intervention. As of 6/30/04 and compared with the quarter ending 9/30/03, the intervention was associated with a 31.5% relative percent increase in the number of GM hypertensives achieving goal blood pressures; the concurrent increase in PrimeCare hypertensives at goal was 21.5%. As of 6/30/04 the increase in the proportion of hypertensives on thiazides did not differ between GM and PrimeCare patients. Once final-quarter data are available, we will conduct time series analyses of 108 weeks (7/1/02-9/30/04) of the concurrent treatment (GMS) and control (PrimeCare) groups.
This implementation intervention appears to have improved blood pressure control rates in hypertensive patients in GMS; its effect on thiazide-prescribing patterns is still uncertain.
Widespread use of thiazide-based antihypertensive regimens could improve outcomes and costs in VHA.