Antihypertensive medication adherence, ambulatory visits, and risk of stroke and death.
BACKGROUND
This study seeks to determine whether antihypertensive medication refill adherence, ambulatory visits, and type of antihypertensive medication exposures are associated with decreased stroke and death for community-dwelling hypertensive patients.


METHODS
This retrospective cohort study included all chronic medication-treated hypertensives enrolled in Tennessee's Medicaid program (TennCare) for 3-7 years during the period 1994-2000 (n = 49,479). Health care utilization patterns were evaluated using administrative data linked to vital records during a 2-year run-in period and 1- to 5-year follow-up period. Antihypertensive medication refill adherence was calculated using pharmacy records.


RESULTS
Associations with stroke and death were assessed using Cox proportional hazards modeling. Stroke occurred in 619 patients (1.25%) and death in 2,051 (4.15%). Baseline antihypertensive medication refill adherence was associated with decreased multivariate hazards of stroke [hazard ratio (HR) 0.91; 95% confidence interval (CI), 0.86-0.97 for 15% increase in adherence]. Adherence in the follow-up period was associated with decreased hazards of stroke (HR 0.92; CI 0.87-0.96) and death (HR 0.93; CI 0.90-0.96). Baseline ambulatory visits were associated with decreased death (HR 0.99; CI 0.98-1.00). Four major classes of antihypertensive agents were associated with mortality reduction. Only thiazide-type diuretic use was associated with decreased stroke (HR 0.89; CI 0.85-0.93).


CONCLUSIONS
Ambulatory visits and antihypertensive medication exposures are associated with reduced mortality. Increasing adherence by one pill per week for a once-a-day regimen reduces the hazard of stroke by 8-9% and death by 7%.
Bailey
James E
JE
Division of General Internal Medicine, Department of Medicine, University of Tennessee Health Science Center, 956 Court Avenue, Coleman D222, Memphis, TN 38163, USA. jeb@uthsc.edu
Wan
Jim Y
JY
Tang
Jun
J
Ghani
Muhammad A
MA
Cushman
William C
WC
D000554:Ambulatory Care Facilities; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D009026:Mortality; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology*; D013714:Tennessee / Q000453:epidemiology
D000959:Antihypertensive Agents