REGIONAL DIFFERENCES IN MORTALITY DURING 15-YEAR FOLLOW-UP OF 11936 HYPERTENSIVE VETERANS

Several different investigators have reported increased stroke mortali ty in the southeastern United States, leading to the introduction of t he term ''Stroke Belt.'' The results presented here from the Veterans Administration Hypertension Screening and Treatment Program (HSTP) dem onstrate an increased all-cause mortality among hypertensive patients seen in HSTP clinics in the southeastern United States when compared w ith similar patients from other HSTP clinics. Several different groupi ngs of southeastern states were examined and compared with nine states west of the Mississippi River. A total of 11 936 male veterans, 5737 of whom were black, were identified as hypertensive during 1974-1976 i n 32 HSTP clinics. Their mean age was 52.4+/-10.4 years, and their mea n pretreatment blood pressure was 153.8+/-19.1/ 100.4+/-9.8 mm Hg. Dur ing a minimum of 13.9 years of followup, 5360 (44.9%) of these patient s died. Proportional hazards modeling was used to fit a basic survival model with terms representing race, age, blood pressure, smoking, and obesity. Risk was increased with higher blood pressure, age, and smok ing and with lower body mass index. For 6 HSTP clinics in an ii-state Stroke Belt (defined as states with stroke mortality >10% above the Un ited States average), the relative risk of death was 1.226 (95% confid ence interval, 1.106-1.358) when compared with 9 states west of the Mi ssissippi River. For two different groupings of southeastern states wi th 10 and 8 HSTP clinics the relative risk of death was 1.231 and 1.29 5. Mean martingale residuals were used to indicate the relative risk a t each clinic after applying statistical controls for age, race, blood pressure, smoking, and body mass index. Four of the 6 Stroke Belt cli nics had positive means, indicating that there was excess all-cause mo rtality among the patients of those clinics. In contrast, only 2 of th e 10 non-Stroke Belt clinics had positive means.