All-cause and cardiovascular mortality in West African villages : a 10-year follow-up using verbal autopsies

INTRODUCTION: To assess predictors of death in a 10-year prospective community-based population study in West Africa. METHODS: 1,013 participants randomly selected from 12 villages (628 women, 481 rural) in Ashanti, Ghana, were screened between June 2001 and June 2002. Few were on drug therapy. Follow-up was completed by December 31st, 2011. They were screened at baseline for cardiovascular and metabolic risk factors. They were then followed-up for the ascertainment of vital status using verbal autopsies (WHO 2007). All-cause and cardiovascular (CV) (VA04 & VA07) deaths were recorded. Time to death was used in a Cox regression model to estimate hazard ratios (HR) and 95% C.I. RESULTS: After a 10-year follow-up, vital status was collected for 1,006 (99.3%) participants. During 9,118 person-years of follow-up, we documented 198 deaths (19.7%) including 64 (6.4%) from CV causes. After adjustment for age, BMI, smoking and locality, men were more likely to die from both all (HR: 1.83 [1.35, 2.48]; p<0.001) and CV causes (2.06 [1.21, 3.51]; p=0.008). After further adjustment for sex, significant independent predictors of deaths from all causes were smoking (1.56 [1.01, 2.42]; p=0.049), living in rural areas (0.73 [0.55, 0.98]; p=0.038), systolic BP above median (1.39 [1.03, 1.88]; p=0.029), HDL-cholesterol above median (0.59 [0.44, 0.79]; p<0.001), serum uric acid above median (1.43 [1.05, 1.95]; p=0.023). Similar estimates were found for CV deaths, with a stronger relationship between higher serum uric acid and CV death (2.48 [1.37, 4.48]; p=0.003). When deaths within the first 2 years of follow up were excluded, the estimates did not vary substantially. CONCLUSIONS: The findings indicate, for the first time in West Africa, that alongside some traditional risk (smoking, higher BP) and protective (living in rural areas, higher HDL-cholesterol) factors, higher serum uric acid is a strong risk factor for all-cause death and especially for CV death.