Background: Stroke burden is a leading cause of disability on developing countries. However, there are no studies assessing the impact of previous non-fatal strokes on all-cause mortality in rural areas of Latin America, where living conditions and health care access are different than in urban centers. Using a population-based prospective cohort study (The Atahualpa Project), we aimed to assess the influence of non-fatal stroke on all-cause mortality in community-dwelling older adults living in a remote rural setting.
Methods: Individuals aged ≥60 years with a non-fatal stroke were detected during yearly door-to-door surveys by the use of validated questionnaires and corroborated by a certified neurologist. Deaths occurring during the follow-up were identified from annual surveys, death certificates review, and other overlapping sources. Univariate tests for equality of survivor functions were used to estimate differences between observed and expected deaths for the presence of a non-fatal stroke. Survival analyses were conducted by the use of the mortality incidence rate ratio (IRR) and by Cox proportional hazard models with subsequent estimation of Kaplan Meier survival curves.
Results: Of 437 individuals aged ≥60 years enrolled during a 5-year period, follow-up was achieved in 417 (95%), contributing 1,776 years of follow-up (average 4.3±1.3 years). Forty-five (10.8%) individuals were stroke survivors. Fifty-one deaths were detected, for an overall cumulative 5-year mortality rate of 12.2% (95% C.I.: 8.9 - 15.6). According to log-rank analysis, the ratio of observed versus expected deaths among stroke survivors was 14/5.12 (p=0.0001). Having history of a non-fatal stroke was significantly related to mortality (IRR: 3.38; 95% C.I.: 1.69 - 6.41; p=0.0005). A fully adjusted Cox proportional hazard model showed that non-fatal strokes independently predicted mortality (hazard ratio: 2.18, SE: 0.75; 95% C.I.: 1.11 - 4.28; p=0.024).
Conclusions: This study shows the importance of a previous non-fatal stroke on the risk of all-cause mortality in inhabitants of a remote rural village. Epidemiological studies assessing the impact of region-specific factors influencing mortality may prove cost-effective for developing preventive strategies.