Disparities in the Burden of Stroke in Mexico: A National and Subnational Analysis of the Global Burden of Disease 1990–2017

Abstract

Background: Stroke burden has been decreasing in high-income countries while increasing in low- to middle-income nations where ischaemic and haemorrhagic stroke are major causes of death and disability. The lack of updated epidemiological information on stroke in Mexico has motivated the development of new estimations based on available data sources and published research. Methods: Data of incidence, prevalence, deaths, premature mortality, disability, and DALYs due to cerebrovascular disease included in the Global Burden of Disease (GBD) 2017 study were analysed to identify differences on the burden of stroke types (i.e., ischaemic stroke [IS], intracerebral haemorrhage [ICH] and subarachnoid haemorrhage [SAH]), sex, age groups, and federal states from 1990 to 2017. To explore disparities due to social and health system variables, the federal states were classified using GBD’s Sociodemographic Index (SDI) and Health Access and Quality (HAQ) Index. Sources available from Mexico included vital registration data and information on stroke incidence, prevalence, and mortality from scientific literature, inpatient hospital data, population surveys, and mortality registries for the period 1990–2017. Findings: In the last 27 years, the number of stroke deaths in Mexico increased from 21,456 in 1990 to 36,653 in 2017, while the age-standardised mortality rate declined 35.8% during the period. Significant reductions in incidence, prevalence, disability, and mortality rates occurred from 1990 to 2005, with no significant changes in the declining trends from 2006 to 2017. Age-standardised mortality rates for IS and ICH were significantly reduced by 46.6% and 30%, respectively, mainly in the period 1990-2005, but not afterwards, while mortality from SAH showed non-significant changes during the whole period. DALYs and premature mortality (YLLs) age-standardised rates exhibited important decreases during the period (41.4% and 48.6%), respectively, also mainly during 1990-2005. The magnitude of decline in all metrics for ICH was more pronounced in women than men. In the case of SAH, females had higher differences in age-standardised mortality, DALYs, YLLs, YLDs, and prevalence rates at the beginning of the study (1990), but men presented higher increases during the whole period. Haemorrhagic stroke presented significantly higher age-standardised mortality, DALYs, YLLs, and incidence rates for ICH than SAH, as well as more important reductions accounted during the period. Stroke burden metrics varied widely by federal state, with less developed states (according to SDI) exhibiting the lowest improvements during the period. Interpretation: Stroke mortality in Mexico showed a decreasing trend without meaningful changes for incidence and prevalence. Reductions in DALYs were mostly explained by decrements in premature mortality and not by changes in disability burden, probably due to a precariously organised acute stroke care. During the last decade a modest declining trend on stroke burden was observed in comparison with the major reduction that occurred in the period 1900-2005. The less developed states showed the lowest reduction in stroke burden. These findings reveal the health disparities in the burden of stroke within the fragmented Mexican Healthcare System. Funding: Funding was provided by The Bill & Melinda Gates Foundation. Declaration of Interests: Vanessa De la Cruz-Gongora, D.Sc: none. Erwin Chiquete, MD, PhD: none. Hector Gomez–Dantes M.D., M.Sc: none. Lucero Cahuana-Hurtado Ph.D: none. Alejandra Montoya-Rodriguez, M.Sc: none. Carlos Cantu-Brito, M.D, Ph.D: none.