Characterizing the epidemiological transition in Mexico: national and subnational burden of diseases, injuries, and risk factors

Abstract

Background: Rates of diseases and injuries and the effects of their risk factors can have substantial subnational heterogeneity, especially in middle-income countries like Mexico. Subnational analysis of the burden of diseases, injuries, and risk factors can improve characterization of the epidemiological transition and identify policy priorities.

Methods and findings: We estimated deaths and loss of healthy life years (measured in disability-adjusted life years [DALYs]) in 2004 from a comprehensive list of diseases and injuries, and 16 major risk factors, by sex and age for Mexico and its states. Data sources included the vital statistics, national censuses, health examination surveys, and published epidemiological studies. Mortality statistics were adjusted for underreporting, misreporting of age at death, and for misclassification and incomparability of cause-of-death assignment. Nationally, noncommunicable diseases caused 75% of total deaths and 68% of total DALYs, with another 14% of deaths and 18% of DALYs caused by undernutrition and communicable, maternal, and perinatal diseases. The leading causes of death were ischemic heart disease, diabetes mellitus, cerebrovascular disease, liver cirrhosis, and road traffic injuries. High body mass index, high blood glucose, and alcohol use were the leading risk factors for disease burden, causing 5.1%, 5.0%, and 7.3% of total burden of disease, respectively. Mexico City had the lowest mortality rates (4.2 per 1,000) and the Southern region the highest (5.0 per 1,000); under-five mortality in the Southern region was nearly twice that of Mexico City. In the Southern region undernutrition and communicable, maternal, and perinatal diseases caused 23% of DALYs; in Chiapas, they caused 29% of DALYs. At the same time, the absolute rates of noncommunicable disease and injury burdens were highest in the Southern region (105 DALYs per 1,000 population versus 97 nationally for noncommunicable diseases; 22 versus 19 for injuries).

Conclusions: Mexico is at an advanced stage in the epidemiologic transition, with the majority of the disease and injury burden from noncommunicable diseases. A unique characteristic of the epidemiological transition in Mexico is that overweight and obesity, high blood glucose, and alcohol use are responsible for larger burden of disease than other noncommunicable disease risks such as tobacco smoking. The Southern region is least advanced in the epidemiological transition and suffers from the largest burden of ill health in all disease and injury groups.

Figure 1. Steps of the Analysis

All calculations were carried out by age group, sex, and state. National and regional estimates of deaths, DALYs, and attributable disease burden were calculated as the sum of state estimates.

Figure 2. Age-Standardized Mortality Rates (A) and Burden of Disease Rates (B) for Mexico and Its Regions, Divided by Disease Category

For comparison, the figure also shows mortality rates for all high-income and low-and-middle-income countries [52]. All rates are standardized to the 2000 national population of Mexico. Regions used to present results are: Northern: Baja California, Baja California Sur, Coahuila, Chihuahua, Nuevo León, Sonora, Tamaulipas; Pacific Central: Aguascalientes, Colima, Jalisco; Central: Durango, Guanajuato, Michoacán, Morelos, Nayarit, Querétaro, San Luis Potosí, Sinaloa, Tlaxcala, Zacatecas, and parts of Mexico State not in the Mexico City region; Mexico City: Distrito Federal and parts of Mexico State in the contiguous urban area; Gulf: Campeche, Quintana Roo, Tabasco, Veracruz, Yucatán; Southern: Chiapas, Guerrero, Hidalgo, Oaxaca, and Puebla (Table S1). Key: Ca, cancers; Cir, liver cirrhosis; Com, communicable; CVD, cardiovascular; DM, diabetes; Inj, injuries; Mat, maternal, perinatal, and nutritional; NCom, other noncommunicable; NP, neuropsychiatric.

Figure 3. National and Regional Under-Five Mortality Rates, Divided by Disease Category

For comparison, the figure also shows the rates for all high-income, upper- and lower-middle-income, and low-income countries [52]. Key: Com, other communicable; Diar, diarrhea; Inj, injuries; NCom, other noncommunicable; Perinatal, perinatal; Resp, respiratory infections.

Figure 4. Mortality (A) and Burden of Disease (B) Attributable to Leading Risk Factors in Four Mexican Regions, Divided by Disease Category

The rates in this figure were not age-standardized. Therefore, the observed regional variation in attributable mortality and burden of disease is partly due to regional variation in age structure. Key: Ca, cancers; Cir, liver cirrhosis; Com, communicable; CVD, cardiovascular; DM, diabetes; Inj, injuries; Mat, maternal, perinatal, and nutritional; NCom, other noncommunicable.

Figure 5. Under-Five Mortality Attributable to Leading Risk Factors in Four Mexican Regions, Divided by Disease Category

Key: Comm, other communicable; Diar, diarrhea; Inj, injuries; NCom, other noncommunicable; Perinatal, perinatal; Resp, respiratory infections.