-from Epidemiological Bulletin, Vol. 21 No. 3, September 2000-
The bilingual publication (in English and Spanish), Mortality Profiles of the Sister Communities on the United States – Mexico Border, 2000 Edition ( 1 ), produced by the Pan American Health Organization (PAHO) in collaboration with the governments of Mexico and the United States, includes the most recent mortality data for the border area of both countries. The aim of the publication was to update to the 1995-1997 period the overall profile of the patterns of mortality previously described in Mortality Profiles of the Sister Communities on the United States–Mexico Border, 1992–1994 (2). The 2000 Edition continues to respond to the need for a comprehensive set of detailed reference tables on mortality with emphasis on smaller geographic areas and on the border area in particular. Although numerous communities have developed on both sides of the border, those with the largest populations were collectively designated by PAHO’s Field Office/US–Mexico Border in El Paso, Texas, as the “Sister Communities.” The counties or municipalities comprising the Sister Communities are shown in Figure 1 and became the unit of analysis. Mortality information from each Sister Community was aggregated to form the corresponding border totals reflecting overall mortality. To develop the mortality profiles of the border area, this information was then analyzed for leading causes of death and patterns of mortality in six broad causal groups and categorized by age and sex. The disparities shown in these profiles by cause, sex, and age group among the Sister Communities can be used to identify common problems and to establish comparisons between Sister Communities and the border region as a whole.
Mortality data for border areas of the United States were provided by the National Center for Health Statistics, U.S. Department of Health and Human Services, and those for Mexico were provided by the Dirección General de Estadística e Informática, Secretaría de Salud. Mid-year population estimates provided by the Consejo Nacional de Población (CONAPO) for Mexico and by the United States Bureau of the Census for the United States were used for the calculation of rates. Estimated populations for 1991–1997 were based on projections from the 1990 census in each country. Mortality and population data corresponding to national, state, and county/municipality levels by sex and cause were sent by both governments to PAHO’s Special Program for Health Analysis where the information was processed, summarized, and analyzed. Tabulations were produced for selected cause groupings, seven broad age groups (under one year, 1-4, 5-14, 15-24, 25-44, 45-64 and 65 years and over) and by sex for the entire country, and for each of the Border States and Sister Communities. These data were then integrated into standardized formats to form a comprehensive set of reference tables and graphs. A synthesis of the main results follows.
The 14 pairs of Sister Communities contain about 95% of the total United States–Mexico border population-an estimated 11 million people in 1997. Population growth during 1993–1997 in the border region has been rapid, averaging about 4.3% per year on Mexico’s side of the border and 1.8% on the United States’ side. A total of 177,909 deaths were registered during 1995–1997 among Sister Communities on both sides of the border, which corresponds to a crude mortality rate of 5.8 per 1,000 population. Of these, a total of 61,104 deaths were recorded among the Sister Communities of Mexico-a crude death rate of 4.7 per 1,000 population. On the United States side, a total of 116,805 deaths were recorded during 1995–1997, which represents a crude death rate of 6.7 per 1,000 population-a rate 43% higher than that on the Mexican side. However, the age-standardized mortality rate was 6.0 per 1,000 population on the Mexican border and 4.4 on the United States border (27% less). The overall age-standardized mortality rate for the combined United States–Mexico border region was 5.0 per 1,000 population.
The proportionate mortality corresponding to the five leading causes of death as a percentage of total deaths from defined causes in the United States–Mexico border region is shown by sex in Figure 2 (in PDF). Deaths from defined causes exclude causes assigned to the category “symptoms, signs and ill-defined conditions (ICD 9: 780–799).” It should be noted that the leading causes of death depend not only on the relative frequency of deaths in a category but also on the definition of the causal categories that are candidates for ranking. A “short” list containing 24 causal groupings of death was used to determine the leading causes of death.
As can be seen in Figure 2, the first five causes of mortality account for about one-half (56%) of the deaths from defined causes in the total population on the Mexico border and for over two-thirds (70%) of deaths on the United States border. They account for about 53% of the deaths in males and 60% in females from defined causes in border areas of Mexico and for 70% and 72% of male and female deaths, respectively, in border areas of the United States.
In the period 1995–1997, as in 1992–1994, the leading cause of death on the border was diseases of the heart (ICD 9: 390–429). In the Mexican Sister Communities, a total of 11,209 deaths (18.7% of deaths from defined causes) were recorded from heart disease. In contrast, mortality was 3 times greater in United States Sister Communities, with 33,420 deaths (29.8% of deaths from defined causes). Within this disease category, ischemic heart disease (ICD 9: 410–414) accounted for 67% of the deaths on the Mexico side and for 64% on the United States side. Proportionately, deaths from heart disease were slightly greater among women than men. On the Mexican border, heart disease accounted for a total of 4,966 female deaths (20.6% of female deaths from defined causes) and 6,242 male deaths (17.4% of male deaths from defined causes). On the United States border, heart disease had a much higher toll: 17,656 male deaths (29% of male deaths from defined causes) and 16,764 female deaths (30.6% of female deaths from defined causes).
Age-standardized death rates per 100,000 population are shown geographically in Figure 3 for the leading causes of death in the Sister Communities. These geographic maps provide the spatial distributions and magnitudes of the leading causes of death and help to identify inequalities in the patterns of mortality. Age-standardized death rates from heart disease for 1995–1997 were 128.5 per 100,000 males and 121.5 per 100,000 females in Sister Communities of Mexico. These rates were 32.7% and 11.6% higher than corresponding nationwide rates for Mexico: males, 96.8; females, 108.9. In contrast, age-standardized rates in Sister Communities of the United States of 123.5 in males and 113.5 in females were 20.8% and 21.5% lower, respectively, than nationwide rates in the United States by sex. The United States Sister Communities also had rates that were 4% and 6.6% lower for males and females, respectively, than for their counterparts in Mexico.
Malignant tumors (ICD 9: 140–208) were ranked as the second leading cause of death on both sides of the border, with a total of 7,388 deaths in Sister Communities of Mexico and 26,657 deaths in Sister Communities of the United States. In the border communities of Mexico, malignant tumors accounted for 12.3% of all deaths from defined causes but the proportion was twice that (23.1%) on the United States side. A review of these deaths by tumor site indicates that, on the Mexico border, malignant neoplasms of the trachea, bronchus, and lung (ICD 9: 162) accounted for 17.3% of deaths; malignant neoplasms of the digestive organs and peritoneum (ICD 9: 150, 152, 155–159) accounted for 16.9% of deaths from malignant tumors; and malignant neoplasms of the cervix, uterus, body, and unspecified parts (ICD 9: 179, 180, 182) accounted for 9.1%. On the United States border, malignant neoplasms of the trachea, bronchus, and lung accounted for 25.5% of all malignant tumors, and malignant neoplasms of the female breast (ICD 9: 174) accounted for 8.3% of the total.
Accidents and adverse effects (ICD 9: E800–E949) were the third leading cause of death in the Sister Communities of Mexico, accounting for 6,346 deaths (10.6% of deaths from defined causes). In contrast, this group of causes was the fifth leading cause of death on the United States border, with 5,507 deaths - 4.8% of deaths from defined causes. However, among United States border males, accidents were the third leading cause of death, with 3,879 deaths (6.4% of male deaths from defined causes). Among Mexican border males, accidents ranked second as leading cause of death, with 5,048 deaths (14% of male deaths from defined causes). Among Mexican border females, deaths from accidents were the fifth leading cause, with 1,295 deaths (5.4% of female deaths from defined causes). However, among United States border females, accidents were not a leading cause of death. Motor vehicle accidents (ICD 9: E810–E825) accounted for 32.4% of deaths from all accidents on the Mexico side and for 45.2% of deaths in this cause group on the United States side. Also, it is of interest to note that accidents and adverse effects were the leading causes of death in all age groups up to 45 years of age (1–4, 5–14, 15–24, and 25–44) on both sides of the border.
The third leading cause of death in communities on the United States border was cerebrovascular disease, with 8,051 deaths, an age-standardized rate of 27.3 per 100,000 population. Nationally, the United States rate was 31.3 (14.7% higher). This disease also ranked third as a leading cause of female mortality with 4,662 deaths, an age-standardized rate of 31.7 per 100,000 population, and it ranked fourth as a cause of male mortality with 3,389 deaths (age-standardized rate of 23.1) in border communities of the United States. All border communities in the United States showed excess female mortality from cerebrovascular disease, with low masculinity mortality ratios calculated as the ratio of male:female age-standardized rates.
Diabetes mellitus (ICD 9: 250) was the fourth leading cause of death among Mexican communities on the border in 1995–1997. A total of 5,706 deaths were registered, accounting for 9.5% of the deaths from defined causes. Diabetes was also the fourth leading cause of death among Mexican border males, with 2,602 deaths recorded-7.2% of male deaths from defined causes. It was the third leading cause of death among Mexican border females, with 3,104 deaths or 12.9% of female deaths from defined causes. The following age-standardized death rates from diabetes were registered for the Mexico border: 63.5 in both sexes, 54.4 in males, and 73.1 in females. Compared with national data, the border rates were 27.6% higher for both sexes, 29.6% higher in males, and 26% higher in females. In comparison, diabetes mortality is about one-fifth the amount in areas of the United States border, with an age-standardized rate of 12.9 per 100,000 population. Compared with United States national data, age-standardized rates on the border were larger-about 0.3% overall (12.9 vs. 12.8), 1.5% higher in males but 1% lower in females.
The fourth leading cause of death in the United States border communities was chronic obstructive pulmonary disease (COPD) (ICD 9: 490–496), with 6,046 deaths, causing 5.2% of total deaths from defined causes. Among males in United States border communities, COPD ranked fifth, with 3,097 deaths (5.1% of male deaths from defined causes); among females it ranked fourth, with 2,949 deaths (5.4% of female deaths from defined causes). Age-standardized death rates from COPD were 20.4 per 100,000 population and 20.5 in males and 20.1 in females in border communities of the United States. These rates compared with United States national data were similar overall (21.0) but 8.6% lower than males nationally (22.3) and 1.4% higher than females nationally (19.8). Although COPD was not a leading cause of death in the border area of Mexico, it accounted for 1,757 deaths (2.9% of deaths from defined causes). The age-standardized rate of 20.2 per 100,000 population was about 1% less than in the United States border area. Masculinity mortality ratios show that mortality from COPD is predominant in men on both sides of the border.
Due to the relatively smaller numbers of deaths occurring in some Sister Communities, deaths over the period 1990–1997 were aggregated in order to determine the leading causes of death within each Sister Community. The leading cause of death in each community over this period was the same-diseases of the heart. Age-standardized rates ranged from a low of 101.3 per 100,000 population in Santa Cruz to a high of 180 in Agua Prieta. Among females, diseases of the heart was the leading cause of death in all communities on both sides of the border. Among males, the leading cause of death was also diseases of the heart in all but Tijuana, where it ranked second and accidents and adverse effects ranked first.
The second leading cause of death in 1990–1997 was malignant neoplasms in all but three communities-Tijuana, Nogales, and Ascención. In these communities, deaths from accidents and adverse effects were second and malignant neoplasms were third. Age-standardized rates for malignant neoplasms ranged from 64.1 in Anahuac to 111.4 in Pima. Among males, the second leading cause of death in 10 communities-Mexicali, San Luis Río Colorado, Nogales, Agua Prieta, Ascención, Juárez, Acuña, Nuevo Laredo, Reynosa, and Matamoros-was accidents and adverse effects; in Tijuana it was heart disease and in the remaining communities it was malignant neoplasms. Standardized rates from accidents and adverse effects ranged from 70.5 in San Luis Río Colorado to 130.4 in Ascención per 100,000 males, whereas standardized rates for malignant neoplasms ranged from 62.9 in Anahuac to 120.9 per 100,000 males in Pima. Among females, malignant neoplasms was the second leading cause of death in all border communities except for Acuña and Piedras Negras, where diabetes mellitus ranked second with rates of 93.1 and 101.4, respectively. In these two communities, malignant neoplasms ranked third. Nogales had the lowest standardized death rate from malignant neoplasms (72.0 per 100,000 females) and the rate in Agua Prieta (111.6 per 100,000 females) was the highest.
The third leading cause of death in 10 communities-five in Mexico and five in the United States-was accidents and adverse effects. In the United States border communities of Santa Cruz, Pima, San Diego, Imperial, Cochise, Val Verde, and Webb, cerebrovascular disease was the third leading cause of death. In the Mexico border communities of Acuña, Nuevo Laredo, San Luis Río Colorado, Piedras Negras, and Anahuac as well as in Maverick, the third leading cause of death was diabetes and in Luna it was COPD.
Of the leading causes of death in 1990–1997, accidents and adverse effects ranked second, third, fourth, or fifth; cerebrovascular disease ranked fifth in Mexico communities and third or fourth in United States communities; COPD was a leading cause only in United States communities-third, fourth, or fifth; certain conditions originating in the perinatal period was a leading cause only in Mexico communities (fourth or fifth); homicide was a leading cause only in Ascención (fifth); diabetes was a leading cause and ranked third, fourth, or fifth; and acute respiratory infections was ranked as a leading cause of death (fifth) only in Ascención and San Diego.
Notes:
(1) Mortality Profiles of the Sister Communities on the Unites States-Mexico Border, 2000 Edition. Pan American Health Organization, 2000. (ISBN 92 75 17382 1)
(2) Mortality Profiles of the Sister Communities on the Unites States-Mexico Border, 1992-1994 (pdf - 3.25MB). Pan American Health Organization, 1999. (ISBN 92 75 07378 3)
View our previous report on Mortality on the US-Mexico border: Epidemiological Bulletin - Vol 20. No. 2, June 1999 (pdf - 326KB).
Source: PAHO. Special Program for Health Analysis (SHA)
Copies of the publication may be obtained through PAHO's Special Program for Health Analysis, at sha@paho.org
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Epidemiological Bulletin , Vol. 21 No. 3, September 2000