Health care utilization among older Mexicans: health and socioeconomic inequalities.

Abstract

To examine the determinants of the utilization of health care services among the population of older adults in Mexico. Three types of health care services are analyzed: preventive care, visits to the doctor, and hospitalizations.
Data was used from the 2001 Mexican Health and Aging Study (MHAS/ENASEM) and estimates were made using multivariate probit regression methods.
Socioeconomic factors, health conditions reported by the individuals, and the availability of health insurance are significant determinants of the differential use of services by older adults.
Specific health conditions are important determinants of use of the various types of health care services. For all three types, however, the availability of health insurance is an enabling factor of health care use. Older age is associated with greater propensity to use health care services but its effect is small when controlling for health conditions.

Full text

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Health care use among older Mexicans
ARTÍCULO ORIGINAL
Health care utilization among older Mexicans:
health and socioeconomic inequalities
Rebeca Wong, MA, PhD, (1) Juan José Díaz, MA, PhD.(2)
(1)
(2)
Maryland Population Research Center University of Maryland. USA.
Grupo de Análisis para el Desarrollo (GRADE). Perú.
Received on: September 22, 2005 Accepted on: November 13, 2006
Correspondence author: PhD Rebeca Wong. Maryland Population Research Center, Department of Sociology, University of Maryland. 0124N Cole Student
Activities Building 162. College Park, MD 20742.
E-mail: wongr@umd.edu
Resumen
Objetivo. Examinar los determinantes del uso de servicios
de salud de la población de adultos de 50 años de edad o
más en México. Se analizan tres tipos de servicios de salud:
cuidados preventivos, visitas al médico y hospitalizaciones.
Material y métodos. Se usan datos del Estudio Nacional
sobre Salud y Envejecimiento en México (MHAS/ENASEM)
del año 2001 y se aplican métodos de regresión multivariada
probit. Resultados. Factores socioeconómicos, las condicio-
nes de salud reportadas y la disponibilidad de derechohabien-
cia son factores determinantes de la propensión diferencial
a usar servicios entre la población. Conclusión. Diferentes
condiciones de salud están asociadas con el uso de los varios
tipos de servicios de salud. Para los tres tipos, sin embargo,
es primordial la derechohabiencia a servicios de salud para
fomentar la utilización de servicios. Asimismo, mayor edad se
asocia con mayor uso de servicios pero su efecto es pequeño
una vez que la salud se toma en cuenta.
Palabras clave: utilización; servicios; envejecimiento; salud;
adultos; México
Abstract
Objective. To examine the determinants of the utilization
of health care services among the population of older adults
in Mexico. Three types of health care services are analyzed:
preventive care, visits to the doctor, and hospitalizations.
Material and Methods. Data was used from the 2001
Mexican Health and Aging Study (MHAS/ENASEM) and
estimates were made using multivariate probit regression
methods. Results. Socioeconomic factors, health conditions
reported by the individuals, and the availability of health
insurance are significant determinants of the differential
use of services by older adults. Conclusion. Specific health
conditions are important determinants of use of the various
types of health care services. For all three types, however, the
availability of health insurance is an enabling factor of health
care use. Older age is associated with greater propensity to
use health care services but its effect is small when controlling
for health conditions.
Key words: utilization; services; aging; health; Mexico
Wong R, Díaz JJ.
Utilización de servicios de salud entre adultos mayores en
México: desigualdades socioeconómicas y en salud.
Salud Publica Mex 2007;49 supl 4:S505-S514.
Wong R, Díaz JJ.
Health care utilization among older Mexicans:
health and socioeconomic inequalities.
Salud Publica Mex 2007;49 suppl 4:S505-S514.
P
most Latin American countries. Unless there is an
improbable increase in fertility or in old age mortal-
ity to offset this momentum, the percentage of the
population aged 60 or older will increase from 7% in
the year 2000 to 12% in 2020 and 28% by 2050.1 The
opulation aging is expected to accelerate in Mexico
after the year 2000, a pattern that characterizes
changes in the relative and absolute size of the older
population in Mexico are occurring during a period of
“epidemiologic polarization,” that is, mortality regimes
under which both infectious and chronic diseases
are simultaneously prevalent.2,3 Levels of infectious
diseases among the elderly are higher than would
be predicted from observed levels of chronic illness.4

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social security system. Given this system of provision
of services, we would expect that health care utilization
would exhibit large variances across the population, and
this is supported by the literature, which indicates that
utilization of health services differs vastly by income
groups in Mexico.2,9 Under this set of conditions, it is
reasonable to argue that the population of Mexico, in
particular those with low socioeconomic status (to which
rural residents tend to disproportionately belong) are
likely to have low exposure to the formal health sector,
and may have a culture of not seeking formal care in
case of illness.
In addition, health inequalities across the Mexican
population have been well documented.3,10,11 These are
profound differences that prevail, as there are vast differ-
ences in the social and economic conditions and access to
health services among the population. As an intermedi-
ate factor that determines health, the patterns of health
care utilization may determine to a great extent the large
health differences. Understanding the patterns of health
care utilization may contribute to better understanding
of the health differences across population groups. In this
paper, we compare the patterns of health care utilization
among populations aged 50 and older in Mexico, control-
ling for aspects of health, access to health insurance, and
the economic and sociodemographic characteristics of
the individuals. This comparison shall shed light on the
possible mechanisms through which health differentials
are obtained. This is done for three service utilization out-
comes: preventive care, doctor visits and hospitalizations.
These three outcomes were selected because they should
be sensitive to availability of health insurance in different
ways, given that their relative out-of-pocket cost and their
perceived need are quite different.
The overarching hypothesis of this research is that
there will be vast differences in the patterns of use of
health care services across the population according to
sociodemographic attributes such as age, gender, and
education. It is expected that, although sociodemo-
graphic characteristics will determine the propensity
to use health care services, a dominant factor for the
use of services will be the health needs. In addition, we
expect that sociodemographic factors and health needs
will affect the propensity to use services differently, de-
pending on the type of services. For example, regardless
of chronic conditions reported by individuals, a higher
likelihood of use of preventive services by women than
men is expected because older women have had more
contact with the health system in their lifetime through
their own reproductive health experiences, as well as
through the use of health care for their children.7,12 It
is expected that older adults living in urban areas will
tend to use health care services more than their coun-
* Recent changes have been implemented in the Mexican public health
system, starting in January 2004. Under the proposed reform, a
“popular health insurance” (seguro popular) is available to all the
population, but the implementation will be gradual and it is too
early to assess the impact of the reform on the health care coverage
of the overall population.
This means that the Mexican aging process is affected
by an unusual interaction of chronic conditions as-
sociated with modern health and mortality risks and
conditions that are residual to a transitional regime.
The aging processes under these peculiar conditions
may be such that the set of symptoms, physical limita-
tions, and functional disability would be expected to
be higher in Mexico than the developed world or less
developed economies, with implications for active life
expectancy and the volume of demand for health care.
The consequences for the Mexican social system that
these conditions impose are uncertain. Adjustments
may include the adoption of therapeutic treatments to
deal with the burden of chronic disease, even as overall
levels of public health expenditures get reduced.5,6
Towards the end of the 1990’s, social security insti-
tutions with health care services covered almost half of
the Mexican population, institutions for the uninsured
covered 40% of the population, 5% used private services,
and 11% had no access to the health system’s facilities.7
Private pharmacies are a major source of informal
care; pharmacists generally prescribe medicines and
treatment in Mexico. According to the 2000 Mexican
Population Census, about 50% of the population aged
65 or older reported to have no health-care-coverage.8
The provision of health services is largely the respon-
sibility of the public sector. The Mexican government
uses general revenues to pay for health care for middle-
and low-income groups in the population, while upper
income households (a minority) use private insurance
or resources to pay for private health care. Coverage
by the social security system is determined largely by
participation in the formal labor market; hence, this
system tends to discriminate against agricultural work-
ers and those living in rural areas, domestic workers,
and small commercial industry workers. These tend to
also be among the poorest sectors of the population.
Once a worker is covered by social security, however,
his/her dependents are generally extended the benefit
of health care.*7
This brief summary suggests that in Mexico, the
population has access to health services based on two
main factors: the level of urbanization of the community
of residence and whether there are services available in
it, and whether or not the population forms part of the

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terparts residing in rural areas because of better access
to health facilities.13 And it is expected that the role of
health insurance coverage will be highly relevant to
the use of health services, in particular preventive care
and hospitalizations. This is because preventive care
is optional and older individuals may choose to forgo
the use of preventive care unless it is available at a low
cost. Regarding hospitalizations, while not optional in
the case of catastrophic care, the relative high cost of
hospitalizations and the lack of low-cost alternatives
in the private sector may render hospitalizations pro-
hibitive unless there is health insurance coverage for
the population. On the other hand, it is expected that
given that there are low-cost alternatives in the private
sector for doctor visits, the role of health insurance in
using this type of services will not be as important as
in the other two types of services.
Material and Methods
Data was used from the 2001 Mexican Health and Aging
Study (MHAS/ENASEM). This is a nationally represen-
tative, prospective panel study of individuals aged 50
and over in Mexico as of 2000.* Interviews were sought
with spouse/partners of sampled persons regardless of
their own age. Data were collected on multiple domains
of health: demographic traits, including the migration
history of respondents, their parents and offspring;
family networks and transfers exchanged; some work
history; income, assets, and pensions; and aspects of the
built environment. States with high rates of emigration
to the U.S. were oversampled. Baseline interviews were
completed with about 15 200 respondents in 2001, with a
follow-up in 2003. The institutional review board of the
Universities of Pennsylvania, Maryland and Wisconsin
approved the survey protocol, according to the ethical
principles for medical research with human subjects
of the Helsinki Declaration. The personnel of the Insti-
tuto Nacional de Estadística, Geografía e Informática
(INEGI) in Mexico gathered the data. The informed
consent of study participants was obtained and the
rights of the informants were guaranteed according
to the Ley de Información Estadística y Geográfica de
México, Chapter 5, Article 38. For further details on
the study, please see Wong, Espinoza, Palloni.14 For the
purposes of this paper, data was used from the baseline
survey gathered in 2001, and individuals aged 50 or
older who completed a direct interview were selected,
with a sample size of about 12 400 individuals.
Probit regression methods were used to estimate
the probability of seeking health care across compari-
son groups. The following explanatory variables were
controlled for, and at least the following factors were
covered (the variables are listed in parentheses):
- Preferences for health and health care (gender,
education).
Factors that enable the utilization of services and
production of health (income, education).
Prices or indicators of access to health services
(availability of health insurance, urban/rural area of
residence).
The need for health care services (age, type of health
conditions reported).
-
-
-
Dependent variable: health care utilization
The regression models were estimated for three dif-
ferent dichotomous dependent variables (yes/no) of
health care utilization: preventive care, doctor visits
and hospitalizations. Preventive care refers to the
use of at least one of the following medical exams or
procedures: vaccination against tetanus, blood test for
cholesterol, and tests for tuberculosis, diabetes and
high blood pressure. Additionally, it includes the use of
vaginal or breast cancer examinations for women, and a
prostate examination for men. The reference period for
these exams and procedures is the last two years. It is
acknowledged that the aggregate (yes/no) measure has
the limitation of referring to different preventive services
for different groups of the population. The measure
intends to capture contact with the health care system
for preventive purposes. Use of doctor visits refers to
whether the individual visited a doctor’s office at least
once during the last 12 months. Use of hospitalizations
refers to whether the individual reports to have spent
at least one night in a hospital during the 12 months
prior to the interview.
Explanatory variables
Standard demographic variables were used such as
age in three categories (50-59, 60-69 and 70 or more),
gender (male/female), current marital status in four
categories (married or cohabitation, single as never-mar-
ried, separated or divorced, and widowed), and years
of education in four categories (0, 1-5, 6, 7 or more). As
a measure of income, the individual total income was
used if the person has no spouse or partner, and the
couple’s income divided by two was used if the person
* The data and documentation can be obtained from http://www.
mhas.pop.upenn.edu.

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is married or cohabitating and currently resides with the
spouse.15 This total income is coded in three categories
(low, medium, and high). A dummy variable was used
for availability of health insurance (considering an indi-
vidual as covered if a person reported to have public or
private health insurance).* The MHAS/ENASEM study
classification of urban/rural residence was adopted,
which defines urban areas as those with 100 000 people
or more or state capitals; the rest are considered rural.
The measures of health status included in the model
are: a) self-reported health in four categories: excellent/
very good, good, fair, poor, b) self report (yes/no) of
having limitations with at least one activity of daily
living or instrumental activity of daily living, and c)
separate self-report (yes/no) of having been diagnosed
with the following chronic conditions: diabetes, heart
disease, stroke, cancer, and lung disease. Self-reports
of diagnosed chronic conditions have two limitations
worth mentioning. First, the diagnosis of the conditions
needs to have been made, and this is subject to access
to diagnostic tests, which implies access to health care
services. Second, the report is subject to recall error,
since the respondent may be confused about the exact
diagnosis, or does not know exactly whether the specific
condition was diagnosed. In general, given the low access
to regular health care services and the relatively low level
of education of the studied population, it is expected that
there may be under-reporting of the chronic conditions.
However, the models in this study control for availability
of health insurance, which takes into account differen-
tial access to health services and diagnostic tests; and
education, which takes into account, albeit partially, the
possible differential recall error. There is confidence that
by including self-reported overall health, disability, and
chronic conditions in the models most of the variation
in use-of-services that is associated with the health care
needs of the individuals is being captured. Past research
has shown that self-reported overall health is a powerful
indicator of health care needs, and it is associated with
a range of conditions in addition to the group of chronic
conditions that are highlighted; for example, aspects of
mental health and satisfaction.16
Predicted probability of utilization
To highlight the inequality in the use of health care ser-
vices, the results of the basic regression model were used
and the estimated probability of using health care was
calculated. This means that holding all other variables
constant (in particular health conditions and socioeco-
nomic characteristics), these are the patterns of use of
services for various groups of interest: men, women,
with/without health insurance, and for residents of
rural/urban areas.
Results
Table I shows the distribution of self-reported utilization
of health care services for the three types of services
according to age group, urban/rural residence and
gender, for individuals aged 50 or older who live in the
community in Mexico. Overall, the unadjusted patterns
of utilization are quite evident for visits to the doctor
and hospitalizations: those residing in urban areas tend
to use health care services more than the rural residents,
women more than men, and older more than younger
persons. For example, in rural areas, 6% of those aged
50-59 report hospitalizations compared to 9% among
those aged 70 or older. Among all women, 70% report
visits to the doctor compared to 55% of all men. For
preventive care, differences in use are quite evident by
area of residence; for example, among persons aged
70 or older, 68% report using preventive care in rural
areas, compared to 85% in urban areas. However, the
age pattern differs for this type of service compared to
the other two that were examined; individuals who are
50-59 tend to use more services than those who are 70
or older, for example.
Table II presents the distribution of self-reported
health conditions and socioeconomic characteristics
of the population by area of residence and gender.
Starting with the socioeconomic conditions, the results
show that the rural population is slightly older than the
urban counterparts. In rural areas, 43% of those aged 50
or older report ages 50-59, compared to 50% in urban
areas. With respect to marital status, one-quarter of the
women are widowed, compared to 10% of the men, and
these patterns seem similar between rural and urban
areas; about 18% of the women are widowed in both
rural and urban areas.
The estimates for educational achievement of the
population confirms that the residents in urban areas
are better educated than their rural counterparts; 42%
of rural residents report zero years of formal education
compared to 18% of urban residents; the education gap
between men and women appears to be not as large as
the one found between rural and urban areas. When
we classify the population according to low-medium-
high income, we find that a higher share of the rural
population (43%) have low income compared to the
urban residents (22%). Similarly, a higher proportion
* Health insurance coverage was coded as Yes if the person declared
to have coverage from IMSS, ISSSTE, PEMEX, Defensa, Marina, or
other public or private health insurance.

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of women (36%) report low income compared to men
(30%). The coverage of health insurance shows large
contrasts as well. Almost three-quarters of the urban
population (73%) have coverage compared to 38% of
those in rural zones. Women show a slightly higher or
similar coverage (56%) than men (52%).
The lower panel in table II shows the prevalence
of self-reported functionality and chronic health condi-
tions, again by area of residence, age and gender. With
respect to self-reported limitations with activities of
daily living or instrumental activities of daily living
(ADL/IADL), the results show similar patterns between
rural and urban residents (around 11%), but higher
prevalence for women (13%) than men (8%). Self-reports
of chronic health conditions show patterns of worse
health among women than men. For example, 17% of
women and 13% of men report diabetes. On the other
hand, 18% of urban residents and 12% of rural report this
condition. However, the report of cancer, stroke, heart
and lung diseases are low compared to diabetes, and
seem similar or slightly lower in rural than urban areas.
With a few exceptions, both in rural and urban areas,
and for men and women, the self-report of disability and
chronic conditions is higher for older individuals than
younger ones. The exceptions refer to persons aged 70
or older, who report lower prevalence of diabetes than
their younger counterparts ages 50-69.

found among individuals aged 50 or older in Mexico
with respect to: utilization of health services, socioeco-
nomic conditions, health care coverage, and self-re-
ported health conditions. The question we address next
is if the patterns of differential use reflect the differences
found in socioeconomic conditions, health care needs, or
both. In other words, can the variation in utilization be
explained by the differences in education, self-reported
health conditions, income, or health care coverage. Fur-
ther, after controlling for socioeconomic conditions and
health conditions, will major gaps remain in the use of
health services according to health care coverage?
Table III presents the results of the multivariate
regression analysis, showing the estimated marginal
effects derived from the model. The marginal effect
is interpreted for a dummy explanatory variable as
the estimated change in the probability of utilization
associated with those who report “yes” in the explana-
tory variable compared to those who report “no.” For a
categorical variable, the marginal effect is the estimated
change in the probability of utilization of those in one
category with respect to the reference (omitted) category
of the same explanatory variable. For example, the
estimated marginal effect of .07 for ADL/IADL in the
hospitalization model implies that, holding all other
variables at the mean value, the probability of hospi-
In summary, these results illustrate the differences
Table 1
PROPORTION USING PREVENTIVE SERVICES, VISITS TO THE DOCTOR, AND HOSPITALIZATIONS BY AGE GROUP, GENDER, AND
URBAN/RURAL RESIDENCE. POPULATION AGED 50 OR OLDER IN MEXICO


Preventive care
50-59
60-69
70- +
Total
Visited a doctor
50-59
60-69
70- +
Total
Stayed at a hospital
50-59
60-69
70- +
Total






Male

0.528
0.576
0.603
0.564

0.479
0.560
0.539
0.522

0.042
0.070
0.087
0.064
Rural
Female

0.798
0.783
0.720
0.775

0.645
0.659
0.683
0.658

0.068
0.087
0.095
0.080

Total

0.678
0.683
0.658
0.675

0.571
0.611
0.607
0.593

0.056
0.079
0.091
0.072

Male

0.741
0.791
0.835
0.776

0.528
0.643
0.668
0.592

0.058
0.065
0.147
0.079
Urban
Female

0.909
0.941
0.886
0.914

0.741
0.767
0.729
0.746

Total

0.836
0.875
0.863
0.853

Male
ALL
Female Total














0.634
0.667
0.692
0.659
0.854
0.856
0.795
0.842
0.757
0.769
0.744
0.758
0.648
0.713
0.701
0.678
0.503
0.595
0.589
0.553
0.693
0.709
0.704
0.700
0.610
0.656
0.646
0.632
0.081
0.110
0.070
0.087
0.071
0.090
0.106
0.084
0.050
0.068
0.110
0.071
0.075
0.098
0.084
0.083
0.064
0.084
0.097
0.078
Note: Use of health care services refers to: Preventive services (tetanus vaccination, tests for cholesterol, diabetes and high blood pressure for men and women;
additionally having done an examination for breast lumps, a pap smear or a mammography for women, and having done a blood test for prostate cancer for
men); Doctor visits refers to having visited the doctor at least once. Hospitalization refers to having spent at least one night at a hospital facility. Preventive
care indicators refer to the last two years, while visits to the doctor and hospitalizations refer to the last 12 months.
Source: MHAS/ENASEM 2001