Lack of health insurance can deprive the poor of access to services or put them at risk of financial hardship. To protect the poor against excessive health expenditures, many countries have implemented mechanisms such as community-based health insurance, (1,2) national health insurance (3-6) and targeted public health insurance. (7,8)
Mexico has multiple health insurance providers. Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado [State Employee's Social Security and Social Services Institute, ISSSTE] provides coverage for government employees and the Instituto Mexicano del Seguro Social [Mexican Social Security Institute, IMSS] covers for private-sector employees. By 2001, however, nearly hall of the Mexican working-age population had no health insurance. (9) The Seguro Popular [People's Insurance], launched that year, represented a major effort to protect the working-age population against steep health-care costs. Enrolment in the Seguro Popular is not dependent on health status or pre-existing illness, there is no co-payment in accordance with the type of health care received, and family contributions are determined solely by ability to pay. (10) Medical interventions are offered mainly through the public health network.
The Seguro Popular, which covers health care for many diseases, including cancer, asthma, anaemia, pneumonia and diabetes, (11) was implemented gradually between 2001 and 2005, but only in communities with health units having accreditation, that is, the proven capacity--medical resources, personnel and infrastructure, etc.--to provide the health interventions covered by the Seguro Popular. Thus, during the implementation phase, people chose to enrol based largely on programme availability at the regional level, and this, in turn, was determined by health infrastructure capacity.
According to WHO estimates, by 2030, approximately 366 million adults will have diabetes (type 2 in over 90% of the cases), and 75% of these adults will be living in developing countries. (12) In Mexico, type 2 diabetes is the leading cause of death among adults, according to the 2007 National Death Registry. (13) Data from the 2005-2006 cross-sectional Encuesta Nacionalde Salud y Nutricion [National Health and Nutrition Survey, ENSANUT] showed that 7.1% of adults reported having been diagnosed with type 2 diabetes by a physician. (14) Test results based on fasting blood serum samples collected for the ENSANUT suggest that a large number of Mexican adults have undiagnosed diabetes and that the estimated overall prevalence of diabetes is about 14%. (S Villalpando, personal communication).
Diabetes requires life-long treatment and periodic clinical follow-up. Health care is needed on a regular basis to attain good control of blood glucose levels, blood pressure, blood lipids and body weight; to reduce or delay the onset of complications, and to delay or prevent death from the disease. Periodic health-care visits (three to four per year, according to Mexican and international guidelines) should include laboratory testing to assess the need for more aggressive therapy. (15,16)
Lifestyle intervention, including a healthy diet and physical activity, is the first line of treatment for diabetes, but the American Diabetes Association and the European Association for the Study of Diabetes (17) recommend aggressive treatment of the disease, including early initiation of insulin therapy. Diabetes management also involves close monitoring for chronic complications affecting the kidneys, eyes or feet. (15,16)
In Mexico, the total annual cost of managing diabetes and its complications in 2000 was estimated at over 15 billion United States dollars (US$), of which approximately US$ 765 million represented direct medication costs. (18) In that same year, an estimated 44% of adults who had been previously diagnosed with diabetes in Mexico reported having no health insurance. (19) Diabetic patients who lack health insurance are less likely to adhere to medical care. (20) The Seguro Popular was intended to improve the treatment options and laboratory tests available to Mexicans with diabetes, as well as to ensure their access to appropriate medication.
Previous empirical research suggests that people who are Seguro Popular beneficiaries have better access to health care than those who are not. Bleich et al. (21) found that hypertensive adults enrolled in the Seguro Popular were more likely to be treated for high blood pressure and to attain good control. Sosa-Rubi et al. (22) found that pregnant women enrolled in the Seguro Popular were more likely to receive formal obstetric care.
This paper examines the effect of Seguro Popular enrolment on access to health care, specifically health resources (medical visits, laboratory tests and use of medication, including insulin injections), and on blood glucose control (as measured by glycosylated haemoglobin, HbA1c, the gold standard for blood glucose control surveillance). (15,16) An HbA1c test is required at least twice a year for diabetes patients with stable blood glucose and at least four times a year for patients without stable blood glucose or for those who have just begun or changed therapy. (16) To reduce confounding in the observational data analysed, we used propensity score matching to estimate the average treatment effect, with "treatment" defined as enrolment in the Seguro Popular.
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Our working hypothesis was that enrolment in the Seguro Popular improves access to treatment and health outcomes among patients with diabetes. This …