Effect of the conditional cash transfer program Oportunidades on vaccination coverage in older Mexican people

Background: Immunization is one of the most effective ways of preventing illness, disability and death from infectious diseases for older people. However, worldwide immunization rates are still low, particularly for the most vulnerable groups within the elderly population. The objective of this study was to estimate the effect of the Oportunidades -an incentive-based poverty alleviation program- on vaccination coverage for poor and rural older people in Mexico. Methods: Cross-sectional study, based on 2007 Oportunidades Evaluation Survey, conducted in low-income households from 741 rural communities (localities with <2,500 inhabitants) of 13 Mexican states. Vaccination coverage was defined according to three individual vaccines: tetanus, influenza and pneumococcal, and for complete vaccination schedule. Propensity score matching and linear probability model were used in order to estimate the Oportunidades effect. Results: 12,146 older people were interviewed, and 7% presented cognitive impairment. Among remaining, 4,628 were matched. Low coverage rates were observed for the vaccines analyzed. For Oportunidades and non-Oportunidades populations were 46% and 41% for influenza, 52% and 45% for pneumococcal disease, and 79% and 71% for tetanus, respectively. Oportunidades effect was significant in increasing the proportion of older people vaccinated: for complete schedule 5.5% (CI95% 2.8-8.3), for influenza 6.9% (CI95% 3.8-9.6), for pneumococcal 7.2% (CI95% 4.3-10.2), and for tetanus 6.6% (CI95% 4.1-9.2). Conclusions: The results of this study extend the evidence on the effect that conditional transfer programs exert on health indicators. In particular, Oportunidades increased vaccination rates in the population of older people. There is a need to continue raising vaccination rates, however, particularly for the most vulnerable older people.