Health cards- maternal reports and the measurement of immunization coverage: the example of Guatemala.

Immunization against major childhood diseases has been an essential component of health policies in developing countries. However- despite its importance and the efforts invested by many organizations in promoting immunization programs- consistent and accurate measurement of immunization coverage has not yet been achieved. In this paper- we explore the implications of alternative methods of measuring immunization coverage rates in Guatemala- using data from the 1987 Encuesta Nacional de Salud Materno Infantil- and we consider the dangers of making inferences about levels and trends in coverage from cross-sectional data. The results indicate that (1) service statistics may well lead to overestimates of coverage/ (2) survey estimates derived from health cards can also produce severely biased estimates/ and (3) in spite of problems associated with maternal recall- mothers' reports of their children's vaccination status probably result in substantially improved estimates of immunization coverage.