Demographic and Health Surveys Methodology - Measure DHS

AssumptionsWhen a child does not have a vaccination card that was shown to the interviewer, two assumptions aremade:1. The vaccinations for DPT 1, 2, and 3 were given at the same time as those for Polio 1, 2,and 3, respectively.2. The ages at vaccinations for children whose mothers reported the vaccination are the same asthose derived from the dates on the vaccination cards.Decisions on AlternativesIn some countries, especially those of Latin America, the recommended age for measles vaccination haschanged from below age 12 months to age 12 months or above. Where this is the case, the age range ofthe children in both numerator and denominator needs to be changed from 12–23 months to 18–29 months. Additionally, age 18 months instead of 12 months should be used as the age by whichvaccinations should have taken place.Care must be taken in comparisons over time and between countries that the same age ranges are used;otherwise, underestimation of vaccination rates may occur where vaccines are recommended to be givenat older ages than before.Guide to DHS Statistics 111 Updated September 2006