Estimation of Age-Appropriate Immunisation Coverage in Assam using Survival Analysis

Abstract

The widely used measure of immunisation coverage, viz., up-to-date immunisation, is a biased estimator of fraction of vaccinated population. It completely ignores the timeliness in receipt of vaccination, which is important for child health and survival. In this paper, the researcher attempts to study the age-appropriate vaccination pattern of two districts, viz., Dibrugarh and Sibsagar of Assam. Multi-stage cluster sampling method was used to select random sample of children to collect information on immunisation in the study area. The techniques of survival analysis were used to estimate the age-appropriate immunisation with respect to different vaccine doses. The up-to-date immunisation coverage was also calculated for comparison purpose. The results revealed that the timeliness in receipt of different doses of vaccination was very less despite a satisfactory level of up-to-date immunisation coverage. Particularly, by age of 14 weeks (the recommended age for the receipt of third dose of DPT and OPV vaccine), only about 5% children were vaccinated with the third dose of DPT and OPV vaccine; while the up-to-date coverage of the two doses were about 86 and 82%, respectively, in the study area. A similar type of result could be observed in other doses also. Thus, it can be concluded that though the child immunisation coverage in Assam has been increasing, there is still a lot of concern over the timeliness of vaccination coverage, which will be able to provide highest protection against vaccine-preventable disease.