Determinants of immunization status of children aged 1-5 years attending a tertiary health care facility: A cross-sectional study

Background: Childhood immunization is one of the key health interventions, which is useful in decreasing the under-five mortality. There has been a recent decline in immunization coverage rates in India as shown by the National Family Health Survey 4. Objective: This study was undertaken with the objective of determining the socio-economic and demographic risk factors associated with partial immunization of children aged 1-5 years attending a tertiary care center in South India. Materials and Methods: This cross-sectional study was done at the outpatient department of Institute of Child Health and Hospital for Children, Chennai, from May 2015 to October 2015. Children aged 1-5 years attending the outpatient department were included by convenient sampling. A sample size of 1100 was calculated based on a pilot study. After obtaining parental informed consent, data were collected on immunization and socio-demographic factors, namely, gender, place of residence, parental education and occupation, family income, number of children, birth order, place of delivery, and awareness of the type of vaccines to be given. The WHO definitions were used to classify immunization status as full, partial, and delayed immunization. Univariate and multivariate logistic regression analyses were performed to determine independent risk factors for partial immunization. Results: Totally, 1104 children were included in the study. 1056 (95.7% [95% confidence interval 94.5-96.9]) were fully immunized, whereas 41 (3.7% [2.59-4.81]) were partially immunized and 7 (0.6% [0.14-1.06]) had delayed immunization. None of the children were totally unimmunized. Univariate analysis identified rural residence, home delivery, having more than 2 children, birth order more than 2, lack of maternal and paternal education beyond primary school level, and lack of awareness on immunization as significant risk factors for partial immunization. After multivariate logistic regression, rural residence, having more than 2 children, and lack of awareness on immunization emerged as independent risk factors for partial immunization. Conclusion: Residing in rural areas, having more than 2 children, and lack of awareness on immunization are significant independent risk factors for a child not being fully immunized