Migration and immunization: determinants of childhood immunization uptake among socioeconomically disadvantaged migrants in Delhi, India

Objective To determine the coverage of childhood immunization appropriate for age among socioeconomically disadvantaged rural–urban migrants living in Delhi and to identify the determinants of full immunization uptake among these migrant children. Methods This is a cross-sectional survey of 746 rural–urban migrant mothers with a child aged up to 2 years, who were interviewed with a pretested questionnaire. Data pertaining to the reception of various vaccines, migration history and some other social, demographic and income details were collected. Multiple logistic regression analyses were performed to identify the determinants of full immunization status. Results Immunization coverage rates were lower among migrants than the general population of Delhi and even lower among recent migrants. The likelihood of a child receiving full immunization rose with age of the mother, her educational attainment and the frequency of her use of health care. The head of household having a secured salaried job also significantly increased the likelihood of full immunization, as did post-natal visits by a health worker. Conclusion Migrant status favours low immunization uptake particularly in the vulnerability context of alienation and livelihood insecurity. Services must be delivered with a focus on recent migrants; investments are needed in education, socio-economic development and secure livelihoods to improve and sustain equitable health care services. Migration et vaccination: déterminants de la prise de la vaccination par les enfants chez les migrants socioéconomiquement défavorisés à Delhi, Inde Objectif: Déterminer la couverture de la vaccination appropriée à l’âge chez les enfants des migrants ruraux-urbains socioéconomiquement défavorisés vivant à Delhi et identifier les déterminants de la prise de la vaccination complète chez ces enfants migrants. Méthodes: Enquête transversale sur 746 mères migrantes rurales-urbaines avec un enfant jusqu’à l’âge de deux ans, qui ont été interviewées au moyen d’un questionnaire testé au préalable. Les données relatives à la prise des différents vaccins, à l’histoire de la migration et à d’autres facteurs sociaux, démographiques et des informations sur le revenu ont été recueillies. Des analyses de régression logistique ont été effectuées afin d’identifier les déterminants du statut de vaccination complète. Résultats: Les taux de couverture vaccinale étaient plus faibles chez les migrants que dans la population générale de Delhi et encore plus faibles chez les migrants récents. La probabilité d’un enfant recevant une vaccination complète augmentait avec l’âge de la mère, son niveau de scolarité et la fréquence de son utilisation des soins de santé. Le chef de ménage ayant un emploi à salaire sûr augmentait également de façon significative la probabilité pour la vaccination complète, de même que des visites postnatales par un agent de santé. Conclusion: Le statut de migrant favorise des taux faibles d’immunisation, particulièrement dans le contexte de la vulnérabilité de l’aliénation et de l’insécurité des moyens de subsistance. Les services doivent être offerts avec un accent mis sur les migrants récents; des investissements sont nécessaires dans l’éducation, le développement socio-économique et les moyens de subsistance afin d’améliorer et de maintenir des services de santééquitables. Migración e inmunización: determinantes de la inmunización infantil entre migrantes con desventaja socio-económica en Delhi, India Objetivo: Determinar la cobertura de inmunización infantil más apropiada, según la edad, entre migrantes rurales con desventaja socio-económica viviendo en Delhi, e identificar los determinantes del completar el programa de inmunización entre estos niños migrantes. Métodos: Estudio croseccional de 746 madres que habían migrado de zonas rurales a zonas urbanas con un niño de hasta dos años de edad, y que fueron entrevistadas utilizando un cuestionario previamente evaluado. Se recolectaron datos sobre la recepción de varias vacunas, historia migratoria y algunos otros detalles sociales, demográficos y de ingresos. Se realizaron análisis de regresión logística múltiple para identificar los determinantes del estado de inmunización completo. Resultado: Las tasas de cobertura de la inmunización eran menores entre migrantes que entre la población de Delhi en general y menores aún entre los recién migrados. La probabilidad de que un niño recibiese una inmunización completa aumentaba con la edad de la madre, su nivel de educación y la frecuencia con la que utilizaba los servicios sanitarios. El que el cabeza de familia tuviese un salario seguro también aumentaba significativamente la probabilidad de una inmunización completa, como lo hacían las visitas post natales realizadas por trabajadores sanitarios. Conclusión: El estatus migratorio favorece una baja participación en el programa de inmunización, particularmente en el contexto de vulnerabilidad, de alienación y de inseguridad en el sustento. Los servicios han de ser entregados poniendo especial énfasis en los recién migrados; es necesario invertir en educación, desarrollo socio-económico y un sustento seguro si se quiere mejorar y hacer sostenibles unos servicios sanitarios equitativos. Of the 9. 7 million child deaths worldwide, 40% occur in the Asia Pacific region (United Nations Children’s Fund 2008). Global under-five mortality has fallen steadily over the past two decades because of increased use of key health interventions such as immunizations (United Nations Children’s Fund 2009). India’s immunization programme is one of the largest in the world in terms of beneficiaries served, vaccinations delivered, and the geographical spread and diversity of the regions covered (Government of India 2009). Despite the basic infrastructure, India remains the nation with the largest number of children who have not received immunizations (United Nations Children’s Fund 2007). Immunization coverage is better in urban than rural areas (International Institute of Population Studies and Macro International 2007). However, we anticipate and argue that within the urban areas disparities and inequities persist in immunization coverage and that the socioeconomically disadvantaged, particularly those who migrated recently from rural villages, are more vulnerable and may contribute to the lower uptake of immunizations. Our study aimed to (i) report the reception of various vaccines appropriate for age among the socioeconomically disadvantaged migrants living in Delhi and (ii) to determine individual-, household- and health care system-level determinants associated with full immunization uptake. Disparities in health conditions and health care utilization are evident between natives and migrants, as well as between recent and long-term residents, who are marginalized and vulnerable until they have adapted to the social and cultural norms of a new place. To understand the use of health care services, determinants models are generally applied, and access is considered as a general concept. Five dimensions of access, namely availability, accessibility, affordability, adequacy and acceptability, influence the course of health-seeking process (Fiedler 1981; Anderson 1995). Obrist et al. (2007) proposed a health access livelihood framework that combines health service and health-seeking approaches and situates access to health care in the broader context of livelihood insecurity. Thus, the degree of access depends on the interplay between the health services and the degree of vulnerability of the community. The vulnerability of migrants, particularly of recent migrants, is obvious in terms of livelihood insecurity, negligence and alienation in the new sociocultural environment. It leads to less control over available resources that are meant for all members of communities including migrants. We hypothesize that socio-economically disadvantaged migrants, particularly recent migrants, are more likely to forego health care than the general population and settled migrants. The study was conducted in National Capital Territory (NCT) of Delhi. Migration is a significant contributor to Delhi’s population growth (Government of National Capital Territory of Delhi 2009a). On the one hand, rapid urban development attracts many people, particularly the poor; on the other hand, rural impoverishment and lack of work push people into the cities. We categorized migrants into two groups: recent migrants and settled migrants. Recent migrants are those who moved to Delhi from rural villages within the last 5 years, and settled migrants are those who have been residing in Delhi for at least 5 years. Both groups are mainly from northern Indian states, particularly Uttar Pradesh and Bihar, and their distribution in terms of place of origin, ethnicity, social class and religion is similar. Health services in NCT of Delhi adopted the universal immunization programme of India, which stipulates that infants should be vaccinated with the following vaccines: a dose of Bacillus Calmette-Guerin (BCG) at birth or as soon as possible i. e. within a month; oral polio vaccine (OPV) within 48 h; three doses each of Diphtheria, Pertussis and Tetanus (DPT) vaccine, OPV at 6, 10 and 14 weeks of life; and one dose of measles vaccine at 9–12 months (World Health Organization 2008). In addition, hepatitis B vaccine is to be provided (at birth or within 48 h, and at 6, 10 and 14 weeks of life) in Delhi (World Health Organization Country office for India 2008; Government of National Capital Territory of Delhi 2009b). Initially, several slums/resettlement colonies where migrants reside were identified by visiting and enquiring from the local community and community leaders. Finally, a total of 30 clusters (from 23 slums and seven resettlement colonies) were selected. Recent and settled migrants were selected from slums as well as resettlement colonies. The sample size was calculated according to Lwanga and Lemeshow (1991). With a conservative choice of immunization coverage not less than 50%, confidence level of 95% and with a relative precision of 10% points on each side, a sample of 384 children was needed. Taking the cluster design effect into consideration, the required sample became 768. To attain this sample size, mothers with children under age 2 years were identified from the selected clusters. The purpose of the study was explained to them and their consent obtained before data collection. The institutional ethics committee approved the study protocol. Demographic and socio-economic details, migration history, the status of immunization received by the youngest child under 2 years and mother’s use of health care services were elicited through interviewer-administered questionnaires. The immunization status of the child was determined from the immunization card, and in the absence of immunization cards, mothers were asked to recall whether the child had received different vaccines (including the number of doses for each) as well as reception of vitamin A supplement. Separate questions were asked to extract information on the each age-appropriate vaccine to be received. Two outcome measures were considered: the likelihood of a child aged 1 year or older having received (i) full immunization against six vaccine preventable diseases (VPDs) (BCG within 1 month of age; three doses each of DPT and OPV at 6, 10 and 14 weeks of age; measles vaccine between 9 and 12 months of age), from now on referred to as full immunization against six VPDs, and (ii) full immunization against seven VPDs (which includes three doses of hepatitis B at 6, 10, 14 weeks of age in addition to the above-mentioned vaccines), from here onwards referred to as full immunization against seven VPDs. Individual-level independent variables of interest were gender and birth order of the child. The household-level characteristics were mother’s age, educational status and mother’s occupational status (working to earn, not working to earn) ; father’s educational status, occupation of the head of household, household income per month (in Indian rupees, 1 INR = US 0. 02), size of the household, social class (scheduled caste or tribe, backward castes, uncategorized castes), religion (Hindu, other than Hindu) and migration status (recent migrants, settled migrants). The Government of India has categorized some ethnic groups (castes and tribes) into scheduled castes, scheduled tribes and backward castes. These categories of people are entitled to positive discrimination in education, employment and other developmental opportunities. Mother’s health care use was assessed by her attendance of antenatal care (ANC) and place of delivery (home, hospital). The system-level variable was post-natal visits by a health worker. Age-appropriate vaccination was taken as the proportion of children who received particular vaccines appropriate for their age to the total number of children in that particular age group, and 95% confidence intervals (CIs) were also calculated. To examine the association of several exposure (independent) variables on full immunization, children over 12 months of age were considered for analysis. Dependent variables were two outcome variables mentioned earlier, and separate logistic regression analyses were carried out. Initially, each independent variable was regressed against each dependent variable. Those variables with a minimum P value of 0. 25 were considered for multiple logistic regression analyses. Hosmer and Lemeshow (2000) recommended a P value of <0. 25 to be used as a screening criterion for variable selection. The use of a more usual value (such as 0. 05) often fails to identify variables known to be important, while the use of a higher P value has the disadvantage of including variables that are of questionable importance (Mickey & Greenland 1989). Multiple logistic regression analyses were carried out by backward likelihood ratio method. The fit of these models was tested by Hosmer and Lemeshow goodness of fit tests. All analyses were carried out using spss 17. 0 (SPSS Inc, Chicago, IL, USA). Of the 770 mothers contacted, 12 (1. 6%) mothers refused to participate in the survey and the data of another 12 mothers were incomplete. Thus, the final analysis is based on data from 746 mothers. Table 1 presents the socio-demographic details of the sampled mothers. More than 50% of the mothers and around 20% of the fathers did not receive any formal education. Regarding the occupation of the head of the household (all were men, except for three widows), the majority were daily wage labourers (both skilled and unskilled) and earned less than INR 6000 (US 120) per month. Many of the participants belong to backward castes and more than 90% are Hindu. Table 2 presents the details on the reception of various vaccines appropriate for age. Around 90% of the children had received BCG vaccine within 1 month of age, but only 75% were given OPV at birth. Only 25% received hepatitis B vaccine at birth. Migrants’ use of immunization services appeared comparable to the general population and among both groups of migrants at first, but by the time the child was 10–14 weeks old it had fallen considerably, especially among recent migrants. Only 67% of recent migrants’ and 82% of settled migrants’ children received measles vaccine. Uptake of vitamin A supplement varied between 72% (recent migrants) and 76% (settled migrants). Full immunization against six VPDs was around 81% among settled migrants, but only around 64% among recent migrants. The proportion of fully immunized children against seven VPDs fell by 20% among settled migrants to 60. 2% and by 25% among recent migrants to 39. 7%. Around 5% of children received no vaccines at all. The associations between full vaccination and selected exposure variables are presented as adjusted odds ratios (AOR) with 95% CI (Table 3). Children of recent migrants were at risk of not receiving full immunization. Compared to recent migrant children, settled migrant children have higher odds of being fully immunized against six VPDs (AOR = 1. 93, 95% CI = and against seven VPDs (AOR = 95% CI = socio-demographic characteristics such as mother’s age, mother’s and occupation of the head of the household were also significantly associated with the full immunization against six VPDs. Mother’s increased level of and the head of the household having a secured salaried job were significantly associated with full as were mother’s use of and post-natal visits by a health worker. The P of the Hosmer and Lemeshow that the models were a The immunization among rural–urban migrants that a proportion of children, particularly recently migrated children, not receive a full course of immunization. Compared with the full immunization status of among the general population of Delhi, the proportion of fully immunized migrant children is lower of Recent migrants’ children particularly are at risk of not being fully and it that migrants the of health care use of urban the majority of migrants have with the health services the child is less than 2 months of age, their immunization coverage particularly among recent migrants. The but we low uptake of immunization to migrants’ and alienation in the new sociocultural environment. We that these groups are not immunization rates in urban areas may as rural–urban migration is Recent migrants’ children were less vaccinated than settled migrants’ children. Immunization status the level of into the new because study population (both recent and was selected from the clusters of health resources was the and because the migrant groups not in their Thus, while migration status is for lower uptake of health care services, migrant may also a as into the new & is associated with vaccination in some & et al. 2008). We did not any in immunization coverage by gender of the with the of other on migrants & with those of et al. and for mother’s age the likelihood of a child being fully We that older mother’s age is associated with and social with older which in better odds of a child being fully of the particularly the mother, and better socio-economic status influence the health-seeking of et al. a higher level of and of services, a secure income the household from the of work also that and lower status may be to full immunization among migrant population in This study the importance of post-natal care in these where more than 50% of occur at Uptake of and post-natal care services the that mothers access immunization services et al. et al. In delivery in increased odds of receiving full immunization against seven VPDs but not six VPDs, because of the place of immunizations are provided on in the community. of services in the community may be the influence of The higher odds of receiving full immunization associated with post-natal visits by a health to that the and influence health-seeking with migrant status, several individual-, household- and system-level are in the in immunization status. Despite of services and immunization and better coverage of immunization in Delhi, recent migrants’ children were not explained that the urban (in terms of and child health is by such as migrants’ lack of social and the of and that the likelihood of full immunization for children of rural–urban migrants is associated with the by migration & Our study the of as recent and settled migrants in the where the of health services is but of and access to the services may The migrated are with the to in with a of living and the of to a new sociocultural environment. migrants, who are with the and some social are better to of health services. Thus, migrant among recent migrants and migrant among settled migrants may be a in full immunization uptake. Our study the to health care services for migrant communities by their sociocultural and and the importance of health care among migrant communities in urban Our are for India’s health care as well as those of other migration is and characteristics are as migrants the vulnerability from alienation and livelihood insecurity. A of the study is which and the of We also did not data on health and other and any on health care Despite these the study has such as the sample two groups of one that has a level of and another that is at the of to a new environment. The children of recent rural–urban migrants are at risk of not being fully immunized because of the livelihood and alienation of their Uptake of antenatal and care leads to increased immunization service by the health care significantly the likelihood of a child receiving full immunization. the particularly to socio-economically disadvantaged migrants in full immunization in and socio-economic secure livelihoods and equitable services are also for and full utilization of immunization services. The study was by the All India Institute of Delhi,