Determinants of immunization status among 12- to 23-month-old children in Indonesia (2008–2013): a multilevel analysis

Since the twentieth century, immunization and vaccination have been recognized as preventive strategies for vaccine-preventable diseases [1]. Data from World Health Organization (WHO) showed that immunization prevents 2,5 million deaths every year in the world [2]. WHO initiated the Expanded Program for Immunization (EPI) in 1974 to protect the population from six diseases: tuberculosis, diphtheria, tetanus, pertussis, measles, and poliomyelitis. This goal was considered an essential element of the WHO strategy to achieve health for all by 2000 [3]. However, in 2008, nearly 1.7 million children under five years old died of vaccine-preventable diseases, and 19.3 million children were missing six basic vaccines in 2010. More than half (53%) of those missing vaccination were in India, Nigeria, and Indonesia [4].

The government of Indonesia (GOI) showed a strong commitment to improving immunization coverage as a priority public health intervention by launching the EPI in 1977. One of the GOI’s strategies for improving immunization coverage is to bring immunization services closer to the community. It extends primary health center services from stationary and mobile health centers to community-based health services that involve non-governmental organizations (NGOs) and civil society organizations (CSOs) at the sub-village and community levels [5]. With a population of more than 220 million, Indonesia has more than 4 million children to immunize annually. The basic vaccines based on Indonesian national policy are bacille Calmette-Guérin (BCG, against tuberculosis); diphtheria, tetanus and pertussis (DTP); oral polio vaccine (OPV); measles; and hepatitis B [5]. Although immunization coverage in Indonesia is increasing year by year, it still falls short of the WHO and UNICEF’s goals as stated in their Global Immunization Vision and Strategy [3]: to reach 90% of children under the age of one with routine immunization nationwide, and at least 80% in every district in the country by the year 2020 [6]. Almost half (46.64%) of children in Indonesia did not receive complete immunization in 2012 [7].

Literature from low- and middle-income countries has shown that low income [8], lack of access to health care, high cost of health care, low parental education [9], delivery unassisted by a professional birth attendant [10], and single mothering [11] are risk factors for low immunization coverage. Identifying the factors that affect childhood immunization is essential for policy makers to establish strategies to increase immunization coverage.

Previous studies have shown that sociodemographic and geographic health factors, such as mothers’ age and education, as well as the availability of professional health attendants, affected the uptake of the first dose of measles vaccinations in Indonesia [12‐14]. However, those studies were limited to measles immunizations and took only household level determinants into account. The districts’ characteristics played a crucial role in successful immunization programs in Indonesia as the country’s regions vary in terms of both geographical and economical characteristics. Furthermore, previous studies have been mostly cross-sectional and have used single-level logistic regression analysis data which failed to capture the hierarchal structure at the district level. The purpose of this study was to identify both the household- and district-level determinants of childhood immunization status in Indonesia from 2008 to 2013.

Using nationally representative data from Indonesia, we found that the percentage of children aged 12–23 months who received complete immunizations increased from 47% in 2008 to 61% in 2013. However, those percentages still fall short of the WHO and UNICEF’s Global Immunization Vision and Strategy goal of 80% coverage [3]. Identifying how socioeconomic factors and district characteristics affect child immunization status is thus essential to improve immunization coverage in Indonesia.

Focusing on household determinants, we found that the presence of a professional birth attendant in the delivery process had a positive and significant association with children’s immunization status. This result supports findings from previous studies linking professional birth attendance and higher immunization coverage [23‐25]. In addition to assisting in the process of delivery, professional birth attendants in Indonesia provide antenatal and perinatal care, nutrition and reproductive advice, and immunization services [13, 26, 27]. Mothers who have more frequent contact with health professionals seem to be more aware of their children’s health as they receive more information about immunization and child health [1, 28]. Furthermore, based on EPI recommendations, health professionals should administer hepatitis B immunization to all newborns within 24 h of birth. Newborns can therefore receive this immunization immediately after birth if a professional birth attendant is present, and their mothers obtain adequate information from health workers about the sequence of immunizations [13, 26, 27].

Children of older mothers were more likely to be fully immunized. Women under 16 years of age in Indonesia were less likely to use any health care than older women. Younger mothers are often unable to make their own decisions; they must discuss decisions with family members. Older mothers are more likely to have experience regarding raising children and more likely to be knowledgeable about children’s health [29]. The importance of maternal education in children’s health is universally recognized. Children of more educated mothers are more likely to be fully immunized [13, 14, 30‐32]. A woman with a better educational background is more likely to be aware of the importance of immunization. It is also possible that better-educated mothers are more receptive to novelty and modern ideas, more confident in making decisions for their families’ health, and more skilled at obtaining health information. Furthermore, preventive health services are more easily accepted by people with better educational backgrounds [33‐36]. Women with the most education are likely to be wealthier; they also have better access to health facilities and immunization services. Education is correlated with family welfare [37].

Household income and wealth index influences the likelihood that children receive complete immunization. This result is similar to the result of many previous studies that show that children from wealthier families are more likely to be immunized than children from poorer families [1, 38‐40]. Although free vaccination services are offered in Indonesia, the time and financial cost of reaching health facilities can be an obstacle to parents. Furthermore, higher wealth index are associated with better health status and health-seeking practices.

With regard to parity status, this study shows that mothers who had more than five children were less likely to immunize their children; the large number of children in the family decreased the chance of children receiving complete immunization. Previous research has shown that children in bigger families had a lower probability of receiving full immunization [41]. As the number of children in a family increases, the mother becomes busier fulfilling her children’s needs. Furthermore, a mother’s attention is divided between children if she has many children [31, 42, 43]. Children in rural areas had no significantly different probability of receiving complete immunization than children in urban areas. This may have been a result of the improvements that have been made to health facilities in rural areas of Indonesia. The GOI’s strategy for distributing health workers to rural regions has also improved rural residents’ access to health care services [5, 44].

Turning to district-level determinants, increasing the number of village health posts and health workers was related to higher immunization coverage. Among these district-level determinants, increasing the number of village health posts had the largest positive association with child immunization status. Previous research has shown that adding one village health post per 1000 population improves the probability that children will receive full immunization by 54% [7]. Village health posts (Posyandu) are community-based sites for health services. Under the auspices of the Ministry of Health, the Family Planning Board, and the Ministry of Internal Affairs. A village health post is a form of community empowerment, and it is managed by, from, and for the community. Community participation is the most essential factor in implementing efforts to maintain and improve basic health. Village health posts need cadres, or village health post volunteers. Cadres are voluntarily selected from among community members to organize the activities of village health posts. Cadres are trained at Puskesmas (primary health centers) by sub-district representatives of the Ministry of Health until they are able to provide the basic health care services required by their community. According to Puskesmas law (Indonesian Health Ministry Regulation No. 75 Year 2014), the medical doctor or midwife from the health center must help cadres master every activity. Furthermore, community leaders support Posyandu through fundraising and encouraging the community to actively participate in the implementation of a village health post. The community is encouraged to set up and staff the village health post once a month in every village [45]. Village health posts have a role in Indonesia’s immunization program, as the village midwife program provides immunizations as well as other maternal and child health services via the extensive village health post network. Cadres assist village midwives in distributing information and in using a personal approach to invite mothers to join the immunization program [12, 46]. The village health post program makes it easy for community members to access the immunization program. Good coordination between health centers and village health posts is an effective element in increasing the number of children who receive full immunization.

In contrast, increasing the density of health centers showed a negative association with immunization status. The most plausible explanation for this is that mothers were likely to take their children to village health posts for immunization, as shown by the positive and significant relationship between higher density of village health posts and immunization status in this study. Providing accessible immunization services is thus crucial to raising immunization coverage. The Indonesian government is committed to widening the network of primary care services that extend to the village level [47]. Health workers, including doctors, nurses, and midwives at health centers, deliver immunizations on a schedule at village health posts. Furthermore, it is easier for parents to transport their children to the village health posts given that village health posts are closer to the community than health centers, which are located in the sub-districts.

Similarly, increasing the number of hospitals is positively associated with immunization coverage. Although the GOI offers children free immunization at village health posts and health centers, increasing the number of hospitals also augments the number of children who receive full immunization. Some wealthier families choose to go directly to hospitals and pediatricians to obtain their children’s immunizations. They believe that the quality of the vaccines administered by pediatricians, who in contrast to other health workers usually use imported vaccines, may be higher quality and less likely to produce side effects.

Our study indicated that presence of higher numbers of health workers (especially midwives) influences immunization coverage, supporting the findings of previous research [48]. In addition to administering vaccines, health workers must prepare vaccines for use and share information about immunization, including immunization schedules and side effects, with patients. Health workers are also responsible for vaccine transportation and storage, thus ensuring vaccine efficacy. Higher health worker density makes a vaccine more available and broadens access for the community [48].

Increasing the number of doctors in Indonesia has a lower probability of increasing the number of children with complete immunization than increasing the number of health workers in general. Misdistribution of health workers is a problem in all developing countries, including Indonesia. In 2013, Indonesia still had not reached the WHO recommended ratio of doctors per 1000 population [49]. Inequalities in the distribution of doctors have been identified as an important policy issue for Indonesia; only 20% of doctors work in rural areas, yet they serve 70% of the population [50]. The Indonesian government introduced a policy to resolve the distribution problem by allowing nurses and midwives to prescribe essential drugs, including the administration of vaccinations, especially in rural and remote areas with few doctors [49]. In addition, health workers in the villages, especially in rural areas, accompany mothers and supervise maternal health from pregnancy through the antenatal care stage. Mothers have easier and more comfortable access to health workers than they do to doctors.

Our research found that most children in Indonesia who received partial immunizations were missing hepatitis B, measles and DPT. Hepatitis B and DPT each consist of a series of three injections, and children with partial immunizations have received only the first one or two injections. One of the possible explanations for partial immunization is the presence of immunization side effects such as fever and rashes. Another explanation may be that mothers forget to have their children immunized once the children reach a certain age, for example 9 months, the age for measles vaccination. Commonly, DPT coverage is accepted as the standard reflecting immunization program performance. The first DPT vaccine dose is an indicator of access to health care services, and the third DPT dose coverage reflects family ability to access and utilize immunization services in multiple visits [51]. The low coverage of DPT services in Indonesia shows that information regarding the need for multiple immunization visits may not reach all mothers. The increasing number of children receiving complete immunization over the years studied shows the effectiveness of the GOI’s program and its commitment to immunization. BCG vaccination was the immunization with the highest coverage. BCG vaccination is given at 0 months. The increasing number of babies delivered with the help of a health worker play a role in increasing the number of children who receive BCG vaccination.

Improving the quality of education and economic conditions among the population are the most important factors in increasing immunization rates, as a component quality of health services in general. Immunization and awareness regarding immunizations are higher among mothers who delivered their babies in the presence of a professional birth attendant. Improving health access and increasing the number of health facilities and health providers in rural areas are also key to improving immunization coverage. To achieve the WHO standard on immunization coverage, as well as to improve the quality of health and health education, policy makers may establish a suitable program to encourage familiarize about immunization, particularly to targeting mothers who have little formal education.