Using Qualitative Systems Mapping to Analyze the Linkages between the Behavioral and Social (BeSD) Determinants of Routine Childhood Immunization in LMICs

"[I]n the context of immunization, the results from this review can serve as a starting point for discussion with both the providers and the recipients of routine vaccination services to better understand the dynamics of the factors in their local context..."

There has been extensive research on the factors affecting the uptake of routine childhood immunisation in the last few decades. There are various measures for identifying vaccination determinants, yet, understanding the complex relationship between the determinants of immunisation has only recently gained attention. Qualitative systems mapping (QSM) using causal loop diagrams (CLDs) is a popular tool in systems analysis. This review maps determinants of vaccination using the behavioral and social drivers (BeSD) framework in 11 low- and middle-income countries (LMICs). It analyses the relationship between determinants affecting immunisation using CLDs.

Developed based on discussions with key stakeholders from both high- and low-income countries, the World Health Organization (WHO)'s BeSD of vaccination framework focuses on the beliefs and experiences of caregivers and includes four themes: (i) thinking and feeling - lack of knowledge regarding the importance or need for vaccination, fear of vaccination, lack of trust in the healthcare provider; (ii) social processes - household norms, influence of religious leaders, neighbours and friends, providers' engagement with the caregiver, and public mechanisms to encourage immunisation; (iii) motivation - intention to get recommended vaccines; and (iv) practical constraints - distance, cost, lack of awareness of vaccination schedule or place and time of vaccination, opportunity cost, and inability to bring the vaccination card.

The review draws on 92 experimental and quasi-experimental impact evaluations (IEs) from 11 LMICs that were published between 2010 and 2020. Secondary literature (93 articles) on the study context or the intervention was also included. The BeSD framework was used to code the determinants identified in the IEs, and their relationships were mapped using QSM. The researchers computed the in-degree (influenced by other determinants) and out-degree scores (influencing other determinants) to assess the extent of the influence of the BeSD determinants on one another. The identified relationships were mapped into CLDs, which are depicted in the article. Factors affecting immunisation are in circles connected by arrows showing the directionality of the relationships.

The results show that determinants pertaining to knowledge, fear of vaccination, religious and personal beliefs, and trust in the health system were influenced by many determinants and were associated with the uptake of services. Restrictive household norms, opportunity cost, and caregivers' experience of quality of services were also affected by several determinants and affected uptake. Studies also showed that lack of knowledge regarding vaccination, lack of trust, fear of vaccination, opportunity cost, and caregivers' experience of immunisation services was associated with whether they seek vaccination for their children. Determinants with a relatively higher out-degree scores (i.e., influenced many other determinants) were trust in the health system, caregivers' experience of quality of care, influence of traditional and religious leaders, physical accessibility, health worker engagement with the community, and health provider availability. Analysis finds that while some determinants like religious leaders negatively impact immunisation uptake, they were and could be leveraged to facilitate access and improve awareness on immunisation. 

The CLDs from this review can be contextualised using feedback from local stakeholders and used for designing tailored interventions.

The results of this review have the following implications for policy and practice.
 

1. Social groups and community mechanisms can be leveraged to improve awareness and attitudes related to immunisation: The review found that community groups can serve as information beds for caregivers and family members regarding immunisation. Community mobilisation efforts that leverage existing social groups in the community to discuss health and immunisation issues can have a significant impact on caregivers' and family members' awareness levels and fears about immunisation.
2. Setting expectations and communicating the role of providers in immunisation can enable building trust: The analysis is consistent with literature that shows that trust is influenced by the caregiver's experience of healthcare, underlining the importance of communication and engagement of the health system with the communities. Behaviour change communication is a crucial aspect of outreach in the community. While training and supportive supervision are important for ensuring that health workers have the knowledge and skill to educate and counsel caregivers regarding immunisation, poor engagement with the community due to excessive workload or inaccessibility can affect caregivers' trust in the health provider. Ensuring that the roles of the key groups and members in the community are clarified can help in building trust.
3. Strengthening health system factors holistically can affect immunisation quality and build trust: The review clearly shows that the caregiver experience of quality of immunisation affects trust in the provider. Caregivers' experience with immunisation depends heavily on all the health system building blocks. Strengthening the health system can improve not only the quality but also the trust levels and linkages between the community and health workers. Given the concurrent influence of these factors on quality, there is a need to take a comprehensive approach that aims to simultaneously strengthen these aspects of the health system.
4. Mitigating the indirect costs associated with immunisation can improve its uptake: It is essential to anticipate the indirect costs to take the child for vaccination or for treatment of side effects. Identification and mitigation of these indirect costs through monetary incentives, transport services, or the planning of immunisation sessions at a time that is most convenient to caregivers will be important in highlighting the benefits of vaccination against the indirect costs that they might incur.
5. Practitioners need to plan for potential high variability in demand for vaccination for ensuring maintenance of high-quality immunisation services: Large increases or decreases in the number of caregivers seeking immunisation have the potential to disrupt services.

In conclusion, this review "underlines the complex interplay and influence that immunization determinants have on each other. Immunization programs in many LMIC countries rely heavily on grassroots-level community health workers who are tasked with providing services until the last mile. Community health workers need to leverage the social groups and networks within these communities to improve awareness and attitudes toward vaccination. In addition, comprehensive strategies that build strong health systems with robust funding, infrastructure, and supplies are critical for the delivery of quality health services, as are provider motivation and retention....Trust in the health system emerged as a latent factor that influenced awareness levels in the community. The results from this QSM highlight the interconnectedness of many of these determinants and point to the need for context specific, comprehensive programs to improve vaccination in LMIC contexts."