In addition to estimating the magnitude of receipt of SMC medicines by ineligible older children, our results show various child, caregiver and SMC-related factors associated with the issue using data collected during comprehensive end-of-round surveys in nine Nigerian states in 2022. We found that about a third of age-ineligible older children sampled received SMC medicines during the 2022 SMC campaigns. This finding lends support to available, though limited, evidence that the administration of SMC medicines to ineligible children is a common occurrence [14]. Administration of SMC medicines to children who do not meet the eligibility criteria for SMC based on their age has various implications and presents numerous challenges as outlined in the following sections.
As the current formulations and dosing of the medicines used in SMC campaigns in Nigeria are intended for children younger than five years, it is possible that administering those medicines to older children represents underdosing. Exposure of children to sub-optimal doses can contribute to the development of parasite resistance [16, 17]. If left unaddressed, this is likely to undermine the programmatic effectiveness of SMC and may weaken the level of confidence that communities have in SMC as a malaria preventive intervention. Our findings show that the majority of ineligible children who received SMC were aged 5 to 6 years. As with other medicines, pharmacometrics of SMC medicines depend primarily on children’s weight[21]. Hence, administration of SMC medicines to children that are just above the eligible age range, whose weight is therefore unlikely to be substantially higher, is less likely to constitute underdosing. Based on our findings and considering the little evidence that SMC may have contributed to the development of resistance in settings in the Sahel region of West and Central Africa[6], the observed trend of receipt of SMC predominantly by children aged 5 to 6 years may be less likely to pose a significant risk of development of drug resistance. The finding that about 40% of older children who received SMC medicines were much older than five years is, nonetheless, concerning giving the implications of sub-optimal dosing in those children. It is an intriguing finding that such a large proportion of much older children received SMC medicines despite the obvious age difference between them and under-5 children. However, such children may not be distinguishable from under-5 children by mere physical appearance, due to the prevalence of malnutrition and stunting in the study setting, and SMC community distributors’ difficulty in ascertaining children’s age due to absence of verifiable home-based birth and civil registration records [8–11].From an operational perspective, however, administering SMC medicines to ineligible children presents a substantial challenge, particularly in terms of ensuring the availability of sufficient SPAQ stock levels to reach the entire target population of eligible children. This has important implications for reaching and sustaining high target population coverage, while maintaining optimal levels of programmatic impact and effectiveness in SMC delivery settings. From an economic perspective, it is likely that administration of SMC medicines to ineligible children increases the cost of SMC and reduces its cost-effectiveness. This is because cost-effectiveness decreases if medicines are given to individuals who are unlikely to benefit, which may also result in a decrease of coverage among eligible children.
Our study has identified various child, caregiver and SMC-related factors that influence the receipt of SMC medicines by ineligible populations of older children. It found that children’s age, and caregivers’ characteristics like age, gender, level of education and employment status were significantly associated with the issue. These findings are consistent with previous evidence that caregiver gender, age and other sociodemographic characteristics can influence children’s uptake of preventive health services and health outcomes[22, 23]. The findings thus underscore the need for context-specific community engagement efforts in future SMC campaigns to be tailored to address these predisposing factors, such as by strengthening knowledge of SMC age eligibility and its importance among younger and male caregivers, and those in households with older children in the 5–6-year age range. These can be achieved by reinforcing the training of SMC community distributors and community engagement personnel; equipping them with the skills required for effective communication of information on SMC eligibility criteria, their importance and other SMC-related information; and improving their competence in tailoring communication strategies to specific household and community level contexts during SMC campaigns.
We found considerable relationships between SMC-specific variables and the receipt of SMC medicines by ineligible children. It is important to note in addition to challenges faced by community distributors in determining children’s exact age, administration of SMC medicines to ineligible children may also reflect the pressure from caregivers on community distributors to provide SMC medicines to older children, as supported by our finding of higher odds of receipt of SMC medicines among age-ineligible children whose caregivers were more confident in SMC’s effectiveness as a malaria prevention intervention. Additionally, it is likely that doses of SMC medicines left with caregivers by community distributors to administer to age eligible children on the subsequent two days following the first dose, were administered to older siblings and other older children in the household for the same reason. As acknowledged earlier, these present a substantial challenge for ensuring that the target population of eligible children are reached and that they receive the complete number of doses of SMC medicines.
To address these challenges, it is pertinent to improve the competence of community distributors in determining children’s age with available home-based records, such as by requesting birth certificates, immunization cards and medical prescriptions for a previous illness. Also, SMC personnel should be better trained on strict compliance with SMC eligibility criteria, even when under pressure to provide SMC medicines to ineligible children. It is also important that community distributors are able to determine children’s age in the absence of verifiable records. One strategy we have seen adopted in some of our implementation settings is the use of historical prompts to validate caregivers’ reports of children’s age. Findings also underscore the need for future SMC campaigns to improve and address gaps in caregivers’ knowledge of SMC age eligibility as illustrated by our findings of higher odds of age-ineligible children receiving SMC medicines among caregivers who were less knowledgeable of SMC age eligibility. This can be achieved through pre-cycle SMC awareness and sensitization campaigns, and by leveraging interactions of community distributors with caregivers to boost their confidence in the effectiveness of SMC while also strengthening their knowledge and perceptions regarding age eligibility and its importance.
Strengths and limitations
Our study is one of the earliest attempts to quantity the extent to which ineligible children are receiving SMC medicines. The large dataset used, and statistical power of our analyses are major merits of the study. The mixed-effects regression approach use in fitting the model, with random intercepts for cluster units (wards) has the advantage of being to appropriately model data with observations that are nested in hierarchical data as with the dataset used in our study, while helping to account for the potential for clustering effect[24]. Overall, our findings provide important evidence on the magnitude and factors associated with the problem, thereby providing useful insights that can help to guide the articulation and deployment of context-specific programme improvement strategies in future SMC campaigns.
A major limitation of the study is that our analytic sample may not be representative of the general population of children aged 5–10 years in the study setting, as ineligible children were sampled from households with SMC eligible children during the same. It is likely that the current estimates of receipt of SMC by ineligible children are overestimated given this consideration. As such, the findings may not have limited generalizability to the wider population of older children in the study setting or similar contexts. Another limitation is the survey’s reliance on self-reporting by caregivers for information about children’s receipt of SMC which are prone to social desirability and recall biases.
Implications for further research
Given these limitations, future assessments should consider a more representative sample of older children by sampling from households irrespective of whether they have SMC-eligible children or not. Further quantitative studies may need to assess factors influencing administration of SMC to age-ineligible children from the perspectives of other stakeholders such as community distributors. The findings also underscore the need for qualitative studies to explore and more deeply understand the individual and contextual factors associated with the administration of SMC medicines to children who are ineligible to receive the medicines. Furthermore, future research may also be needed to assess the impact of such occurrences on SMC coverage, adherence to the full three-day course, effectiveness, cost-effectiveness, and the prevalence of resistance markers.