Children are highly valued and viewed as a vital stakeholder in every culture around the globe. In terms of social security investment and prospects, children provide a window for the present generation to project into the future. Consequently, getting children is an avenue for evaluating success and accomplishment in certain cultures. For this purpose, childbirth generally attracts happiness and celebration among individuals. Marriage without children, on the other hand, is usually characterised by tension and conflict, particularly in Africa. Also, if the couple in question cannot produce at least a child out of it, such a marriage can be considered unproductive and unprofitable in most cultures. At the heart of many divorce cases in Africa for example, is the twin dilemma of barrenness and impotence, and to a lesser degree, male sex orientation and preference. Despite the high premium put on child ownership, child survival in Sub-Saharan Africa remains a major challenge [30].
The concerted efforts aimed at achieving the Millennium Development Goals (MDGs) around the world, especially in developed countries, have reflected a marked decline in infant mortality. But this reduction is not fairly spread as most Sub-Saharan African countries are still battling with the under-five mortality [34]. It has been documented that child mortality outlook in the Sub-Saharan Africa is a gloomy one as the region is still recording the worst Under-Five Mortality Rate (UFMR) in the world [36]. It is alarming to note that 98% of the global under-five deaths occur in 42 less developed countries [30]. Optimistically, however, it has been estimated that the Sustainable Development Goal (SDG) target of 25% decrease in under-five mortality by 2030 [24] is likely to be reached by a few Sub-Saharan African countries if other variables remain constant.
Medically, certain vaccine-preventable diseases such as measles, pertussis, diphtheria, polio, tuberculosis and tetanus have been linked to child mortality [23]. The problem of child mortality is remotely and complexly related to certain living conditions such as access to clean drinking water and sanitation facilities [36]. Interestingly, as captured in both the MDG4 and Sustainable Development Goals (SDGs), under-five mortality, which is the death of a child from day one to five years, has generated a great deal of interest and concern [32]. The phenomenon of child mortality transcends medical causes to include certain socio-economic and demographic variables in a broader context. As several studies [35, 18, 5] have suggested, a multi-dimensional approach is needed to tackle this menace.
In different but related studies, a mother's age was considered as a non-factor for the uneven distribution of mortality under the age of five [35, 32]. Some scholars have further noted that house settlement patterns and rural-urban differentials were risk factors for child mortality [3, 12, 15]. Health care systems, health care financing, poverty and access to maternal health services are remotely and complexly identified as correlates of child mortality [31, 33, 39, 1]. For example, as a complex phenomenon, child mortality has been largely associated with maternal health status because children under-five years of age have always been considered to be under the custody of their mothers except in certain exceptional circumstances. Consequently, the conditions of mothers influence the survival chances of the children [30].
Child death has some cross-cutting impacts on culture, economics, government and families as a significant public health problem for the population. For example, based on the infant mortality trend study of 2,976 million child deaths as of 2013, it was estimated that the African continent would suffer the effect of child deaths amounting to around 6 percent of its non-health Gross Domestic Product (GDP) [20]. Rising infant mortality still has the ability in the near future to decrease the productive influence of the working community. Moreover, infant death leaves behind some devastating physical, psychological and emotional impacts on family members. Child death deprives ageing parents of future care in Africa, where the care of elderly persons is one of the major traditional responsibilities of family members.
As a way of tackling child mortality, many countries in the world depend on their respective health-care system. But governments of most countries in Africa are yet to provide robust funding of their health-care systems as many people still depend on the out-of-pocket payment to receive health services. Similarly, child immunisation in Africa is still being confronted by myriad of challenges ranging from religious belief, negative politicising, geographical inaccessibility, to poor or lack of physical infrastructural facilities. In the light of the foregoing, this study assessed effects of health care expenditure and immunisation on the under-five mortality rate in selected African countries for the period of 17 years (2000–2017). In measurable terms, the study is bound by the following specific objectives, namely to: assess the effect of Domestic Government General Expenditure on Health (DGGEH) on Under-Five Mortality Rate (UFMR) in selected African countries; assess the effect of Domestic Private Health Expenditure (DPHE) on under-five mortality rate; examine the impact of External Health Expenditure (EHE) on UFMR in the selected countries; examine the impact of Diphtheria Immunisation (DI) on UFMR in the selected African countries.
Domestic government general expenditure on health is used as one of the proxies for health expenditure in this study. It can be referred to both capital and recurrent health expenditure of the government, including revenue as domestic grants, transfers, health subsidies, organisational health financing programmes, voluntary health insurance beneficiaries and national health insurance scheme [21]. Some documented studies have linked health expenditure to health outcomes (child mortality). Some of these studies used data from time series in the health economics literature, while others used panel data sets. A study found a significant long-term association between government spending on health and child mortality in several developing countries [22]. Similarly, several different but related study results found that government spending on health was significantly associated with decreasing child mortality [4, 8, 6, 11, 21]. In contrast, a few studies have found that public health spending in high-income countries has not had a significant impact on child mortality [10, 2].
Another form of expenditure is Domestic Private Health Expenditure (DPHE). This encompasses household out-of pocket, funds from corporations and non-governmental organisations. A group of authors has noted that DPHE had a significant influence on under-five mortality [22]. That is, private expenditure on health reduced child mortality significantly. Also, total health expenditure in 47 African countries has been found to have a significant impact on under-five mortality [4]. However, another study discovered that the association between private health spending and child mortality was negligible one [21]. As part of the expenditure component, External Health Expenditure (EHE) comprises all financial inflows and resources that come into the national health system from outside the country [21]. More importantly, the issue is the effects of such inflows and resources on the health outcome like child mortality. Against this background, it was opined that external spending on health in the form of aid had a significant impact on the mortality of children under five [25]. Another research has also reaffirmed that external health investment is strongly correlated with child and neonatal mortality [21]. In the same way, a study showed that when external health resources are improved, they contribute to a reduction in infant mortality [8]. A research affecting 10 selected African countries equally found that external health spending in the form of aids and immunisation was an effective factor in reducing mortality for children under five [2].
One of the main ways of addressing childhood morbidity worldwide has been the regular and periodic immunisation of children under five. Some of the diseases that can be treated by the Expanded Immunisation Programme (EPI) include measles, pertussis, diphtheria, polio, tuberculosis, and tetanus (Matthews and Diamond, 1999). However, the interest of this study is partly to assess the effect of diphtheria immunisation (% of children ages 12–23 months) on the under-five mortality rate in selected African countries. In addition, a couple of studies have stated that immunisation is an important factor in reducing the mortality of children [26, 7]. Similarly, it has been revealed that immunisation raises the probability of infant survival and was viewed as one of the most effective ways to stem the tide of child mortality [37]. The accessible literature reviewed in this study has indicated that there is still a need for further research relating private health spending, external health expenditure and immunisation to under-five mortality, as the current body of literature on the topic still leaves some gaps. Besides, the time frame covered in the available literature needs to be updated as the current study fills in the gaps in terms of time frame (2000–2017) and combined variables (health care expenditure and immunisation).
With regard to the theoretical perspective, Grossman's health production and investment model is being adopted for this research. According to Becker, health in this case is conceptualised as both a consumable item and an investment resource [29]. The model opined that an individual chooses their level of health and by extension, their life span. It further postulated that time was a variable factor that contributes to declining health status in both objective and subjective terms. However, through certain social determinants such as diet, exercise, medical care and life-style decisions, it could be replenished and counter-balanced. On the other hand, ageing, smoking, extreme opioid use and exposure to other toxic compounds may make the health capital of an individual depreciate. In this context, the level of health an individual has is a function of the amount of resources allocated to its investment. Also, an individual is viewed as a “manufacturer” as well as a “user” of health and that the demand for health is not for immediate consumption but for the production of other goods. So, one’s level of health is not attributed to certain external social factors but endogenously influenced. In other words, Grossman's main argument for health investment is that health care services are not requested for their own purposes, but for the impact on health itself. Ageing influences the state of health and requires constant health care services. However, the impact of ageing on wellbeing is mitigated by educational level and a balanced style of living [29].
The model can be sustained in this study when health expenditure (domestic government general, domestic private, external health expenditures and diphtheria immunisation) is viewed as an investment tailored towards improving maternal and child health status (reduction in under-five mortality). In this case, expenditure on and utilisation of maternal and child health services is considered as derived demand capable of impacting on child mortality rate. Within the theoretical purview of the household health production function of Grossman, both increase and decrease in child mortality is predicated on the amount of resources allocated to health. It is taken for granted that more increase in health and education is likely to translate into reduction in under-five mortality in the selected African countries. Moreover, it can be deduced that the age-long uneven distribution of child mortality across and within various regions of the world is neither accidental nor incidental but it can be related to varying investment in health capital among other factors. “Other things being equal”, the insightful understanding of Grossman’s model is that, more investment in health capital leads to desirable child health status and by extension declining child mortality. Even though Grossman’s model is subject to some methodological and empirical flaws, however, the theory has continued to stand the test of time with regard to investment in health capital.