2.1 Research model and hypothesis
This study developed a conceptual model as depicted in Figure 1 and seven hypotheses for analysing the determinants of health expenditure otherwise known as the demand for care. The conceptual model is set up in line with the literature on the variables which are known to have a significant effect on the growth of health expenditure per capita. The hypotheses are therefore postulated as:
H1: There are significant relationships between the socio-demographic indicators and the level of growth in health expenditure.
The level of socio-demographic composition specific to the country’s health system plays an important role in its demand for health. Thus, the log level of the share of population above the age of 65 years, the log of years of schooling, and the log of compensation of employees were first introduced in the literature by Grossman (1972). Similarly, the log level of female labour force participation rate was used by Gerdtham and Jönsson (2000) and the log of population density was used by Crivelli, Filippini and Mosca (2006). Therefore, the lower the numerical values of the variables constituting the socio-demographic indicator, the lower would be the level of growth in health care expenditure.
H2: There are significant relationships between the performance of economic indicators and the pace of growth in health expenditure.
Several studies have also established the empirical connections regarding the growth in economic indicators and the level of public health spending growth. The log level of per capita GDP was used by Newhouse (1977) and the log level of domestic public expenditure as a percentage of GDP was used by Hitiris (1997). Moreover, the log level of the unemployment rate as a percentage of labour force was used by Christiansen et al. (2006) and the log level of gross capital formation is included following Feng, Xia and Kong (2018) Therefore, the greater the performance of the economic indicators, the higher would be the level of growth in health expenditure, ceteris paribus.
H3: There are significant relationships between the health system capacity indicators and the growth in health expenditure.
The strength and capacity of the health systems indicators are also considered crucial factors determining the level of health expenditure growth. The log level of physician density was used among others (Gerdtham and Jönsson, 2000), the log level of hospital beds is included following Christiansen and Bech (2006) and the log level of nursing and midwives density per 1,000 people by Winkelmann, Muench and Maier (2020). The log level of research and development expenditure as a percentage of GDP was included following the Okunade and Murthy (2002). Hence, the greater the strength of the health systems capacity indicators, the larger would be the growth of health care expenditure.
H4: There is a significant direct effect of behavioural indicators on health care expenditure growth.
H5: The behavioural indicators further moderate the growth in health care expenditure through the socio-demographic indicators.
The rising prevalence of alcohol and tobacco consumption increases the NCDs risk factors leading to a higher premature mortality rate from NCDs among the active workforce further exerting downward pressure on labour supply.
Therefore, the behavioural indicators explain the level of indirect variation in health expenditure through the socio-demographic, economic, and health system capacity indicators.
H6: The behavioural indicator moderates the growth of health care expenditure through the economic indicators.
Clearly, with an increase in the global burden of non-communicable diseases which are linked directly to behavioural risk factors, the stronger the pace of growth in the economy the higher would be the share of resources channelled to the health system for the procurement, maintenance and improvement of the capacity of the health system for in services delivery.
H7: The behavioural indicators also moderate the rate of growth in health care expenditure through the health system capacity indicators. In a given health care system where the prevalence of tobacco and alcohol consumption is high, there would be a high burden of non- communicable diseases that require a functional health system for the provision of preventive, diagnostic and curative care efficiently.
Following Grossman’s theoretical model, the depreciation rate of human capital is attributed to lifestyle variables like tobacco and alcohol consumption as used in the Gerdtham and Jönsson (2000) studies. Therefore, the behavioural indicators moderate both the cost of health care and the three key determinants (socio-demographic, economic, and health system capacity indicators).
2.2 Selection of indicators
The magnitude of socio-demographic indicators of a given health system serves as an important factor in the analysis of health care expenditure growth. In line with the extant literature, this study includes the percentage of the population above the age of 65 years threshold since it’s the age cohort in greater demand for health care (Grossman, 1972). The Grossman theoretical model also considered the wage rate (compensation per employee) as a crucial variable in the demand for care (Grossman, 1972). All else constant, the higher the wage rates the higher the resources for the demand for care. Education level is also a relevant variable in determining access to health care. Differences in education levels among individuals affect utilization of health care and adherence to medical prescriptions. Similarly, population density shows the level of people’s concentration in a given, and thus in a country with higher population density, the demand for care would be high since diseases could be spread more easily and therefore difficult to be controlled (Gerdtham and Jönsson, 2000). Female labour force participation is increasingly considered as an important demographic factor in the analysis of development. In a context where female labour force participation is high, they are economically empowered to have better access for maternal and child care health which are essential to curb the rate of maternal and neonatal maternity (Gerdtham and Jönsson, 2000)
The level of the economic capacity of a country determines the overall share of its health care expenditure. The per capita GDP level measured in (PPP) gives the total income earned by the individuals living in a country determined by the demand for care in a given context. Thus, the higher the income the higher demand for care. The level of government health expenditure as a percentage of GDP is commonly used as an indicator for financing health care (Hitiris, 1997). Gross capital formation refers to the additional investment to existing capital stock or inventory level which results in augmenting productivity level (Feng, Xia and Kong, 2018). An increase in productivity would raise income and employment thereby leading to more economic growth. The rate of unemployment of a country shows the national estimates of the abled workforce that could not get paid jobs at the wage rate prevailing in the market (Christiansen et al., 2006). Prolong unemployment leads to poor health status and in some cases leads to premature death due to in-access or poor access to required health services at the needed time.
The capacity of the health system of a country would be the first to consider when assessing its efficiency in health services delivery. This study, therefore, considers four indicators as of paramount importance in this regards in line with the literature i.e. physician density following Gerdtham and Jönsson (2000) studies, hospital beds following Christiansen study, nurses and midwives following Winkelmann, Muench and Maier (2020) studies, and expenditure on research and development as a share of GDP following Okunade and Murthy (2002) studies. The densities of physicians, hospital beds, and nurses as well as midwives all are measured per 1,000 people and shows the strength of the health systems in providing both in-patient and out-patient care as well as during emergency periods. Also, in a context where expenditure on R&D is reasonably budgeted and used for the intended purposes, scientific advances through innovations and discoveries results which eventually increase the capacity of the health systems for efficient care delivery.
In the last one and a half-decade, the menace of raising premature mortality from non-communicable diseases becomes a common threat to longevity across the globe. The prevalence of alcohol and tobacco consumption are the main behavioural factors attributed to the growing risk factors of the burden of non-communicable diseases and their associated mortality. The behavioural indicators are assumed to moderate the depreciating state of health capital further escalating the pace of health expenditure growth in two ways. First, is the direct effects on driving health expenditure growth and secondly through the socio-demographic, the economic, and the health system capacity indicators. As a consequence, this study includes alcohol and tobacco consumption prevalence following Gerdtham and Jönsson (2000) studies.
The outcome variable of this study includes both public and private health expenditure measured in PPP international US$. Though in many studies that examine the growth of health expenditure and its determinants like Hartwig and Sturm, (2018) among others used only per capita public health expenditure due to the nature of the study, this study includes per capita private health expenditure to capture its dynamics that is usually unaccounted for in the previous studies and also to balance the endogenous construct.
Table 1 Descriptive Assessment of Index Descriptors
Construct
|
Code
|
Indicator
|
Observation
|
Mean
|
SD
|
Min.
|
Max.
|
Exogenous
(Multiple Indicator Construct)
|
Socio-demographic (SD)
|
X11
|
Population ages 65 and above (% of total population)
|
255
|
1.240
|
0.723
|
-0.377
|
2.574
|
X12
|
Population density (people per sq. km of land area)
|
255
|
1.96
|
0.545
|
0.86
|
3.26
|
X13
|
Labor force, female (% of total labor force)
|
255
|
1.30
|
0.179
|
0.90
|
1.67
|
X14
|
Years of Schooling
|
255
|
2.015
|
0.410
|
0.182
|
2.564
|
X15
|
Compensation of employees (% of expense)
|
255
|
3.489
|
0.414
|
1.238
|
4.248
|
Exogenous
(Multiple Indicator Construct)
|
Economic Factor (EF)
|
X21
|
GDP per capita, PPP (constant 2011 international $)
|
255
|
4.389
|
0.405
|
3.42
|
5.09
|
X22
|
Domestic general government health expenditure (% of GDP)
|
255
|
2.762
|
0.442
|
1.16
|
3.52
|
X23
|
Gross capital formation (% OF GDP)
|
255
|
1.382
|
0.119
|
0.97
|
1.69
|
X24
|
Unemployment, total (% of total labor force) (modelled ILO estimate)
|
255
|
0.693
|
0.446
|
-0.82
|
1.21
|
Exogenous
(Multiple Indicator Construct)
|
Health System capacity (HSC)
|
X31
|
Physicians (per 1,000 people)
|
255
|
0.436
|
0.596
|
-1.518
|
1.348
|
X32
|
Hospital beds (per 1,000 people)
|
255
|
0.655
|
0.569
|
-4.605
|
1.509
|
X33
|
Nurses and midwives (per 1,000 people)
|
255
|
1.032
|
0.551
|
-0.352
|
1.967
|
X34
|
Research and development expenditure (% of GDP)
|
255
|
-1.013
|
1.183
|
-4.055
|
1.505
|
Exogenous
(Multiple Indicator Construct)
|
Behavioural Factor (BH)
|
X41
|
Prevalence of current tobacco use (% of adults)
|
255
|
1.357
|
0.147
|
0.98
|
1.64
|
X42
|
Total alcohol consumption per capita (litres of pure alcohol, projected estimates, 15+ years of age)
|
255
|
-0.168
|
0.654
|
-2.30
|
1.09
|
Endogenous
(Single Indicator Construct)
|
Health Care Expenditure (HCE)
|
X51
|
Domestic general government health expenditure per capita, PPP (current international $)
|
255
|
0.389
|
0.193
|
-0.68
|
0.80
|
X52
|
Domestic private health expenditure per capita, PPP (current international $)
|
255
|
2.585
|
0.287
|
1.83
|
3.14
|
Source: Authors’ Calculation.
2.3. Data Source
In this study, 15 countries of the Middle-East region are included based on their geographic location as visualised in Figure 2 and data that is publicly available for 2004 to 2020 periods. Apparently, a substantial difference exists among the member countries under study as documented by World Development Indicators (2020). In spite of these noticeable differences, these countries are always reported as one homogeneous unit. The exceedingly higher rate of health expenditure among these countries has warrants investigation into the principal causes behind the exponential surge for appropriate policy intervention. Specifically, the data of this study is obtained from the World Bank Development Indicators and the detailed descriptions of the indicators included in this study are illustrated in Table 1.
2.4. Model selection - PLS-SEM Path Model
Owing to the predictive nature of this study, variance-based Structure Equation Modelling (PLS-SEM) is employed to establish a linkage between the set of latent variables involved in the study. SEM-based on a two-step approach has two well-known estimating techniques: CB-SEM (Covariance Based – Structural Equation Modelling) and PLS-SEM (Partial Last Square – Structural Equation Model). CB-SEM works on the fundamental to reduce the deviation between estimated data and sample matrices through model estimates but PLS-SEM outweighs by using an iterative sequence of OLS regression to maximize the impact of exogenous constructs on endogenous construct (Astrachan, Patel and Wanzenried, 2014). Furthermore, both SEM techniques stemmed from the same basis but PLS-SEM has become more popular in recent years due to its capability of operating multiple latent constructs in a model (Zhu et al., 2019). Moreover, the Partial Least Square-Structural Equation Modelling (PLS-SEM) is a general estimation technique that involves alternate least square algorithms which extend principal component analysis (PCA) and canonical correlation analysis (CCA). The outer model or measurement model and inner model or structural model are two formal sets of linear equations that are used to define the PLS path model. Figure 3 represents the PLS path model adopted for evaluation in the study.
The structural model is evaluating the construct-to-construct plausible relationships. The development of the path model is from left to right. The latent variables on the left side are exogenous variables and variables on the right-hand side are endogenous variables. The inner model relationship between the latent variables is represented as:
Where β represents the standardised path coefficients and ζ represents the inner model residuals assumed to satisfy the expected relationship and non-correlation.
A comprehensive description of workflow methodology for hypothesised model validation is represented in Figure 4.