Study population and context
This study was conducted in Ethiopia in 2019 as part of the revision of the country’s EHSP [7]. Ethiopia has a large disease burden, with average life expectancy of 65.5 [16, 17]. Communicable, maternal, neonatal, and nutritional disorders (CMNNDs) represent the greatest disease burden, accounting for 58% of disability-adjusted life year (DALY) loss in 2017. In the same year, the burden of NCDs, such as cardiovascular diseases, diabetes and cancer, accounted for 34% of the burden. About 8% of the DALYs were from emergencies and injuries [17]. Furthermore, Ethiopia is a low-income country, with a Gross Domestic Product (GDP) per capita of US$953 in 2019 [18] and a per capita health expenditure of about US$33 in 2016/17 [19]. Further reduction or slow increment of the health expenditure is expected in Ethiopia because of the impact of COVID-19 pandemic on the economic growth of the country and its global impact. Therefore, it is crucial to invest limited resources efficiently.
Interventions
A breakdown of interventions by the conditions they prevent or treat is provided in Table 1. A total of 1,018 interventions were analysed for the EHSP. The current version of the WHO-CHOICE generalised cost-effectiveness analysis (GCEA) tool includes about 400 interventions [20], of which 159 were found to be relevant for the Ethiopian EHSP. We grouped the 159 interventions into 12 groups that matches with the sub-programme areas classification of intervention list in the EHSP. In general, and slightly over half of them fell under either reproductive, maternal, neonatal and child health (RMNCH) (28.3%), mental health (12.6%) or policies against NCDs (10.1%), such as physical inactivity, excessive alcohol use and tobacco, sugar and salt intake (Table 1).
Health effects of the interventions
We used the WHO-CHOICE GCEA tool to analyse the country-level health benefits of each intervention [21]. This model examines for each disease of interest (by incidence, remission and case fatality rates) how proportions of the population transit between health states in the presence or absence of an intervention. The Global Burden of Disease disability weights were used to evaluate the health state in the time spent in each health state, and the health effects generated by each intervention are presented as healthy life years (HLYs) gained [22].
We applied various integrated impact-modelling modules of the latest version of Spectrum software to model the health benefits of each intervention [22] and applied the DemProj module to project population growth and other underlying demographic parameters (Table 1). This module uses World Population Prospects 2017 data from the United Nations Population Division. The FamPlan module was used to estimate the impact of family planning interventions. In this module, we used data from the 2016 Ethiopian Demographic Health Survey. We employed the AIDS Impact Module (AIM) (which was initially developed by UNAIDS to make national and regional HIV estimates every two years) to estimate the impact of interventions against HIV, and we employed the TIME Estimates and TIME impact Module to estimate the health impact of tuberculosis (TB) interventions. For RMNCH, nutrition and Water Sanitation and Hygiene (WASH) interventions, the Lives Saved Tool (LiST) module was employed, and we used the non-communicable disease impact module to calculate the impact of NCD policy interventions and other interventions against cancer and respiratory disease as well as mental health, neurological and substance use disorders [22].
The spectrum software includes default input for many countries based on data from various sources (i.e. systematic reviews, individual studies, national and regional reports, GBD etc.). We downloaded and used country-specific data for Ethiopia in the Spectrum software. The Country Data Package was prepopulated with the total population, population in need, target population, disease burden and effect size for each intervention. We carefully reviewed all the default input with programme area experts at the Ministry of Health, and appropriate changes were made when deemed necessary. A more detailed explanation of each of the intervention input assumptions is provided elsewhere [23] [22].
Table 1. Frequency and proportion of interventions evaluated by sub-programme area, 2019.
Intervention by sub-programme area
|
N
|
%
|
Spectrum impact model used
|
RMNCH
|
44
|
28.3
|
LiST, FamPlan
|
Mental health
|
20
|
12.6
|
NCD impact
|
Policy interventions on NCDs
|
16
|
10.1
|
NCD impact
|
Cervical cancer
|
13
|
8.2
|
NCD impact
|
Respiratory disease
|
12
|
7.6
|
NCD impact
|
Colorectal cancer
|
11
|
6.9
|
NCD impact
|
Breast cancer
|
10
|
6.3
|
NCD impact
|
Tuberculosis
|
10
|
6.3
|
TIME Estimates and TIME impact
|
Nutrition
|
9
|
5.7
|
LiST
|
HIV/AIDS
|
5
|
3.1
|
AIM and GOALS
|
Malaria
|
5
|
2.5
|
LiST
|
Water hygiene and sanitation
|
4
|
2.5
|
LiST
|
Total
|
159
|
100
|
|
Note: The level of detail varies across the sub-programme areas.
Costs of interventions
The identification, measurement and valuation of the costs of all the interventions were conducted from the health system’s perspective, accounting for the full cost of delivering an intervention, regardless of who currently pays for it. The ingredients costing approach was used, in which each input of delivering the intervention is identified and the quantity of each resource required by the intervention is multiplied by the unit price of each input (i.e., the unit price × quantity approach was applied) [12]. In the WHO-CHOICE GCEA tool, all the ingredients, based on expert recommendations, are provided as default values, and the country team reviewed the inputs and made changes when necessary. For example, all the drugs and supplies needed to provide each service were systematically identified, accounting for the cost of delivering the drugs and supplies from the point of production or purchase to the point of use (i.e., the cost of transportation, storage, shipment and customs clearance). Default prices for drugs and suppliers within the GCEA tool are taken from an international drug price database (MSH). We updated the prices of some drugs and supplies based on data from the Ethiopian Pharmaceutical Supply Agency and the Logistics Department of the Ministry of Health. To account for the cost of delivering drugs and supplies, an average mark-up of 6% of the price was generally taken. For drugs needing a cold supply chain, an additional 13% of the cost of the drug was taken as mark-up as the cold-chain system incurs an additional cost. For Long-lasting Insecticidal Nets (LLINs), a 26% mark-up was taken as LLINs are relatively bulky and their transportation, loading and unloading incur an additional cost [24].
Health personnel costs for providing the interventions were also included. The salary scale of the health workforce, such as the salaries and benefits of nurses, doctors and pharmacists, was based on the most up-to-date data from the Human Resource Department of the Ministry of Health of Ethiopia. Staff time use was calculated on the assumption that, on average, each person works eight hours per day over 230 working days per year. Inpatient cost per day and outpatient cost per visit were taken from the WHO-CHOICE model [25].
Programme costs were also included in this analysis [24]. Programme costs are the non-health care delivery costs associated with delivering an intervention programme that are incurred at a level other than the intervention’s point of delivery. They include costs incurred at district, provincial or central levels and exclude costs incurred at facility or patient levels. They include the cost of administration and planning, media and communication, law enforcement, training, monitoring and evaluation. All costs were valued using 2019 US dollars (USDs). All cost input data originally collected in Ethiopian Birr (ETB) were first converted to USD using the average exchange rate for the year and were later converted to 2019 USD using the GDP deflator.
Cost-effectiveness analysis
To account for the impact of an intervention in the long term (steady state), we followed in this cost-effectiveness analysis model a hypothetical Ethiopian population cohort over a 100-year time horizon starting in 2019. The average cost effectiveness of the intervention was computed as a ratio of the total cost of the intervention to total health life years (HLYs) gained from the intervention [12, 26]. The interventions were ranked and compared based on their ACERs. Both costs and health outcomes were discounted at an annual rate of 3% [13].
Cost-effectiveness thresholds
A cost-effectiveness threshold (CET) is an explicit cut-off point for assessing the opportunity cost of interventions, with interventions having a cost-effectiveness ratio below the threshold being considered to offer good value for money [27]. There is a long-standing debate concerning the CET [18, 28, 29]. In the case of sector-wide analysis of health interventions using a GCEA, a CET is not required because the purpose of a GCEA is to compare the whole list of interventions against the comparator of doing nothing, and the ACERs of interventions should be compared with one another, even across programme areas, and not against a predefined CET [14, 15]. In this study, therefore, we did not apply a CET; instead, we report the ACERs in ascending order in bar graphs for each programme area. However, we use US$100 and US$1,000 per HLY gained as references to summarise and present the ACER results.