Over the last two decades, the concept of social health insurance (SHI) has gained attention in social policy development discourse [1,2,3]. SHI is seen as the most sustainable healthcare financing model for providing financial risk protection for majority of the population in low and middle-income countries (LMICs) [4, 5]. The SHI concept has become more imperative following the World Health Assembly’s call for universal health coverage (UHC) in health systems in 2005 [1, 6] and the inclusion of UHC in the UN Sustainable Development Goals (SDGs) in 2015. The SDG goal 3, target 8, mandates member countries to “Achieve universal health coverage, including financial risk protection, access to quality essential healthcare services and access to safe, effective, quality and affordable essential medicines and vaccines for all” by the year 2030 [7, 8]. The overarching goal of UHC is that in an event of illness or sickness, all people will have access to the quality, essential health service they need without being exposed to financial hardship [2, 7].
Many African countries particularly those in the sub-Saharan Africa (SSA) are at different stages of SHI implementation aimed at achieving UHC [9, 10]. It is a general belief that UHC is a panacea for reducing out-of-pocket payment and inequity in access to and utilization of healthcare services [6, 9]. One distinct characteristic for SHI attractiveness in the sub-region is that it does not depend exclusively on public finance, but instead shares the responsibility of health financing among the population [11, 12].
Ghana, a lower middle-income country in SSA, implemented a National Health Insurance Scheme (NHIS) in 2004 to provide financial risk protection for all residents [13,14,15,16,17]. It was fashioned out to address the challenges of the out-of-pocket payment system of paying for healthcare services in the 1990s, popularly referred to as “cash and carry”. The cash and carry system was introduced at that time to recover at least 15% of recurrent expenditure and drugs [13, 18, 19] but it led to increased inequality in healthcare access and preventable deaths [10, 14, 18, 20]. The NHIS is managed by the National Health Insurance Authority (NHIA), a regulatory body mandated by law to oversee operations of public and private health insurance schemes in the country . Since its implementation, the NHIS has made gains in population coverage, increased access to healthcare services by reducing out-of-pocket payment and contributed to raising revenue of healthcare providers .
At present, the NHIA has 159 district offices and five satellite offices across the 10 administrative regions of the country. It also has over 4000 network of public and private healthcare providers nationwide, rendering services under the minimum benefit package to card-bearing members . The NHIS reportedly covers 95% of disease conditions afflicting the population [14, 21] and the benefit package is same for all card-bearing members. Broadly, it covers general consultation and medicines at the outpatient and inpatient departments; minor surgeries; admissions at the general wards; maternal care services; dental services; ear, nose and throat (ENT) services; and all emergency services. It, however excludes preventive services provided by the Ministry of Health, for example, immunization . Services that have the potential to threaten sustainability of the scheme, for example, surgeries other than road traffic accidents and non-essential health services such as cosmetic surgeries are also excluded from the benefit package [14, 20, 21]. The NHIS is largely tax-financed through a 2.5% valued-added tax (VAT) on selected goods and services [17, 20, 21]. Other sources of funding include two and a half percentage point deductions from the formal sector workers social security contributions, premium from the informal sector workers, internally generated funds from activities of the scheme and donor support from development partners [20, 21].
Membership of the scheme is mandatory, but enforcement has been challenging, making enrolment practically voluntary. Members are broadly categorized into exempt and non-exempt groups. The exempt groups comprise those who do not pay premium to the scheme; persons below the age of 18 years, elderly aged 70 years and above, indigents (extreme poor), Social Security and National Insurance Trust (SSNIT) pensioners and beneficiaries of the Livelihood Empowerment Against Poverty (LEAP) programme. The formal sector workers or contributors of SSNIT are also exempted because their premium is income-rated and deducted at source. Following implementation of the free maternal healthcare policy in July, 2008 , pregnant women are also added to exempt group. However, all members of the exempt group with the exception of indigents, LEAP beneficiaries and pregnant women, pay registration and renewal fee of GHS8.00 ($1.18) and GHS5.00 ($1.13), respectively. The non-exempt groups are those who pay premium directly to the scheme, and they are the workers in the informal sector of the economy. In addition to the premium, the informal sector workers also pay registration and renewal fees. By design, the premium is graduated from GHS7.20 ($1.62) to GHS48.00 ($10.83) based on income levels of the members. However, due to lack of data on income levels, particularity for the informal sector workers, a flat premium is charged during registration but varies from GHS15.00 ($3.39) in the rural areas to GHS22.00 ($4.97) in the cities.
There are several studies on enrolment in the NHIS, particularly population coverage, renewal of membership and equity [17, 24,25,26,27,28,29,30,31]. However, the settings and data of these studies are limited. A study that examined enrolment by member groups was limited to one region and found significant differences among them . Another study that examined enrolment by geographical region used data from literature for only two periods, 2005 and 2008 and found variations across the regions . What is lacking in literature so far, is longitudinal analysis of a national level enrolment data of the NHIS to examine trends and characteristics by geographical region and member groups. The present study seeks to fill this gap by analysing population coverage, membership retention and growth rates over an 8-year period. This study focuses on one of the three dimensions of UHC-population coverage [7, 32]. We believe that findings of this study would inform policy decision-making to improve enrolment, revenue and risk pooling of the NHIS. The study would also serve as evidence for LMICs implementing SHI programmes.
Conceptual framework for the study
Although the study focuses on trends and characteristic of enrolment, it is situated in the Wipf and Garand framework for assessing product awareness and client satisfaction with life and SHI programmes . According to the framework, the coverage ratio, renewal ratio and growth ratio are the three key indicators for assessing performance of health insurance schemes where enrolment is voluntary (Fig. 1). These indicators are important determinants for long-term viability of micro-insurance and SHI programmes with voluntary enrolment because they indicate how readily the target population enrol in the programme and retain coverage.
The coverage ratio measures proportion of the target population participating in the programme, serving as a key indicator of marketing effectiveness and programme’s success . The marketing effectiveness, however depends largely on client’s satisfaction with the services and the perceived value of the programme [30, 33,34,35,36]. Voluntary enrolment of large proportion of the target population, particularly in SHI programmes, gives an indication of acceptance of the risk-pooling concept and understanding of the programme including how to access the benefits. Usually, a very low coverage ratio is an indication of adverse selection, where majority of the sick enrol in the programme.
The renewal ratio measures the proportion of insured that stay enrolled in the programme after their coverage term expires. It also gives an indication of the programme’s marketing performance and how satisfied the insured are. A very high renewal ratio, such as 90% or more, signifies that 1) there is a good understanding of the needs of the target population; 2) the price is acceptable to the target population; 3) the service levels are reasonable; and/or 4) the benefit is highly valued by the community . On the other hand, low renewal ratio is an indication of client dissatisfaction, probably due to poor education and sensitization, poor services at healthcare provider facilities, unacceptable product value and unsatisfactory claims payment such as lengthy delays [24, 30, 33, 37]. A low renewal ratio could also mean that the insured does not know how and where to renew. It is recommended that a renewal ratio of at least 85% should be set as a minimum standard for insurance schemes with voluntary participation .
The growth ratio, which is the ratio of increase in the number of clients, measures how fast the number of clients in the programme is increasing or decreasing. Thus, it depends on the rate of coverage and renewal in the SHI programme. Generally, it increases at the initial stages of implementation of health insurance programmes but begins to decline as participation reaches its peak. A positive trend of the growth rate often indicates marketing success and product appeal. It also indicates social relevance of the programme to the target population. However, a declining growth rate indicates a loss of value and better alternative risk protection options . It is suggested that for SHI programmes to remain viable from medium to long term, at least a zero growth rate should be maintained .