The Impact of Health Insurance in Low- And Middle-Income Countries

Chapter 2: A Review of the Evidence

13 Chapter 2 A Review of the Evidence Ursula Giedion and Beatriz Yadira Díaz We used a detailed protocol to evaluate the robustness of the available evidence on the impact of health insurance in low- and middle-income countries—on access, use, financial protection, and health status (box 2.1). Of 49 quantitative studies, about half provide reasonably robust evidence. They indicate that health insurance improves access and use, seems to improve financial protection in most cases, but has no conclusive impact on health status. The third result may be related to the difficulties of establishing a causal link between health insurance and currently available information on health status. The positive effect of health insurance on medical care use has been widely demonstrated and generally accepted. Hadley (2003), in his review of research published in the past 25 years on health insurance in the developed world, concludes that there is a compelling case for the positive correlation between having health insurance and using more medical care. Little evidence exists, however, on the impact of health insurance in the developing world, and only a few studies have tried to summarize what is available either in some regions or for specific types of health insurance. Whether health insurance is a recommendable strategy to improve access to health care in low- and middle-income countries is hotly debated but insufficiently documented. For example, a resolution adopted at the 2005 World Health Assembly invited member states to ensure that their health financing systems include a method for 14 Chapter 2 prepaying financial contributions for health care. But a recent joint nongovernmental organization briefing paper laments the lack of evidence on whether health insurance can really work in low-income countries and concludes that health insurance “so far has been unable to sufficiently fill financing gaps in health systems and improve access to quality health care for the poor” (Oxfam and others 2008). What do we really know about the impact of health insurance in low- and middle-income countries? This chapter synthesizes the best available evidence regarding the impact of health insurance in low- and middle-income countries on access, use, financial protection, and health status. It emphasizes the results of the 10 studies that provide the most robust evidence and belong to the top quartile score after applying our quality assessment tool.1 We extend this analysis to the second quartile whenever the evidence is especially scarce (box 2.2). Box 2.1 The key analytical question The purpose of health insurance is threefold : increase access and use by making health services more affordable, improve health status through increased access and use, and mitigate the financial consequences of ill health by distributing the costs of health care across all members of a risk pool. The key analytical question in this chapter is: What does the literature say about the impact of health insurance on access and use of health care, on health status, and on financial protection? Evaluating the impact of health insurance is, methodologically, a challenging endeavor. It requires econometric methods to tackle issues such as potential selection bias and the bidirectional relationship between health insurance and health status. It also requires quality data on households and providers to measure outcomes of interest, to correct for differences among the insured and uninsured, and to account for supply constraints— and, above all, profound knowledge of the specific health insurance scheme being evaluated. Often one or more of these items are missing, and analysts must cope as best they can. Some policy reforms aim to use health insurance to change supplier and provider behavior as well as to create a more elastic form of financing than government tax revenue can provide. However, this review focuses on a circumscribed number of performance dimensions and does not include the literature evaluating other consequences of health insurance, such as changes in the organization of health systems or the overall efficiency of health insurance as compared with other financing mechanisms. It is limited to studies that attempt to establish a causal relationship between health insurance and health-related outcome indicators. It thus excludes studies that present descriptive statistics only or that resort to qualitative analysis when evaluating health insurance in low-income countries. A Review of the Evidence15 Box 2.2 Robustness of the evidence base The robustness of the evidence was determined on the basis of five general criteria: quality of the study...