Case studies are in-depth investigations of a single instance of a phenomenon in its real-life context (Yin 1994 ). They are to be distinguished from other research designs, such as controlled comparisons, formal modelling, quantitative analyses and randomized-controlled experiments. A substantial body of work offers guidance on case study methodology (Yin 1994 ; Brady and Collier 2004 ; George and Bennett 2004 ; McKeown 2004 ; Yin 2004 ).
Case study methodologists argue that asking just a few basic questions about the case can improve the value of the study considerably. First, what is it a case of (George and Bennett 2004 )? Is it, say, an example of health policy implementation failure, of effective transfer of a health policy from one country to another, of health policy network influence on agenda setting, of the influence of political factors on health policy evaluation? Sometimes cases may be clearly identifiable by the researcher at the start of the study, sometimes they may be constructed or re-constructed during the course of the research as the analysis reveals their defining characteristics (Ragin and Becker 1992 ). The process of clarifying ‘the case’ enables the researcher to specify a body of knowledge to which he or she may make a contribution. Second, why is this case a useful one to study (George and Bennett 2004 )? Does it offer the possibility of comparing the explanatory value of alternative theories? Is it an unusual example of policy effectiveness, potentially offering insight into factors that facilitate policy impact? It is consideration of these issues that help the researcher to select the tools and theories that might frame a study, and to determine which methods will be used.
A study on the global availability of praziquantel, a drug for the tropical disease schistosomiasis, offers clear answers to both questions (Reich and Govindaraj 1998 (link)). The researchers document how the discovery of this effective drug did not automatically result in it reaching the poor in developing countries. They identify this as a case of the gap between drug development and drug availability for the poor—an issue of concern for many tropical disease pharmaceuticals—and highlight the usefulness of this case in revealing the influence of political and economic factors on this gap. Their careful case selection and classification enable them to suggest a set of policy prescriptions on surmounting the drug development–availability gap, recommendations that apply well beyond the case itself.
Another means of facilitating generalization is increasing the number of cases. Doing so is not always easy, since investigating even a single case is a time and resource intensive process that requires careful consideration of historical and contextual influences. Comparative case studies may introduce the further challenges of working across multiple languages and cultures. It can also be difficult to find sufficient funds for undertaking such research. Yet there are several strong examples in the health policy field.
Lee et al. (1998 (link)) used matched country comparisons to investigate factors influencing the development of strong national family planning programmes. They conducted four country comparisons: Bangladesh/Pakistan, Tunisia/Algeria, Zimbabwe/Zambia and Thailand/Philippines. Each pair was matched on socio-economic characteristics, but differed on the strength of the family planning programme. The comparisons enabled the researchers to point to three factors that shaped the development of effective programmes: the formation of coalitions among policy elites, the spread of policy risk, and the country's financial and institutional stability. Walt et al. (1999 (link)) considered individual cases of donor aid coordination in the aid-dependent countries of Bangladesh, Cambodia, Mozambique, South Africa and Zambia to develop generalizations concerning the origins and effectiveness of aid coordination mechanisms. Shiffman (2007 (link)) explored agenda-setting for maternal mortality reduction in five countries: Guatemala, Honduras, India, Indonesia and Nigeria. He identified nine factors that shaped the degree to which this issue emerged as a political priority. He found that while international donors played a role, even more critical were efforts by national champions.
Collectively, these different examples highlight the value of cross-country comparative study approaches, where comparisons between similar (and different) country contexts can help disentangle generalizable from country context-specific effects in policy adaptation, evolution and implementation. Comparisons can be incorporated into study design, ad-hoc, as in the case of Lee et al. (1998 (link)) above; researchers can select as case studies several countries with a shared feature (Brugha et al. 2005 ), seeBox 1 ; or comparison can be made post-hoc, as in the case of Walt et al. (1999 (link)). Clearly, multi-country studies are more time and resource intensive.
Case study methodologists argue that asking just a few basic questions about the case can improve the value of the study considerably. First, what is it a case of (George and Bennett 2004 )? Is it, say, an example of health policy implementation failure, of effective transfer of a health policy from one country to another, of health policy network influence on agenda setting, of the influence of political factors on health policy evaluation? Sometimes cases may be clearly identifiable by the researcher at the start of the study, sometimes they may be constructed or re-constructed during the course of the research as the analysis reveals their defining characteristics (Ragin and Becker 1992 ). The process of clarifying ‘the case’ enables the researcher to specify a body of knowledge to which he or she may make a contribution. Second, why is this case a useful one to study (George and Bennett 2004 )? Does it offer the possibility of comparing the explanatory value of alternative theories? Is it an unusual example of policy effectiveness, potentially offering insight into factors that facilitate policy impact? It is consideration of these issues that help the researcher to select the tools and theories that might frame a study, and to determine which methods will be used.
A study on the global availability of praziquantel, a drug for the tropical disease schistosomiasis, offers clear answers to both questions (Reich and Govindaraj 1998 (link)). The researchers document how the discovery of this effective drug did not automatically result in it reaching the poor in developing countries. They identify this as a case of the gap between drug development and drug availability for the poor—an issue of concern for many tropical disease pharmaceuticals—and highlight the usefulness of this case in revealing the influence of political and economic factors on this gap. Their careful case selection and classification enable them to suggest a set of policy prescriptions on surmounting the drug development–availability gap, recommendations that apply well beyond the case itself.
Another means of facilitating generalization is increasing the number of cases. Doing so is not always easy, since investigating even a single case is a time and resource intensive process that requires careful consideration of historical and contextual influences. Comparative case studies may introduce the further challenges of working across multiple languages and cultures. It can also be difficult to find sufficient funds for undertaking such research. Yet there are several strong examples in the health policy field.
Lee et al. (1998 (link)) used matched country comparisons to investigate factors influencing the development of strong national family planning programmes. They conducted four country comparisons: Bangladesh/Pakistan, Tunisia/Algeria, Zimbabwe/Zambia and Thailand/Philippines. Each pair was matched on socio-economic characteristics, but differed on the strength of the family planning programme. The comparisons enabled the researchers to point to three factors that shaped the development of effective programmes: the formation of coalitions among policy elites, the spread of policy risk, and the country's financial and institutional stability. Walt et al. (1999 (link)) considered individual cases of donor aid coordination in the aid-dependent countries of Bangladesh, Cambodia, Mozambique, South Africa and Zambia to develop generalizations concerning the origins and effectiveness of aid coordination mechanisms. Shiffman (2007 (link)) explored agenda-setting for maternal mortality reduction in five countries: Guatemala, Honduras, India, Indonesia and Nigeria. He identified nine factors that shaped the degree to which this issue emerged as a political priority. He found that while international donors played a role, even more critical were efforts by national champions.
Collectively, these different examples highlight the value of cross-country comparative study approaches, where comparisons between similar (and different) country contexts can help disentangle generalizable from country context-specific effects in policy adaptation, evolution and implementation. Comparisons can be incorporated into study design, ad-hoc, as in the case of Lee et al. (1998 (link)) above; researchers can select as case studies several countries with a shared feature (Brugha et al. 2005 ), see