Case study design has been used frequently in health and social sciences to answer complex research questions due to its flexible and pragmatic approach [
1]. Case study has been described as a ‘study of the particular’ (p XI) [
2] as it is allows for the study of highly context-bound phenomena with a multiplicity of variables not amenable to control. More often than not, case study is undertaken in ‘real life situations’ (p 104) [
3]. It is particularly useful in organisational research [
4,
5] as the methods of data collection and analysis used are selected on a pragmatic basis [
6] conducive to undertaking research in clinical settings. Although much has been written about case study in terms of the difference in the epistemological bases of seminal authors such as Stake and Yin, Merriam contends that “there is little consensus on what constitutes a case study or how this type of research is done”(p26) [
6]. Although it is differentiated from other qualitative approaches as the focus of the research bounded by the case, this lack of certainty in definition of case study has led to some confusion, as although there is some overlap on what a case is or is not, there are significant philosophical differences between key authors. For the purpose of illustration only, let us consider three key authors in the area of case study; Merriam, Stake and Yin, in terms of where they might theoretically position case study within a qualitative-quantitative continuum. Merriam [
6] contends that the single defining characteristic of case study research lies in the bounding of ‘the case’, that is giving consideration to the case as “a thing, a single entity, a unit around which there are boundaries” (p27). Case study typically utilises qualitative and quantitative data sources, selected to encapsulate the complexity of the phenomenon. Merriam [
6] offers precise direction for the researcher employing a case study design in terms of using a theoretical framework to define the problem, and suggests sampling of the case (and within the case) from typical or unique examples or a range of examples to achieve maximum variation. Data are typically collected from multiple sources and can be subjected to a range of analytical strategies such as those used in, but not limited to, grounded theory, ethnography or other approaches that involve developing systems to categorise data. Although firmly grounded in a qualitative paradigm, she offered an intensely pragmatic approach to using case study in the field, and therefore (metaphorically speaking) could be located in the middle of the continuum. Stake [
7] contends that the most critical role of the researcher is that of interpreter, one who constructs a view of the phenomenon through explanation and description “providing readers with good raw material for their own generalizing” (p102). Consequently, as Stake is firmly rooted in an interpretative paradigm, he could be considered to be located on the far left of the continuum. Given Stake’s position that the researcher must be “ever-reflective” (p 927) to find meanings in the data, his creative approach may have contributed to a perception that case study design is somewhat ‘elusive’ [
8], as authors in nursing journals, in particular, fail to define their interpretations or offer a rationale for the approach taken [
9]. Alternatively, Yin contends that a systematic approach to data collection and analysis is crucial to ensuring the methodological integrity of case study, and to demonstrate rigour, the procedural steps undertaken must be made explicit [
2,
8,
10]. Using our continuum, Yin could be positioned on the far right, as his view also allows for the inclusion of quantitatively generated data, requires data to be collected through clearly articulated steps, integrating multiple sources of evidence to create a database of evidence in the form of narratives, documents, fieldnotes, observations etc. to increase the reliability of the case study. For this study, we consider case study as a research strategy, aligned with the position held by Yin [
5,
11], as given the nature of this nationwide evaluation, the large membership of the research team and multiple case sites, a structured rather than a reflective approach to data collection and analysis was required. However, the study was also influenced by the need to take a pragmatic approach [
6], as data were being collected within the context of healthcare delivery.
This
aim of this paper is to use The SCAPE Study: Specialist Clinical and Advanced Practitioner Evaluation in Ireland (present authors 2010) to illustrate how case study was used to strengthen a Sequential Explanatory Mixed Methods Design [
12]. The SCAPE study evaluated the role of Clinical Nurse and Midwife Specialists (CNS/CMS) and Advanced Nurse and Midwife Practitioners (ANP/AMP), in a 3-phase study focusing on the clinical, professional and economic impact of the roles within the Irish publically funded health service. The paper will make particular reference to how case study ‘fit’ within a multiphase design, was bounded by data from phase 1 and relevant theoretical frameworks, and discuss how case study assisted in uncovering the complexity of specialist and advanced practice roles. The case study approach was deemed most appropriate for the proposed study as it examined a contemporary topic, (clinical nurse specialist and advanced nurse practitioner roles, skills, and impact), in a real life situation, (ward/unit setting), where it was difficult to extract practices from the influence of the social environment. It was important therefore, that the influence of contextual conditions on nurses’ and midwives’ practice was examined.