How to analyze time and change in qualitative longitudinal materials? : Insights from a literature review of longitudinal qualitative studies in nursing.

Background Longitudinal qualitative research can give new insights in social processes and experiences over time. In recent years, there has been a growing interest in conducting longitudinal qualitative research within nursing. However, the definition of what constitutes longitudinal qualitative research is unclear, the methodological literature scarce, and the variation of procedures great. This review of longitudinal qualitative articles within the nursing field aims to identify and describe various types of qualitative longitudinal approaches. Materials and Method Searches in pubmed identified over a hundred qualitative nursing articles with data collection over time. These articles were analyzed regarding 1) described analysis procedure, 2) how the results related to aspects of time and change, and 3) if results were person oriented vs category oriented. Results Five different types of longitudinal qualitative approaches were identified. In total, a large part of the papers described as having a longitudinal design performed a data collection over time, but did not integrate ideas of time or change in their analysis or results. Four fruitful approaches to analyzing longitudinal qualitative data were identified; time-line, pool, phase and pattern-oriented approaches. Articles classified as using any of these approaches have a clear perspective of time or change in the results. However, depending on type of approach different aspects of time, change, and process are in focus. Further, using different approaches yielded different kinds of results. Conclusion All approaches have pros and cons and researchers need to make informed decisions when choosing which approach they will take when analyzing qualitative longitudinal material