Analyzing variations in changes over time: development of the Pattern-Oriented Longitudinal Analysis approach.

Longitudinal qualitative research in nursing is rare but becoming more common. Data collection and analysis over time provide some intriguing possibilities to better understand processes, development, and change in illness experience, healthcare organizations, and self-management. This paper aims to present a process for analyzing qualitative longitudinal data material, namely the Pattern-Oriented Longitudinal Analysis approach (POLA). We developed this approach after synthesizing experiences from two longitudinal qualitative projects and comparing our procedures and reflections with the relevant literature. Using the POLA approach, researchers can describe complexity and variation in changes over time. During the analysis process, emphasis is put on visualizing and identifying change at both an individual and a group level. Ontological and epistemological assumptions for the approach are also described. The benefit of this approach is the possibility to describe complexity and diversity in processes over time, which is important for the development of nursing knowledge. The analysis approach can be further used and developed by researchers seeking to understand variance or contextual features in processes and changes over time.