An Investigation of Nomothetic Versus Idiographic Assessment in Chronic Pain

Endometriosis, vulvodynia, and fibromyalgia are chronic pain conditions that cause great suffering. Despite the significant prevalence of all three conditions, they are receiving relatively little attention in psychological treatment research. Despite the popularity of methods that rely on aggregated group data, such as randomized controlled trials (RCTs), concerns have been raised in recent years about the generalizability of results from these methods to the individual level - group-to-individual generalizability. Since psychological treatments in the clinic are focused on enhancing the well-being of a specific individual this might affect how researchers should study these conditions. The current project aims to investigate: (a) item suitability for daily assessment of psychological variables, (b) group-to-individual generalizability in outcome measures frequently used in psychological studies and treatments of chronic pain, (c) relations over time between process and outcome variables, and (d) possible differences in results obtained across three pain conditions.