Validation of hourly pain intensity profiles with chronic pain patients.

This study examines how empirically derived pain intensity profiles relate to psychological adjustment in chronic pain patients. Hourly pain intensity ratings over the course of a day of 189 chronic pain patients were categorized into 6 groups using a hierarchical regression analysis technique. The profiles reflected linear, curvilinear, multilinear or "no profile" effects. Judges' ratings of pain intensity profiles were found to be less reliable than ratings based on empirical analysis. The majority of patients showed linear profiles while 26% of the patients showed no consistent relationship between hourly pain intensity and time of day. Patients who showed no consistent trend in their pain ratings reported having significantly higher ratings of emotional distress. They tended to have conflicts at home and showed more pain behavior than patients who had a distinct pain profile. Support is given for the potential clinical utility of pain rating profiles.