Risk factors of chronicity in lumbar disc patients. A prospective investigation of biologic, psychologic, and social predictors of therapy outcome.

Study Design: The current prospective longitudinal study examined the predictive value of psychological, somatic and social variables for the prediction of the short- and long-term follow-up in 111 consecutively selected patients with acute radicular pain and a lumbar disc prolapse or protrusion.

Objectives: The criteria for the therapy outcome were the intensity of persistent pain at the time of the discharge from the hospital and 6 months later and the application for early retirement at the 6 month follow-up.

Methods: As for the psychological predictors, we examined depression (Beck Depression Inventory BDI), daily hassles (Kiel Interview of the Subjective Situation KISS), pain coping strategies (Kiel Pain Inventory KSI), and Health locus of control (GKU). As somatic predictors, we assessed the duration of pain before treatment, previous operations, paresis, disc displacement, scoliosis, adipositas, treatment, and age. As social predictors, we assessed the social status, occupational characteristics, and the duration of inability to work.

Results: The results indicated that persistent pain was best predicted by a combination of somatic (degree of disc displacement), psychological (depression and the pain coping strategies avoidance behavior, endurance strategies, nonverbal pain behavior and search for social support), and social parameters (social status and sitting position) with a correct prediction in 86%. The application for early retirement at the 6 month follow-up was best predicted by depression and stress at work.

Conclusions: The results lead to several hypotheses about biopsychosocial interrelations within the chronification of radicular pain and provide the clinician with a short screening instrument for early diagnosis of chronification.