This cluster randomized waiting-list controlled study will evaluate the effectiveness of pain management group activity organized by the OH on pain intensity and associated disability, and co-occurrence of mental or sleep problem in patients with chronic pain.

Pain is very prevalent among the working population causing a considerable amount of work disability days. Pain management group therapy has shown to have a significant effect on chronic pain. However, little is known of the effect of such therapy on work disability. There are especially very few studies prescribing the effectiveness of pain management groups provided by the occupational health service.

Inclusion Criteria:

- chronic pain + increased risk of work disability (based on a screening survey)

Exclusion Criteria:

• a malignant disease such as cancer, or severe mental illness such as depression causing significant functional disability.
• participating in another pain group elsewhere.
• in the middle of a major life crises such as divorce.