The purpose of this study is to determine the reliability and responsiveness of the Pain Self-Efficacy Questionnaire (PSEQ) in a chronic low back pain (CLBP) population referred to The Danish Rheumatism Associations´ rehabilitation centre Sano Aarhus.

Chronic low back pain (CLBP) is a highly prevalent health condition, and the leading cause of years lived with disability both globally and in Denmark. In the majority of patients with CLBP, no underlying pathology or cause can be identified and CLBP is acknowledged to be multifactorial. CLBP is defined by symptoms lasting for a period longer than three months. The high prevalence of CLBP causes a substantial impact on patients and their families, communities and health-care systems, as well as a financial burden. Besides pain and disability people with CLBP often experience psychosocial consequences with signs of anxiety and depression and effects on social, leisure, and work life.

An important component in rehabilitation is documentation of treatment outcomes. This demands that a change over time can be measured. To determine effect, the measurement tool must detect real or important change over time. This requires the measurement tool is reliable, and therefore will show no real or important change in periods where the patient is stable. If the measurement tool shows real or important change, in periods where there is no change in the patient state, the results can not be predicted as an effect from an intervention, but due to uncertainty of measurement tool.

The measurement tool is selected by the recommendation of literature and involvement of clinicians and patients at sano, and examines patient with CLBP.

It is found necessary to determine the reliability and responsiveness of the PSEQ on the CLBP population referred to Sano Aarhus. Data will be electronically entered in, stored in and collected from Sanos internal database (SanoBasen).

Inclusion Criteria:

• referred to The Danish Rheumatism Associations' rehabilitation centre Sano

Exclusion criteria:

• a rated physical status of > 3 according to the American Society of Anesthesiologists Physical Status Classification System
• axial spondyloarthritis
• spinal fracture within the last 3 months
• severe osteoporosis
• active cancer
• active psychiatric pathology assessed by general practitioner before referral
• pregnancy
• low Danish language skills
• no e-mail address

Patients with chronic low back pain (defined as pain lasting for more than 12 months) with or without sciatica and/or with or without generalized pain identified by ICD-10 codes.