Effectiveness of a cognitive-behavioral group intervention for knee osteoarthritis pain: protocol of a randomized controlled trial

Background: Knee osteoarthritis is the most common type of arthritis, with pain being its most common symptom. Little is known about the psychological aspects of knee osteoarthritis pain. There is an emerging consensus among osteoarthritis specialists about the importance of addressing not only biological but also psychosocial factors in the assessment and treatment of osteoarthritis. As few studies have evaluated the effect of psychological interventions on knee osteoarthritis pain, good quality randomized controlled trials are needed to determine their effectiveness. Methods/Design: We intend to conduct a 6-week single-blinded randomized controlled trial with a 12-month follow-up. Altogether, 108 patients aged from 35 to 75 years with clinical symptoms and radiographic grading (KL 2-4) of knee osteoarthritis will be included. The clinical inclusion criteria are pain within the last year in or around the knee occurring on most days for at least one month, and knee pain of >= 40 mm on a 100-mm visual analogue scale in the WOMAC pain subscale for one week prior to study entry. Patients with any severe psychiatric disorder, other back or lower limb pain symptoms more aggravating than knee pain, or previous or planned lower extremity joint surgery will be excluded. The patients will be randomly assigned to a combined GP care and cognitive-behavioral intervention group (n = 54) or to a GP care control group (n = 54). The cognitive-behavioral intervention will consist of 6 weekly group sessions supervised by a psychologist and a physiotherapist experienced in the treatment of pain. The main goals of the intervention are to reduce maladaptive pain coping and to increase the self-management of pain and disability. The follow-up-points will be arranged at 3 and 12 months. The primary outcome measure will be the WOMAC pain subscale. Secondary outcome measures will include self-reports of pain and physical function, a health related quality of life questionnaire, and various psychological questionnaires. Personnel responsible of the data analysis will be blinded. Discussion: This study addresses the current topic of non-pharmacological conservative treatment of knee OA-related pain. We anticipate that these results will provide important new insights to the current care recommendations.