Kool 2005.

Methods	RCT
Participants	174 workers with subacute LBP and sick leave of > 6 weeks in last half year. mean age 42, 79% male
Interventions	Intervention: Function‐Centered Treatment for 6 days a week for 3 weeks. The FCT was based on work hardening and functional restoration programmes. Treatment activities were chosen based on a patient’s required capacities, as identified in the work‐related assessment. Treatment consisted of work simulation, strength and endurance training through isokinetic exercise, cardiovascular training performed by walking and aqua‐aerobics, sports therapy, and self‐exercise. Patients were told that increasing activity  might cause more pain because the body had to adjust to the activity again. All team members emphasized that patients should continue therapeutic activities even if their pain increased. The treatment protocol did not contain massage, hot packs, and other passive treatments because we did not believe that they facilitate an increase in activity and self‐efficacy, nor has the research literature shown them to be effective. Control: Pain‐Centered Treatment. The primary goal in the PCT group was to reduce pain. The secondary goal was to increase strength and decrease disability. The physical therapist examined the patients to identify painful movements and limitations in mobility, strength, and muscle length in the lumbar region and lower extremities. Treatment was for 2.5 hours a day and consisted of individually selected passive and active mobilization, stretching, strength training, and a mini back school. Unlike with the FCT group, patients in the PCT group were told to stop activities when pain increased. Passive pain modulating treatments such as hot packs, electrotherapy, or massage were used daily. Low‐intensity movement therapy in the pool and progressive muscle relaxation further enhanced relaxation. Progressive muscle relaxation used systematic contraction and relaxation of specific muscle groups. Patients were encouraged to incorporate relaxation techniques into daily living as a coping skill to reduce stress, muscle tension, and pain.
Outcomes	Measured at 1 year after treatment: number of calender work days, the rate of patients receiving unemployment benefits or permanent benefits.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	an independent and blinded research assistant performed concealed randomisation within these 4 strata using a randomisation schedule with blocks of 2 generated on a computer by an independent researcher
Allocation concealment (selection bias)	Low risk	see above
Blinding (performance bias and detection bias) All outcomes ‐ outcome assessors?	Low risk	days at work and other work‐related outcomes were assessed with a questionnaire sent to employers and the patients' primary physicians, who were blinded to the patients' group assignment
Blinding (performance bias and detection bias) All outcomes ‐ patients?	High risk	patients aware intervention content, but not of other treatment
Blinding (performance bias and detection bias) All outcomes ‐ care provider?	High risk	care providers aware of allocation and intervention content
Incomplete outcome data (attrition bias) All outcomes ‐ drop‐outs?	Low risk	1 dropout
Incomplete outcome data (attrition bias) All outcomes ‐ ITT analysis?	Low risk	ITT analysis
Selective reporting (reporting bias)	Low risk	no such suggestions found
Similarity of baseline characteristics?	Low risk	no significant differences found
Co‐interventions avoided or similar?	High risk	subjects used other health care providers between 3 and 12 months
Compliance acceptable?	Low risk	all patients attended at least 90% of the scheduled treatments
Timing of the outcome assessment similar?	Low risk	all subjects followed up post treatment and at 3 months