Bronfort 2012.

Methods	Type of trial: RCT Number analysed/randomly assigned: 147/272 Intension‐to‐treat analysis: calculated
Participants	Acute/subacute mechanical neck pain (grade I or II according to Bone and Joint Decade 2000‐2010 Task on Neck Pain and Its Associated Disorders classification)
Interventions	INDEX TREATMENT Spinal manipulation therapy (A): technique: low‐amplitude spinal adjustments (high‐velocity type of joint thrust manipulation) and mobilisation. Specific spinal level to be treated was left to the discretion of the provider. Light‐soft massage, assisted stretching and cold and hot packs to facilitate manipulation treatment; timing: at baseline; frequency: left to the provider's discretion (mean visits = 15.3); duration: 15 to 20 minutes; route: cervical spine and thoracic spine COMPARISON TREATMENT Medication (B): technique: NSAID, acetaminophen or both. Second line of therapy for those who did not respond was narcotic medication. Muscle relaxants were also used (choice made by the physician); timing: at baseline; frequency: left to the physician's discretion (mean visits = 4.8); dose: choice made by the physician; duration: 15 to 20 minutes (included brief history and examination); route: oral Home exercise (C): technique: self mobilisation exercise (gentle controlled movement) of the neck and shoulder (neck retraction, rotation, extension, flexion, lateral bending motions and scapular retraction with no resistance); timing: at baseline; frequency: 6 to 8 times per day; dose: 5 to 10 rep/exercise; route: cervical and shoulder joint CO‐INTERVENTION: avoided in trial design: additional treatment for neck pain from non‐study healthcare providers, 4 participants (n = 3 in the medication group and n = 1 in the HEA group) reported to visit other healthcare providers during 12‐week interventions; by week 52, participants in each treatment group sought additional health care after completing the treatment phase (n = 18 in the SMT group, n = 14 in the medication group, n = 17 in the HEA group) Duration of treatment: maximum 12 weeks; number of treatment sessions was left to the discretion of the provider Duration of follow‐up: 40 weeks
Outcomes	PAIN (NRS, 0 to 10) Baseline mean: A 5.27, B 4.93, C 5.05 End of study mean: A 1.60, B 2.14, C 1.92 Absolute benefit: A 3.67, B 2.79, C 3.13 Reported results: significant favouring A over B at IP and LT SMD (A vs C): IP ‐0.13 (95% CI ‐0.43 to 0.16), IT ‐0.16 (95% CI ‐0.45 to 0.13), LT 0.06 (95% CI ‐0.23 to 0.35) SMD (A vs B): IP ‐0.34 (95% CI ‐0.64 to ‐0.05), IT ‐0.21 (95% CI ‐0.50 to 0.08), LT ‐0.32 (95% CI ‐0.61 to ‐0.02); NNTB 12 FUNCTION (NDI, 0 to 50) Baseline mean: A 24.22, B 25.12, C 25.12 End of study mean: A 9.99, B 11.07, C 10.20 Absolute benefit: A 14.23, B 14.05, C 14.92 Reported results: significant favouring A over B at IP and IT SMD (A vs C): IP ‐0.21 (95% CI ‐0.50 to 0.08), IT ‐0.01 (95% CI ‐0.30 to 0.28), LT ‐0.02 (95% CI ‐0.31 to 0.27) SMD (A vs B): IP ‐0.35 (95% CI ‐0.64 to ‐0.06), IT ‐0.30 (95% CI ‐0.59 to ‐0.00), LT ‐0.11 (95% CI ‐0.40 to 0.18); NNTB 15 GPE (9‐point scale, 1 to 9) End of study mean: A 2.22, B 2.57, C 2.43 Reported results: significant improvement favouring A over B PATIENT SATISFACTION (7‐point scale, 1 to 7) End of study mean: A 1.67, B 2.48, C 2.06 Reported results: significant improvement favouring A over B QoL (PCS component of SF‐36, 0 to 100) Baseline mean: A 43.36, B 46.27, C 45.31 End of study mean: A 52.51, B 51.13, C 52.48 Absolute benefit: A 9.15, B 4.86, C 7.17 Reported results: not significant SMD (A vs C): IP 0.08 (95% CI ‐0.21 to 0.37), IT ‐0.05 (95% CI ‐0.35 to 0.24), LT 0.00 (95% CI ‐0.29 to 0.29) SMD (A vs B): IP 0.14 (95% CI ‐0.15 to 0.43), IT 0.22 (95% CI ‐0.07 to 0.51), LT 0.19 (95% CI ‐0.10 to 0.49) SIDE EFFECTS Aggravation of pain: A 28/91, B 0/90, C 37/91   Headache: A 5/91, B 0/90, C 3/91  Stiffness: A 5/91, B 0/90, C 4/91  Not specified: A 4/91, B 5/90, C 0/91    Paraesthesia: A 2/91, B 0/90, C 3/91 Nausea: A 1/91, B 5/90, C 1/91    Crepitus: A 0/91, B 0/90, C 3/91 Increased blood pressure: A 0/91, B 1/90, C 0/91  Stress incontinence: A 0/91, B 1/90, C 0/91  Disturbed sleep: A 0/91, B 4/90, C 0/91 Congestion: A 0/91, B 6/90, C 0/91 Rash: A 0/91, B 7/90, C 0/91  Cognitive symptoms: A 0/91, B 10/90, C 0/91  Dry mouth: A 0/91, B 10/90, C 0/91  Gastrointestinal symptoms: A 0/91, B 17/90, C 0/91  Drowsiness: A 0/91, B 18/90, C 0/91    COST OF CARE: NR
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Page 2, left column, at the bottom
Allocation concealment (selection bias)	Low risk	Page 2, right column, at the top
Blinding of Participants (performance bias)	High risk	Not possible owing to design
Blinding of Personal (performance bias)	High risk	Not possible owing to design
Blinding of the Outcome assessor (detection bias)	High risk	Not possible owing to design
Incomplete outcome data (attrition bias)	Unclear risk	Study flow diagram is unclear – are long‐term dropouts 31 or 52 (short term + long term). Also, long‐term dropout in medication group is 34.4%. Unclear whether dropouts in each week of diagram are the same participants
Randomized Participants analysed were allocated (attrition bias)	Low risk	Page 3, right column, paragraph 3
Selective outcome (reporting bias)	Low risk	Page 2, right column, paragraph 2 – similar to Evans 2003 pilot
Similar groups at baseline?	Low risk	Table 1
co‐interventions avoided or similar?	High risk	Table 2 – Variety of co‐interventions were provided to SMT group; types of other interventions used by each group are not reported
Compliance acceptable?	Unclear risk	Unsure whether participants were compliant with home exercises
Similar timing of outcome assessment?	Low risk	Page 3, right column, paragraph 2