Table 2. Summary results from the 15 included trials.

Studies	Countries	N	WAD	Design	Intervention 1	Intervention 2	Intervention 3	Outcome Measures	Follow-up period	Main Results
Aigner et al. 2006 [29]	Austria	53	II	Parallel RCT with single blind	Collar and laser acupuncture	Collar and placebo laser acupuncture	-	-CROM,Subjective symptoms (neck pain, dizziness, paresthesia and tinnitus),Sick leave	3 weeks (Clinically)8-12 Months (Postal)	No significant difference between interventions in all outcome measures
Bonk et al. 2000 [30]	Germany	147	0-II	Parallel RCT	Active therapy (active mobilization and exercise)	Collar therapy	Control	-Subjective symptoms (such as pain, stiffness), CROM	3 months	No significant difference between interventions at 3 months
Borchgrev-ink et al. 1998 [31]	Norway	201	0-II	Parallel RCT with single blind	Act-as-usual	Immobilisati-on	-	-Subjective symptoms using questionnaire, Pain (VAS), CROM, Shoulder movement, Sick leave	6 months	I1>I2 significantly in improvement neck pain (p<0.01), pain during daily activities (p< 0.05), headaches (p<0.01), painful regions (p<0.01), and memory and concentration problems (p<0.001) at 6 months. ROM of neck and shoulder did not differ between interventions.
Conforti and Fachinetti 2013 [54]	Italy	135	I-II	Parallel RCT with single blind	HPLT	PT (manual therapy, passive and active exercise)	-	-Pain (VAS), The date of return to work	6 weeks	I1 > I2significantly improved in both pain (p = 0.005) and the date of return to work (p<0.001)
Dehner et al. 2006 [55]	Germany	70	II	Parallel RCT	2 days with collar + standard PT after a weeks	10 days with collar + standard PT after a weeks	-	-Pain (VAS), Disability (VAS), CROM	6 months	No significant difference between interventions in all outcome measures
Dehner et al. 2009 [32]	Germany	90	II	Parallel RCT	Active physical therapy	Passive physical therapy	Act as usual	-Pain (VAS), CROM, Period of disability/ sickness costs	2 months	- Pain improvement: I1>I2>I3 significantly- CROM: I1 = I2 = I3- Period of disability: I1 = I2<I3
Ferrari et al. 2005 [33]	Canada	112	I-II	Parallel RCT with single blind	Education pamphlet	Control group	-	-The number of recovery	3 months	No significant difference between interventions
Foley-Nolan et al. 1992 [34]	Ireland	40	0-II	Parallel RCT with single blind	PEMT + collar + active exercise	Placebo + collar + active exercise	-	-Pain (VAS), CROM, Number of analgesics	3 months	I1>I 2 significantly improved in terms of pain (VAS) at 2 and 4 weeks but no significance at 12 weeks. For the CROM, I1>I2 significantly at 3 months (p<0.001).
Jull et al. 2013 [56]	Australia	101	II	Parallel RCT with single blind	Multiprofess-ional intervention	Usual care	-	-Pain (VAS), NDI, IES, PFActS-C, GHQ 28, CROM, Craniocervical flexor test, Balance, Cervical proprioception, PPT, HPT, CPT, Sympathetic vasoconstrictor response, Types and dosage of medications	12 months	No significant difference between interventions in all outcome measures but the recovery of pain and disability between baseline, 6 and 12 months has significant differences in both interventions.
Ottosson et al. 2007 [35]	Sweden	127	I-II	Parallel RCT with unblind	Educational programme + self-care (exercise for relaxation and postural control)	Standard Rx.(basic medications)	-	-Self-reported recovery, SF-36, SMFA, Pain and mental distress (VAS), Sick leave	12 months	I1>I2 significantly in terms of self-reported recovery (p<0.03) but no significant difference in other outcomes between interventions
Picelli et al. 2011 [36]	Italy	18	I-II	Parallel RCT with single blind	Neck fascia manipulation	Neck mobilization exercise + stretching	-	-CROM, Pain (VAS), NDI, PPT	2 weeks	CROM: I1>I2 significantly (p<0.01) but other outcome measures, no significant differences between interventions.
Rosenfeld et al. 2003 [37][Rosenfeld et al. 2006 reporting same trail][57]	Sweden	102	0-II	Parallel RCT with single blind	Active mobilization within 96 hours or Active mobilization 14 days	Standard Rx. (rest, collar and gradual self-mobil)within 96 hrs or Standard Rx. (rest, collar and gradual self-mobil) 14 days	-	-Pain (VAS), CROM, Sick leave	3 years	Pain and sick leave I1<I2 significantly (p<0.05) but no significance in CROM (p = 0.06–0.08)
Schnabel et al. 2004 [58]	Germany	200	I-II	Parallel RCT with un- blind	Mobilisation exercise	Collar therapy	-	-Pain (VAS), Disability (VAS)	6 weeks	I1>I2 significantly in improving pain and disability (p<0.05)
Scholten-Peerters et al. 2006 [59]	Netherlands	80	I-II	Parallel RCT with single blind	Education and exercise by PTs	Education by GPs	-	-Pain (VAS), Functional recovery (VAS), SF-36, CROM, TSK, PCI, NDI, Disability in housekeeping and social activities (VAS)	13 months	At 12 weeks, I1>I2 significantly for CROM improvement but in long term I2>I1 significantly in terms of functional recovery, coping, and physical functioning.
Vassiliou et al. 2006 [38]	Germany	200	I-II	Parallel RCT with unblind	PT + active exercise	Standard Rx (drugs + soft collar)	-	-Pain and disability (NRS), Number of days with oral medication, The period of soft collar	6 months	I1>I2 significantly improved in terms of pain intensity and disability. Other outcomes had been reported but no compare using statistic procedure.

CPT: Cold Pain Threshold, CROM: Cervical Range of Motion, GHQ 28: General Health Questionnaire, HPLT: High Power Laser Therapy, HPT: Hot Pain Threshold, I: Intervention, IES: Impact of Events Scale, NDI: Neck Disability Index, NRS: Numeric Rating Scale, PCI: Pain Coping Inventory, PFActS-C: Pictorial Fear of Activity Scale-Cervical, PPT: Pressure Pain Thresholds, PT: Physiotherapy, RCT: Randomised Controlled Trail, Rx: Treatment, SMFA: Short Musculoskeletal Function Assessment, SF-36: Functional Health Status (Short Form 36), TSK: Tampa Scale for Kinesiophobia, VAS: Visual Analogue Scale