Research Review by Dr. Shawn Thistle©

Date:

Apr. 2007

Study Title:

Neck collar, "act-as-usual", or active mobilization for whiplash injury? A randomized parallel-group trial

Authors:

Kongsted A et al.

Publication Information:

Spine 2007; 32(6): 618-625.

Summary:

Forced acceleration-deceleration trauma to the cervical spine, termed whiplash, is common, and is often associated with regional neck pain and stiffness, headache, or shoulder and periscapular pain in the posttraumatic period. Although many patients recover, there is an estimated risk of 10% for developing chronic whiplash associated disorder (WAD).

Only a few factors have been shown to predict a higher risk for developing chronic WAD including high initial pain level, high initial headache intensity, radicular symptoms, female gender, and reduced neck mobility.

Surprisingly little high quality research is available to guide treatment decisions for acute whiplash patients. Logic dictates that whiplash induces damage to cervical spine structures, although it is strongly purported that psychosocial factors can predispose, and precipitate its associated symptoms.

This randomized, parallel-group trial compared the effect of three early intervention strategies in patients deemed to be high risk for developing chronic WAD. Participants were recruited from emergency units and general medical practitioners in Denmark. They were between 18 and 75 years of age, and had to be involved in a frontal or rear-end collision which provoked symptoms within 72 hours.

Exclusion criteria included: cervical fractures or dislocations, amnesia or unconsciousness in relation to the accident, injuries other than the whiplash injury, significant pre-existing somatic or psychiatric disease, and known alcohol or drug use. Participants were also excluded if they reported average neck pain in the preceding six months greater than 2 out of 10 on a 10 point box scale.

Patients believed to be at high risk of developing chronic WAD were chosen for randomization. This was done by establishing a "risk score" - which took into account gender, combined cervical range of motion, and the number of non-painful complaints (please note the authors made no reference to the validity of this selection method). Those with "marked" symptoms and an increased  score were included.

458 patients participated in this trial, and were randomized to one of three treatment groups:
  1. Immobilization in Neck Collar - patients were instructed to wear a semi-rigid collar (Rehband, Otto Bock Scandanavia AB, Sweden) during all waking hours of the day for a 2-week period. Participants could maintain normal activity as permitted while wearing the brace. These patients then consulted a physiotherapist after the 2-week period for an active mobilization program (maximum 2 treatments per week for 4 weeks) - see #3.
  2. Act-as-usual - patients received detailed information about whiplash outlining the generally positive prognosis and the importance of staying active. This information session lasted about one hour.
  3. Active Mobilization - patients underwent treatment based on Mechanical Diagnosis and Treatment (MDT or McKenzie) principles. Consultations took place a maximum of 2x/week for 6 weeks. Patients were instructed to perform progressive light repetitive rotational movements (pain-free ROM, 10x/hour), and end range motion in each direction every day. If the patient did not respond, passive mobilization and soft tissue techniques were employed.
Patients were followed for one year. The primary outcome measures in this study were self-reported neck pain and headache (10 point box scale), and neck functional disability (measured with the Copenhagen Neck Functional Disability Index). Secondary outcomes included the Short-Form-36 and neck mobility (ROM).

Pertinent Results:

  • average age of participants was ~ 34 years of age
  • no baseline differences were noted among the three intervention groups
  • during the observation period, all three groups reported reduced headache and neck pain intensity
  • most recovery in all groups occurred in the first three months after injury
  • improvements in primary outcomes were similar in all three groups
  • improvement in secondary outcomes was noted in 38% of the collar group, 33% in the "act-as-usual" group, and 40% in the mobilization group (worsening was reported in 12%, 17%, and 10% respectively)
  • 37% of participants received other treatments outside of the study protocol in the first three months (35% in the collar group, 44% "act-as-usual", 32% mobilization respectively)
  • the most common treatment sought outside the study protocol was massage, mobilization, or manipulation directed at the neck
  • 25 patients in the '"act-as-usual" group were lost to follow-up (only 5 in the mobilization group and 8 in the collar group)
  • poor compliance was noted in ~25% of the collar group, while only 6% in the mobilization group

Conclusions & Practical Application:

The authors conclude that since equivalent outcomes were noted across the three intervention groups, that advice to act-as-usual is as effective as prescribing immobilization or a structured mobilization program (pg. 624). As the cheapest of the three interventions, this conclusion would be attractive to insurance companies and policy makers. Based on this study, this conclusion may be presumptuous for the following reasons:
  • the high drop-out rate in the "act-as-usual" group suggests that participants felt the intervention was not effective, despite the authors' recommendation that this represents the best treatment option - this may have resulted in an overestimation of the effectiveness of this intervention
  • the method for selecting patients at high risk of developing chronic WAD has not been validated, and may have skewed the selection of patients for this study in a manner that affected the outcome
  • a high percentage of patients in this study sought other treatments, with no attempt to account for this potential influence
  • further, the most commonly sought treatment outside the study protocol resembled one of the interventions (active mobilization)- this could bias the results in all groups toward a common value, leading to the conclusion that no intervention is superior
The conclusion presented by the authors in this paper appears biased against active care and manual therapy, and is not strongly supported by the data presented, nor the statistical methods employed. Future research is required to better answer this question.