Value-based cognitive-behavioural therapy for the prevention of chronic whiplash associated disorders: protocol of a randomized controlled trial

Participants are recruited between 2 to 3 months after the whiplash injury. This is done through the National Patient Register that provides names and addresses on patients who fulfil the ICD-10 diagnose code for a whiplash injury (distorsio columnae cervicalis) and are situated in the region Zealand were the study intervention takes place. Monthly, a research assistant identifies all new whiplash cases in the region Zealand. Potential participants are contacted by letter and invited to participate in the study. All potential participants are asked to rate their average level of pain on a numerical pain rating scales (NRS) ranging from 0 (no pain) to 10 (worst possible pain). Participants who volunteer to participate and experience pain levels corresponding to ≥ 4 on average are further screened by a brief telephone interview. During the telephone screening the participants are orally informed of the project and asked additional questions regarding experienced daily life difficulties in relation to their whiplash trauma. Participants who fulfil the outlined criteria for inclusion (for details, look beneath) and accept participation are referred to one of two trained, clinical psychologist for their first counselling session. Participants are informed that they are allowed to bring a relative to the first consultation. Written informed consent will be obtained from all participants prior to entry into the study. Before the first session and randomization, they receive a letter with additional written information about the study, a statement of consent and the baseline questionnaire. At the first consultation and before randomization, all participants and their relatives are thoroughly informed about the randomization procedure, the intervention, and expected outcome of the study. Participants, who at any given time in the process, do not wish to participate, are not questioned further about this decision.

All participants are between the age of 18 and 65-years old and are diagnosed with WAD grade I-II [23]. At 3-months post injury, they are experiencing disability in at least one important life domain (≥5 on the pain disability index) and moderate levels of pain (average pain intensity ≥ 4 on the NRS scale). Also, they have to meet at least one of the psychological risk criteria: elevated levels of pain catastrophizing, fear-avoidance beliefs, symptoms of anxiety and/or depression, and posttraumatic stress symptoms). Clinically relevant cut-off score criteria are based on previous studies [21, 24, 25]. Criteria of exclusion is treatment for other damages sustained in connection with the whiplash trauma, psychiatric disorders, active abuses of alcohol, drugs, or medication, ongoing rehabilitation or other treatment for pain besides physiotherapy and pharmacological treatment, and non-Danish speaking.

Patients are randomized by random permuted blocks of 4 to 8 by the study statistician at University of Southern Denmark. Randomization is consecutively numbered in sealed opaque envelopes. Patients will randomly be allocated to one of two treatment groups (A or B) in a crossover design with both groups receiving the V-CBT intervention, however with a delayed onset for group B. Group A is scheduled for V-CBT within one week of randomization and group B with a delayed onset of 3-months after randomization. Measurements of effect are carried out at baseline before randomization (3 months post-injury), post-treatment/wait-list (3 months post randomization), and at follow-up (9 months post randomization/12 months post-injury). At all time points patients are asked which potential additional treatment they have received. The clinical psychologists are not blinded to which intervention the patients receive. However, at the point of analysis, the two groups will be coded as X and Y in order to blind the researcher who will conduct analysis.

The V-CBT is a manualized program specifically tailored for prevention of disability and psychological distress after whiplash injuries [26]. The theoretical foundation of the program is learning theory as outlined by Fordyce [27], and value-based behaviour change strategies as described in contextual cognitive-behavioural therapy [19, 28, 29]. The V-CBT program has a common goal with acceptance and commitment therapy (ACT), to improve daily life functioning and facilitate behaving in accordance with personal values and life-goals. Although, the V-CBT program facilitates behavioural changes according to personal values and life goals, the program does not directly target psychological flexibility by the use of acceptance and mindfulness strategies. The first session of the program is dedicated to assessing personal values and daily life goals. Values and life goals are assessed by an interview based on the patient’s response on the pain disability index, on which affected life domains are reported.

The V-CBT program is rooted in learning theory [27] reflected in the primary focus on imaginal- and in-vivo exposure strategies. For these reasons we have chosen to name the program Value-based Cognitive behavioural therapy. Within the framework of learning theory it is emphasized how negative reinforcement can result in avoidance behaviour and limitations of activity and how events only loosely associated with earlier aversive events may come to serve as cues and conditioned negative reinforces resulting in more avoidance behaviour and activity restrictions. Combining the principles of learning theory with value-based actions, the primary goal of the program is functional restoration of everyday life activities and not necessary symptom eradication. Two trained clinical psychologists deliver the intervention. The psychologists have several years of experience delivering CBT and receive bi-weekly supervision. The program consists of 10 weekly one-hour individual sessions. For a program description, see Table 1.

Before the first session, all patients receive a 14-min psycho-educational video produced with the purpose of reassurance after acute and subacute whiplash injury. The video includes education in the physiology of a cervical strain, possible symptoms and prognosis, coping strategies, and encouragement to gradually maintain pre-injury activity.

The main components of the V-CBT program are: 1) Education in pain theory and active coping, 2) unlearning fear-conditioned movement restrictions, 3) gradual increase in activity, 4) daily program of movement or excises, 5) change of dysfunctional thoughts and catastrophizing and focused treatment of mild PTSD-symptoms by imaginal and in-vivo exposure, and 6) development of a plan on how to return to work or relevant activities. The patients are expected to participate actively between sessions by doing homework. Weekly goals regarding resumption of daily activities or tasks are set throughout the program.

To our knowledge no similar studies have been conducted. For this reason, the power calculation is estimated according to the earlier studies using CBT and acceptance-based strategies with functional restoration and activity engagement as their primary goal. From these earlier results, a moderate effect size is to be expected (η_p² = 0.25) [19, 20]. By putting the level of significance at 5 %, the power at 80 %, and the expected dropout at 9 months post-randomization to be 10 %, it is calculated that there should be 40 patients in each group (A & B).

The primary and secondary outcomes measured for both groups at baseline before randomization (3 months post-injury), 3 months post-randomization, and 9 months post randomization (12 months post-injury) will be analysed using linear mixed-effects models (random coefficient models and multilevel models). With the mixed effects model approach all available data will be used and intention-to-treat analyses applied.

The study is presented and approved of The Regional Scientific Ethical Committee for Southern Denmark (J.nr. S-20130103) and the Danish Data Protection Agency. All procedures in the study are in accordance with the second declaration of Helsinki. The intervention is an additional offer to treatment as usual, and everybody is free to say no to participation.