Secondary Logo

Journal Logo

Recommendations For Core Outcome Domain Set For Whiplash-Associated Disorders (CATWAD)

Chen, Kenneth BExSpSc (Hons)*,†; Andersen, Tonny PhD; Carroll, Linda PhD§; Connelly, Luke PhD†,∥,¶; Côté, Pierre PhD#,**,††; Curatolo, Michele PhD‡‡; Elliott, James PhD§§,∥∥; Grant, Genevieve PhD†,¶¶; Jull, Gwendolen PhD##; Kasch, Helge PhD***,†††,‡‡‡; MacDermid, Joy PhD§§§,∥∥∥; Malmström, Eva-Maj PhD¶¶¶,###; Maujean, Annick PhD*,†; McLean, Samuel A. MD****; Nielsen, Mandy PhD††††; Rebbeck, Trudy PhD†,∥∥; Söderlund, Anne PhD‡‡‡‡; Sterling, Joanna M Psych*; Treleaven, Julia PhD##; Walton, David M. PhD§§§; Westergren, Hans PhD¶¶¶,###; Sterling, Michele PhD*,†,§§§§

doi: 10.1097/AJP.0000000000000735
Original Articles
Free
SDC

Objective: Inconsistent reporting of outcomes in clinical trials of treatments for Whiplash-associated Disorders (WAD) hinders effective data pooling and conclusions that can be drawn about the effectiveness of tested treatments. The aim of this study was to provide recommendations for core outcome domains that should be included in clinical trials of WAD.

Materials and Methods: A 3-step process was used: (1) A list of potential core outcome domains were identified from the published literature. (2) Researchers, health care providers, patients, and insurance personnel participated and rated the importance of each domain via a 3-round Delphi survey. A priori criteria for consensus were established. (3) Experts comprising researchers, health care providers, and a consumer representative participated in a multidisciplinary consensus meeting that made final decisions on the recommended core outcome domains.

Results: The literature search identified 63 potential core domains. A total of 223 participants were invited to partake in the Delphi surveys, with 41.7% completing round 1, 45.3% round 2, and 51.4% round 3. Eleven core domains met the criteria for inclusion across the entire sample. After the expert consensus meeting, 6 core domains were recommended: Physical Functioning, Perceived Recovery, Work and Social Functioning, Psychological Functioning, Quality of Life, and Pain.

Discussion: A 3-step process was used to recommend core outcome domains for clinical trials in WAD. Six core domains were recommended: Physical Functioning, Perceived Recovery, Work and Social Functioning, Psychological Functioning, Quality of Life, and Pain. The next step is to determine the outcome measurement instruments for each of these domains.

*Recover Injury Research Centre

NHMRC Centre of Research Excellence in Road Traffic Injury Recovery, The University of Queensland, Herston

##Division of Physiotherapy, School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia

§§§§Menzies Health Institute Queensland, Griffith University, Parklands

The University of Queensland Centre for the Business and Economics of Health, PACE, Woollongabba, Queensland

∥∥Faculty of Health Sciences, The University of Sydney, Sydney, NSW

¶¶Faculty of Law, Australian Centre for Justice Innovation (ACJI), Monash University, Melbourne, Vic.

††††Chronic Pain Australia, Sydney, NSW, Australia

Department of Psychology, University of Southern Denmark, Odense M

***Research Unit, Spinal Cord Injury Centre of Western Denmark

†††Department of Neurology, Regional Hospital of Viborg, Viborg

‡‡‡Department of Clinical Medicine, Aarhus University, Aarhus, Denmark

§School of Public Health, University of Alberta, Edmonton, AB

#Faculty of Health Sciences, University of Ontario Institute of Technology

**UOIT-CMCC Centre for Disability Prevention and Rehabilitation, Oshawa

††Dalla Lana School of Public Health, University of Toronto, Toronto, Canada

§§§School of Physical Therapy, Western University, Australia

∥∥∥Hand and Upper Limb Centre, St. Joseph’s Health Centre, London, ON, Canada

Department of Sociology and Business Law, The University of Bologna, Bologna, Italy

‡‡Department of Anesthesiology & Pain Medicine, University of Washington, Seattle, WA

§§Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL

****Department of Anesthesiology, Institute for Trauma Recovery, University of North Carolina School of Medicine, Chapel Hill, NC

¶¶¶Department of Pain Rehabilitation, Skåne University Hospital

###Department of Clinical Sciences, Lund University, Lund

‡‡‡‡Department of Physiotherapy, School of Health, Care and Social Welfare, Mälardalen University, Västerås, Sweden

The consensus meeting was funded by the NHMRC Centre of Research Excellence in Road Traffic Injury Recovery and a grant from the Menzies Health Institute, Queensland, Parklands, Australia. J.M. was supported by a Canadian Institutes of Health Research Chair in Gender, Work and Health and the Dr James Roth Chair in Musculoskeletal Measurement and Knowledge Translation, London, Ontario, Canada. The remaining authors declare no conflict of interest.

Reprints: Michele Sterling, PhD, Recover Injury Research Centre, The University of Queensland, 288 Herston Road, Brisbane, QLD 4029, Australia (e-mail: m.sterling@uq.edu.au).

Received February 6, 2019

Received in revised form May 4, 2019

Accepted May 21, 2019

Back pain and neck pain are the leading causes of global disability, and this burden is increasing.1 Whiplash-Associated Disorders (WAD), as a consequence of motor vehicle crash, lead to substantial costs related to treatment of physical and mental health and lost productivity.2 WAD incurs greater disability than nontraumatic neck pain3 and likely contributes significantly to the global burden of musculoskeletal conditions.

Many cohort studies and randomized clinical trials have been conducted for WAD, and numerous and varied outcome measures have been used. This makes effective data pooling difficult and often precludes meta-analysis. Authors of recent systematic reviews note the inconsistent use of validated outcome measures as a limitation of current research,4,5 with some querying the appropriateness of data pooling for this reason.5 There is a need for the use of validated outcomes in clinical trials of WAD such that meaningful conclusions about treatment effectiveness can be made.6,7

The development of a core outcome set (COS) would mitigate these issues. A COS represents an agreed set of outcomes recommended for inclusion and reporting in all clinical trials for specific health conditions.8 Inclusion of the COS would be mandatory in all clinical trials but additional outcomes may also be included as relevant to the nature of the treatment/s being tested.8 The first step in the development of a COS is to agree upon the core outcome domains that should be measured.8 Following this, evaluation of outcome instruments that measure the core domains would be undertaken with the final stage being the recommendation of the COS.9

The Outcome Measures in Rheumatology (OMERACT) in arthritis10 was the first initiative in the development of a COS for musculoskeletal pain conditions, followed by the Initiative on Methods Measurement and Pain Assessment in Clinical Trials (IMMPACT) for pain in general.11,12 More recently, COSs have also been developed for painful shoulder conditions13,14 and for low back pain.15,16 The International Classification of Function, Disability and Health (ICF) has also recognized the importance of core sets of constructs (ICF codes) that are most relevant to different health conditions and created Core Sets for multiple health disorders.17,18 Considering the significant burden of WAD, its often compensable nature, and the available evidence indicating that the condition shows unique clinical features compared with nontraumatic neck pain,3,19 it is unlikely to be sufficiently served by generic musculoskeletal or pain COS.

The aim of this study was to develop a set of core outcome domains recommended for use in all clinical trials for WAD. A 3-step process was used: (1) identification of outcome domains via a literature survey; (2) a 3-round Delphi survey of relevant stakeholders to reach consensus on the identified core domains; (3) a multidisciplinary meeting to finalize the domains. This study is the first stage in the development of a COS for this condition.

Back to Top | Article Outline

MATERIALS AND METHODS

The protocol for the development of this COS has been registered in the COMET database and published in detail elsewhere.20

Back to Top | Article Outline

Scope and Definition

WAD were defined as the clinical manifestations (eg, neck pain, headache, dizziness) that arise as a result of an acceleration-deceleration mechanism of energy transfer to the neck. It may result from rear-end or side-impact motor vehicle collisions, but can also occur during diving or following falls.21 WAD grades I to III21 are the focus of the development of the COS. They are intended for use in all clinical trials (of any intervention) in a research or clinical setting.

Back to Top | Article Outline

Procedure

An International Steering Committee was formed comprising 9 researchers in the area of WAD from 3 continents. The day-to-day running of the studies involved in the development of the core domains was undertaken by the Queensland, Australia, team (M.S., A.M., K.C., and J.S.). These researchers undertook the initial review of the literature and the conduct of the Delphi surveys. The remaining members of the Steering Committee (L.C., M.C., J.E., D.M.W., and H.K.) advised on the studies via regular Skype meetings and email. The Steering Committee developed the protocol for the development of the COS before the commencement of the process.20

A 3-step process was used as outlined:

Back to Top | Article Outline

Step 1: Identification of Core Domains

The aim of step 1 was to identify domains used in the research of WAD, either in measuring outcomes of clinical trials or in measuring outcomes of clinical studies. Four databases (Cochrane Library, CINAHL, PubMed, and Embase) were searched for clinical trials, randomized controlled trials, and systematic reviews relating to WAD from inception until the date of the searches (November 1, 2017). All references were exported to an endnote library and sorted by the domains included as outcome measures. Two of the authors (A.M. and J.S.) reviewed the sorted references and discussed any points of difference with regard to the assigned domains. The search strategy used is outlined in Appendix 1 (Supplemental Digital Content 1, http://links.lww.com/CJP/A581). Once identified, the listed core domains were then reviewed by the International Steering Committee, and additional suggested domains were added. The extracted domains were then classified on the basis of the OMERACT Filter 2.0 framework, which consists of 3 core areas that cover the Impact of Health Condition (“Death,” “Life Impact,” and “Resource Use/Economic Impact”), and which describe Pathophysiological Manifestations.22

Back to Top | Article Outline

Step 2: Delphi Surveys

The Delphi method consists of successive surveys that involve a panel of participants. This method provides many advantages including anonymity of responses; no direct interaction between participants, which avoids influential decision making due to overly vocal, senior, or domineering individuals; and allowing involvement of geographically distant participants.23 The Human Research Ethic Committee, The University of Queensland, approved of this study (#2018000680).

Back to Top | Article Outline
Participants

Researchers, health care providers, patients, and compensation insurance personnel were invited to participate in the Delphi survey. One reviewer (A.M.) identified researcher participants through a search on PubMed, CINAHL, and Embase, and additional researchers were then suggested by the Steering Committee through convenience sampling. Those who had published at least 2 scientific papers in the area of WAD and comprised clinical researchers, methodologists, and health economists qualified to be researcher participants. Heath care clinician participants were from a wide range of disciplines, including physiotherapists, general practitioners, chiropractors, and psychologists, with experience in the management of patients with WAD or in the provision of interventions in previous clinical trials for WAD. Insurance personnel participants were involved in the management of the Compulsory Third Party or workers’ compensation schemes. Health care providers and insurance personnel were identified through convenience sampling. Patient participants were those with or who had experienced WAD. They were recruited from various sources including physiotherapy clinics, general medical practices, respondents to advertisements, and participants involved in previous research studies.

All participants were contacted by email, provided with the Participant Information Sheet, which detailed the aims and objectives of the study, and asked for consent to participate. The final list of potential stakeholders was managed by the project team, and names in the list remained blinded to all participants.

Back to Top | Article Outline
Delphi procedure

This study comprised a 3-round Delphi survey, consisting of open-ended and close-ended questions, used to reach consensus on core outcome domains. The Delphi survey was conducted using the SurveyMonkey platform, and invitations were sent by email. All participants were invited to each round of the survey, excluding individuals who opted out of receiving emails from SurveyMonkey or who explicitly requested to be removed from the study.

The first round of Delphi survey consisted of all the potential core domains identified in step 1, and 3 additional open-ended questions: (1) Are there any additional outcome domains you think should be included? If Yes, can you nominate them here and briefly outline why they should be included? (2) What is the optimal number of domains that should be included in this Core Outcome Set for WAD? (3) Are there any outcome domains above that you think could be combined? If so, which ones? Each domain was accompanied by a brief description to facilitate common understanding of the construct (Table 1). Participants were instructed to rate the importance of each domain on a Likert scale from 1 to 9, with 1 to 3 labeled “not important,” 4 to 6 “important but not critical,” and 7 to 9 labeled “critical.” A priori cutoff criteria were established for retaining domains into the subsequent rounds, on the basis of COMET recommendations.20,24 Participants were given 2 weeks to respond before a reminder email was sent. Items rated 7 to 9 by 50% or more participants and 1 to 3 by no >15% of participants in at least 1 stakeholder group were retained in round 2. Suggestions from respondents for the inclusion of additional domains or combination of domains were also included in round 2, after review by the International Steering Committee.

TABLE 1

TABLE 1

In the second round, results of round 1 were emailed to all participants together with the round 2 survey. The overall process was similar to round 1, and, again, all participants were given 2 weeks to respond to the survey. Round 2 also consisted of a single question of rating the importance of each domain, with the same Likert scale as in round 1. Stricter cutoff criteria were implemented for round 2,24 with items rated 7 to 9 by over 70% of respondents and 1 to 3 by <15% of respondents in at least 1 stakeholder group retained. The establishment of stricter cutoff criteria through the Delphi rounds and providing feedback of results from a previous round is recommended in order to reduce the likelihood of eliminating outcomes that may have been rated more highly in subsequent rounds.24

In the third round, the overall process remained the same, with results from the round 2 and the round 3 surveys emailed to participants. Consensus was established that a domain would be taken to the final consensus meeting if it received a rating of 7 to 9 by ≥70% and 1 to 3 by ≤15% by all 4 stakeholder groups or rated as 7 to 9 by ≥90% of 1 stakeholder group.25

At the end of each round of the Delphi survey, frequencies for the response options were calculated for the whole group and separately for each group of stakeholders to establish whether there were discrepancies among the stakeholder groups.

Back to Top | Article Outline

Step 3: Final Decisions

The results from all rounds of the Delphi survey were presented at a consensus meeting. Attendees at this meeting included the International Steering Committee, clinical researchers, health care providers, and insurance and patient representatives. The discussion was held in order to make final decisions on the core domains. If voting was required, then >50% support was required for an outcome domain to be included as part of the COS.20

Back to Top | Article Outline

RESULTS

List of Potential Core Domains

The list of identified potential domains included 35 outcome domains, classified on the basis of OMERACT Filter 2.0 recommendation,22 and is as follows: 23 under “Life Impact,” 3 under “Resource Use/Economic Impact,” 1 under “Death,” and 7 under “Pathophysiological Manifestations,” The list of outcome domains selected and accompanying description used in the Delphi survey is presented in Table 1.

A total of 223 participants consisting of 74 health care providers, 60 clinical researchers, 25 insurance personnel, and 63 patients were invited to participate in the Delphi survey. Characteristics of the participants are outlined in Table 2. Insurer and patient participants were all from Australia. A flowchart of response rates for all 3 Delphi rounds is presented in Figure 1.

TABLE 2

TABLE 2

FIGURE 1

FIGURE 1

Back to Top | Article Outline

Round 1 Delphi Survey

The first round ran from May 2 to June 6, 2018. This was longer than proposed (5 vs. 3 wk) in order to send further reminder emails to meet the proposed response rate of at least 40%.20 Ninety-three (42%) of the 223 invited participants completed the survey. Five participants declined participation, and 4 emails were not delivered (Fig. 1). The response rates of each stakeholder group can be seen in Table 3.

TABLE 3

TABLE 3

The results of the participants’ rating on the 35 outcome domains are presented in Figure 2. Two domains, “Pain Biomarkers” and “Informal Care,” did not meet the a priori criteria and were excluded from round 2. Two domains, “Number of Deaths” and “Health Care Services” marginally met the criteria for retention but only in 1 stakeholder group each. These 2 domains were presented to the International Steering Committee for consideration of exclusion from round 2, with the final consensus (100% agreement) being the removal of “Number of Deaths” and retention of “Health Care Services.”

FIGURE 2

FIGURE 2

Twenty-one participants nominated additional domains to be included. Fourteen of the nominated domains were rejected, as they were duplicates, irrelevant, or inapplicable as a COS domain. The remaining 7 domains were presented to the International Steering Committee for final decision for inclusion in round 2, with the final consensus of adding “Perceived Injustice,” “Beliefs/Expectations,” and “Optimism” under the domain “Psychological Functioning,” “Intimacy” added under “Quality of Life,” “Physical Activity” added under “Physical Functioning,” and an additional domain of “Time to Recovery” (Appendix A, Supplemental Digital Content 1, http://links.lww.com/CJP/A581).

Ninety-two participants answered the question on the optimal number of domains, and 91 participants indicated a specific number ranging from 3 to 30. One participant suggested an excessive number of 69 domains, which was excluded from consideration. Twenty-three (25%) participants suggested “5” as the optimal number, and 22 (23.9%) participants suggested “10” (Table 4), with the majority in favor of a small COS.

TABLE 4

TABLE 4

Fifty-five (60.4%) participants indicated generally that some domains should be combined, and 53 (58.2%) participants identified specific domains that could be combined. These proposed combinations and the International Steering Committee decision are depicted in Table 5.

TABLE 5

TABLE 5

Twenty-five outcome domains were included in the second round of the Delphi survey. These were as follows: Satisfaction with Care/Treatment, Physical Functioning, Perceived Recovery, General Health, Work Related Factors, Satisfaction with Social Roles and Activities, Fatigue, Autonomy, Psychological Functioning, Self-Efficacy, Cognitive Functioning, Sleep, Quality of Life, Pain, Use of Pain Medication, Dizziness, Visual Disturbances, Swallowing Difficulties, Sensory Symptoms, Range of Motion, Neck Posture, Muscle Function, Proprioception, Health Care Services, and Time to Recovery.

Back to Top | Article Outline

Round 2 Delphi Survey

Round 2 ran from June 18 to July 16, 2018. The survey was extended by an additional week to improve response rates in order to meet the a priori criteria. Two hundred twenty-two participants were emailed the results from round 1 and invited to participate in the second round. Figure 1 and Table 3 depict the participant responses.

Eight domains, namely (1) “General Health,” (2) “Dizziness,” (3) “Visual Disturbances,” (4) “Swallowing Difficulties,” (5) “Sensory Symptoms,” (6) “Muscle Function,” (7) “Proprioception,” and (8) “Health Care Services,” did not meet the a priori criteria for retention and were therefore excluded (Fig. 3).

FIGURE 3

FIGURE 3

Back to Top | Article Outline

Round 3 Delphi Survey

Round 3 ran from July 17 to August 10, 2018. Two hundred twenty-one participants were emailed the results from round 2 and invited to participate in the final round. Figure 1 and Table 3 depict the participant responses. Eleven domains, namely (1) “Physical Functioning,” (2) “Perceived Recovery,” (3) “Work Related Factors,” (4) “Satisfaction with Social Roles and Activities,” (5) “Autonomy,” (6) “Psychological Functioning,” (7) “Self-Efficacy,” (8) “Cognitive Functioning.” (9) “Sleep,” (10) “Quality of Life” and (11) “Pain,” met the a priori criteria for retention (Fig. 4).

FIGURE 4

FIGURE 4

Back to Top | Article Outline

Final Consensus Meeting

Before the meeting, the results of all 3 rounds of the Delphi survey were collated and sent to all participants. A 2-day face-to-face consensus meeting was held at the conclusion of the IASP World Congress in Boston 2018. There were 19 attendees, and, for those who were unable to attend in person (n=1), the results of discussion and voting were emailed, and their support or otherwise was gained before the final decisions were made. At the commencement of the meeting, the Delphi results were presented.

Discussions were first held about the number of core domains to be included. There was full agreement that the ideal number was ∼5, but the final decision on this would be made after discussion and voting on the core domains. The final number of core domains was eventually determined as 6.

Discussions were then held around the 11 core domains, and the following recommendations were voted by a majority of the attending committee:

  • 100% agreement to include “Self-Efficacy” under the domain of “Psychological Functioning.”
  • 100% agreement to include “Autonomy” under the domain of “Satisfaction with social roles and activities.”
  • 100% agreement to merge “Work Related Factors” and “Satisfaction with social roles and activities” into 1 domain “Work and Social Factors.”
  • 100% agreement to remove “Cognitive Functioning” due to broadness and difficulties in measurement of this domain.
  • 100% agreement to include “Sleep” under the domain of “Physical Functioning.” The committee recognized that “Sleep” was rated highly by all stakeholder groups, (Fig. 4) and there was much discussion about whether or not it should be a domain on its own or incorporated under a broader domain. After discussion, there was 100% agreement to include it under “Physical Functioning,” but it was acknowledged that sleep is not only a physical construct.
  • 89% agreement to include “Perceived Recovery.” There was a discussion that this construct may be subject to recall bias and influenced by current health status.26

At the conclusion of the meeting, the domains “Physical Functioning,” “Perceived Recovery,” “Work and Social Functioning,” “Psychological Functioning,” “Quality of Life,” and “Pain” were deemed the final set with 100% consensus.

Back to Top | Article Outline

DISCUSSION

We undertook a 3-step process consistent with recommendations of the COMET initiative9 and with a priori established protocol20 to develop a set of core outcome domains for use in clinical trials for WAD. International, multidisciplinary, and multistakeholder consensus was achieved. Six core domains were recommended for inclusion in all clinical trials of WAD. These were: “Physical Functioning,” “Perceived Recovery,” “Work and Social Functioning,” “Psychological Functioning,” “Quality of Life,” and “Pain.”

Back to Top | Article Outline

Physical Functioning

A common objective of most interventions is to improve physical functioning. Patients with WAD also report this as being important to them.27,28 This core domain is recommended by IMMPACT for chronic pain and by low back pain initiatives.12,15,16 Physical function is a broad domain that can encompass various aspects of a person’s life, ranging from ability to carry out daily activities, for example, household tasks, recreational activities, or self-care, to specific strength, endurance, and functional capacity.

We included “sleep problems” under this domain. Sleep problems have not been included in other COSs including those by IMMPACT, or low back pain, but, as it was rated very highly by all stakeholder groups in our Delphi survey, the consensus meeting participants felt its inclusion was necessary. Recent studies show that sleep disruption is an important aspect of various musculoskeletal conditions.29 It would seem to be also important for patients with WAD.30 After discussion at the consensus meeting, the final decision was not to include it as a separate domain. Reasons for this decision included that, at this stage, the research of sleep and its role in WAD is limited and that there would be difficulties in measuring this construct to warrant inclusion as a stand-alone domain. It was agreed to include it under the domain of Physical Functioning, but it was acknowledged that sleep is not only a physical construct.

Back to Top | Article Outline

Perceived Recovery

The question as to whether or not a patient feels that his or her condition has improved or deteriorated as a result of an intervention is fundamental to both clinical research and practice. However, this domain attracted much discussion with respect to limitations such as participant recall bias and that it could be strongly influenced by the patient’s current health status.26 Despite the limitations, the concept of clinical relevance to an individual is identified as critical in the choice of outcome measures.31 Including measures of perceived global improvement allows the patient to aggregate the effect of the intervention on all aspects of their condition, or at least those important to that individual. The patient may include pain relief, physical and psychological function, and side effects among other factors into an overall perception of the benefit of the intervention for them.11 Participant rating of global improvement usually involves just a single item question on a Likert scale, allowing for an outcome domain that is neither time-consuming nor arduous.

Back to Top | Article Outline

Work and Social Functioning

This is a broad domain and encompasses the health condition’s impact on an individual’s ability to interact with others, ability to build and maintain relationships, engage in their desired community social life and work environment, ability to work or return to work, and efficacy during work. This domain was not included as a core domain for nonspecific low back pain,15,16 but was recommended by IMMPACT as a supplemental domain.12 The consensus decision of this study was informed by the high rating of importance (>85%) by all 4 stakeholder groups for both domains “Work Related Factors” and “Satisfaction with Social Roles and Activities.” This result is consistent with findings from qualitative studies of patients with WAD.32 There was a discussion of paid and unpaid work roles and how these vary by gender and age. The group acknowledged that return to work does not necessarily mean paid work for all people. During discussions, it was noted that some available instruments such as health-related quality of life questionnaires include items about social functioning and work-related factors, potentially supporting a short list of measurement instruments required at the next stage of development of the COS.

Back to Top | Article Outline

Psychological Functioning

A recent systematic review indicated greater impact of psychological distress in patients with WAD compared with spinal cord injury and traumatic brain injury.33 Various psychological factors have been shown to be associated with WAD, including posttraumatic stress symptoms,34 pain catastrophizing,35 fear of movement,36 and depression37 among others. In our study, the description accompanying the domain “Psychological Functioning” includes subdomains fear of movement, stress associated with the crash, general stress, anxiety, depression, hyperarousal, perceived injustice, beliefs, self-efficacy, and optimism. Researchers could adopt any of these subdomains should the clinical trial require a specific psychological outcome to be measured, depending on the design and nature of the intervention conducted.

Back to Top | Article Outline

Quality of Life

This domain includes patients’ perceptions on their position in life, taking into consideration the culture and value systems in which they live, and in relation to their personal values, goals, expectations, standards, and concerns.38 It is a broad-ranging concept incorporating components of a patient’s self-reported physical heath, psychological state, social functioning, interaction with salient features of their environment, and level of independence.39 These components have been found to be of importance from a patient’s perspective.40 This core domain has been included in COS for low back pain and shoulder disorders.13–16

Back to Top | Article Outline

Pain

The inclusion of Pain as a core domain is consistent with other outcome recommendations for chronic pain in general12 and for chronic regional pain syndrome.41 Similar initiatives for low back pain were more specific and recommended “pain intensity.”15,16 Managing pain has been nominated as being important by patients with WAD,42 and the measurement of pain intensity is commonly used in clinical trials.43 Patients with WAD also commonly report widespread pain, pain that changes over time, and different pain qualities such as burning or throbbing pain.44 It has been argued that it is not pain intensity per se that is important but how much the pain bothers or interferes with patients’ daily lives that is more relevant.45 These factors may need to be considered at the next stage of the COS development—the recommendation of core outcome measurement set.

Back to Top | Article Outline

Other Considerations

There was a discussion about the importance of economic analyses in clinical trials for WAD. The committee recommended that an economic or cost-effectiveness analysis is a critical component of phase III and IV trials. However, the committee agreed that economic evaluations should not be included in Phase I and II trials.

Discussion was also held around the acute versus chronic stages of WAD and whether the different outcome measures should be recommended on the basis of time frame after injury. For discussion purposes, the IASP definition of chronic pain as persistent or recurrent pain lasting >3 months was used.46 It was agreed that the core domains recommended by the committee are relevant for both acute and chronic WAD and that no differentiation between recovery stages was made.

The management of patients with WAD often occurs in an environment where health and compensation systems intersect. Compensation systems vary greatly between jurisdictions, for example, “no fault” schemes versus “tort-based” schemes with evidence indicating that compensation-related factors can influence health outcomes.47 The committee agreed that clinical trials for WAD should specify and describe the nature of the compensation and/or health system in which the jurisdiction operates.

This is the first study to identify core outcome domains for use in clinical trials of WAD. Strengths include a previously developed and published protocol, methods that follow recommendations of COMET, and being consistent with other initiatives including IMMPACT and OMERACT. We included international, multidisciplinary, and multistakeholder participants in both the Delphi surveys and the consensus meeting. There are several limitations to our study. Response rates of patients and insurers in each Delphi round was low, which could have led to an underestimation or overestimation of the importance of certain domains. However, despite this, the response from these stakeholder groups was in line with the other groups. Furthermore, the primary objective of this study was to develop a core set for inclusion for all clinical trials, and not to develop a comprehensive set of domains important to all stakeholders. In addition, all of our insurer and patient participants were from Australia and may not be representative of the views of these stakeholders in other countries. Nevertheless, these participant groups were from the 3 largest states—New South Wales, Queensland, and Victoria, where different insurance schemes operate. Queensland and New South Wales are tort-based and fault-based systems, respectively, whereas Victoria operates under a “no fault” system; hence, we do have views from the 2 main types of compulsory third-party schemes.

Following this study, the next step of the development of COS for clinical trials on WAD is to determine the measurement instruments for each of these domains. Selection of outcome measurement instruments will be guided by the published methodological guideline.9

Back to Top | Article Outline

REFERENCES

1. Vos T, Allen C, Arora M, et al. Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries: a systematic analysis for the Global Burden of Disease Study 2015. Lancet. 2015;388:1545–1602.
2. Connelly L, Supangan R. The economic costs of road traffic crashes: Australia, staes and territories. Accid Anal Prev. 2006;38:1087–1093.
3. Anstey R, Kongsted A, Kamper S, et al. Are people with whiplash-associated neck pain different from people with nonspecific neck pain? J Orthop Sports Phys Ther. 2016;46:894–901.
4. Sarrami P, Armstrong E, Naylor JM, et al. Factors predicting outcome in whiplash injury: a systematic meta-review of prognostic factors. J Orthop Traumatol. 2017;18:9–16.
5. Walton D, Macdermid J, Giorgianni A, et al. Risk factors for persistent problems following acute whiplash injury: update of a systematic review and meta-analysis. J Orthop Sports Phys Ther. 2013;43:31–43.
6. Meeus M, Nijs J, Hamers V, et al. The efficacy of patient education in whiplash associated disorders: a systematic review. Pain Physician. 2012;15:351–361.
7. Wiangkham T, Duda J, Haque S, et al. The effectiveness of conservative management for acute whiplash associated disorder (WAD) II: a systematic review and meta-analysis of randomised controlled trials. PLoS ONE. 2015;10:e0133415.
8. Williamson PR, Altman DG, Blazeby JM, et al. Developing core outcome sets for clinical trials: issues to consider. Trials. 2012;13:132.
9. Prinsen CA, Vohra S, Rose MR, et al. How to select outcome measurement instruments for outcomes included in a “Core Outcome Set”—a practical guideline. Trials. 2016;17:449.
10. Tugwell P, Boers M, Brooks P, et al. OMERACT: an international initiative to improve outcome measurement in rheumatology. Trials. 2007;8:38.
11. Dworkin RH, Turk DC, Farrar JT, et al. Core outcome measures for chronic pain clinical trials: IMMPACT recommendations. Pain. 2005;113:9–19.
12. Turk DC, Dworkin RH, Allen RR, et al. Core outcome domains for chronic pain clinical trials: IMMPACT recommendations. Pain. 2003;106:337–345.
13. Buchbinder R, Page MJ, Huang H, et al. A preliminary core domain set for clinical trials of shoulder disorders: a report from the OMERACT 2016 Shoulder Core Outcome Set Special Interest Group. J Rheumatol. 2017;44:1880–1883.
14. Ramiro S, Page MJ, Whittle SL, et al. The OMERACT core domain set for clinical trials of shoulder disorders. J Rheumatol. 2019. [Epub ahead of print].
15. Chiarotto A, Deyo RA, Terwee CB, et al. Core outcome domains for clinical trials in non-specific low back pain. Eur Spine J. 2015;24:1127–1142.
16. Chiarotto A, Boers M, Deyo RA, et al. Core outcome measurement instruments for clinical trials in nonspecific low back pain. Pain. 2018;159:3.
17. Laxe S, Zasler N, Selb M, et al. Development of the International Classification of Functioning, Disability and Health core sets for traumatic brain injury: an International consensus process. Brain Inj. 2013;27:379–387.
18. Roe C, Bautz-Holter E, Cieza A. Low back pain in 17 countries, a Rasch analysis of the ICF core set for low back pain. Int J Rehabil Res. 2013;36:38–47.
19. Scott D, Jull G, Sterling M. Widespread sensory hypersensitivity is a feature of chronic whiplash-associated disorder but not chronic idiopathic neck pain. Clin J Pain. 2005;21:175–181.
20. Maujean A, Carroll L, Curatolo M, et al. A core outcome set for clinical trials in whiplash associated disorders (WAD): a study protocol. Trials. 2018;19:635.
21. Spitzer W, Skovron M, Salmi L, et al. Scientific Monograph of Quebec Task Force on Whiplash Associated Disorders: redefining “Whiplash” and its management. Spine. 1995;20(suppl 8):1–73.
22. Boers M, Idzerda L, Kirwan JR, et al. Toward a generalized framework of core measurement areas in clinical trials: a position paper for OMERACT 11. J Rheumatol. 2014;41:978–985.
23. Sinha IP, Smyth RL, Williamson PR. Using the Delphi technique to determine which outcomes to measure in clinical trials: recommendations for the future based on a systematic review of existing studies. PLoS Med. 2011;8:e1000393.
24. Williamson PR, Altman DG, Bagley H, et al. The COMET Handbook: version 1.0. Trials. 2017;18(suppl 3):280.
25. Wylde V, MacKichan F, Bruce J, et al. Assessment of chronic post-surgical pain after knee replacement: development of a core outcome set. Eur J Pain. 2015;19:611–620.
26. Kamper S, Ostelo R, Knol D, et al. Global perceived effect scales provided reliable assessments of health transition in people with musculoskeletal disorders, but ratings are strongly influenced by current status. J Clin Epidemiol. 2010;63:760–766.
27. Maujean A, Sterling J, Sterling M. What information do patients need following a whiplash injury? The perspectives of patients and physiotherapists. Disabil Rehabil. 2018;40:1135–1141.
28. Walton DM, Macdermid JC, Taylor T. What does ‘recovery’ mean to people with neck pain? Results of a descriptive thematic analysis. Open Orthop J. 2013;7:420–427.
29. Kelly GA, Blake C, Power CK, et al. The association between chronic low back pain and sleep: a systematic review. Clin J Pain. 2011;27:169–181.
30. Valenza MC, Valenza G, Gonzalez-Jimenez E, et al. Alteration in sleep quality in patients with mechanical insidious neck pain and whiplash-associated neck pain. Am J Phys Med Rehabil. 2012;91:584–591.
31. Middel B, Stewart R, Bouma J, et al. How to validate clinically important change in health-related functional status. Is the magnitude of the effect size consistently related to magnitude of change as indicated by a global question rating? J Eval Clin Pract. 2001;7:399–410.
32. Soderlund A, Nordgren L, Sterling M, et al. Exploring patients’ experiences of the whiplash injury-recovery process—a meta-synthesis. J Pain Res. 2018;11:1263–1271.
33. Craig A, Tran Y, Guest R, et al. Psychological impact of injuries sustained in motor vehicle crashes: systematic review and meta-analysis. BMJ Open. 2016;6:e011993.
34. Sterling M, Hendrikz J, Kenardy J. Similar factors predict disability and PTSD trajectories following whiplash injury. Pain. 2011;152:1272–1278.
35. Sullivan M, Adams H, Martel M, et al. Catastrophizing and perceived injustice: risk factors for the transition to chronicity after whiplash injury. Spine. 2011;36:s244–s249.
36. de Jong JR, Vangronsveld K, Peters ML, et al. Reduction of pain-related fear and disability in post-traumatic neck pain: a replicated single-case experimental study of exposure in vivo. J Pain. 2008;9:1123–1134.
37. Phillips L, Carroll L, Cassidy D, et al. Whiplash-associated disorders: who gets depressed? Who stays depressed? Eur Spine J. 2010;19:945–956.
38. Carlesso LC, Walton DM, MacDermid JC. Reflecting on whiplash associated disorder through a QoL lens: an option to advance practice and research. Disabil Rehabil. 2012;34:1131–1139.
39. Kuyken W, Orley JKuyken W, Orley J. The Development of the World Health Organisation Quality of Life Assessment Instrument (the WHOQOL). Quality of Life Assessment: International Perspectives, Vol 53. Berlin, Germany: Springer; 1994:41–57.
40. Hoving JL, O’Leary EF, Niere KR, et al. Validity of the Neck Disability Index, Northwick Park Neck Pain Questionnaire, and problem elicitation technique for measuring disability associated with whiplash-associated disorders. Pain. 2003;102:273–281.
41. Grieve S, Perez R, Birklein F, et al. Recommendations for a first Core Outcome Measurement set for complex regional PAin syndrome Clinical sTudies (COMPACT). Pain. 2017;158:1083–1090.
42. Rydstad M, Schult ML, Lofgren M. Whiplash patients’ experience of a multimodal rehabilitation programme and its usefulness one year later. Disabil Rehabil. 2010;32:1810–1818.
43. Walton D. A review of the definitions of ‘recovery’ used in prognostic studies on whiplash using an ICF framework. Disabil Rehabil. 2009;31:943–957.
44. Sterling M, Pedler A. A neuropathic pain component is common in acute whiplash and associated with a more complex clinical presentation. Man Ther. 2009;14:173–179.
45. Dunn KM, Croft PR. Classification of low back pain in primary care: using “bothersomeness” to identify the most severe cases. Spine (Phila Pa 1976). 2005;30:1887–1892.
46. Treede R-D, Rief W, Barke A, et al. A classification of chronic pain for ICD-11. Pain. 2015;156:1003–1007.
47. Murgatroyd DF, Casey PP, Cameron ID, et al. The effect of financial compensation on health outcomes following musculoskeletal injury: systematic review. PLoS ONE. 2015;10:e0117597.
Keywords:

whiplash; outcome; domains; neck; pain

Supplemental Digital Content

Back to Top | Article Outline
Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.