Understanding Functioning and Health in Patients with Whiplash-Associated Disorders M.A. Schmitt Understanding Functioning and Health in Patients with Whiplash-Associated Disorders PhD Thesis, Utrecht University, the Netherlands ISBN © 2010, M.A.Schmitt © Artwork cover design: Manon Schmitt Printed by: Understanding Functioning and Health in Patients with Whiplash-Associated Disorders Functionele Gezondheid na een Whiplash Trauma (met een samenvatting in het Nederlands) Proefschrift ter verkrijging van de graad van doctor aan de Universiteit Utrecht op gezag van de rector magnificus, prof. dr. J.C. Stoof, ingevolge het besluit van het college voor promoties in het openbaar te verdedigen op dinsdag 26 januari 2010 des middags te 2.30 uur door Martinus Adreanus Schmitt geboren op 28 februari 1956 te Tilburg Promotoren: Prof. dr. P. J. M. Helders Prof. dr. Y. van der Graaf Co-promotoren: Dr. N. L. U. van Meeteren Dr. A. de Wijer Inhoudsopgave 1. General Introduction 2 2. Defining Functioning and Health of People with Whiplash- Associated Disorders; the use of a Conceptual Framework 18 3. Multidimensional Measurement in Patients with Whiplash- Associated Disorders 38 a. Validation of the Dutch Language Version of the Neck Bournemouth Questionnaire in a population with sub acute and chronic whiplash associated disorders 40 b. Content Validity of the Dutch Version of the Neck Bournemouth Questionnaire in a population with sub acute and chronic whiplash associated disorders 72 4. Development of a preliminary Core Set for Measuring Functional Health in Patients with Whiplash Associated Disorders: a Delphi Study 92 5. Measurement in patients with Whiplash Associated Disorders: the development of the Whiplash specific Activity and participation List (WAL) 114 6. Relationship between Clinical and Psychological Factors and Functional Health Status in Patients with chronic Whiplash Associated Disorders 136 7. Functional health status in subjects after a motor vehicle accident, with emphasis on whiplash associated disorders. Design of a descriptive, prospective inception cohort study 160 8. General Discussion 180 9. Summary 206 10. Nederlandse samenvatting 214 11. Curriculum Vitae 222 12. Dankwoord 226 1 1 General Introduction General Introduction 3 Chapter 1 Whiplash Associated Disorders The social and financial consequences of a minor injury to the cervical spine, frequently referred to as whiplash-associated disorders (WAD), are considerable.1 The Quebec Task Force on Whiplash-Associated Disorders defined whiplash as “an acceleration-deceleration mechanism of energy transfer to the neck which may result in bony or soft tissue injuries”. 2 In the past, whiplash injury was described in relation to car collisions, especially rear-end collisions, but nowadays a specific injury mechanism is no longer considered a prerequisite, and neck strain subsequent to any kind of accident is referred to as minor injury to the cervical spine. 3 WAD are considered a multidimensional process involving physical, affective, cognitive, and social aspects. 4 In the acute stage, the cardinal manifestation of whiplash injury is neck pain, attributed to soft-tissue injuries of the cervical region. 5,6 The mean recovery time varies between 17 and 262 days. 7 Late whiplash syndrome is present by definition when patients still have symptoms after 6 months. 8-10 The late whiplash syndrome comprises various disabling symptoms, including radiating pain in the upper limb, fatigue, concentration difficulties, dizziness, visual and auditory symptoms, emotional disturbances (anxiety, depression, general irritability, poor coping strategies, low self-efficacy beliefs), and high levels of disability. 11-13 Residual symptoms are more prevalent among individuals with a high initial pain intensity, decreased cervical range of motion, a high number of complaints, psychological and psychosocial factors, and crash related factors. 14 4 General Introduction Frequency of reported minor injuries to the cervical spine, whiplash-associated disorders, and costs When reporting on the frequency of minor injuries to the cervical spine, and WAD, it is important to distinguish between medical reports, governmental reports, and insurance company reports as sources of data. In most countries, minor injuries of the cervical spine and their medical consequences are not systematically registered. Moreover, differences in registration models and terminology make it difficult to compare data, which makes it difficult to describe general trends in the frequency of such disorders. The incidence of WAD varies worldwide, ranging from 39 per 100,000 inhabitants in Australia, 4 to 70 per 100,000 inhabitants in Quebec, Canada, 2 and 123 per 100,000 in the Netherlands (as reported in 2008).3 In Sweden, whiplash injuries accounted for approximately 60% of the injuries due to vehicle crashes that resulted in disability in the period 1990 - 1995. 6 Of all patients (400,000-600,000) with WAD in the Netherlands, 22.7% are aged 20-30 years, 13.3% are aged 31-35 years, 14.7% are 36-40 aged, and 9.7% are older than 50 years.15 Over the past 10 years, insurance companies have noticed an increase in the reporting of minor cervical spine injuries and their associated costs. 3 In some European countries the changes are associated with an increased incidence of minor cervical spine injury leading to higher costs, whereas in other countries changes relating to claims frequencies for minor cervical spine injury have not been recorded. The Comité Européen des Assurances (CEA) and the Association for the Study and Compensation of Bodily Injury (AREDOC) carried out a study of the incidence and cost of minor cervical spine injury in ten European countries, in order to assess patterns of trauma incidence and related expenditure in different countries. 16 Data of this study are summarized in Table I. 5 Chapter 1 Table I: Number of inhabitants, number of bodily injuries and claimed costs, based on data of 10 European countries Country Number Total Number Number Costs of Costs of Average costs (x 1000) of number (x 1000) (x 1000) of bodily claims related per claim inhabitants (x 1000) of of bodily claims linked injuries in € to cervical related to in 2003 and Motor injuries to minor injury in € (%) minor cervical vehicles on Liability (%) cervical injury injury in € the road in claims (%) 2002 (bodily and material) Belgium 10310/ 5737 420 50 (12) Not known 1.4 billion Not known Not known Switzerland 7316/ 4808 300 30 (10) 10 (33) 860 million 350 million 35000 (40) Germany 82433/ 3960 424 (10.7) 200 (47) 5346 billion 500 million (9) 2500 53306 Spain 40683/ 2320 250 (10.8) 80 (32) 2199 billion Not known Not known 25066 Finland 5220/ 3980 89 12 (13) 1 (8.5) 190 million 1.5 million 1500 (.78) France 59637/ 2500 225 (9) 6.5 (3) 3950 billion 19.75 million 2625 35396 (40) Italy 57321/ 4700 846 (18) 558 (66) 748 billion 2393 million 4288 42107 (32.6) Netherlands 16195/ 8389 600 48 (8) 19 (40) 800 million 320 million 16500 (40) Norway 4528/ 2752 165 15 (9.1) 8 (53) 121 million 48 million (40) 6050 United 59088/ 2900 493 (17) 375 (76) 2159 billion 108 billion 2878 Kingdom 30403 (50) Source: Comité Européen des Assurances (CEA) 16 Bodily injuries account for between 8% (in the Netherlands) and 18% (in Italy) of all insurance claims, i.e., including both bodily injuries and property damage. 17 Minor cervical spine injuries account for between 3% (in France) and 76% (in Great Britain) of all bodily injuries, with a mean of 40% over the ten countries studied.17 In terms of percentage of total expenditure for personal damage, expenditure for minor cervical spine injuries is the highest in Great Britain where it reaches a value of 50%. In Switzerland, the Netherlands and, Norway 40% of total expenditure relates to minor cervical spine injury, whereas in Italy this value is about 33%. 16 The countries with the lowest expenditure for minor cervical spine injury are France (0.5%), Finland (0.78%) and Germany (9%). 16 In the participating countries, the average cost for minor cervical spine injury as a subdivision of all bodily injuries is 27%. 16 With an average of €35,000 Switzerland has the highest cost per claim followed by the Netherlands (€16,500) and Norway (€6,050). 16 The 6 General Introduction countries with the lowest average cost per claim are Finland (€1,500), Germany (€2,500), France (€2,625) and Great Britain (€2,878). 16 The average cost for all participating countries is slightly less than €9,000. 3 Explanations of Whiplash-Associated Disorders There is considerable debate among clinicians and researches about explanations of WAD following minor injuries to the cervical spine. 18, 19 Several theories attempt to explain chronic WAD as a consequence of physical damage resulting from the acute injury. 20 In most cases, patients have either grade I or grade II WAD as described by the Quebec Task Force meaning that the tissue damage of the cervical spine is minimal, if present. 20 Clinicians are frequently challenged by patients with severe physical, psychological and neuropsychological symptoms after a minor injury to the cervical spine, whereas many car crash victims are able to function effectively within several days after the accident, without any functional limitations. Such contrasts in functional consequences of minor injuries to the cervical spine suggest that the clinical picture of patients with WAD cannot be explained by tissue damage alone. The level of clinical signs and symptoms may be influenced by factors beyond the cervical tissue damage itself. Examples of non-disorder factors include patient’s physiological status, socio-cultural background, type of work performance, and severity of coexistent conditions.21, 22 It is unclear which of these factors contributes the most to the development of chronic WAD and it remains unclear what the contribution is of the (potential) cervical tissue damage. 12, 21 The concepts of functioning and health Terminological overlap and confusion characterize the field of functioning and health concepts.