- Email: [email protected]
Is It Time for a Population Health Approach to Neck Pain?
LITERATURE REVIEW—PUBLIC HEALTH IS IT TIME FOR NECK PAIN?
A
POPULATION HEALTH APPROACH
TO
J. David Cassidy, DC, PhD, DrMedSc, and Pierre Côté, DC, PhD
ABSTRACT Objective: Neck pain and its associated disorders (NPAD) cause significant health burden in the general population and after road traffic and occupational injury. Individual-level health care treatments have been well studied, but populationhealth approaches to this problem have not. We used a best-evidence synthesis to examine population-level approaches to the prevention and control of NPAD. Methods: The systematic review examined studies published between 1980 and 2006 that addressed the incidence, prevalence, risk factors, prevention, cost, assessment and classification, interventions, and course and prognostic factors for NPAD. Citations were screened for relevance, scientifically reviewed, and synthesized. Valid studies addressing public policies or population-level approaches to the prevention and control of NPAD were identified and used in the evidence synthesis. Results: Only 8 of the 552 scientifically admissible studies were considered relevant to a public or population health approach to preventing and controlling the burden of NPAD. For whiplash-associated disorders, active head restraints and seat backs were protective in rear-end collisions; insurance policies affected the incidence and recovery; government funding of multidisciplinary rehabilitation programs did not benefit recovery; and early intensive health care delayed recovery. In the workplace, 2 randomized trials failed to show any preventive effect for ergonomic interventions or physical training and stress management. One study documented the societal cost of neck pain. Conclusions: There is little evidence on which to make public or population-level recommendations, despite the important public health burden and costs of NPAD. Population-level approaches to preventing and controlling NPAD should be investigated. (J Manipulative Physiol Ther 2008;31:442-446) Key Indexing Terms: Public Health; Neck Pain; Prevention and Control; Health Policy
Centre of Research Expertise for Improved Disability Outcomes (CREIDO), Toronto Western Hospital, Toronto, Ontario, Canada. Division of Health Care and Outcomes Research, University Health Network, Toronto, Ontario, Canada. Department of Public Health Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada. Department of Health Policy, Management and Evaluation, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada. Dr Cassidy is supported in part by a Centre of Research Expertise grant from the Ontario Workplace Safety and Insurance Board. Dr Côté is supported by a New Investigator Award from the Canadian Institutes of Health Research. Submit requests for reprints to: J. David Cassidy, DC, PhD, DrMedSc, Toronto Western Hospital, Toronto, Ontario, Canada (e-mail: [email protected]). Paper submitted June 6, 2008; in revised form June 6, 2008; accepted June 12, 2008. 0161-4754/$34.00 Copyright © 2008 by National University of Health Sciences. doi:10.1016/j.jmpt.2008.06.008
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eck pain is a common, persistent, and recurrent ailment that is associated with considerable disability and cost to society.1-6 For the most part, neck pain and its associated disorders (NPAD), which include headache, arm pain, thoracic backache, and temporomandibular pain, have been managed at the level of the individual patient. 7 However, this approach has not alleviated the societal burden of neck pain because clinical interventions have little effect over the long-term (natural history) and neck pain is highly recurrent and persistent.8,9 Although individual patient care may produce meaningful benefits for individuals with acute neck pain, the average effect sizes are too small and short-lasting to justify the widespread introduction of any particular treatment service as a matter of public policy or prevention. In addition, some treatments can have iatrogenic effects over the long-term, even though they may be helpful in managing individual episodes of NPAD over the short-term.10,11
N
Journal of Manipulative and Physiological Therapeutics Volume 31, Number 6
Fig 1. Shifting the population distribution of the severity of neck pain.
Risk, prognostic, and illness-related factors that have considerable impact on health are often socially influenced, and individually tailored treatment is unlikely to address this.12-14 Moreover, modification of the community environment (physical, social, psychosocial, economic, and legal/ regulatory) could produce more efficient long-term population health gains than individually targeted interventions.15 For example, a 3-year media campaign in Victoria, Australia, was able to alter community and practitioner beliefs about back pain and produce a marked reduction in workers' compensation claims, number of disability days, and payments for medical care.16 A recent survey in Canada confirmed that public beliefs about back pain are not always in harmony with current scientific evidence.17 Population-level health interventions are targeted at communities and are intended to promote or protect the public's health. They may be targeted at health beliefs and behaviors, or public policies and regulations. They are designed to make small shifts in the distribution of illness frequency or severity across the entire population (Fig 1). If a disease is highly prevalent, persistent, and recurrent, then small shifts in its overall distribution of severity or prevalence can result in large overall health gains at the population level. The Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders completed a systematic review and best-evidence synthesis on the scientific evidence addressing the incidence, prevalence, risk, prognosis, diagnosis, and intervention for neck pain. The purpose of this paper was to synthesize the accepted studies from the task force review that could inform a population-level approach to NPAD.
METHODS Details of our best-evidence synthesis methods have been recently published.18 Briefly, the Task Force searched Medline between 1980 and 2006, and included seminal papers published before 1980 (eg, papers brought to our attention by content experts and those consistently cited in the modern literature). They included English, French, and
Cassidy and Côté Population Approach to Neck Pain
Swedish reports published in journals, systematic reviews, conference proceedings, technical reports, unpublished manuscripts, and books. Only reports relevant to neck pain with or without its associated disorders (eg, radiating arm pain, upper thoracic pain, headache, and temporomandibular joint pain) were selected for review. These reports had to contain scientific data concerning incidence, risk factors, prevalence, prevention, diagnosis, intervention, prognosis, natural history, or economic cost. They also reviewed relevant systematic reviews and guidelines. They excluded cases series, unless they were judged to be of special interest with respect to complications of care or surgery, and they excluded simulation studies, cadaver and animal studies, and studies with less than 20 human subjects with neck pain or at risk for neck pain. They did not review papers on pathologic neck pain (eg, fracture, dislocation, tumor, skin lesions, throat disorders, inflammatory disorders, cervical myelopathy, infectious diseases, or spinal cord injury). We did not review opinion papers, but did search the reference lists of all papers for relevant studies. Each study was reviewed for relevance and then systematically reviewed for bias by rotating teams of task force members.19 The reviews assessed the scientific quality, with an emphasis on the study's internal validity and its clinical relevance. They used a priori criteria and computerized critical review forms, similar to the review forms used by the Québec Task Force on Whiplash Associated Disorders and the World Health Organization Collaborating Centre for Neurotrauma, Prevention, Management and Rehabilitation Task Force on Mild Traumatic Brain Injury.20,21 These criteria were used as a guide to identify methodological strengths and sources of bias, and to facilitate the Scientific Secretariat's discussions of the methodological and clinical features of the study. Review forms were programmed on a Microsoft Access database (Microsoft Corp, Redmond, Wash) and the reviews were completed electronically. Studies were judged as scientifically admissible for inclusion in the best-evidence synthesis or inadmissible in cases where the consensus of scientific judgment was that the study could not be accepted owing to biases and methodological flaws. If consensus could not be reached, the study was brought to a meeting of the Scientific Secretariat of the task force for discussion, and where necessary, the advice and expertise of our Advisory Committee members were sought. Where task force members were authors or coauthors of a paper, they were not present during the presentation and discussions of the study. Accepted studies were identified as relating to incidence, prevalence, risk, or prevention of NPAD;3,5,6 assessment issues related to neck pain;22 prognosis or course (natural history) of neck pain;23-25 intervention for neck pain;9,26 and economic costs of NPAD. Data from studies judged as scientifically admissible were abstracted into evidence tables relating to each of these topics, and evidence from these studies was synthesized in our reports. Some studies related to more than one topic and were included in more than one
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set of evidence tables. Finally, we identified accepted studies that dealt with neck pain at the population level or that provided evidence for population-level health policy approaches to the prevention and control of NPAD. We also canvassed opinions on this topic from members of the task force. This was accomplished at several discussions and debates of the scientific secretariat of the task force and a discussion at the last meeting of the full task force.
RESULTS After applying selection criteria, 1203 studies were identified as relevant to the Task Force mandate and were subjected to the critical review process. Of these, 552 (46%) were accepted as scientifically admissible and informed their best evidence synthesis. The breakdown of critically appraised studies by topic area, and the number rated as admissible, is reported in Table 1.18 Some studies related to more than one topic area. Only 8 accepted studies were identified as having been conducted at the population level and/or having population-level health implications.10,11,27-33 Borghouts et al27 document the cost-of-illness of neck pain in The Netherlands in 1996. The total cost was estimated to be US$686 million, which represented approximately 1% of total health care expenditures and 0.1% of the gross domestic product of The Netherlands. Only 23% of costs were direct, and paramedical care (90% physical therapy) accounted for the greatest proportion at 84%. Disability accounted for the largest proportion (50%) of indirect costs at US$341 million. These costs are substantial and likely reflect the economic burden of neck pain in other developed countries. Traffic collisions are a source of neck pain and can lead to future health complaints, including chronic recurrent neck pain.34,35 The task force accepted 2 studies that observed insurance policy changes at the population level that impacted on whiplash-associated disorders (WAD). In the first study, a 28% reduction in the incidence of WAD occurred when insurance payments for pain and suffering were eliminated in the Canadian province of Saskatchewan.28 This included claims, as well as all those requiring treatment for their neck injury. In addition, there was a 54% decrease in the time-toclaim closure after this policy change. Further analyses of this cohort showed that claim closure times were highly associated with prior improvements in pain, physical functioning, and depression.36 Two additional analyses from this database showed that the type and intensity of clinical care influence how populations recover from acute WAD.11,29 Compared to minimal general practitioner care (1-2 visits in the first month after the injury) or low utilization chiropractic care (1-6 visits in the first month after the injury), higher utilization medical care and/or chiropractic care was associated with substantial delays in recovery that were not explained by injury severity or other factors. In a second population-based cohort study, the effect of a new province-wide government policy of funding rehabilita-
Journal of Manipulative and Physiological Therapeutics July/August 2008
Table 1. Summary of reviewed and accepted studies by area of interest18
Area of interest
Studies reviewed in area
Number accepted (%)
Risk Diagnosis Prognosis Intervention Economic costs Total
469 274 226 359 14 1342 ⁎
249 (53%) 95 (35%) 70 (31%) 170 (47%) 13 (93%) 597 (45%)
⁎ The task force reviewed 1203 studies, some of which related to more than one area of interest.
tion services for WAD was documented.10 When compared to the usual insured practitioner care, specialized rehabilitation services that included fitness training and multidisciplinary inpatient and outpatient rehabilitation programs did not benefit recovery from WAD. In essence, this study tested implementing the Québec Task Force recommendations at the population level.21 These results demonstrate the importance of evaluating the effect of guideline recommendations generated from systematic reviews of intervention studies (ie, randomized controlled trials) at the population level.14,15 Prevention of WAD is an important issue, and the introduction of headrests on passenger seats in the 1970s was an important countermeasure to limit sprain and strain to the cervical spine from rear-end collisions.37 The Neck Pain Task Force accepted 2 studies observing the effect of headrests on WAD claims from the United States.6 The first study suggests that headrests protect female, but not male, drivers from WAD.30 The second study showed that recently redesigned active head restraints, which decrease the distance between the back of the head and the headrest, are associated with a decrease in neck injury claims.31 The greatest effect was attributed to movable head restraints and seats that close this gap during the collision, followed by those that have improved geometry to narrow this distance. The task force accepted 2 studies that addressed prevention of work-related neck pain that could be used to inform occupational health policies about prevention.3 Gerr et al32 examined the effect of postural and ergonomic interventions at computer workstations in a randomized controlled trial of prevention of neck pain and upper extremity musculoskeletal disorders. Compared to no intervention, there were no beneficial outcomes from interventions that improved sitting postures at workstations in 375 workers who used computer keyboards for more than 15 hours per week. Horneij et al33 examined the effect of a physical training and a stress management program for reducing or preventing neck and shoulder pain in female home-care nursing aids and assistants. These programs had no preventive effect.
DISCUSSION The Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders found little evidence to support public or population-level approaches to preventing
Journal of Manipulative and Physiological Therapeutics Volume 31, Number 6
and controlling the burden of NPAD. We did find evidence to suggest that commonly applied ergonomic and postural interventions were not helpful at the workplace, and that physical training and stress management could not prevent neck pain in nurses.3 In WAD, we found that insurance benefits, both medical and legal, can influence recovery from injury.25 We also found that modern headrests and seat backs can prevent WAD.6 The lack of population level research on neck associated disorders is disappointing, but also creates an opportunity to explore a different approach to the prevention and control of NPAD.38 It is important that public health policies promote prevention and recovery from neck pain and not create incentives for illness behavior or inappropriate and excessive individual care. Studies from the Canadian province of Saskatchewan have shown that the removal of payments for pain and suffering for whiplash injury resulted in a substantial decline in number of persons seeking care and substantial improvement in recovery times.28,36 In addition, ongoing early and intense clinical care and rehabilitation were shown to delay recovery.10,11 We need more research on fair and equitable injury compensation policies that promote recovery, rather than promote disability and inappropriate patterns of care. It is important to take an evidence-based approach to population health promotion and policy making.14 However, it is not always possible or practical to undertake randomized controlled trials at the population level.12,15,39 Well-designed observational studies can suggest answers at this level and test the effectiveness of interventions from randomized controlled trials and clinical guidelines at the population level.10,15 We think researchers and public policy makers should look carefully at the results of our best evidence syntheses and use them to inform future initiatives. Rather than repeating similar intervention studies, we need to test innovative approaches addressing risk and prognostic factors, including social policies and health promotion strategies that affect NPAD in populations.38 Our focus on individual patient care alone is not likely to impact on the societal burden of NPAD. There are strengths and weaknesses to this review. The Task Force undertook a comprehensive review and synthesis of the NPAD literature. However, there were few studies focused on a population health approach to the problem to inform our discussions. Furthermore, we did not expand the review beyond the mandate of NPAD to review population health strategies in other health disorders.38,40 However, the Task Force did rigorously review and synthesize the scientific literature on the prevalence, incidence, risk, prevention, prognosis, diagnosis, and treatment of NPAD, and from that vantage point, we considered this issue.
CONCLUSION The Task Force published a new conceptual model of NPAD that includes societal considerations. We recommend that the research community, clinicians, and public health
Cassidy and Côté Population Approach to Neck Pain
policy makers begin to exchange knowledge to collaborate on population-level initiatives to address the burden of NPAD. We need novel and creative alternatives to the status quo. In fact, good health policies should compliment and even improve the effectiveness of delivery of individual patient care. We recommend an effort be made to conduct research at the population health level to explore methods to prevent and control these disorders.
Practical Applications • Neck pain and its associated disorders are common in society and represent a significant health burden and cost. • Individual-level health care treatments have not controlled this problem. • There have been few scientific studies of population-level interventions or prevention programs for neck pain and their associated disorders. • Automotive seat and head rest design, injury insurance policies, and government funding of rehabilitation programs can affect WAD incidence and recovery. • We recommend new research efforts be directed toward a population health and public policy approaches to preventing and controlling the health burden of NPAD.
ACKNOWLEDGMENT The authors would like to acknowledge the assistance of the members of the Decade of the Bone and Joint 2000-2010 Task Force on Neck Pain and Its Associated Disorders.
REFERENCES 1. Côté P, Cassidy JD, Carroll L. The Saskatchewan Health and Back Pain Survey. The prevalence of neck pain and related disability in Saskatchewan adults. Spine 1998;23:1689-98. 2. Côté P, Cassidy JD, Carroll L. The factors associated with neck pain and its related disability in the Saskatchewan population. Spine 2000;25:1109-17. 3. Côté P, van der Velde G, Cassidy JD, Carroll LJ, Hogg-Johnson S, Holm LW, et al. The burden and determinants of neck pain in workers: results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Spine 2008; 33:S60-74. 4. Côté P, Kristman V, Vidmar M, Van Eerd D, Hogg-Johnson S, Beaton D, et al. The prevalence and incidence of work absenteeism involving neck pain: a cohort of Ontario lost-time claimants. Spine 2008;33:S192-8. 5. Hogg-Johnson S, van der Velde G, Carroll LJ, Holm LW, Cassidy JD, Guzman J, et al. The burden and determinants of neck pain in the general population: results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Spine 2008;33:S39-51. 6. Holm LW, Carroll LJ, Cassidy JD, Hogg-Johnson S, Cote P, Guzman J, et al. The burden and determinants of neck pain in
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whiplash-associated disorders after traffic collisions: results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Spine 2008;33:S52-9. Côté P, Cassidy JD, Carroll L. The treatment of neck and low back pain: who seeks care? who goes where? Med Care 2001; 39:956-67. Côté P, Cassidy JD, Carroll LJ, Kristman V. The annual incidence and course of neck pain in the general population: a population-based cohort study. Pain 2004;112:267-73. Hurwitz EL, Carragee EJ, van der Velde G, Carroll LJ, Nordin M, Guzman J, et al. Treatment of neck pain: noninvasive interventions: results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Spine 2008;33:S123-52. Cassidy JD, Carroll LJ, Côté P, Frank J. Does multidisciplinary rehabilitation benefit whiplash recovery? results of a population-based incidence cohort study. Spine 2007;32:126-31. Côté P, Hogg-Johnson S, Cassidy JD, Carroll L, Frank JW, Bombardier C. Initial patterns of clinical care and recovery from whiplash injuries: a population-based cohort study. Arch Intern Med 2005;165:2257-63. Black N. Why we need observational studies to evaluate the effectiveness of health care. BMJ 1996;312:1215-8. Guzman J, Hurwitz EL, Carroll LJ, Haldeman S, Côté P, Carragee EJ, et al. A new conceptual model of neck pain: linking onset, course, and care: the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Spine 2008;33:S14-23. Heller RF, Page J. A population perspective to evidence based medicine: “evidence for population health”. J Epidemiol Community Health 2002;56:45-7. Wyatt M, Underwood MR, Scheel IB, Cassidy JD, Nagel P. Back pain and health policy research: the what, why, how, who, and when. Spine 2004;29:E468-75. Buchbinder R, Jolley D, Wyatt M. Population based intervention to change back pain beliefs and disability: three part evaluation. BMJ 2001;322:1516-20. Gross DP, Ferrari R, Russell AS, Battie MC, Schopflocher D, Hu RW, et al. A population-based survey of back pain beliefs in Canada. Spine 2006;31:2142-5. Carroll LJ, Cassidy JD, Peloso PM, Giles-Smith L, Cheng CS, Greenhalgh SW, et al. Methods for the best evidence synthesis on neck pain and its associated disorders: the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Spine 2008;33:S33-8. van der Velde G, vanTulder M, Côté P, Hogg-Johnson S, Aker P, Cassidy JD, et al. The sensitivity of review results to methods used to appraise and incorporate trial quality into data synthesis. Spine 2007;32:796-806. Carroll LJ, Cassidy JD, Holm L, Kraus J, Coronado VG. Methodological issues and research recommendations for mild traumatic brain injury: the WHO Collaborating Centre Task Force on Mild Traumatic Brain Injury. J Rehabil Med 2004:113-25. Spitzer WO, Skovron ML, Salmi LR, Cassidy JD, Duranceau J, Suissa S, et al. Scientific monograph of the Quebec Task Force on Whiplash-Associated Disorders: redefining qwhiplashq and its management. Spine 1995;20:1S-73S. Nordin M, Carragee EJ, Hogg-Johnson S, Weiner SS, Hurwitz EL, Peloso PM, et al. Assessment of neck pain and its associated disorders: results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Spine 2008;33:S101-22. Carroll LJ, Hogg-Johnson S, van der Velde G, Haldeman S, Holm LW, Carragee EJ, et al. Course and prognostic factors for neck pain in the general population: results of the Bone and
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Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Spine 2008;33:S75-S82. Carroll LJ, Hogg-Johnson S, Côté P, van der Velde G, Holm LW, Carragee EJ, et al. Course and prognostic factors for neck pain in workers: results of the Bone and Joint Decade 20002010 Task Force on Neck Pain and Its Associated Disorders. Spine 2008;33:S93-S100. Carroll LJ, Holm LW, Hogg-Johnson S, Côté P, Cassidy JD, Haldeman S, et al. Course and prognostic factors for neck pain in whiplash-associated disorders (WAD): results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Spine 2008;33:S83-92. Carragee EJ, Hurwitz EL, Cheng I, Carroll LJ, Nordin M, Guzman J, et al. Treatment of neck pain: injections and surgical interventions: results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Spine 2008;33:S153-69. Borghouts JA, Koes BW, Vondeling H, Bouter LM. Cost-ofillness of neck pain in The Netherlands in 1996. Pain 1999;80: 629-36. Cassidy JD, Carroll LJ, Côté P, Lemstra M, Berglund A, Nygren A. Effect of eliminating compensation for pain and suffering on the outcome of insurance claims for whiplash injury. N Engl J Med 2000;342:1179-86. Côté P, Hogg-Johnson S, Cassidy JD, Carroll L, Frank JW, Bombardier C. Early aggressive care and delayed recovery from whiplash: Isolated finding or reproducible result? Arthritis Rheum 2007;57:861-8. Farmer CM, Wells JK, Werner JV. Relationship of head restraint positioning to driver neck injury in rear-end crashes. Accid Anal Prev 1999;31:719-28. Farmer CM, Wells JK, Lund AK. Effects of head restraint and seat redesign on neck injury risk in rear-end crashes. Traffic Inj Prev 2003;4:83-90. Gerr F, Marcus M, Monteilh C, Hannan L, Ortiz D, Kleinbaum D. A randomised controlled trial of postural interventions for prevention of musculoskeletal symptoms among computer users. Occup Environ Med 2005;62:478-87. Horneij E, Hemborg B, Jensen I, Ekdahl C. No significant differences between intervention programmes on neck, shoulder and low back pain: a prospective randomized study among home-care personnel. J Rehabil Med 2001;33:170-6. Berglund A, Alfredsson L, Cassidy JD, Jensen I, Nygren A. The association between exposure to a rear-end collision and future neck or shoulder pain: a cohort study. J Clin Epidemiol 2000;53:1089-94. Berglund A, Alfredsson L, Jensen I, Cassidy JD, Nygren A. The association between exposure to a rear-end collision and future health complaints. J Clin Epidemiol 2001;54:851-6. Côté P, Hogg-Johnson S, Cassidy JD, Carroll L, Frank JW. The association between neck pain intensity, physical functioning, depressive symptomatology and time-to-claim-closure after whiplash. J Clin Epidemiol 2001;54:275-86. Nygren A. Injuries to car occupants–some aspects of the interior safety of cars. A study of a five-year material from an insurance company. Acta Otolaryngol Suppl 1984;395:1-164. Carroll LJ, Hurwitz EL, Côté P, Hogg-Johnson S, Carragee EJ, Nordin M, et al. Research priorities and methodological implications: the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Spine 2008;33:S214-20. Black N. What observational studies can offer decision makers. Horm Res 1999;51(Suppl 1):44-9. Haldeman S, Carroll LJ, Cassidy JD. The empowerment of people with neck pain: introduction: the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Spine 2008;33:S8-S13.
A
POPULATION HEALTH APPROACH
TO
J. David Cassidy, DC, PhD, DrMedSc, and Pierre Côté, DC, PhD
ABSTRACT Objective: Neck pain and its associated disorders (NPAD) cause significant health burden in the general population and after road traffic and occupational injury. Individual-level health care treatments have been well studied, but populationhealth approaches to this problem have not. We used a best-evidence synthesis to examine population-level approaches to the prevention and control of NPAD. Methods: The systematic review examined studies published between 1980 and 2006 that addressed the incidence, prevalence, risk factors, prevention, cost, assessment and classification, interventions, and course and prognostic factors for NPAD. Citations were screened for relevance, scientifically reviewed, and synthesized. Valid studies addressing public policies or population-level approaches to the prevention and control of NPAD were identified and used in the evidence synthesis. Results: Only 8 of the 552 scientifically admissible studies were considered relevant to a public or population health approach to preventing and controlling the burden of NPAD. For whiplash-associated disorders, active head restraints and seat backs were protective in rear-end collisions; insurance policies affected the incidence and recovery; government funding of multidisciplinary rehabilitation programs did not benefit recovery; and early intensive health care delayed recovery. In the workplace, 2 randomized trials failed to show any preventive effect for ergonomic interventions or physical training and stress management. One study documented the societal cost of neck pain. Conclusions: There is little evidence on which to make public or population-level recommendations, despite the important public health burden and costs of NPAD. Population-level approaches to preventing and controlling NPAD should be investigated. (J Manipulative Physiol Ther 2008;31:442-446) Key Indexing Terms: Public Health; Neck Pain; Prevention and Control; Health Policy
Centre of Research Expertise for Improved Disability Outcomes (CREIDO), Toronto Western Hospital, Toronto, Ontario, Canada. Division of Health Care and Outcomes Research, University Health Network, Toronto, Ontario, Canada. Department of Public Health Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada. Department of Health Policy, Management and Evaluation, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada. Dr Cassidy is supported in part by a Centre of Research Expertise grant from the Ontario Workplace Safety and Insurance Board. Dr Côté is supported by a New Investigator Award from the Canadian Institutes of Health Research. Submit requests for reprints to: J. David Cassidy, DC, PhD, DrMedSc, Toronto Western Hospital, Toronto, Ontario, Canada (e-mail: [email protected]). Paper submitted June 6, 2008; in revised form June 6, 2008; accepted June 12, 2008. 0161-4754/$34.00 Copyright © 2008 by National University of Health Sciences. doi:10.1016/j.jmpt.2008.06.008
442
eck pain is a common, persistent, and recurrent ailment that is associated with considerable disability and cost to society.1-6 For the most part, neck pain and its associated disorders (NPAD), which include headache, arm pain, thoracic backache, and temporomandibular pain, have been managed at the level of the individual patient. 7 However, this approach has not alleviated the societal burden of neck pain because clinical interventions have little effect over the long-term (natural history) and neck pain is highly recurrent and persistent.8,9 Although individual patient care may produce meaningful benefits for individuals with acute neck pain, the average effect sizes are too small and short-lasting to justify the widespread introduction of any particular treatment service as a matter of public policy or prevention. In addition, some treatments can have iatrogenic effects over the long-term, even though they may be helpful in managing individual episodes of NPAD over the short-term.10,11
N
Journal of Manipulative and Physiological Therapeutics Volume 31, Number 6
Fig 1. Shifting the population distribution of the severity of neck pain.
Risk, prognostic, and illness-related factors that have considerable impact on health are often socially influenced, and individually tailored treatment is unlikely to address this.12-14 Moreover, modification of the community environment (physical, social, psychosocial, economic, and legal/ regulatory) could produce more efficient long-term population health gains than individually targeted interventions.15 For example, a 3-year media campaign in Victoria, Australia, was able to alter community and practitioner beliefs about back pain and produce a marked reduction in workers' compensation claims, number of disability days, and payments for medical care.16 A recent survey in Canada confirmed that public beliefs about back pain are not always in harmony with current scientific evidence.17 Population-level health interventions are targeted at communities and are intended to promote or protect the public's health. They may be targeted at health beliefs and behaviors, or public policies and regulations. They are designed to make small shifts in the distribution of illness frequency or severity across the entire population (Fig 1). If a disease is highly prevalent, persistent, and recurrent, then small shifts in its overall distribution of severity or prevalence can result in large overall health gains at the population level. The Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders completed a systematic review and best-evidence synthesis on the scientific evidence addressing the incidence, prevalence, risk, prognosis, diagnosis, and intervention for neck pain. The purpose of this paper was to synthesize the accepted studies from the task force review that could inform a population-level approach to NPAD.
METHODS Details of our best-evidence synthesis methods have been recently published.18 Briefly, the Task Force searched Medline between 1980 and 2006, and included seminal papers published before 1980 (eg, papers brought to our attention by content experts and those consistently cited in the modern literature). They included English, French, and
Cassidy and Côté Population Approach to Neck Pain
Swedish reports published in journals, systematic reviews, conference proceedings, technical reports, unpublished manuscripts, and books. Only reports relevant to neck pain with or without its associated disorders (eg, radiating arm pain, upper thoracic pain, headache, and temporomandibular joint pain) were selected for review. These reports had to contain scientific data concerning incidence, risk factors, prevalence, prevention, diagnosis, intervention, prognosis, natural history, or economic cost. They also reviewed relevant systematic reviews and guidelines. They excluded cases series, unless they were judged to be of special interest with respect to complications of care or surgery, and they excluded simulation studies, cadaver and animal studies, and studies with less than 20 human subjects with neck pain or at risk for neck pain. They did not review papers on pathologic neck pain (eg, fracture, dislocation, tumor, skin lesions, throat disorders, inflammatory disorders, cervical myelopathy, infectious diseases, or spinal cord injury). We did not review opinion papers, but did search the reference lists of all papers for relevant studies. Each study was reviewed for relevance and then systematically reviewed for bias by rotating teams of task force members.19 The reviews assessed the scientific quality, with an emphasis on the study's internal validity and its clinical relevance. They used a priori criteria and computerized critical review forms, similar to the review forms used by the Québec Task Force on Whiplash Associated Disorders and the World Health Organization Collaborating Centre for Neurotrauma, Prevention, Management and Rehabilitation Task Force on Mild Traumatic Brain Injury.20,21 These criteria were used as a guide to identify methodological strengths and sources of bias, and to facilitate the Scientific Secretariat's discussions of the methodological and clinical features of the study. Review forms were programmed on a Microsoft Access database (Microsoft Corp, Redmond, Wash) and the reviews were completed electronically. Studies were judged as scientifically admissible for inclusion in the best-evidence synthesis or inadmissible in cases where the consensus of scientific judgment was that the study could not be accepted owing to biases and methodological flaws. If consensus could not be reached, the study was brought to a meeting of the Scientific Secretariat of the task force for discussion, and where necessary, the advice and expertise of our Advisory Committee members were sought. Where task force members were authors or coauthors of a paper, they were not present during the presentation and discussions of the study. Accepted studies were identified as relating to incidence, prevalence, risk, or prevention of NPAD;3,5,6 assessment issues related to neck pain;22 prognosis or course (natural history) of neck pain;23-25 intervention for neck pain;9,26 and economic costs of NPAD. Data from studies judged as scientifically admissible were abstracted into evidence tables relating to each of these topics, and evidence from these studies was synthesized in our reports. Some studies related to more than one topic and were included in more than one
443
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set of evidence tables. Finally, we identified accepted studies that dealt with neck pain at the population level or that provided evidence for population-level health policy approaches to the prevention and control of NPAD. We also canvassed opinions on this topic from members of the task force. This was accomplished at several discussions and debates of the scientific secretariat of the task force and a discussion at the last meeting of the full task force.
RESULTS After applying selection criteria, 1203 studies were identified as relevant to the Task Force mandate and were subjected to the critical review process. Of these, 552 (46%) were accepted as scientifically admissible and informed their best evidence synthesis. The breakdown of critically appraised studies by topic area, and the number rated as admissible, is reported in Table 1.18 Some studies related to more than one topic area. Only 8 accepted studies were identified as having been conducted at the population level and/or having population-level health implications.10,11,27-33 Borghouts et al27 document the cost-of-illness of neck pain in The Netherlands in 1996. The total cost was estimated to be US$686 million, which represented approximately 1% of total health care expenditures and 0.1% of the gross domestic product of The Netherlands. Only 23% of costs were direct, and paramedical care (90% physical therapy) accounted for the greatest proportion at 84%. Disability accounted for the largest proportion (50%) of indirect costs at US$341 million. These costs are substantial and likely reflect the economic burden of neck pain in other developed countries. Traffic collisions are a source of neck pain and can lead to future health complaints, including chronic recurrent neck pain.34,35 The task force accepted 2 studies that observed insurance policy changes at the population level that impacted on whiplash-associated disorders (WAD). In the first study, a 28% reduction in the incidence of WAD occurred when insurance payments for pain and suffering were eliminated in the Canadian province of Saskatchewan.28 This included claims, as well as all those requiring treatment for their neck injury. In addition, there was a 54% decrease in the time-toclaim closure after this policy change. Further analyses of this cohort showed that claim closure times were highly associated with prior improvements in pain, physical functioning, and depression.36 Two additional analyses from this database showed that the type and intensity of clinical care influence how populations recover from acute WAD.11,29 Compared to minimal general practitioner care (1-2 visits in the first month after the injury) or low utilization chiropractic care (1-6 visits in the first month after the injury), higher utilization medical care and/or chiropractic care was associated with substantial delays in recovery that were not explained by injury severity or other factors. In a second population-based cohort study, the effect of a new province-wide government policy of funding rehabilita-
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Table 1. Summary of reviewed and accepted studies by area of interest18
Area of interest
Studies reviewed in area
Number accepted (%)
Risk Diagnosis Prognosis Intervention Economic costs Total
469 274 226 359 14 1342 ⁎
249 (53%) 95 (35%) 70 (31%) 170 (47%) 13 (93%) 597 (45%)
⁎ The task force reviewed 1203 studies, some of which related to more than one area of interest.
tion services for WAD was documented.10 When compared to the usual insured practitioner care, specialized rehabilitation services that included fitness training and multidisciplinary inpatient and outpatient rehabilitation programs did not benefit recovery from WAD. In essence, this study tested implementing the Québec Task Force recommendations at the population level.21 These results demonstrate the importance of evaluating the effect of guideline recommendations generated from systematic reviews of intervention studies (ie, randomized controlled trials) at the population level.14,15 Prevention of WAD is an important issue, and the introduction of headrests on passenger seats in the 1970s was an important countermeasure to limit sprain and strain to the cervical spine from rear-end collisions.37 The Neck Pain Task Force accepted 2 studies observing the effect of headrests on WAD claims from the United States.6 The first study suggests that headrests protect female, but not male, drivers from WAD.30 The second study showed that recently redesigned active head restraints, which decrease the distance between the back of the head and the headrest, are associated with a decrease in neck injury claims.31 The greatest effect was attributed to movable head restraints and seats that close this gap during the collision, followed by those that have improved geometry to narrow this distance. The task force accepted 2 studies that addressed prevention of work-related neck pain that could be used to inform occupational health policies about prevention.3 Gerr et al32 examined the effect of postural and ergonomic interventions at computer workstations in a randomized controlled trial of prevention of neck pain and upper extremity musculoskeletal disorders. Compared to no intervention, there were no beneficial outcomes from interventions that improved sitting postures at workstations in 375 workers who used computer keyboards for more than 15 hours per week. Horneij et al33 examined the effect of a physical training and a stress management program for reducing or preventing neck and shoulder pain in female home-care nursing aids and assistants. These programs had no preventive effect.
DISCUSSION The Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders found little evidence to support public or population-level approaches to preventing
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and controlling the burden of NPAD. We did find evidence to suggest that commonly applied ergonomic and postural interventions were not helpful at the workplace, and that physical training and stress management could not prevent neck pain in nurses.3 In WAD, we found that insurance benefits, both medical and legal, can influence recovery from injury.25 We also found that modern headrests and seat backs can prevent WAD.6 The lack of population level research on neck associated disorders is disappointing, but also creates an opportunity to explore a different approach to the prevention and control of NPAD.38 It is important that public health policies promote prevention and recovery from neck pain and not create incentives for illness behavior or inappropriate and excessive individual care. Studies from the Canadian province of Saskatchewan have shown that the removal of payments for pain and suffering for whiplash injury resulted in a substantial decline in number of persons seeking care and substantial improvement in recovery times.28,36 In addition, ongoing early and intense clinical care and rehabilitation were shown to delay recovery.10,11 We need more research on fair and equitable injury compensation policies that promote recovery, rather than promote disability and inappropriate patterns of care. It is important to take an evidence-based approach to population health promotion and policy making.14 However, it is not always possible or practical to undertake randomized controlled trials at the population level.12,15,39 Well-designed observational studies can suggest answers at this level and test the effectiveness of interventions from randomized controlled trials and clinical guidelines at the population level.10,15 We think researchers and public policy makers should look carefully at the results of our best evidence syntheses and use them to inform future initiatives. Rather than repeating similar intervention studies, we need to test innovative approaches addressing risk and prognostic factors, including social policies and health promotion strategies that affect NPAD in populations.38 Our focus on individual patient care alone is not likely to impact on the societal burden of NPAD. There are strengths and weaknesses to this review. The Task Force undertook a comprehensive review and synthesis of the NPAD literature. However, there were few studies focused on a population health approach to the problem to inform our discussions. Furthermore, we did not expand the review beyond the mandate of NPAD to review population health strategies in other health disorders.38,40 However, the Task Force did rigorously review and synthesize the scientific literature on the prevalence, incidence, risk, prevention, prognosis, diagnosis, and treatment of NPAD, and from that vantage point, we considered this issue.
CONCLUSION The Task Force published a new conceptual model of NPAD that includes societal considerations. We recommend that the research community, clinicians, and public health
Cassidy and Côté Population Approach to Neck Pain
policy makers begin to exchange knowledge to collaborate on population-level initiatives to address the burden of NPAD. We need novel and creative alternatives to the status quo. In fact, good health policies should compliment and even improve the effectiveness of delivery of individual patient care. We recommend an effort be made to conduct research at the population health level to explore methods to prevent and control these disorders.
Practical Applications • Neck pain and its associated disorders are common in society and represent a significant health burden and cost. • Individual-level health care treatments have not controlled this problem. • There have been few scientific studies of population-level interventions or prevention programs for neck pain and their associated disorders. • Automotive seat and head rest design, injury insurance policies, and government funding of rehabilitation programs can affect WAD incidence and recovery. • We recommend new research efforts be directed toward a population health and public policy approaches to preventing and controlling the health burden of NPAD.
ACKNOWLEDGMENT The authors would like to acknowledge the assistance of the members of the Decade of the Bone and Joint 2000-2010 Task Force on Neck Pain and Its Associated Disorders.
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