Abstract
Objective The aim of the current review was to determine the predictive strength of low recovery expectations for activity limitation outcomes in people with non-chronic NSLBP. Methods A systematic review of prognostic studies was performed. Included studies took baseline measures in the non-chronic phase of NSLBP, included at least one baseline measure of recovery expectation, defined as a prediction or judgement made by the person with NSLBP regarding any aspect of prognosis, and studied a sample with at least 75% of participants with NSLBP. Results Recovery expectations measured using a time-based, specific single-item tool produced a strong prediction of work outcome. Recovery expectations measured within 3 weeks of NSLBP onset provide a strong prediction of outcome. It is not clear whether predictive strength of recovery expectations is affected by the length of time between the expectation measure and outcome measure. Conclusion Recovery expectations when measured using a specific, time-based measure within the first 3 weeks of NSLBP can identify people at risk of poor outcome.
References
Iles RA, Davidson M, Taylor NF. A systematic review of psychosocial predictors of failure to return to work in non-chronic non-specific low back pain. Occup Environ Med. 2008;65:507–17. doi:10.1136/oem.2007.036046.
Waddell G, Burton AK, Main CJ, editors. Screening to identify people at risk of long-term incapacity for work. London: Royal Society of Medicine Press Ltd; 2003.
Truchon M, Fillion L. Biopsychosocial determinants of chronic disability and low-back pain: a review. J Occup Rehabil. 2000;10:117–42. doi:10.1023/A:1009452019715.
Waddell G. The epidemiology of low back pain. The back pain revolution. 2nd ed. Edinburgh: Churchill Livingstone; 2004. p. 27–44.
Loisel P, Durand M, Berthelette D, et al. Disability prevention: new paradigm for the management of occupational back pain. Disease Manag Health Outcomes. 2001;9:351–60. doi:10.2165/00115677-200109070-00001.
Rutjes A, Reitsma J, Di Nisio M et al. Design related bias and sources of variation in diagnostic accuracy studies. 12th Cochrane Colloquium: bridging the gaps, 2004, Oct 2–6; 2004; Ottawa, 2004. p. 49–50.
WHO. Towards a common language for functioning, disability and health: ICF. 2002 [cited 23/11/2007]; Available from http://www.who.int/classifications/icf/site/beginners/bg.pdf.
Linton SJ, Gross D, Schultz IZ, et al. Prognosis and the identification of workers risking disability: research issues and directions for future research. J Occup Rehabil. 2005;15:459–74. doi:10.1007/s10926-005-8028-x.
McIntosh G, Frank J, Hogg-Johnson S, et al. Low back pain prognosis: structured review of the literature. J Occup Rehabil. 2000;10:101–15. doi:10.1023/A:1009450102876.
Hayden JA, Cote P, Bombardier C. Evaluation of the quality of prognosis studies in systematic reviews. Ann Intern Med. 2006;144:427–37.
Steenstra IA, Verbeek JH, Heymans MW, et al. Prognostic factors for duration of sick leave in patients sick listed with acute low back pain: a systematic review of the literature. Occup Environ Med. 2005;62:851–60. doi:10.1136/oem.2004.015842.
Babyak MA. What you see may not be what you get: a brief, nontechnical introduction to overfitting in regression-type models. Psychosom Med. 2004;66:411–21. doi:10.1097/01.psy.0000127692.23278.a9.
Garson DG. Mulitple regression. [cited 2007 15/10/07]; Available from http://www2.chass.ncsu.edu/garson/PA765/regress.htm. 2007.
Hartvigsen J, Lings S, Leboeuf-Yde C, et al. Psychosocial factors at work in relation to low back pain and consequences of low back pain; a systematic, critical review of prospective cohort studies. Occup Environ Med. 2004;61:10p. (Online).
Norman GR, Streiner DL. Biostatistics: the bare essentials. St Louis: Mosby; 1994.
Tabachnick BG, Fidell LS. Using multivariate statistics. 4th ed. Boston: Allyn and Bacon; 2001.
Enthoven P, Skargren E, Carstensen J, et al. Predictive factors for 1 and 5 year outcome for disability in a working population of patients with low back pain treated in primary care. Pain. 2006;122:137–44. doi:10.1016/j.pain.2006.01.022. see comment.
Skargren EI, Oberg BE. Predictive factors for 1 year outcome of low-back and neck pain in patients treated in primary care: comparison between the treatment strategies chiropractic and physiotherapy. Pain. 1998;77:201–7. doi:10.1016/S0304-3959(98)00101-8.
Butler RJ, Johnson WG, Cote P. It pays to be nice: employer-worker relationships and the management of back pain claims. J Occup Environ Med/Am College Occup Environ Med. 2007;49:214–25.
Jamison J. Expectations: a case study describing the outcome expectations of chiropractors and their patients. Chiropr J Aust. 2001;31:133–8.
Bekkering GE, Hendriks HJ, van Tulder MW, et al. Prognostic factors for low back pain in patients referred for physiotherapy: comparing outcomes and varying modeling techniques. Spine. 2005;30:1881–6. doi:10.1097/01.brs.0000173901.64181.db.
Boersma K, Linton SJ. Expectancy, fear and pain in the prediction of chronic pain and disability: a prospective analysis. Eur J Pain: Ejp. 2006;10:551–7. doi:10.1016/j.ejpain.2005.08.004.
Gross D, Battie M. Predicting timely recovery and recurrence following multidisciplinary rehabilitation in patients with compensated low back pain. Spine. 2005;30:235–40. doi:10.1097/01.brs.0000150485.51681.80.
Heymans Martijn M, de Vet Henrica CW, Knol Dirk L, et al. Workers beliefs and expectations affect return to work over 12 months. J Occup Rehabil. 2006;16:685–95. doi:10.1007/s10926-006-9058-8.
Merkesdal S, Mau W. Prediction of costs-of-illness in patients with low back pain undergoing orthopedic outpatient rehabilitation. Int J Rehabil Res. 2005;28:119–26. doi:10.1097/00004356-200506000-00004.
Hazard R, Haugh L, Reid S, et al. Early prediction of chronic disability after occupational low back injury. Spine. 1996;21:945–51. doi:10.1097/00007632-199604150-00008.
Shaw WS, Pransky G, Patterson W, et al. Patient clusters in acute, work-related back pain based on patterns of disability risk factors. J Occup Environ Med/Am College Occup Environ Med. 2007;49:185–93.
Schultz IZ, Crook JM, Berkowitz J, et al. Biopsychosocial multivariate predictive model of occupational low back disability. Spine. 2002;27:2720–5. doi:10.1097/00007632-200212010-00012.
Feuerstein M, Harrington CB, Lopez M, et al. How do job stress and ergonomic factors impact clinic visits in acute low back pain? A prospective study. J Occup Environ Med/Am College Occup Environ Med. 2006;48:607–14.
Jellema P, van der Horst HE, Vlaeyen JW, et al. Predictors of outcome in patients with (sub) acute low back pain differ across treatment groups. Spine. 2006;31:1699–705. doi:10.1097/01.brs.0000224179.04964.aa.
Dionne CE, Bourbonnais R, Fremont P, et al. A clinical return-to-work rule for patients with back pain. Can Med Assoc J. 2005;172:1559–67. doi:10.1503/cmaj.1041159.
Turner JA, Franklin G, Fulton-Kehoe D, et al. Worker recovery expectations and fear-avoidance predict work disability in a population-based workers’ compensation back pain sample. Spine. 2006;31:682–9. doi:10.1097/01.brs.0000202762.88787.af.
Kuijer W, Groothoff JW, Brouwer S, et al. Prediction of sickness absence in patients with chronic low back pain: a systematic review. J Occup Rehabil. 2006;16:439–67.
Shaw WS, Pransky G, Patterson W, et al. Early disability risk factors for low back pain assessed at outpatient occupational health clinics. Spine. 2005;30:572–80. doi:10.1097/01.brs.0000154628.37515.ef.
Karjalainen K, Malmivaara A, Mutanen P, et al. Outcome determinants of subacute low back pain. Spine. 2003;28:2634–40. doi:10.1097/01.BRS.0000099097.61495.2E.
Hagen EM, Svensen E, Ericksen HR. Predictors and modifiers of treatment effect influencing sick leave in subacute low back pain patients. Spine. 2005;30:2717–23. doi:10.1097/01.brs.0000190394.05359.c7.
Kapoor S, Shaw WS, Pransky G, et al. Initial patient and clinician expectations of return to work after acute onset of work-related low back pain. J Occup Environ Med/Am College Occup Environ Med. 2006;48:1173–80.
Schultz IZ, Crook J, Meloche GR, et al. Psychosocial factors predictive of occupational low back disability: towards development of a return-to-work model. Pain. 2004;107:77–85. doi:10.1016/j.pain.2003.09.019.
Schultz IZ, Crook J, Berkowitz J, et al. Predicting return to work after low back injury using the psychosocial risk for occupational disability instrument: a validation study. J Occup Rehabil. 2005;15:365–76. doi:10.1007/s10926-005-5943-9.
Steenstra IA, Koopman FS, Knol DL, et al. Prognostic factors for duration of sick leave due to low-back pain in dutch health care professionals. J Occup Rehabil. 2005;15:591–605. doi:10.1007/s10926-005-8037-9.
Hagen EM, Eriksen HR, Ursin H. Does early intervention with a light mobilization program reduce long-term sick leave for low back pain? Spine. 2000;25:1973–6. doi:10.1097/00007632-200008010-00017.
Pengel LH, Herbert RD, Maher CG, et al. Acute low back pain: systematic review of its prognosis. BMJ (Clinical Research Ed.). 2003;327:323. doi:10.1136/bmj.327.7410.323.
Waddell G. Pain and disability. The back pain revolution. 2nd ed. Edinburgh: Churchill Livingstone; 2004. p.27–44.
Streiner DL, Norman GR. Health measurement scales. 2nd ed. Oxford: Oxford university press; 1995.
Crook J, Milner R, Schultz IZ, et al. Determinants of occupational disability following a low back injury: a critical review of the literature. J Occup Rehabil. 2002;12:277–95. doi:10.1023/A:1020278708861.
Altman DG, Machin D, Bryant TN, et al. Statistics with confidence. 2nd ed. Bristol: BMJ Books; 2000.
Moher D, Cook DJ, Eastwood S, et al. Improving the quality of reports of meta-analyses of randomised controlled trials: the QUOROM statement. Quality of reporting of meta-analyses. Lancet. 1999;354:1896–900. doi:10.1016/S0140-6736(99)04149-5.
Altman DG. Systematic reviews of evaluations of prognostic variables. BMJ (Clinical Research Ed.). 2001;323:224–8. doi:10.1136/bmj.323.7306.224.
Linton SJ. Occupational psychological factors increase the risk for back pain: a systematic review. J Occup Rehabil. 2001;11:53–66. doi:10.1023/A:1016656225318.
MacEachen E, Clarke J, Franche R, et al. The process of return to work after injury: findings of a systematic review of qualitative studies (working paper #299). 2005.
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Mr. Ross Iles is supported by an Australian Postgraduate Award and is a participant in the Work Disability Prevention CIHR Strategic Training Programme at the Universite de Sherbrooke, Canada.
Appendices
Appendix 1
Medline Search Strategy
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1.
low back pain.mp. or exp Low Back Pain
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back pain.mp. or exp Back Pain
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3.
sciatica.mp. or SCIATICA
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4.
backache.mp.
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Spinal Stenosis/or back ache.mp.
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6.
lumbar pain.mp.
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1 or 2 or 3 or 4 or 5 or 6
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8.
Functional Status/or activity limitation$.mp. or Disability Evaluation/
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disability.mp. or “SEVERITY OF DISABILITY”/
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10.
oswestry.mp
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11.
participation restriction.mp.
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12.
roland morris disability questionnaire.mp.
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13.
RMDQ.mp.
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14.
8 or 9 or 10 or 11 or 12 or 13
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(recover$ adj2 expect$).mp. [mp = title, original title, abstract, name of substance word, subject heading word]
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(predict$ adj2 recover$).mp. [mp = title, original title, abstract, name of substance word, subject heading word]
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17.
(recover$ adj2 belief$).mp. [mp = title, original title, abstract, name of substance word, subject heading word]
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expectation$.mp.
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15 or 16 or 17
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7 and 14 and 19
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(outcome$ adj2 expect$).mp. [mp = title, original title, abstract, name of substance word, subject heading word]
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18 or 19 or 21
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7 and 14 and 22
Appendix 2
Criteria Required to Satisfy Quality Ratings and Justification of Criteria
S1: Study provided clearly defined inclusion and exclusion criteria
Defining inclusion criteria is important as it may determine the external validity of the study [8, 11]. This criterion was satisfied if inclusion or exclusion criteria were stated.
S2: The stage when initial measures were applied is clearly stated
Due to the natural progression and recurrent nature of LBP, the stage when baseline measures were taken is of importance when determining prognosis [4, 8, 48]. Stating that all measures were taken during the subacute phase was not sufficient to satisfy the criterion, as a person with limitation for 4 weeks has a better prognosis than a person with limitation after 12 weeks despite both fitting the description of sub acute phase. The criterion was satisfied when a time period was stated or mean/median time after injury baseline measures were taken was provided.
S3: The study used representative sampling techniques
In order to determine whether selection bias existed, a clear description of the sampling strategy and referral process should be given [9, 48]. To satisfy this criterion it was determined the study had to clearly describe that either random allocation or consecutive cases were selected in order to eliminate bias.
S4: Important characteristics of the sample were described
To adequately describe sample characteristics, a minimum of mean age and proportion of either sex was required as well as the distribution of all measures taken at baseline.
S5: The setting and study site were clearly described
To satisfy the last sampling criterion, the study had to give a description of the study setting, including the referral process, as this information is also necessary to determine the internal validity of the study [9, 49].
PI1: Clearly defined constructs of what is measured was provided
In order to eliminate bias when selecting potential prognostic indicators, the variables chosen should have a clear, sensible and reproducible definition [9, 10]. This criterion was satisfied if suitable definitions were provided.
PI2: Justification of the measures used was given
Variables that may affect activity limitation due to NSLBP are recognised as multifactorial, spanning personal, social and environmental domains [5, 50]. Therefore to satisfy the quality criteria studies had to provide a theoretical background as justification of the selection of the prognostic indicators measured.
PI3: The study used standardised, psychometrically sound instruments for all measures taken
The method of measurement of the indicators should be reliable and valid in order to eliminate bias [8–10]. This criterion was satisfied if instruments with demonstrated measurement properties (reliability and validity) were used. If a new tool was used the study provided information regarding the tested measurement properties of the tool.
A1: Multivariate techniques were used to adjust for potential confounding variables
Activity limitation due to NSLBP is a multifactorial process and a result of interactions between multiple variables. The aim of multivariate techniques in prognosis is to produce an equation that arrives at a predicted outcome that is as close as possible to the measured outcome [16]. Therefore a study satisfied this criterion if it employed a multivariate analysis such as multiple linear regression or Cox hazard ratios.
A2: The analysis avoided over fitting the data
In order to perform multivariate analysis there must be a high enough ratio of participants to variables measured, otherwise the derived equation will match every case and yield no useful information on prognosis [16]. Over fitting (entering too many variables compared to participants) will reduce the validity of a predictive model. Babyak [12] recommends a ratio of at least 15 participants to each variable entered into the equation and this rule of thumb was used to determine whether a study satisfied the second criterion.
A3: Prospective validation in another cohort was performed
The development of a prognostic model based on a particular sample may only be applicable to, or ‘fit’ the sample it was derived from. Prospective validation on a group of participants different to the group used to establish the model is essential to determine if it is generalisable to all people from the same population [9].
FU1: The duration of follow up was greater than or equal to 6 months
The longer activity limitation continues the more likely it is to persist [3]. Even though the likelihood of activity limitation decreasing after 3 months is similar to the likelihood of a decrease after 6 months, the longer time period was chosen as a quality criterion to allow greater opportunity to predict a positive outcome.
FU2: The data was complete for at least 80% of the sample measured at baseline
The third follow up criterion required complete data for at least 80% of the sample measured at baseline, as complete data is important in determining the validity of results [9, 10, 48, 49].
FU3: Outcome measurements were blinded
To avoid bias in assessing outcomes, blinded assessment (determining outcomes unaware of group allocation or predictor variables) should be used [9, 10, 48, 49]. This criterion was satisfied if it was clear from the study that the assessment of outcome was performed without knowledge of baseline variables of participants.
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Iles, R.A., Davidson, M., Taylor, N.F. et al. Systematic Review of the Ability of Recovery Expectations to Predict Outcomes in Non-Chronic Non-Specific Low Back Pain. J Occup Rehabil 19, 25–40 (2009). https://doi.org/10.1007/s10926-008-9161-0
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DOI: https://doi.org/10.1007/s10926-008-9161-0