Abstract
The purpose of this prospective, single site cohort quasi-experimental study was to determine the responsiveness of the numerical rating scale (NRS), Roland–Morris disability questionnaire (RMDQ), Oswestry disability index (ODI), pain self-efficacy questionnaire (PSEQ) and the patient-specific functional scale (PSFS) in order to determine which would best measure clinically meaningful change in a chronic low back pain (LBP) population. Several patient-based outcome instruments are currently used to measure treatment effect in the chronic LBP population. However, there is a lack of consensus on what constitutes a “successful” outcome, how an important improvement/deterioration has been defined and which outcome measure(s) best captures the effectiveness of therapeutic interventions for the chronic LBP population. Sixty-three consecutive patients with chronic LBP referred to a back exercise and education class participated in this study; 48 of the 63 patients had complete data. Five questionnaires were administered initially and after the 5-week back class intervention. Also at 5 weeks, patients completed a global impression of change as a reflection of meaningful change in patient status. Score changes in the five different questionnaires were subjected to both distribution- and anchor-based methods: standard error of measurement (SEM) and receiver operating characteristic (ROC) curves to define clinical improvement. From these methods, the minimal clinically important difference (MCID) defined as the smallest difference that patients and clinicians perceive to be worthwhile is presented for each instrument. Based on the SEM, a point score change of 2.4 in the NRS, 5 in the RMDQ, 17 in the ODI, 11 on the PSEQ, and 1.4 on the PSFS corresponded to the MCID. Based on ROC curve analysis, a point score change of 4 points for both the NRS and RMDQ, 8 points for the ODI, 9 points for the PSEQ and 2 points for the PSFS corresponded to the MCID. The ROC analysis demonstrated that both the PSEQ and PSFS are responsive to clinically important change over time. The NRS was found to be least responsive. The exact value of the MCID is not a fixed value and is dependent on the assessment method used to calculate the score change. Based on ROC curve analysis the PSFS and PSEQ were more responsive than the other scales in measuring change in patients with chronic LBP following participation in a back class programme. However, due to the small sample size, the lack of observed worsening of symptoms over time, the single centre and intervention studied these results which need to be interpreted with caution.
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References
Waddell G (2006) Preventing incapacity in people with musculoskeletal disorders. Br Med Bull 77–78:55–69
Turk DC, Dworkin RH, Revichi D et al (2008) Identifying important outcome domains for chronic pain clinical trials: an IMMPACT survey of people with pain. Pain 137:276–285
Taylor W (2005) Musculoskeletal pain in adult New Zealand population: prevalence and impact. N Z Med J 118:1221
Lewis J, Hewitt J, Billington L et al (2005) A randomized control trial comparing two physiotherapy interventions for chronic low back pain. Spine 30:711–721
Heymans M, van Tulder M, Esmail R et al (2005) Back schools for nonspecific low back pain: a systematic review within the framework of the Cochrane Collaboration Back Review Group. Spine 30:2153–2163
NICE clinical guideline 88 (May 2009) Low back pain. Early management of persistent non-specific low back pain
Underwood M, Morton V, Farrin A (2007) Do baseline characteristics predict response to treatment for low back pain? Secondary analysis of the UK BEAM dataset. Rheumatology 46(8):1297–1302
Turk DC (2002) Clinical effectiveness and cost-effectiveness of treatments for patients with chronic pain. Clin J Pain 18:355–365
O’Sullivan P (2005) Diagnosis and classification of chronic low back pain disorders: maladaptive movement and control impairments as underlying mechanism. Man Ther 10:116–121
Wand BM, O’Connell NE (2008) Chronic non-specific low back pain—sub-groups or a single mechanism? BMC Musculoskelet Disord 9:11
Hurst H, Bolton J (2004) Assessing the clinical significance of change scores recorded on subjective outcome measures. J Manipulative Physiol Ther 27:26–35
Beaton D, Tarasuk V, Katz J et al (2001) Are you better? A qualitative study into the meaning of being better and its implications for health status measurement. Arthritis Rheumatol 42(supplement):S274
Terwee C (2003) On assessing responsiveness of health-related quality of life instruments: guidelines for instrument evaluation. Qual Life Res 12:349–362
Hägg O, Fritzell P, Nordwall A (2003) The clinical importance of changes in outcome scores after treatment for chronic low back pain. Eur Spine J 12:12–20
Jaeschke R, Singer J, Guyatt G (1989) Measurement of health status. Ascertaining the minimal clinical important difference. Control Clin Trials 10:407–415
Crosby R, Kolotkin R, Williams G (2003) Defining clinically meaningful change in health-related quality of life. J Clin Epidemiol 56:395–407
Fritz J, Irrgang J (2001) A comparison of a modified Oswestry low back pain disability questionnaire and the Quebec back pain disability scale. Phys Ther 81:776–788
Terwee C (2007) Quality criteria were proposed for measurement properties of health status questionnaires. J Clin Epidemiol 60:34–42
Dworkin RH, Turk DC, Farrar JT (2005) Core outcome measures for chronic pain clinical trials: IMMPACT recommendations. Pain 113:9–19
Lauridsen H, Hartvigsen J, Korsholm L et al (2007) Choice of external criteria in back pain research: Does it matter? Recommendations based on analysis of responsiveness. Pain 131:112–120
Ostelo R, Deyo R, Stratford P et al (2008) Interpreting change scores for pain and functional status in low back pain. Spine 33:90–94
Roland M, Morris R (1983) A study of the natural history of back pain. Part 1: development of a reliable and sensitive measure of disability in low back pain. Spine 8:141–144
Fairbank J, Pynsent P (2000) The Oswestry disablility index. Spine 25:2940–2953
Nicholas M (1989) Self-efficacy and chronic pain. Paper presented at the annual conference of the British Psychological Society, St. Andrews
Stratford P, Gill C, Westaway M et al (1995) Assessing disability and change on individual patients: a report of a patient specific measure. Physiother Can 47:258–263
Davidson M, Keating J (2002) A comparison of five low back disability questionnaires: reliability and responsiveness. Phys Ther 82:8–24
De Vet H, Terwee C, Knol D, Bouter L (2006) When to use agreement versus reliability measures. J Clin Epidemiol 59:1033–1039
Ostelo R, de Vet H (2005) Clinically important outcomes in low back pain. Best Pract Res Clin Rheumatol 19:593–607
Deyo R, Centor R (1986) Assessing the responsiveness of functional scales to clinical change: an analogy to diagnostic test performance. J Chronic Dis 39:897–906
Beurskens A, de Vet H, Koke A (1996) Responsiveness of functional status in low back pain: a comparison of different instruments. Pain 65:71–76
Grotle M, Brox JL, Vallestad N (2004) Functional status and disability questionnaires: what do they assess? A systematic review of back-specific outcome questionnaires. Spine 30:130–140
Brouwer S, Kuijer W, Dijkstra P, Goeken L et al (2003) Reliability and stability of the Roland Morris questionnaire: intraclass correlation and limits of agreement. Disabil Rehabil 26:162–165
Department of Health (2008) High quality care for all—NHS next stage review final report, section 4. Quality at the heart of everything we do, Crown Copyright, The Stationery Office, p 47. http://www.tsoshop.co.uk
Wyrwich K, Tierney W, Wolinsky F (1999) Further evidence supporting an SEM-based criterion for identifying meaningful intra-individual changes in health-related quality of life. J Clin Epidemiol 52:861–873
Childs J, Riva S, Fritz J (2005) Responsiveness of the numeric pain rating scale in patients with low back pain. Spine 30:1331–1334
Stratford P, Binkley J, Riddle D, Guyatt G (1998) Sensitivity to change of the Roland-Morris back pain questionnaire: Part 1. Phys Ther 78:1186–1196
Wyrwich K (2004) Minimal important difference thresholds and the standard error of measurement: is there a connection? J Biopharm Stat 14:97–110
Farrar JT, Young J, LaMoreaux L et al (2001) Clinical importance of changes in chronic pain intensity measured on an 11-point numerical pain rating scale. Pain 94:149–158
Salaffi F, Stancati A, Silvestri C, Ciapetti A, Grassi W (2004) Minimal critical important changes in chronic musculoskeletal pain intensity measured on a numerical rating scale. Eur J Pain 8:165–172
Baldwin ML, Butler RJ, Johnson WG et al (2007) Self-reported severity measures as predictors of return to work outcomes in occupational back pain. J Occup Rehabil 17:68
Beurskens A, de Vet H, Koke A (1999) A patient specific approach for measuring functional status in low back pain. J Manipulative Physiol Ther 22:144–148
Pengel L, Refshauge K, Maher C (2004) Responsiveness of pain, disability, and physical impairment outcomes in patients with low back pain. Spine 29:879–883
Chatman A, Hyams S, Neel J et al (1997) The patient specific functional scale: measurement properties in patients with knee dysfunction. Phys Ther 77:820–829
Hudak P, Wright J (2004) The characteristics of patient satisfaction measures. Spine 25:3167–3317
Asghari A, Nicholas M (2001) Pain self-efficacy beliefs and pain behaviour. A prospective study. Pain 94:85–100
Nicholas M (2007) The Pain self efficacy questionnaire: taking pain into account. Eur J Pain 11:153–163
Williams A, Richardson P, Nicholas M, Pither C, Harding V, Ralphs J (1996) Inpatient versus outpatient pain management results of a chronic pain trial. Pain 66:13–22
Norman G, Stratford P, Regehr G (1997) Methodological problems in the retrospective computation of responsiveness to change: the lesson of Cronbach. J Clin Epidemiol 50:869–879
Schmitt J, Di Fabio R (2005) The value of prospective and retrospective global change criterion measures. Arch Phys Med Rehabil 86:2270–2276
Von Korff M, Jensen P, Karoli P (2000) Assessing global pain severity by self-report in clinical and health services research. Spine 25:3140–3151
De Vet H (2007) Reproducibility and responsiveness of evaluative outcome measures. Int J Technol Assess Health Care 17:479–487
Yelland J, Schluter P (2006) Defining worthwhile and desired responses to treatment of chronic low back pain. Pain Med 7:38–45
Walsh D, Kelly S, Johnson P et al (2003) Performance problems of patients with chronic low back pain and the measurement of patient-centered outcome. Spine 29:87–93
Westaway M, Stratford P, Binkley J (1998) The patient specific functional scale: validation of its use in persons with neck dysfunction. J Sports Phys Ther 27:331–338
Jordan K, Dunn K, Lewis M et al (2006) A minimal clinically important difference was derived for the Roland-Morris disability questionnaire for low back pain. J Clin Epidemiol 59:45–52
Dworkin R, Turk D, Wyrwrich K, Beaton D et al (2008) Interpreting the clinical importance of treatment outcomes in chronic pain trials: IMMPACT recommendations. J Pain 9:105–121
Haywood K (2006) Patient reported outcome I: Measuring what matters in musculoskeletal care. Musculoskeletal Care 4:187–203
Greenhalgh J, Long A, Flynn (2005) The use of patient reported outcome measures in routine clinical practice: lack of impact or lack of theory? Soc Sci Med 60:833–843
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Maughan, E.F., Lewis, J.S. Outcome measures in chronic low back pain. Eur Spine J 19, 1484–1494 (2010). https://doi.org/10.1007/s00586-010-1353-6
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DOI: https://doi.org/10.1007/s00586-010-1353-6