Measuring Health: A Guide to Rating Scales and Questionnaires

Non-specific low back pain

Study Design. Literature review, expert panel, and a workshop during the "VIII International Forum on Primary Care Research on Low Back Pain" (Amsterdam, June 2006). Objective. To develop practical guidance regarding the minimal important change (MIC) on frequently used measures of pain and functional status for low back pain. of Background Data. Empirical studies have tried to determine meaningful changes for back pain, using different methodologies. This has led to confusion about what change is clinically important for commonly used back pain outcome measures. Methods. This study covered the Visual Analogue Scale (0-100) and the Numerical Rating Scale (0-10) for pain and for function, the Roland Disability Questionnaire (0-24), the Oswestry Disability Index (0-100), and the Quebec Back Pain Disability Questionnaire (0-100). The literature was reviewed for empirical evidence. Additionally, experts and participants of the VIII International Forum on Primary Care Research on Low Back Pain were consulted to develop international consensus on clinical interpretation. Results. There was wide variation in study design and the methods used to estimate MICs, and in values found for MIC, where MIC is the improvement in clinical status of an individual patient. However, after discussion among experts and workshop participants a reasonable consensus was achieved. Proposed MIC values are: 15 for the Visual Analogue Scale, 2 for the Numerical Rating Scale, 5 for the Roland Disability Questionnaire, 10 for the Oswestry Disability Index, and 20 for the QBDQ. When the baseline score is taken into account, a 30% improvement was considered a useful threshold for identifying clinically meaningful improvement on each of these measures. Conclusion. For a range of commonly used back pain outcome measures, a 30% change from baseline may be considered clinically meaningful improvement when comparing before and after measures for individual patients. It is hoped that these proposals facilitate the use of these measures in clinical practice and the comparability of future studies. The proposed MIC values are not the final answer but offer a common starting point for future research.

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Interpreting change scores for pain and functional status in low back pain: towards international consensus regarding minimal important change.

QUITE apart from the academic consideration that vital and medical statistics now form an obligatory part of the education of students seeking the University of London's diploma in public health, the demand for information about the methods of vital and medical statistics is increasing. The most casual reader of the newspapers is now aware that population problems are of serious practical importance and that the publications of the General Register Office cannot be ignored. It is scarcely an exaggeration to say that the recently issued preliminary report on the census of 1931 is one of the most sensational documents which has appeared for years, and that he who reads it intelligently will understand what is meant by saying that civilisation is in the melting pot. An Introduction to Medical Statistics. By Hilda M. Woods William T. Russell. Pp. x + 125. (London: P. S. King and Son, Ltd., 1931.) 7s. 6d.

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An Introduction to Medical Statistics

ESPEN guidelines on definitions and terminology of clinical nutrition

Background and Purpose. The aim of this study was to examine 5 commonly used questionnaires for assessing disability in people with low back pain. The modified Oswestry Disability Questionnaire, the Quebec Back Pain Disability Scale, the Roland-Morris Disability Questionnaire, the Waddell Disability Index, and the physical health scales of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) were compared in patients undergoing physical therapy for low back pain. Subjects and Methods. Patients with low back pain completed the questionnaires during initial consultation with a physical therapist and again 6 weeks later (n=106). Test-retest reliability was examined for a group of 47 subjects who were classified as “unchanged” and a subgroup of 16 subjects who were self-rated as “about the same.” Responsiveness was compared using standardized response means, receiver operating characteristic curves, and the proportions of subjects who changed by at least as much as the minimum detectable change (MDC) (90% confidence interval [CI] of the standard error for repeated measures). Scale width was judged as adequate if no more than 15% of the subjects had initial scores at the upper or lower end of the scale that were insufficient to allow change to be reliably detected. Results. Intraclass correlation coefficients (2,1) calculated to measure reliability for the subjects who were classified as “unchanged” and those who were self-rated as “about the same” were greater than .80 for the Oswestry and Quebec questionnaires and the SF-36 Physical Functioning scale and less than .80 for the Waddell and Roland-Morris questionnaires and the SF-36 Role Limitations–Physical and Bodily Pain scales. None of the scales were more responsive than any other. Discussion and Conclusion. Measurements obtained with the modified Oswestry Disability Questionnaire, the SF-36 Physical Functioning scale, and the Quebec Back Pain Disability Scale were the most reliable and had sufficient width scale to reliably detect improvement or worsening in most subjects. The reliability of measurements obtained with the Waddell Disability Index was moderate, but the scale appeared to be insufficient to recommend it for clinical application. The Roland-Morris Disability Questionnaire and the Role Limitations–Physical and Bodily Pain scales of the SF-36 appeared to lack sufficient reliability and scale width for clinical application.

A Comparison of Five Low Back Disability Questionnaires: Reliability and Responsiveness

Objectives: To identify psychosocial predictors of failure to return to work in non-chronic (lasting less than 3 months) non-specific low back pain (NSLBP). Methods: A systematic review of prognostic studies was carried out. Medline, Embase, PsychINFO, CINAHL and PEDro electronic bibliographic databases up to April 2006 were searched. Included studies took baseline measures in the non-chronic phase of NSLBP (ie, within 3 months of onset), included at least one psychosocial variable and studied a sample in which at least 75% of participants had NSLBP. Baseline measures had to be used to predict at least one work-specific outcome. Results: The search identified 24 studies meeting the inclusion criteria. From these studies there is strong evidence that recovery expectation is predictive of work outcome and that depression, job satisfaction and stress/ psychological strain are not predictive of work outcome. There is moderate evidence that fear avoidance beliefs are predictive of work outcome and that anxiety is not predictive of work outcome. There is insufficient evidence to determine whether compensation or locus of control are predictive of work outcome. Conclusions: To predict work outcome in non-chronic NSLBP, psychosocial assessment should focus on recovery expectation and fear avoidance. More research is needed to determine the best method of measuring these constructs and to determine how to intervene when a worker has low recovery expectations.

https://oem.bmj.com/content/oemed/65/8/507.full.pdf

Psychosocial predictors of failure to return to work in non-chronic non-specific low back pain: a systematic review

Backgound and Purpose. Evidence-based practice is the explicit use of current best evidence in making decisions about the care of individual patients and is a concept of growing importance for physiotherapy. The aim of the present study was to investigate Australian physiotherapists' self-reported practice, skills and knowledge of evidence-based practice and to examine differences between recent and experienced graduates, physiotherapists with low and high levels of training and physiotherapists working in private practice and hospital settings. Method. A survey was sent to 230 physiotherapists working in hospitals and in private practice. One hundred and twenty-four were completed and returned. Results. Although 69.4% of respondents said they frequently (at least monthly) read research literature, only 10.6%, 15.3% and 26.6% of respondents, respectively, searched PEDro, Cochrane and Medline or Cinahl databases frequently, and only 25.8% of respondents reported critically appraising research reports. Recent graduates rated their evidence-based practice skills more highly than more experienced graduates, but did not perform evidence-based practice tasks more often. Physiotherapists with higher levels of training rated their evidence-based practice skills more highly, were more likely to search databases and to understand a range of evidence-based practice terminology than those with lower levels of training. Private practice and hospital physiotherapists rated their evidence-based practice skills equally and performed most evidence-based practice activities with equal frequency. Conclusions. Respondents had a positive attitude toward evidence-based practice and the main barriers to evidence-based practice were time required to keep up to date, access to easily understandable summaries of evidence, journal access and lack of personal skills in searching and evaluating research evidence. Efforts to advance evidence-based practice in physiotherapy should focus on reducing these barriers. Copyright © 2006 John Wiley & Sons, Ltd.

Evidence based practice: a survey of physiotherapists' current practice

Existing instruments for measuring mobility are inadequate for accurately assessing older people across the broad spectrum of abilities. Like other indices that monitor critical aspects of health such as blood pressure tests, a mobility test for all older acute medical patients provides essential health data. We have developed and validated an instrument that captures essential information about the mobility status of older acute medical patients. Items suitable for a new mobility instrument were generated from existing scales, patient interviews and focus groups with experts. 51 items were pilot tested on older acute medical inpatients. An interval-level unidimensional mobility measure was constructed using Rasch analysis. The final item set required minimal equipment and was quick and simple to administer. The de Morton Mobility Index (DEMMI) was validated on an independent sample of older acute medical inpatients and its clinimetric properties confirmed. The DEMMI is a 15 item unidimensional measure of mobility. Reliability (MDC90), validity and the minimally clinically important difference (MCID) of the DEMMI were consistent across independent samples. The MDC90 and MCID were 9 and 10 points respectively (on the 100 point Rasch converted interval DEMMI scale). The DEMMI provides clinicians and researchers with a valid interval-level method for accurately measuring and monitoring mobility levels of older acute medical patients. DEMMI validation studies are underway in other clinical settings and in the community. Given the ageing population and the importance of mobility for health and community participation, there has never been a greater need for this instrument.

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The de Morton Mobility Index (DEMMI): an essential health index for an ageing world.

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.

Megan Davidson

Papers

A Comparison of Five Low Back Disability Questionnaires: Reliability and Responsiveness

Psychosocial predictors of failure to return to work in non-chronic non-specific low back pain: a systematic review

Evidence based practice: a survey of physiotherapists' current practice

The de Morton Mobility Index (DEMMI): an essential health index for an ageing world.

Systematic review of the ability of recovery expectations to predict outcomes in non-chronic non-specific low back pain.