The Use of Functional Outcome Assessments
In our practice, we use validated patient questionnaires as a principal method of measuring outcomes for patients with back pain (Revised Oswestry and/or Roland-Morris) and neck pain (Neck Pain Disability Index). This is a brief discussion of the scientific acceptance and now widespread use of this type of outcome measure. It is given because traditionally practitioner measurements (e.g. range of motion measured by straight leg raise, x-ray, etc. and strength measures) have been thought more objective and valid than patient-centered survey instruments (questionnaires).
Current health science literature now says that carefully designed, proven questionnaires have at least equal scientific validity to practitioner measurement.1, 2 Both the Oswestry Low-Back Pain Disability Questionnaire (Oswestry) 3, 4, 5 and the Roland-Morris Low-Back Pain Disability Questionnaire (Roland-Morris) 4, 5, 6 have been shown in randomized controlled trials to have validity and reliability in measuring results for patients with back pain under chiropractic or medical management. The Neck Pain Disability Index, is an adaptation of the Oswestry for neck pain patients by chiropractic researchers and its validity and reliability have also been confirmed by randomized controlled trial.7
The current North American Guidelines for Chiropractic Practice have a chapter on measuring results (outcomes assessment). This deals specifically with the use of patient questionnaires to measure function and pain, and on the basis of the literature, rates use of such questionnaires as established for assessing patients with back pain, neck pain and other neuromusculoskeletal disorders.
A great advantage of patient-centered questionnaires is that they measured results directly. Patients indicate in specific ways whether treatment is improving pain levels, function, and reducing disability. Questionnaires are a great addition to the practitioner's analytical toolbox. Practitioner measurements are firstly indirect - it may be, in some patients, for example, that varying degrees of straight-leg raise or x-ray changes have nothing to do with the pain - and secondly there is increasing evidence that they are often less reliable, valid and scientifically sound than patient questionnaires.2
1 Measuring Health: A Guide to Rating Scales and Questionnaires McDowell I, Newell C, Oxford Press, New York 1987.
2 Measuring the Functional Status of Patients with Low Back Pain, Deyo R, Archives of Physical Medicine and Rehabilitation 1988, 69:1044-1053.
3 Fairbanks J, Davies J et al (1980) The Oswestry Low Back Pain Disability Questionnaire, Physiotherapy 66:271-272
4 Meade TW, Dyer Set al (1990) Low Back Pain of Mechanical Origin: Randomised Comparison of Chiropractic and Hospital Outpatient Treatment, Br Med J300:1431-37
5 Hsiieh CJ, Phillips RB et al (1992) Functional Outcomes of Low Back Pain: Comparison of Four Treatment Groups in a Randomized Controlled Trial, J Manipulative Physiol Ther,15(1):4-9.
6 Roland M, Morris R (1983) Study of Natural History of Back Pain. Part I: Development of Reliable and Sensitive Measure of Disability in Low Back Pain, Spine 8:141
7 Vernon H, Mior S (1991) The Neck Disability Index: A Study of Reliability and Validity, J Manipulative Physiol Ther 14(7):409-415.