I’ve already written about my frustration with standard 0–10 pain scales. Reducing a chronic condition to a single number obscures a great deal of relevant information. Plus, this number is mostly helpful for administering pain meds.
I knew there must be better ways to measure back pain.* There must be scales that acknowledge the complexity of the condition, and reveal the sacrifices that are made to avoid pain. I set out to find them, and had some success.
*Sciatica is grouped with low back pain, since it’s most commonly caused by spinal problems such as a herniated disc, spondylolisthesis, or stenosis (Ropper & Zafonte, 2015).
I discovered that there’s no shortage of tools. But no method is perfect, and all involve tradeoffs. Questionnaires must be nuanced, and appropriate for the back pain population. They must also be easy for patients to understand, and easy for doctors and researchers to administer and score.
In this article, I describe three of the most popular questionnaires that are used in both research studies and doctors’ offices. The questionnaires themselves, along with scoring instructions, can be found here:
SF-36
The SF-36 (so called because it’s a short-form health survey with 36 questions) was developed in the early 1990s. At the time, quality of life was gaining recognition as an important but overlooked measure of treatment success. It was considered particularly relevant for chronic and incurable diseases which could only be treated, rather than cured (Hays, Sherbourne, & Mazel, 1995).
The SF-36 wasn’t specifically intended to measure sciatica, or back pain, or any other specific condition. Rather, it was an all-purpose questionnaire that could be administered to everyone, regardless of their state of health.
In this, it was successful, and is now the most widely-used patient-reported health survey worldwide. It was immediately adopted by researchers, and by the turn of the century, it had appeared in over 1,000 papers (Ware, 2000).
The 36 questions are broad-ranging, and cover health-related limitations on activities, mental health, pain intensity, and health changes over time.
One drawback of the SF-36 is its convoluted scoring process, which is done in two steps. First, the answer for each question is converted to a point value between 0–100. Then, the point values are averaged across eight categories. (Physical functioning, with ten questions, is the largest.) The higher the score, the better a patient’s health.
Each question and answer has to be cross-checked against two separate tables, and the answers need to be converted and averaged. This makes it hard to tally the answers on the fly.
On the other hand, the separation of questions into categories makes it easier to compare different dimensions of health (e.g., physical functioning vs. emotional well-being).
The Oswestry Disability Index
The Oswestry Low Back Pain Disability Questionnaire (also known as the Oswestry Disability Index or ODI), was born in the late 1970s at a specialist referral clinic in the UK.
At the clinic, back pain patients were interviewed by three professionals – an orthopedic surgeon, an occupational therapist, a physiotherapist (the UK equivalent of a physical therapist). The interviewers noted which activities that were most commonly affected by back pain, and put together a questionnaire based on common themes.
The Oswestry Low Back Pain Disability Questionnaire was first published in 1980, and soon became one of the most popular methods for assessing back pain. Its brevity was part of its charm; it could be filled out in under five minutes, and scored in less than a minute (Roland & Fairbank, 2000).
The ODI was divided into ten sections, each of which asked how back pain interfered with a specific aspect of a patient’s life, such as sleeping or personal care (Fairbank, Davies, Couper, & O’Brien, 1980).
In each section, patients would be asked to select one of six statements, which represented increasingly severe limitations. For example, Section 9 – Social Life contained the following options:
- My social life is normal and gives me no extra pain.
- My social life is normal but increases the degree of pain
- Pain has no significant effect on my social life apart from limiting my more energetic interests, e.g. dancing, etc.
- Pain has restricted my social life and I do not go out as often.
- Pain has restricted my social life to my home.
- I have no social life because of pain.
Each answer was assigned a point value from 0 (no disability) to 5 (maximal disability). The answers were then tallied, and divided by the total possible score. Results were assigned a percentage value. This method acknowledged that some sections (such as Section 8 – Sex Life) might not be relevant to all patients.
Patients who scored between 80–100% on this scale were said to be, “[E]ither bed-bound or exaggerating their symptoms (Fairbank, Davies, Couper, & O’Brien, 1980).”
Since its introduction, the ODI has been modified and adapted to various ends. In 1989, a research group in the UK updated the wording, and removed many of the original references to medication. This version (version 2.0) has largely supplanted the original.
Professional organizations representing different medical specialties adopted modified versions, and the questionnaire has been translated and adapted for other countries and cultures (Fairbank & Pynsent, The Oswestry Disability Index, 2000).
The Roland-Morris Disability Questionnaire
Like the Oswestry Disability Index, the Roland-Morris Disability Questionnaire (often abbreviated as RDQ) originated in the UK. It was originally intended as a research tool, rather than a means of monitoring patients in a clinical setting.
The RDQ is based on the longer and more general Sickness Impact Profile (SIP). The 136 questions in the SIP were whittled down to 24 yes-or-no statements for the RDQ, and the phrase, “because of my back” was added. Sometimes, this is adjusted to, “because of my back or leg problems,” which is more suitable for patients with sciatica (Roland & Fairbank, 2000).
Because the questions only require yes-or-no answers, the RDQ is easy to administer, and can be done over the phone. Scoring requires no math beyond counting. Results range from 0 (no disability) to 100 (maximal disability).
Both the ODI and the RDQ focus on physical function, and pay relatively little attention to psychological distress. Both can be administered and scored without too much fuss. Even the creators of the tests concede that the, “differences between these instruments are not great. Both are widely used, having been extensively tested, and are applicable in a wide variety of settings (Roland & Fairbank, 2000).”
So when should doctors and researchers use one over the other?
In studies of patients with moderate disability, the choice is largely a matter of preference. Either the ODI or RDQ will do the job equally well.
But for patients at the extreme ends – either severely disabled or mostly okay – there may indeed be a difference. The ODI is better at revealing the nuances between severely disabled patients, while the RDQ is more revealing for patients at the low end of the spectrum (Roland & Fairbank, 2000).
The authors go on to say that, “The situation in which a choice between the two instruments would be most clear cut would be when a validated translation exists for one but not the other.”
Final Thoughts
Each of these three questionnaires is superior to a simple pain rating scale for assessing back pain. Each provides a more detailed view of a patient’s capabilities and limitations, and make it easier to monitor progress. And importantly, all three of these questionnaires show an awareness of typical back pain complications.
However, none of these tools distinguish between the causes of back pain, or recognize that symptoms are clustered according to pathology. (E.g., a patient with a herniated disc won’t have the same pain triggers as a patient with spinal stenosis.) If the administering physician is well-versed in back pain, this needn’t be an issue. In fact, if the purpose of the survey is diagnosis, it may even be helpful.
But in my experience, few doctors have that sort of specialized knowledge, and the lack of differentiation makes me question the usefulness of these tools for clinical studies.
Selecting questions to include necessarily involves selecting questions to exclude. Patients might experience severe limitations (e.g., not being able to play with their grandchildren, not being able to drive) which remain unrecognized because they aren’t on the form.
Despite their limitations, each of these forms earns its place. Each one has a long track record, and extensive data about its validity and reliability. Each is easy for patients to understand, and can be administered quickly.
References
- 36-Item Short Form Survey Instrument (SF-36). (n.d.). Retrieved December 3, 2020, from RAND Corporation: https://www.rand.org/health-care/surveys_tools/mos/36-item-short-form/survey-instrument.html
- About Us. (n.d.). Retrieved December 3, 2020, from John Ware Resarch Group (JWRG): http://www.jwrginc.com/about/
- Fairbank, J. C., & Pynsent, P. B. (2000). The Oswestry Disability Index. Spine, 25(22), 2940-2953.
- Fairbank, J. C., Davies, J. B., Couper, J., & O’Brien, J. P. (1980). The Oswestry Low Back Pain Disability Questionnaire. Physiotherapy, 66(8), 271-273.
- Hays, R. D., Sherbourne, C. D., & Mazel, R. M. (1995). User’s Manual for the Medical Outcomes Study (MOS) Core Measures of Health-Related Quality of Life. Santa Monica, CA: RAND.
- Ramkumar, D. B., Pearson, A. M., Spratt, K., & Weinstein, J. N. (2018). Outcomes Research for Spinal Disorders. In S. R. Garlin, F. J. Eismont, G. R. Bell, J. S. Fischgrund, & C. M. Bono, Rothman-Simeone and Herkowitz’s The Spine, Seventh Edition (pp. 155-166). Elsevier.
- Roland, M., & Fairbank, J. (2000, December 15). The Roland-Morris Disability Questionnaire and the Oswestry Disability Questionnaire. Spine, 25(24), 3115-3124.
- Ropper, A. H., & Zafonte, R. D. (2015, March 26). Sciatica. The New England Journal of Medicine, 372, 1240-1248. doi:10.1056/NEJMra1410151
- Ware, J. E. (2000, December 15). SF-36 Health Survey Update. Spine, 25(24), 3130-3139.
