Oswestry Disability Index (ODI) Calculator for Low Back Pain

How does the Oswestry Disability Index (ODI) calculator for low back pain work?

This is a health tool designed to aide in the management of spinal disorders and is one of the most common and simple to use systems. It represents a self report scale that analyses lifestyle activities and the perceived impact of low back pain and disability degree on the patient’s ability to perform them as normal.

The Oswestry Disability Index (ODI) calculator for the management of low back pain patients comprises of 10 items, each with 6 answer choices on a 0 to 5 points scale, statements referring to the patient’s life in different scenarios.

Each of the questions is put in such way to reflect the impairment due to low back pain or leg pain and the subject is able to fill in the questionnaire in less than 5 minutes. The areas approached include:

■ Pain Intensity – degree of toleration before resorting to pain medication;

■ Personal Care – ability to care after oneself without aid and to what extent;

■ Lifting – ability to lift different size weights with or without pain;

■ Walking – distance than can be walked with or without aid;

■ Sitting – ability to sit and any prevention caused by pain;

■ Standing – evaluating the ability to stand unaided and for how long;

■ Sleeping – sleep deprivation, insomnia and need for medication due to pain;

■ Sex Life – impairment and even prevention of intercourse due to pain;

■ Social Life – dysfunctionalities in the way patient interacts socially caused by pain;

■ Traveling – ability to travel short or long journeys with or without pain.

ODI is a recognized tool for its psychometric properties that defines outcome in condition specific spinal disorders, being one of the basis on which the Neck Disability Index (NDI) was constructed.

Subsequent to the original study, several studies have reviewed and validated the method by collating data from populations of healthy and back pain patients. The results have once again validated it as a worthwhile outcome measure.

ODI score interpretation

Each of the 10 items is scored between 0 and 5. Usually the 0 end answers reflect a no or little impairment or inability to continue with the assessed activity, while answers closer to the 5 point end reflect an increased severity in the dysfunction caused by low back pain or leg pain.

This means that the overall score range is between 0 and 50, with 0 being least affected and 50 most severely affected.

However, it seems that even patients who have been in treatment and are already recovering won’t usually attain scores closer to 0 but more like between 5 and 15 (10 - 30%).

Beside this numeric result, a percentage score is also calculated by multiplying the former by 2. Therefore a score of 15 in the ODI reflects a 30% percentage.

In the original study there have been established specific cut offs between the gravity categories as well as certain brief guidelines in regard to condition management.

■ 0% to 20% (minimal disability): Patients can cope with most activities of daily living. No treatment may be indicated except for suggestions on lifting, posture, physical fitness and diet. Patients with sedentary occupations (ex. secretaries) may experience more problems than others.

■ 21% to 40% (moderate disability): Patients may experience more pain and problems with sitting, lifting and standing. Travel and social life are more difficult. Patients may be off work. Personal care, sleeping and sexual activity may not be grossly affected. Conservative treatment may be sufficient.

■ 41% to 60% (severe disability): Pain is a primary problem for these patients, but they may also be experiencing significant problems in travel, personal care, social life, sexual activity and sleep. A detailed evaluation is appropriate.

■ 61% to 80% (crippled): Back pain has an impact on all aspects of daily living and work. Active treatment is required.

■ 81% to 100%: These patients may be bed bound or exaggerating their symptoms. Careful evaluation is recommended.

The Minimum Detectable Change at 90% confidence is of 10% points, meaning at least a 10% change is required in monitoring reassessments (baseline monitoring every 2 weeks) to be clinically meaningful.

References

1) Fairbank JC, Pynsent PB. (2000) The Oswestry Disability Index. Spine (Phila Pa 1976).; 25(22):2940-52; discussion 2952.

2) Fairbank JC, Couper J, Davies JB, O'Brien JP. (1980) The Oswestry low back pain disability questionnaire. Physiotherapy; 66(8):271-3.

3) Vianin M. (2008) Psychometric properties and clinical usefulness of the Oswestry Disability Index. J Chiropr Med; 7(4): 161–163.

4) Tonosu J, Takeshita K, et al. (2012) The normative score and the cut-off value of the Oswestry Disability Index (ODI). Eur Spine J; 21(8):1596-602.