Oswestry Disability Index: Is Telephone Administration Valid?

Background: The Oswestry Disability Index (ODI) is among the most widely used patient reported outcome measures for the assessment of spinal conditions. Traditionally, the ODI has been administered in outpatient clinics on a face-to-face basis, which can be expensive and time consuming. Furthermore, the percentage of patients lost to clinical follow-up is high, particularly after 2-5 years. Thus, telephonic administration of the ODI, if valid, could be a convenient way of capturing patient outcomes and increasing follow-up rates. The objective of this study was to validate telephonic administration of the ODI compared to face-to-face administration.

Methods: A convenience sample of individuals with and without back pain in an academic medical center were recruited for this study. Face-to-face administration of the ODI was completed and retested 24 hours later via phone. Test-retest reliability was determined by calculating the intraclass correlation coefficient.

Results: 22 individuals completed the ODI questionnaire face-to-face, then via telephone 24 hours later. There was a mean 2% (± 3) intra-rater ODI score difference (range: 0% to 12%). The intraclass correlation coefficient overall was 0.98 (95% CI: 0.96, 0.99, p<0.001) with a range of 0.95 to 1.0, revealing near-perfect test-retest reliability.

Conclusions: Administration of the ODI questionnaire over the phone has excellent test-retest reliability when compared to face-to-face administration. Telephone administration is a convenient and reliable option for obtaining follow-up outcomes data.

Clinical Relevance: Telephonic administration of the ODI is scientifically valid, and should be an accepted method of data collection for state-level and national-level outcomes projects.