Psychometric Properties of Commonly Used Low Back Disability Questionnaires: Are They Useful for Older Adults with Low Back Pain?

Abstract

OBJECTIVES: To evaluate the psychometric properties of two commonly used low back pain (LBP) disability questionnaires in a sample solely comprising community-dwelling older adults. DESIGN: Single-group repeated measures design. SETTING: Four continuing care retirement communities in Maryland and in Virginia. Participants. Convenience sample of 107 community-dwelling men and women (71.9%) aged 62 years or older with current LBP. Outcome Measures. All participants completed modified Oswestry Disability (mOSW) and Quebec Back Pain Disability (QUE) questionnaires, as well as the Medical Outcomes Survey Short-Form 36 questionnaire at baseline. At follow-up, 56 participants completed the mOSW and the QUE for reliability assessment. RESULTS: Test-retest reliability of the mOSW and QUE were excellent with intraclass correlation coefficients of 0.92 (95% confidence interval [CI]: 0.86, 0.95) and 0.94 (95% CI: 0.90, 0.97), respectively. Participants with high pain severity and high levels of functional limitation had higher scores on the mOSW (P < 0.0001) and QUE (P < 0.001) scales than other participants, which represents good construct validity for both scales. The threshold for minimum detectable change is 10.66 points for the mOSW and 11.04 points for the QUE. Both questionnaires had sufficient scale width to accurately measure changes in patient status. CONCLUSIONS: It appears that both questionnaires have excellent test-retest reliability and good construct validity when used to evaluate LBP-related disability for older adults with varying degrees of LBP. Neither questionnaire appears to have superior psychometric properties; therefore, both the Oswestry and Quebec can be recommended for use among geriatric patients with LBP.