Comparing three measures of sleep disturbance in persons with chronic low back and neck pain.

OBJECTIVES

To evaluate the concordance among three sleep disturbance items from the Oswestry Disability Index (ODI), Neck Disability Index (NDI), and the Patient-Reported Outcomes Measurement Information System (PROMIS).

METHODS

We examined the effects of item wording in a sample of patients with chronic low back pain (CLBP) and chronic neck pain (CNP) who responded to three measures that included sleep disturbance items. We administered the items at baseline and 3-month follow-up in an observational study of patients in the United States (N=1,020). We estimated associations among the items using correlations and cross-tabulations.

RESULTS

Polychoric correlations among the sleep items ranged from 0.56 to 0.71. The ODI, NDI, and PROMIS-29 were strongly correlated at baseline and three months later. The cross-tabulations revealed that the ODI and NDI responses were compressed, with most responses indicating low levels of sleep disturbance. Answers to the PROMIS-29 item were more widely distributed across its response categories.

CONCLUSION

When determining the value of each measure, researchers should weigh their different properties and tie the selected measures to their unique research objectives.