Predicting SF-6Dv2 utility scores for chronic low back pain using the Oswestry Disability Index and Roland-Morris Disability Questionnaire

ABSTRACT

Background: Generic preference-based measures are used to evaluate disability and health-related quality of life (HRQoL).

Objective: To evaluate if Short Form Six-Dimensions (SF-6Dv2) is correlated with specific current questionnaires used in chronic low back pain (CLBP) and if a predictive equation of SF-6Dv2 could be established.

Methods: Between October 2018 and January 2019, an online survey on CLBP was conducted. HRQoL was measured with two specific questionnaires, i.e. Oswestry Disability Index (ODI) and Roland-Morris Disability Questionnaire (RMDQ), and with the new version of the SF-6Dv2 as a generic preference-based measure.

Results: 402 subjects completed at least two of the three HRQoL questionnaires. Mean (95% confidence interval) of SF-6Dv2, ODI, or RMDQ were, respectively, 0.561 (0.553–0.569), 43.7 (42.1–45.2), and 10.3 (9.8–10.8). SF-6Dv2 was moderately correlated with ODI and RMDQ (r = −0.635 and r = −0.542, p < 0.001). The best model to predict SF-6Dv2 explained 50.6% of variability and included ODI. The correlation between actual and predicted SF-6Dv2 was 0.71.

Conclusion: This study demonstrated that SF-6Dv2 was moderately correlated with ODI and RMDQ and that ODI was a better predictor. There was a strong correlation between actual and predicted SF-6Dv2 from multivariate models. These results suggest that the model can be used in similar studies to estimate the SF-6Dv2 when it was not measured.

KEYWORDS:

• Chronic low back pain
• disability
• health-related quality of life
• SF-6Dv2
• utility score
• QALY

Acknowledgments

We would like to thanks all those who participated in this study, particularly members of the Association québécoise de la douleur chronique (AQDC). TGP is member of the FRQS-funded Centre de recherche de l’Institut universitaire en santé mentale de Montréal.

Declaration of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewers disclosure

Peer reviewers on this manuscript have no relevant financial relationships or otherwise to disclose.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the HB-HTA unit of the CIUSSS de l’Estrie – CHUS.