Validity of the short musculoskeletal function assessment questionnaire in patients with a spine fracture

Abstract

Abstract Purpose The aim of this study was to validate the use of the Short Musculoskeletal Function Assessment (SMFA) questionnaire in patients with a spine fracture. Methods Cross-sectional cohort of individuals that had sustained a spine fracture (C1-L5) one year earlier. Patients were asked to fill out SMFA, Oswestry Disability Index (ODI), EQ-5D-3L and EQ-VAS. Spearman’s rank correlation coefficient (rho) was used to assess convergent validity for each patient-reported outcome measure (PROM). Bland–Altman plots were used to assess PROM agreement. Results 82 patients completed all questionnaires. The correlations between SMFA Dysfunction and Bother indices and ODI were 0.89 and 0.86, with EQ-5D-3L index 0.89 and 0.80, and with EQ-VAS 0.80 and 0.73, respectively. The correlation for separate categories of the SMFA dysfunction index (daily activities, emotional status, arm and hand function, mobility) ranged between 0.71–0.87 for ODI, 0.72–0.84 for EQ-5D-3L index, and 0.67–0.77 for EQ-VAS. A selection of the ten items of SMFA that had the highest correlations with ODI resulted in a correlation of 0.91. The agreements between SMFA indices and ODI in Bland–Altman plots were good with small differential biases and minimal proportional biases, but worse for SMFA and EQ-5D-3L index and EQ-VAS. Conclusion The SMFA indices are highly correlated with ODI in patients with a spine fracture. The Dysfunction index and Bother index, or selected SMFA items, may be used to assess outcome in patients with spine fractures as an alternative to ODI.