Cross-cultural adaptation and validation of the Danish version of the Short Musculoskeletal Function Assessment questionnaire (SMFA).

PURPOSE: The aim of this study was to translate and culturally adapt the Short Musculoskeletal Function Assessment (SMFA) into Danish (SMFA-DK) and assess the psychometric properties.

METHODS: SMFA was translated and cross-culturally adapted according to a standardized procedure. Minor changes in the wording in three items were made to adapt to Danish conditions. Acute patients (n = 201) and rehabilitation patients (n = 231) with musculoskeletal problems aged 18-87 years were included. The following analysis were made to evaluate psychometric quality of SMFA-DK: Reliability with Chronbach's alpha, content validity as coding according to the International Classification of Functioning, Disability and Health (ICF), floor/ceiling effects, construct validity as factor analysis, correlations between SMFA-DK and Short Form 36 and also known group method. Responsiveness and effect size were calculated.

RESULTS: Cronbach's alpha values were between 0.79 and 0.94. SMFA-DK captured all components of the ICF, and there were no floor/ceiling effects. Factor analysis demonstrated four subscales. SMFA-DK correlated good with the SF-36 subscales for the rehabilitation patients and lower for the newly injured patients. Effect sizes were excellent and better for SMFA-DK than for SF-36.

CONCLUSION: The study indicates that SMFA-DK can be a valid and responsive measure of outcome in rehabilitation settings.