Cross-Cultural Adaptation and Validation of the Dance Functional Outcome Survey for Turkish Dancers (DFOS-TR)

In dance, injuries are significant factors that can bring an active dance career to an end. A patient-reported outcomes questionnaire with established validity and reliability is useful for determining and evaluating the functional status of dancers before or after injuries. However, no valid and reliable survey is available in Turkish to assess dancers' functionality levels. The objective of this study was to translate, culturally adapt, and validate the characteristics of the Turkish version of the Dance Functional Outcome Survey (DFOS-TR) in adult dancers.

The DFOS-TR underwent forward translation, reconciliation, backward translation, and thorough review by an expert committee to ensure optimal alignment with the original English DFOS. A sample of 113 dancers (55 injured and 58 healthy) voluntarily participated in the research. Construct validity was assessed by comparing DFOS-TR to SF-36 using Pearson correlations; exploratory factor analysis and internal consistency were conducted; and sensitivity was evaluated through the generation of receiver operating characteristic curves and calculation of the area under the curve (AUC). Test-retest reliability was assessed by examining 26 dancers over a 15-day period, employing intraclass correlation (ICC). Various methods were employed, including ICC, standard error of measurement (SEM), minimal detectable change at the 95% confidence interval (MDC95), and standardized response mean (SRM). DFOS-TR scores were compared using paired samples t-test and two-way repeated measures ANOVA (p<0.05). The scores of injured dancers were examined to identify any floor or ceiling effects.

The DFOS-TR demonstrated very high test-retest reliability (ICC=0.84). Single-factor loading in exploratory factor analysis confirmed the scale's unidimensionality and high internal consistency (a=0.79), A positive moderate correlation was found between SF-36 physical component and DFOS-TR total score (r=0.44; p=0.046) and activities of daily living (ADL) subscore (r=0.58; p=0.006). Cut-off value of 85.5 for DFOS-TR total score yielded in 87.3% sensitivity and 36.2% specificity. The scale did not exhibit ceiling or floor effects among the injured dancers, indicating robust measurement properties.

The DFOS-TR can be used as a reliable, internally consistent, and effective measurement tool for Turkish-speaking dancers in health as well as during and after lumbar or lower extremity injuries.