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Dance Functional Outcome Survey

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Purpose

The DFOS is a 14-question “self-report questionnaire for healthy and injured [modern, ballet, contemporary] dancers, focusing on lower back and lower extremities.” (Bronner, S., Chodock, E., Urbano, I.E.R., & Smith, T., 2019) The survey addresses activities of daily living and dance/technique abilities.  

Link to Instrument

Instrument Details

Acronym DFOS

Area of Assessment

Functional Mobility
Pain
Occupational Performance

Assessment Type

Patient Reported Outcomes

Cost

Free

Actual Cost

$0.00

Key Descriptions

  • 14 questions
    - ADL and dance/technique specific
    - “requiring answers of agreement or disagreement to a statement”
  • 1 general dance performance grade question
    - 0-100 scale
  • ADL section: Max 40 points
  • Technique section: Max 50 points
    - Total of 90 points max
  • Higher score reflects higher function

Number of Items

14 questions + 1 self-perception question

Time to Administer

15 minutes

Required Training

No Training

Age Ranges

Adolescent

13 - 17

years

Adult

18 - 64

years

Instrument Reviewers

Stephanie Beasley, SPT, B.S. Kinesiology. University of North Texas Health Science Center at Fort Worth

Kathleen Luedtke-Hoffmann, PT, MBA, PhD. University of North Texas Health Science Center at Fort Worth

Body Part

Back
Lower Extremity

ICF Domain

Activity
Participation

Measurement Domain

Participation & Activities
Motor

Considerations

  • During  initial analysis, the authors assessed only adult dancers ages 15 - 18+
     
  • DFOS has only been analyzed in modern, ballet, and contemporary dance populations due to the survey addressing specific ballet technique and movement. DFOS may not be beneficial to use with dancers with different dance training.
     
  • Encourage dancers to fill out all questions on the survey to the best of their ability. An online version of the survey that requires question completion before moving on to the next question can be utilized.
     
  • For the DFOS-Spanish analyzations (de-la-Cruz-Torres, B., Barrera-García-Martín, I., Romero-Morales, C., & Bronner, S., 2020), inclusion criteria for injured dancers differed from the inclusion criteria for other DFOS (English) analyses (Bronner, S., Chodock, E., Urbano, I. E. R., & Smith, T., 2019) which may explain the differences in normative data between DFOS-Sp and DFOS.
    • DFOS-Sp: “...clinical diagnosis of any musculoskeletal injury in the low back or lower extremity verified on ultrasound or magnetic resonance imaging” (de-la-Cruz-Torres 2020).
    • DFOS (English): inclusion criteria were new referral for musculoskeletal injury to the low back or lower extremity (Bronner 2019).

Mixed Populations

back to Populations

Standard Error of Measurement (SEM)

Modern/Ballet (Bronner, S., E. Chodock, I. E. R. Urbano and T. Smith (2019); n = 198; mean age = 24.56 +/- 6.22; age range = 18-51;  dance training years = 14.92 +/- 6.55)

  • Combined Healthy and Injured Groups

DFOS total: SEM = 2.31

ADL portion: SEM = 1.29

Technique portion: SEM = 1.86
 

  • Healthy group
    • SEM = 0.58 - 0.86
  • Injured group
    • SEM = 1.72 - 3.22

 

(Bronner, S., Smith, T., Brown, K., Urbano, I. R. (2016); n = 89)

  • DFOS total score: SEM = 2.44
  • Technique: SEM = 3.30
  • ADL: SEM = 2.63

 

Spanish - Contemporary/Ballet (de-la-Cruz-Torres, B., I. Barrera-García-Martín, C. Romero-Morales and S. Bronner (2020); n = 89; mean age = 20.12 +/- 4.30 yrs; dance training = 11.39 +/- 5.64 yrs)

  • Combined Healthy and Injured Groups
  • DFOS-Sp total: SEM = 1.60
    • ADL portion: SEM = 0.92
    • Technique portion: SEM = 1.02
  • Healthy Group
  • SEM = 1.29-1.93
  • Injured group
  • SEM = 0.66-1.49

Minimal Detectable Change (MDC)

Modern/Ballet (Bronner, S., E. Chodock, I. E. R. Urbano and T. Smith (2019))

  • Calculated using MDC = 1.96 x SEM x square root of 2
  • MDC for Combined Healthy and Injured Groups
    • MDC = 6.40 points

 

Spanish - Contemporary/Ballet (de-la-Cruz-Torres, B., I. Barrera-García-Martín, C. Romero-Morales and S. Bronner (2020)

  • Calculated using MDC = 1.96 x SEM x square root of 2
  • MDC for Combined Healthy and Injured Groups
    • MDC = 4.43 points

Cut-Off Scores

Modern/Ballet (Bronner, S., E. Chodock, I. E. R. Urbano and T. Smith (2019))

  • Cutoffs were 77.5 for the DFOS total score (based on sensitivity and specificity values of 0.92 and 0.82, respectively)
    • 35.5 for ADL subscore (sensitivity 0.85; specificity 0.82)
    • 43.5 for technique subscore (sensitivity 0.91;  specificity 0.81)

 

Spanish - Contemporary/Ballet (de-la-Cruz-Torres, B., I. Barrera-García-Martín, C. Romero-Morales and S. Bronner (2020)

  • Cutoffs were 80.5 for DFOS-Sp total (sensitivity and specificity values 0.76 and 0.78, respectively)
    • 34.5 for ADL scores (sensitivity 0.76; specificity 0.74)
    • 45.5 for Technique scores (sensitivity 0.77; specificity 0.68)

Normative Data

Modern/Ballet (Bronner, S., E. Chodock, I. E. R. Urbano and T. Smith (2019))

  • Data from 725 participants
    • Healthy dancers scored avg 85.75 +/- 5.64
    • Injured dancers scored avg 32.11 +/- 24.4

 

Spanish - Contemporary/Ballet (de-la-Cruz-Torres, B., I. Barrera-García-Martín, C. Romero-Morales and S. Bronner (2020))

  • Data from 127 participants
    • Healthy dancers scored avg 83.34 +/- 7.66
    • Injured dancers scored avg 71.35 +/- 13.84

Test/Retest Reliability

Modern and Ballet (Bronner, S. and I. R. Urbano (2018); n = 80; mean age = 25.69 +/- 5.49; dance training years = 14.71 +/- 6.22; Time between assessments: 4-9 days)

  • High: DFOS LS v. LS (r = .99), VAS v. VAS (r = 0.94) - 16-item
    • Removal of the two back-related items (making it a 14 item questionnaire) improved technique and total score correlations and internal consistency.
    • LS v. VAS (r=0.74)

(Bronner, S., E. Chodock, I. E. R. Urbano and T. Smith (2019; n =198; 130 female, 68 male; mean ± SD age, 24.56 ± 6.22 years; range, 18–51 years; time between assessments: 4-9 days)

  • Combined healthy and injured group
    • Very high test-retest reliability (ICC = 0.99)
  • High healthy-group test-retest reliability of DFOS total score (ICC = 0.95), ADL (ICC = 0.89), and technique subscores (ICC = 0.92)
    • Moderate test-retest reliability specifically for rond de jambe item (ICC = 0.67)
    • SEM ranged from 0.58 to 0.86 (healthy group)
  • High injured-group reliability for all DFOS scores and items
    • SEM ranged from 1.72 to 3.22 (injured group)

 

(Bronner, S., Smith, T., Brown, K., Urbano, I. R. (2016) Abstract only; n = 89)

  • High: Total scores (r = 0.836); Technique sub-score (r = 0.803); ADL sub-score (r=0.797)

 

Spanish - Contemporary/Ballet (de-la-Cruz-Torres, B., I. Barrera-García-Martín, C. Romero-Morales and S. Bronner (2020); n = 89; mean age = 20.12 +/- 4.30 yrs; dance training = 11.39 +/- 5.64 yrs; time between assessments: 7-10 days)

  • Combined Healthy and Injured Group
    • Very High test-retest: ICC ≥ 0.98 for DFOS-Sp total, ADL and technique scores
    • Very High item-level reliability: ICC ≥ 0.92
  • Healthy group
    • High test-retest:
      • DFOS-Sp total: ICC = 0.92
      • ADL: ICC = 0.89
      • Technique: ICC = 0.91
    • High item-level reliability:
      • ICC range = 0.70-0.92
      • Moderate item-level for stairs, developpe, rond de jambe
        • ICC range = 0.66-0.69
  • Injured group
    • Very high: ICC = 0.99 for all DFOS-Sp scores and item level

Internal Consistency

Modern and Ballet (Bronner, S., E. Chodock, I. E. R. Urbano and T. Smith (2019) n = 725; had professional, pre-professional, teachers/ choreographers/ directors; age = 22.51 +/- 7.02; dance training years = 13.48 +/- 7.01)

  • Excellent: Cronbach’s alpha for all 14 items (0.96), 6 items within ADL portion (0.90), and 8 technique portion items (0.92)

 

(Bronner, S. and I. R. Urbano (2018); n = 80; Mean age was 26±5 yrs with 15±6 yrs dance training)

  • Excellent: Cronbach’s alpha 0.97 for 14-item questionnaire
    • Cronbach’s alpha 0.90 for 16-item questionnaire

(Bronner, S., Smith, T., Brown, K., Urbano, I. R. (2016) Abstract only; n = 89)

  • High: Cronback’s alpha (0.83) for all 14 items  

 

Spanish - Contemporary/Ballet (de-la-Cruz-Torres, B., I. Barrera-García-Martín, C. Romero-Morales and S. Bronner (2020); n = 89; mean age = 20.12 +/- 4.30 yrs; dance training = 11.39 +/- 5.64 yrs)

  • Excellent: Cronbach’s alpha values for all 14-items (0.91, CI=0.88-0.94), 6 items within ADL (0.91), and 8 items within technique (0.91).

Criterion Validity (Predictive/Concurrent)

Concurrent Validity

Modern/Ballet (Bronner, S. and I. R. Urbano (2018))

Scores

DFOS v. CinnKnee

DFOS v. FAQ

DFOS v. Oswestry

Total score

0.75

0.67*

0.73

ADL

0.68

0.42

0.67

 Walking

0.77

 

 

 Overall mvt v. Overall activity, Work

0.77

0.78

 

 Stairs

0.91

0.28

 

 Stability

0.21

0.37

 

 Pain

0.37

0.48

0.48

Technique/Sport

0.66†

0.45

0.67

 Plié v. Squat

 

0.82

 

 Turn, Jump, Travel v. Run, Jump, Twist

0.65

0.70

 

Self-rating

0.60

 

0.43

*FAQ total score minus stiffness question; † Technique score minus 2 back items; Abbreviations: Cincinnati Knee Rating System=CinnKnee; Foot-Ankle Questionnaire=FAQ; versus=v; activities of daily living=ADL; movement=mvt

 

(Bronner, S., Smith, T., Brown, K., Urbano, I. R. (2016) n = 51)

  • Moderate: DFOS v. SF-36 PCS (physical component); r = 0.605
  • Weak: DFOS v. SF-36 MCS (mental component); r = 0.400

Construct Validity

Modern and Ballet (Bronner, S., E. Chodock, I. E. R. Urbano and T. Smith (2019) n = 725; had professional, pre-professional, teachers/choreographers/directors; age = 22.51 +/- 7.02; dance training years = 13.48 +/- 7.01)

  • Strong correlations between SF-36 PCS (physical component summary) and DFOS total score (r = 0.79) and subscores (ADL, r = 0.79; technique, r = 0.77)
     
  • Weak correlations between SF-36 MCS (mental component summary) and DFOS total score (r = 0.26) and subscores (ADL, r = 0.31; technique, r = 0.26)

 

Spanish - Contemporary/Ballet (de-la-Cruz-Torres, B., I. Barrera-García-Martín, C. Romero-Morales and S. Bronner (2020); n= 127; mean age = 20.12 +/- 4.30 yrs; dance training = 11.39 +/- 5.64 yrs)

  • Moderate Pearson correlation between SF-36 PCS (physical component summary) vs. DFOS-Sp total (r= 0.61) and subscores (ADL, r = 0.56; technique, r = 0.58)
    • Individual ADL-items vs. PCS-domains (r = 0.26-0.54)
    • Individual Technique-items vs. PCS-domains (r = 0.20-0.50)
       
  • Weak to no correlations between SF-36 MSC (mental component summary) vs. DFOS-Sp total and subscores
    • Weak correlation: Individual ADL-items vs MSC-domains & Technique-items vs. MCS-domain

Face Validity

Modern and Ballet (Bronner, S. and I. R. Urbano (2018))

“DFOS was submitted to an expert panel of 17 dance professionals (clinicians and dancers) and a specialist in outcomes development. They assessed what body regions were best reflected, if it was user-friendly, applicable to a wide range of training levels and populations, and how dancers would respond to the test length. We revised or dropped questions if 20% or more of the experts questioned them. The remaining 16 questions were re-weighted and assigned either 0–5 or 0–10 points based on expert item ranking. A score of 100 represented maximal function, with ADL and Technique representing 40 and 60 points, respectively.”

 

(Bronner S, Turner R. (1999) Abstract)

“Experts in the area of dance medicine (orthopaedists and physical therapists),

dance education and research, and elite dancers reviewed the DFOS for content validity.”

Floor/Ceiling Effects

Modern and Ballet (Bronner, S., E. Chodock, I. E. R. Urbano and T. Smith (2019)

  • The tool does not demonstrate floor or ceiling effects.

Spanish - Contemporary/Ballet (de-la-Cruz-Torres, B., I. Barrera-García-Martín, C. Romero-Morales and S. Bronner (2020)

  • The tool does not demonstrate floor or ceiling effects.

Responsiveness

Modern and Ballet (Bronner, S., E. Chodock, I. E. R. Urbano and T. Smith (2019) n = 47; mean age = 27.60 +/- 6.26 years)

  • Highly responsive in reflecting the functional status of dancers
    • scores taken when dancer was healthy, injured, discharged, and 3 months after discharge
  • Excellent sensitivity for distinguishing between healthy and injured
    • AUC value of 0.94
       

Spanish - Contemporary/Ballet (de-la-Cruz-Torres, B., I. Barrera-García-Martín, C. Romero-Morales and S. Bronner (2020)

  • Internal Responsiveness (n=51; 46 female, 5 male; mean age 19.12 +/- 3.02 years)
    • Highly responsive and sensitive; scores showed significant differences across time for DFOS-Sp total
      • scores were taken at injured, discharge and 3-months
      • AUC = 0.82

Bibliography

Bronner, S., Chodock, E., Urbano, I. E. R., & Smith, T. (2019). Psychometric Properties of the Dance Functional Outcome Survey (DFOS): Reliability, Validity, and Responsiveness. J Orthop Sports Phys Ther, 49(2), 64-79. doi:10.2519/jospt.2019.8247
 

Bronner, S., Smith, T., Brown, K., Urbano, I. R. (2016 February). Reliability and validity of a dance outcomes instrument. Research Gate. https://www.researchgate.net/profile/Shaw_Bronner/publication/295829904_Reliability_and_validity_of_a_dance_outcomes_instrument/links/56cdc6f908ae059e37533149.pdf (Abstract)

Bronner S, Turner R. The Dance Functional Outcome System (DFOS): A new measurement tool. J Orthop Sports Phys Ther 1999; 29: A-20 (Abstract)          
 

Bronner, S., & Urbano, I. R. (2018). Dance Functional Outcome Survey: Development and Preliminary Analyses. Sports Med Int Open, 2(6), E191-e199. doi:10.1055/a-0729-3000
 

de-la-Cruz-Torres, B., Barrera-García-Martín, I., Romero-Morales, C., & Bronner, S. (2020). Cross-Cultural Adaptation of the Dance Functional Outcome Survey (DFOS) for Spanish Dancers. Diagnostics (Basel), 10(3). doi:10.3390/diagnostics10030169

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