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Community-dwelling experienced manual wheelchair users: (Rushton et al., 2013; n = 83; median age = 50; male = 69.9%; median years using manual wheelchair = 13.0 years)

• SEM for entire group (n = 83): 5.9

Power wheelchair users: (Rushton et al., 2018; n = 73; mean age = 60.5 (7.1) years; male = 50.7%; mean years using a power wheelchair = 11.2 (10.0))

• SEM for entire group (n = 73): 4.101 (calculated) 

Community-dwelling experienced manual wheelchair users: (Rushton et al., 2013)

• MDC for entire group (n = 83): 16.4

Power wheelchair users: (Rushton et al., 2018)

• MDC at 95% CI for the entire group (n = 73): 11.37 (calculated)

Community-dwelling experienced manual wheelchair users: (Rushton et al., 2013)

Demographic, clinical, and wheelchair use characteristics for the WheelCon-M

Wheelcon-M: Wheelchair Use Confidence Scale for manual wheelchair users; IQR: interquartile range

Community-dwelling experienced manual wheelchair users: (Rushton et al., 2013; test-retest interval = 1 week)

• Acceptable test-retest reliability (ICC = 0.84)

Power wheelchair users: (Rushton et al., 2018; data collection interval = 1 month)

• Acceptable test-retest reliability (ICC = 0.85)

Community-dwelling experienced manual wheelchair users: (Rushton et al., 2013)

• Excellent internal consistency (Cronbach¡¯s alpha = 0.92*)

Power wheelchair users: (Rushton et al., 2018)

• Excellent internal consistency (Cronbach¡¯s alpha = 0.92*)

*Scores higher than .9 may indicate redundancy in the scale questions

Concurrent Validity:

Community-dwelling experienced manual wheelchair users: (Rushton et al., 2013)

• Adequate concurrent validity between the WheelCon-M 2.1 and relevant outcome measures:
  • Wheelchair Skills Test 4.1 (r = 0.52, p < 0.001)
  • Wheelchair Skills Test ¨C Questionnaire 4.1 (r = 0.58, p < 0.001)
  • Barthel Index (r = 0.32, p = 0.004)
  • Hospital Anxiety and Depression Scale (r = -0.43, p < 0.001)
  • Life Space Assessment (r = 0.38, p < 0.001)
• Poor concurrent validity between the WheelCom-M 2.1 and the Interpersonal Support Evaluation List - 12 item (r = 0.21, p = 0.057)

Power wheelchair users: (Rushton et al., 2018)

• Correlations between WheelCon-P and validation outcome measures:
  • Adequate correlation with the Assistive Technology Outcomes Profile for Mobility (ATOP-activity): (r = 0.36)
  • Adequate correlation with the Assistive Technology Outcomes Profile for Mobility (ATOP-participation): (r = 0.47)
  • Adequate correlation with the Life-Space Assessment (LSA): (r = 0.39)
  • Adequate correlation with the Wheelchair Skills Test Questionnaire for powered wheelchair users, version 4.1 (WST-Q): (r = 0.49)
  • Adequate correlation with the Wheelchair Skills Test for powered wheelchair users, version 4.1 (WST): (r = 0.42)
  • Adequate correlation with the Hospital Anxiety and Depression Scale (HADS-anxiety): (r = -0.47)
  • Adequate correlation with the Hospital Anxiety and Depression Scale (HADS-depression): (r = -0.34)
  • Poor correlation with the Interpersonal Support Evaluation List (ISEL): (r = 0.26)

Convergent validity:

Power Wheelchair Users: (Sakakibara et al., 2018; n = 189; age ¡Ý 19 years; mean age = 56.7 (13.0) years; male = 50.3%; mean years of wheelchair use experience = 20.4 (16.4) years; response format modified from 0-100 to 0-10; 59-item WheelCon-P)

The 59-items of the WheelCon-P were divided into two broad conceptual areas depending upon whether the item asked about physical (mobility items, n = 42) or social (social situation items, n = 17) aspects of wheelchair use. Parallel principal components analyses were conducted to determine that all of the items on each scale comprised a single dimension. Rasch analyses were then conducted on the two subscales. A 16-item short form of the WheelCon-P was created based on the results of these analyses and the Rasch rating scale model was applied to it as well. The Rasch analyses conducted on the dimensions and short form resulted in:

• 11 items related to Mobility Self-Efficacy had a good fit in the Rasch Rating scale model. With the exception of the two lowest and highest scores, all other measurements (96% of all measurements) had reliability estimates ¡Ý 0.70.
• 5 items related to Social Situation Self-Efficacy had a good fit in the Rasch Rating scale model. With the exception of the two lowest and highest scores, all other measurements (92% of all measurements) had reliability estimates ¡Ý 0.70.
• For the WheelCon-P Short Form comprised of the above 16 items, 13 items related had a good fit in the Rasch Rating scale model. With the exception of the two lowest and highest scores, all other measurements (98% of all measurements) had reliability estimates ¡Ý 0.70.

Discriminant validity:

Community-dwelling experienced manual wheelchair users: (Rushton et al., 2013)

• Adequate discriminant validity between scores on the WheelCon-M 2.1 and years of wheelchair experience (r = 0.32, p = 0.003)
• Poor discriminant validity between scores on the WheelCon-M 2.1 and age (r = ¨C0.19, p = 0.780).
  
   

Manual wheelchair users: (Sakakibara et al., 2015; n = 220; mean age = 54.2 (13.0); male = 63.2%; ¡Ý 6 months experience w/daily wheelchair use; mean years of wheelchair use = 17.9 (14.7) years; response format modified from 0-100 to 0-10)

• Principal components analysis indicated the presence of two dimensions: Mobility Efficacy (46 items) and Self-Management Efficacy (25 items). Separate Rasch analyses conducted on the dimensions resulted in:
• 13 items related to Mobility Efficacy had a good fit in the Rasch rating scale model. With the exception of the two lowest and highest scores, all remaining standardized (97% of all scores) had reliability estimates ¡Ý 0.70. 
• 8 items in the Self-Management efficacy subscale fit the Rasch Rating Scale model. With the exception of the two lowest and highest scores, all remaining standardized (95% of all scores) had reliability estimates ¡Ý 0.70.

Persons who use a manual wheelchair, professionals, & researchers: (Rushton et al., 2011; n = 43; structured interviews conducted to generate items followed by a Delphi survey for item selection)

The WheelCon-M appears to have good content validity, as it was based on a thorough review of the literature and the items determined by a panel of 43 experts including persons who use wheelchairs, health care professionals, and researchers. Each expert ranked the items quantitatively and qualitatively.  ¡°We believe this group of individuals is a representative sample of experts in the area of wheeled mobility and/or confidence (p. 59).¡±

Healthcare Professionals and Power Wheelchair Users: (Rushton et al., 2017; Health Care Professionals Focus Group: n = 12, mean age = 42.1 (8.5), age range = 28-54, female = 83%; Power Wheelchair Users Focus Group: n = 6, mean age = 44.8 (20), age range = 25-65, female = 50% ; Think Aloud Group; n = 6, Mean Age = 54.8 (6), age range = 25-65, female = 50%)

The WheelCon-P was developed by adapting the WheelCon-M through two phases. The first phase involved item modification using a focus group study of 12 healthcare professionals including occupational therapists and physical therapists with an average of 14 years of experience and 6 power wheelchair users with an average of 8 years using a power wheelchair. The second phase involved items refinement using a think aloud process of 6 wheelchair users with an average of 8 years using a power wheelchair. The study resulted in developing the content of the 59-item WheelCon-P.

Power Wheelchair Users: (Rushton et al., 2018)

• Excellent: No floor effects
• Adequate ceiling effect of 4.1% found (3 participants reported a score of 100 at baseline and post-1 month)

Community-dwelling experienced manual wheelchair users: (Rushton et al., 2013)

¡°The SEM [standard error of measurement] was 5.9 and the SRD [smallest real difference] was 16.4 providing an indication of the minimal change in score that would reflect a meaningful change beyond measurement error for a group of individuals and a single individual respectively¡± (Rushton et al., 2013, p. 64).