Validity testing
Both the Kaiser-Meyer-Olkin (KMO) and Bartlett Sphericity tests were
performed to determine if the data collected by the questionnaire were
suitable for the factor analysis. The test results showed that the KMO
values of the Activity subscale and Participation subscale were .914 and
.893, respectively; KMO values > .5 indicated that there
were common factors in the questionnaire items, i.e., the factors were
independent. The results of Bartlett’s chi-square test were all
statistically significant (p < .001), indicating that
the factors were independent and exclusive. Therefore, the questionnaire
data collected in this study were suitable for factor analysis.
EFA was used to extract the construct of the scale. The Activity
subscale had 3 factors with an eigenvalue > 1, explaining
75.176% of the total variance in the scale. However, according to the
scree plot, the curve flattened after the fourth factor. Therefore,
based on the standard and scree plots for the factors with eigenvalues
> 1.0 and combined with clinical experience and the
factorial structure of the raw scores,30-33,36 we
postulated that the Activity subscale of the Chinese version of the
PaArticular Scales had 3 main factors: lower-limb activity, upper-limb
activity, and self-care activity. Table 3 shows the factor structure
after rotation. A factor with an eigenvalue > 1 was
obtained from the Participation subscale, explaining 62.83% of the
total variance in the scale. However, according to the scree plot, the
curve flattens after the second factor. The Participation subscale of
the Chinese version of the PaArticular Scales had only 1 major factor:
participation. Tables 3 and 4 show the factor structure after rotation
of the Activity and Participation subscales.
For content validity, correlation coefficients for factors 1, 2, and 3
and the item-to-subscale were obtained; the ranges for these
coefficients were .725-.888, 706-.886, and .622-.853, respectively, and
the Cronbach’s α was .958, .951, and .910, respectively.
For the criterion-related validity and according to the classification
proposed by Cohen,37 Pearson’s product-moment
correlation revealed that the correlation coefficient (r ) between
the Chinese version of the PaArticular Scales and the WHODAS 2.0-36
items was .770, which was interpreted as a large coefficient, with ap -value less than .001, indicating a highly significant result.
The correlation coefficient (r ) between the Chinese version of
the PaArticular Scales and the WHOQOL-BREF was -.553, which was
interpreted as a large coefficient, with a p -value less than
.001, indicating a highly significant result. The correlation
coefficients between the Activity subscale and the WHODAS 2.0 ̵̵36 items
and WHOQOL-BREF were .722 and -.502, respectively, the correlation
coefficients between the Participation subscale and the WHODAS 2.0 ̵̵36
items and WHOQOL-BREF were .742 and -.580, respectively; all the
correlation coefficients were highly significant (Table 5).