Table 3 Comparison of the psychometric properties of the 2 formats of the 16-item EQS-H (Study B – 4-point Likert scale and Study C – 5-point Likert scale)
Study B 4-point Likert scale (N = 1246) | Study C 5-point Likert scale (N = 886) | |||||
|---|---|---|---|---|---|---|
Items properties | MI1 | RS2 | Global | MI1 | RS2 | Global |
# of items in the scale | 9 | 7 | 16 | 8 | 8 | 16 |
% of questionnaires with at least 1/2 the items completed | 96.2 | 100.0 | 100.0 | 96.2 | 99.2 | 98.6 |
# of items with "Missing data" >20% | 1 | 0 | 1 | 0 | 0 | 0 |
# of items with "Does not apply" response >20% | 1 | 0 | 1 | 0 | 0 | 0 |
# of items with ceiling effect >50% | 7 | 7 | 14 | 0 | 0 | 0 |
# of items with floor effect >50% | 0 | 0 | 0 | 0 | 0 | 0 |
Scaling properties | ||||||
Mean score (+-SD) | 79.9 (20.8) | 93.6 (11.4) | - | 59.2 (21.0) | 69.0 (19.8) | 64.2 (18.7) |
Skewness value/SE | -1.23/0.07 | -2.41/0.07 | - | -0.08/0.08 | -0.23/0.08 | -0.07/0.08 |
Median | 85.7 | 100 | - | 59.4 | 68.8 | 64.1 |
Ceiling effect (%) | 24.7 | 61.2 | - | 4.3 | 8.4 | 2.6 |
Floor effect (%) | 0.5 | 0 | - | 0.4 | 0 | 0 |
Inter-scale correlation | 0.26 | - | - | 0.67 | - | - |
# of item correlation with own scale >0.40 | 9 | 7 | - | 8 | 8 | - |
# of item correlation with own scale greater than with other scales | 9 | 7 | - | 8 | 8 | - |
Cronbach's αgoefficient | 0.80 | 0.81 | - | 0.92 | 0.93 | 0.95 |
Sum of square of the factors before rotation | 32.5% | 33.0% | 65.5% | |||
% of variance explained by the factor | 22% | 21% | 43% | 11.0% | 54.5% | 65.5% |