## 3 Results
### Validation of the ABIS-E
#### 3.2.2 Validity  
* **Construct validity**  
To evaluate the structural validity of the ABIS-E, factor analysis was used. Principal component extraction with Varimax rotation was performed. The Kaiser-Meyer-Olkin (KMO) sample adequacy measure was 0.779. The significance level of [PERSON]'s test of sphericity was \(p=0.000\). The high value of the KMO measure obtained and the significance \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Scale Means if Item** & **Scale Variance if Item** & **Corrected Item–Total** & **Cronbach’s Alpha if** \\  & **Removed** & **Removed** & **Correlation** & **Item Removed** \\ \hline Item 1 & 49.19 & 122,518 & 0.531 & 0.729 \\ Item 2 & 49.14 & 122,953 & 0.390 & 0.737 \\ Item 3 & 47.66 & 152,312 & \(-\)0.436 & 0.797 \\ Item 4 & 48.11 & 120,154 & 0.568 & 0.725 \\ Item 5 & 49.78 & 125,479 & 0.434 & 0.736 \\ Item 6 & 49.41 & 122,634 & 0.527 & 0.729 \\ Item 7 & 48.58 & 127,275 & 0.347 & 0.741 \\ Item 8 & 49.44 & 121,194 & 0.559 & 0.726 \\ Item 9 & 48.51 & 118,365 & 0.596 & 0.722 \\ Item 10 & 49.27 & 122,813 & 0.428 & 0.735 \\ Item 11 & 48.79 & 124,054 & 0.426 & 0.735 \\ Item 12 & 48.44 & 150,722 & \(-\)0.367 & 0.798 \\ Item 13 & 48.07 & 127,981 & 0.255 & 0.748 \\ Item 14 & 49.51 & 119,892 & 0.619 & 0.722 \\ Item 15 & 49.03 & 126,388 & 0.351 & 0.741 \\ Item 16 & 48.19 & 153,129 & \(-\)0.433 & 0.801 \\ Item 17 & 49.08 & 120,604 & 0.483 & 0.730 \\ Item 18 & 49.16 & 117,889 & 0.616 & 0.720 \\ Item 19 & 48.15 & 120,158 & 0.439 & 0.733 \\ Item 20 & 49.56 & 118,889 & 0.617 & 0.721 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Summary element–total statistics of the Spanish version of the Amputee Body Image Scale (ABIS-E). level of the sphericity test (\(p<0.05\)) confirm that the data set is suitable for factor analysis. In terms of total variance, the three factors accounted for 60.26% of total variance, which can be considered as a reasonable factor number. In the rotation phase of the factor analysis, the aim was to achieve simpler and theoretically more meaningful factor solutions. The Varimax rotation was used to investigate factor loadings. The three factors (social, personal, and functional) were labelled according to the items' nature of construct. Factor 1 was a personal factor (items 6, 8, 1, 16, 12, 10, 11, 4, 9, 2, and 5); factor 2 was a social factor (items 14, 20, 18, 17, 3, 15, 19, and 7); and factor 3 was a functional factor (items 7 and 13) (Table 2). **Convergent validity**  
[PERSON]'s and [PERSON]'s correlation indices were used to determine the convergent validity between the factors extracted from the ABIS-E and the other questionnaires used. Significant correlations were obtained between factor 1 \"Personal\" of the ABIS with the PEQ questionnaire dimensions: appearance (rho = \(-0.535\), \(p\) = 0.000); wellness (rho = \(-0.570\), \(p\) = 0.000). The negative values are due to the inverse relationship of their scores: higher values for the ABIS show a disturbance of body image, while for the PEQ they mean higher functionality. The highest correlation found was between the item \"How annoying is it to see people looking at you and your prosthesis?\" and factor 1 \"Personal\" (rho = 0.712, \(p\) = 0.000). Comparing the ABIS with the BPI questionnaire, a statistically significant correlation was observed with its dimensions (interference/severity), although the coefficient was insufficient to be considered relevant (rho \(<0.3\), \(p<0.05\)). As for the HADS questionnaire, significant correlations were obtained between the factor 1 \"Personal\" and the two dimensions of the HADS questionnaire: depression (r = 0.677, \(p\) = 0.000) and anxiety (rho = 0.575, \(p\) = 0.000). Correlation analysis with the EQ-5D-5L quality of life questionnaire showed a statistically significant correlation between factors 1 (personal) and 3 (functional). The highest correlation was observed between the EQ-5D-5L dimension \"anxiety/depression\" and factor 1 (rho = 0.609, \(p\) = 0.000), considered an average correlation.