For these reasons, Structural Equation Modeling (SEM) will be used in this study to assess the …show more content…
It allows people to rate the severity of pain and the impact of the pain on the main aspects of feeling and function. It has fifteen items and two subscales: pain severity and pain interference. Each item is rated on an eleven-point scale, from 0-10, where 0 indicates no problems and 10 indicates maximal problems [212]. The reliability and validity of BPI are supported by the literature. Test-retest reliability of pain severity and interference are 0.98 and 0.79, respectively. Construct validity was tested through the correlations with the same construct; the correlation between the pain severity subscale and the pain intensity scale (chronic pain grade) was 0.6. The correlation between pain interference subscale and disability scale (chronic pain grade) was 0.64 [213]. BPI was chosen because it measures pain severity as well as the reaction to the pain, which are the dimensions of pain. Also, it assesses the variability of pain over time: pain at its “worst,” “least,” “average,” and “now”