Psychometric Evaluation of the Perceived Stress Scale in Multiple Sclerosis

Multiple sclerosis (MS) is a progressive disease characterized by neurological symptoms and sometimes heightened levels of distress. The Perceived Stress Scale (PSS) is often used in MS samples to measure stress but has not been validated in this population. Participants ( n=446 ) completed the PSS as well as measure of depression, anxiety, and mental and physical health. Factor analyses indicated that the general factor of a bifactor model accounted for a large amount of the variance in the 14-item and 10-item versions of the PSS. The 4-item PSS had two factors, the Stress subscale and the Coping subscale, but a one-factor model also fits the data well. Total scores and both subscales had sufficient reliability and validity for all versions of the PSS, although a few items of the 14-item PSS had low item-total correlations. This study supports the use of the total score of the PSS in MS but also suggests that the 10-item PSS had better psychometric properties than the 14-item PSS.