Psychometric properties of the 14, 10 and 4-item " Perceived Stress Scale" among asthmatic patients in Iran

Objective (s): The “Perceived Stress Scale” (PSS) is one of the most widely used instruments for measuring psychological stress in a range of clinical and nonclinical settings. The aim of the present study was to examine the psychometric properties of the all three versions of the PSS (PSS-14، PSS-10، and PSS-4) among asthmatic patients in Iran. A total of 106 asthmatic patients referring to several clinics in Sanandaj were selected by convenience sampling for this study. The PSS-14 and the short-form version of the “Depression Anxiety and Stress Scale” (DASS-21) were administrated to all participants. The psychometric properties of the PSS were examined: construct validity using confirmatory factor analysis (CFA)، convergent validity by evaluating the relationship with DASS-21 and internal consistency using Cronbach’s alpha. The findings of CFA revealed that a two-factor model for all three versions of PSS، containing both negative and positive factors، fit the data significantly better than a one-factor model. The Cronbach’s alpha coefficients for the PSS-14، PSS-10، and PSS-4 were 0. 90، 0. 90، and 0. 77، respectively. All three versions of the PSS were significantly positively correlated with the DASS-21 and its subscales، indicating an acceptable convergent validity. Moreover، women scored higher than men on the PSS. All three versions of the PSS demonstrated adequate psychometric properties for measuring psychological stress among asthmatic patients.