Measuring Psychological Strains: A Psychometric Study to Develop a Shortened Version of the Psychological Strain Scales

The Psychological Strain Scale (PSS) has been widely used in various populations to assess the risks of suicidality and mental disorders. The current study aims to shorten the original 40-item scale and test its psychometric properties. Data were derived from three samples in China: (1) undergraduate students (n = 10,742), (2) non-medical office employees (n = 1044), and (3) hospital workers (n = 949). A questionnaire was administered to the samples at about the same time of the year 2017. Data were randomly divided into Sub-study 1 (70% of the sample) and Sub-study 2 (30% of the sample). In Sub-study 1, principal component analyses were run and five items with the highest factor loadings within each subscale were retained, resulting in a 20-item PSS scale. Cronbach's α estimates were above 0.70. In Sub-study 2, confirmatory factor analyses for the three samples revealed RMSEA values below 0.10, PNFI values below 0.50 for all samples, and CFI, TLI and NFI values above 0.90 for the student and non-medical office employee samples, but the hospital worker sample had a TLI of 0.88. The PSS-20 and its subscales were significantly associated with past-year suicidal ideation. The PSS-20 has acceptable psychometric properties but requires further testing in university students and hospital workers.