Abstract
BACKGROUND: As work environments rapidly evolve due to profound social and technological changes, evaluating psychosocial work conditions and identifying risk factors affecting worker well-being has become a key public health priority. The Copenhagen Psychosocial Questionnaire (COPSOQ III) is among the most used tools for assessing the psychosocial work environment, covering both working conditions and occupational health outcomes. This study aimed to evaluate the psychometric properties of the long and middle versions of the COPSOQ III and to develop and assess a novel single-item-per-scale screening version (the COPSOQ III screening) using a nationwide sample of working adults in the Czech Republic. METHODS: Data were collected through an online panel survey administered by a professional research agency. The final research sample included 1,444 respondents (52.4% men, 47.6% women), selected through quota sampling to approximate key demographic characteristics of the Czech population. The long and middle versions of the COPSOQ III were administered. The new screening version (the COPSOQ III screening) was developed by selecting the item with the highest factor loading from each scale of the long version, resulting in a 45-item instrument. Factorial validity and measurement invariance were assessed using confirmatory factor analysis (CFA). RESULTS: CFA supported the factorial validity of the long and middle versions, with acceptable to strong model fit indices. Internal consistency was satisfactory across most scales, and measurement invariance was confirmed across sex, employment sector, managerial status, and length of employment. The screening version demonstrated high concordance with the long version, with an average item-scale shared variance of 77.2% and no scale below 60%. Given its substantial reduction in length and limited information loss, the screening version demonstrated a favorable balance between brevity and retained variance. CONCLUSIONS: The Czech COPSOQ III, in the long and middle versions, is a valid and reliable tool for assessing psychosocial working conditions. The screening version offers a promising option for time-efficient assessment and initial workplace screening; however, further validation is needed to provide more robust evidence regarding its psychometric qualities. TRIAL REGISTRATION: non-applicable.