RESUMO
AIM: To assess the psychometric properties regarding the Portuguese version of the Practice Environment Scale of the Nursing Work Index. BACKGROUND: The Practice Environment Scale of the Nursing Work Index is the most widely used measure for assessing the practice environment. A model with a higher number of factors appears to be more adequate to Portuguese settings. METHOD: A confirmatory factor analysis was performed to the Practice Environment Scale of the Nursing Work Index using a sample of 850 Portuguese nurses. Three models were tested: the original model, a seven-factor model and a higher-order model. An analysis of invariance was performed in two subsets to confirm the stability of the solution. RESULTS: The seven-factor model fit better to the data than the original model. After refinement, this solution showed suitability and a stable factor structure. Reliability, convergent validity and discriminant validity were confirmed. A second-order factor solution also showed suitability. CONCLUSION: The seven-factor structure of the Practice Environment Scale of the Nursing Work Index showed a better goodness-of-fit to Portuguese settings than the original structure. The second-order factor solution allows an overall assessment of practice environments. IMPLICATIONS FOR NURSING MANAGEMENT: The Portuguese version of the Practice Environment Scale of the Nursing Work Index is a valuable tool for assessing Portuguese nursing practice environments. The seven-factor solution of the Practice Environment Scale of the Nursing Work Index showed high specificity.