BACKGROUND: The importance of the practice environment in the provision of care and its relation with patient outcomes and nurse-reported outcomes, support the need to have an instrument to measure such practice environment.
OBJECTIVE: To evaluate the validity and reliability of the Spanish version of the Practice Environment Scale of the Nursing Work Index (PES-NWI), determining the content validity, test-retest reliability, internal consistency and construct validity.
DESIGN: A cross-sectional survey of bedside care nurses undertaken in 2009 in medical, surgical and critical care wards of 33 Spanish National Health Service hospitals with more than 150 beds.
METHODS: The validation process followed the internationally recognized guidelines about psychometric properties of instruments: translation and back-translation, content validity, test-retest reliability, internal consistency and construct validity. Other study variables included, like nurses' intention to leave and job satisfaction.
RESULTS: The Intraclass Correlation Coefficient (ICC) for an overall score on the 31 item questionnaire was 0.87 (CI 95%: 0.85-0.89). Cronbach's alpha was 0.90 (CI 95%: 0.87-0.93). The weighted Kappa Index obtained for each of the items ranges from 0.24 (CI 95%: 0.22-0.26) to 0.51 (CI 95%: 0.49-0.53). The Content Validity Index score ranges from 0.5 for the item "Opportunities for advancement" to 1. Five of the terms attain this maximum level of agreement: "Active staff development or continuing education programs for nurses", "Enough registered nurses on staff to provide quality patient care", "Enough staff to get the work done", "Management that listens and responds to employee concerns" and "Collaboration between nurses and physicians".
CONCLUSIONS: The validation process indicates that the Spanish version of the PES-NWI is valid and reliable in its current version and it can be used to measure the practice environment of Spanish nurses working in clinical practice in hospitals of the Spanish NHS.
