The Knowledge-about-Older-Patients - Quiz (KOP-Q) for nurses: Cross-cultural validation between the Netherlands and United States of America.

Background: The Knowledge about Older Patients-Quiz (KOP-Q) is designed as a unidimensional scale measuring knowledge of hospital nurses about older patients. Furthermore, the KOP-Q measures a second unidimensional construct, certainty of hospital nurses about their knowledge. The KOP-Q is developed and validated in the Netherlands. Whether the KOP-Q can be used in other countries is unknown given the cultural and language differences.

Objectives: Investigate the level of measurement invariance of the KOP-Q between the Netherlands and United States of America (USA).

Design: A multicenter international cross-sectional design.

Settings: Four general hospitals in the Netherlands and four general hospitals in the USA.

Participants: Nurses from the Netherlands (n=201) and the USA (n=130) were invited to participate by email from the ward manager, distributing flyers and present messages on the online hospital communication boards. Questions of the KOP-Q were completed online.

Method: The level of measurement invariance (configural, metric or scalar invariance) across countries was tested by running increasingly constrained structural equation models, and testing whether these models fitted the data.

Results: Both the knowledge and certainty construct of the KOP-Q proved unidimensional in the Netherlands and USA sample. Test results of the measurement invariance across the Netherlands and USA indicated a stable, partial scalar invariance (15 items full scalar invariance) for the knowledge items and full scalar invariance for the certainty items.

Conclusions: The KOP-Q shows to function uniformly across both language groups and can therefore be used to assess nurses' knowledge and their certainty about this knowledge which can be important for educational and/or quality improvement programs in the USA. Furthermore, the KOP-Q is suitable to make comparisons between the Netherlands and the USA using latent variable models. Before the KOP-Q can be used in other countries, cross-cultural tests should again be performed.