RESUMO
AIMS: To develop and psychometrically test a Theory of Planned Behaviour (TPB) questionnaire to assess nurses' intention to use physical restraints (PRs) in intubated patients. DESIGN: A psychometric instrument validation study conducted in three phases. METHODS: A theory-driven questionnaire was developed. Eight experts validated the content of the preliminary 58-item questionnaire. A pilot study was conducted including 101 critical care nurses to test the reliability of the items. Construct validity and reliability were tested in a cross-sectional study of 12 units from eight hospitals in Spain (N = 354) from October - December 2017. Participants completed the questions based on the TPB, and socio-demographic and professional variables. RESULTS: The instrument comprised 48 items. All the direct and indirect constructs exhibited acceptable reliability. Confirmatory factor analysis indicated satisfactory fit indices for factorial structure according to the TPB. Nurses showed favourable attitudes, low perception of social pressure and modest perception of behaviour control. Perceived behavioural control and attitude were moderately positively correlated with the intention to use restraints, whereas subjective norm revealed the lowest correlation. Overall, the model explained 33% of the variance in intention. CONCLUSIONS: The Physical Restraint TPB questionnaire is a 48-item self-reporting theoretically based instrument with acceptable reliability and construct validity to identify nurses' intentions to use PRs in intubated patients. IMPACT: Unravelling the key determinants of nurses' intentions to use PRs should be examined to tailor quality improvement projects aimed at de-implementing restraints use in practice and to promote safer care.