Development and psychometric property testing of a skin tear knowledge assessment instrument (OASES) in 37 countries

Abstract

Aim: To develop and psychometrically evaluate a skin tear knowledge assessment instrument (OASES). Design: Prospective psychometric instrument validation study. Method: The skin tear knowledge assessment instrument was developed based on a literature review and expert input (N = 19). Face and content validity were assessed in a two-round Delphi procedure by 10 international experts affiliated with the International Skin Tear Advisory Panel (ISTAP). The instrument was psychometrically tested in a convenience sample of 387 nurses in 37 countries (April–May 2020). Validity of the multiple-choice test items (item difficulty, discriminating index, quality of the response alternatives), construct validity, and test–retest reliability (stability) were analysed and evaluated in light of international reference standards. Results: A 20-item instrument, covering six knowledge domains most relevant to skin tears, was designed. Content validity was established (CVI = 0.90–1.00). Item difficulty varied between 0.24 and 0.94 and the quality of the response alternatives between 0.01–0.52. The discriminating index was acceptable (0.19–0.77). Participants with a theoretically expected higher knowledge level had a significantly higher total score than participants with theoretically expected lower knowledge (p