Development and validation of a theoretical test in endosonography for pulmonary diseases

Theoretical testing provides the necessary foundation to perform technical skills. Additionally, testing improves the retention of knowledge. The aims of this study were to develop a multiple-choice test in endosonography for pulmonary diseases and to gather validity evidence for this test. Initially, 78 questions were constructed after informal conversational interviews with 4 international experts in endosonography. The clarity and content validity of the questions were tested using a Delphi-like approach. Construct validity was explored by administering the test to 3 groups with different levels of endosonography experience: 27 medical students, 18 respiratory physicians with limited endosonography experience, and 14 experts in endosonography. Two Delphi iterations reduced the test to 52 questions. After item analysis, the final test consisted of 46 questions with a mean item discrimination of 0.47 and a mean item difficulty of 0.63. The internal consistency reliability was calculated at 0.91. The 3 groups performed significantly differently (ANOVA: p <0.001), and post hoc tests were significant. The experts performed significantly more consistently than the novices (p = 0.037) and the intermediates (p <0.001). This study provides a theoretical test in endosonography consisting of multiple-choice questions. Validity evidence was gathered, and the test demonstrated content and construct validity