Development and psychometric evaluation of an instrument for medical students’ self-assessment of professionalism: Reliability, content, and construct validity of the MediProf questionnaire

Objective: The aim of this study was to develop a self-assessment instrument for measuring medical professionalism among medical students and to conduct an initial evaluation of its psychometric properties. Methods: The MediProf questionnaire was developed in an iterative process based on the Professionalism Scale Germany (Pro-D). It comprises a total of 64 items, of which 61 are rated on a four-point Likert scale (1=strongly disagree; 4=strongly agree) and cover four dimensions of medical professionalism: towards 1) oneself, 2) patients, 3) other healthcare professions, and 4) society. Three items assess the relevance and the extent to which the topic is addressed at the respondents’ own institution. Comprehensibility and feasibility were evaluated in two pretests. In 2024, the questionnaire was administered online to 224 medical students. Statistical analyses were conducted using SPSS and Stata. In addition to calculating scale scores per dimension, item discrimination, and item difficulty, we assessed internal consistency using Cronbach’s alpha (α) and conducted a confirmatory factor analysis. Multiple linear regression analyses were used to examine the influence of sociodemographic factors on self-assessed professionalism. Results: Analysis of the complete questionnaire data from 155 students demonstrated good internal consistency for the MediProf questionnaire across all 61 items (α=0.90), with good to acceptable values for the individual dimensions: 1) α=0.84; 2) α=0.75; 3) α=0.77; and 4) α=0.62. Most items showed good discrimination. The factor analysis indicated an overall relationship between the items and the four dimensions, with high interdependencies and weak factor loadings. Students rated their professionalism overall as high (mean=3.3; SD=0.2). Regression analyses revealed no significant influence of sociodemographic variables on self-assessed professionalism. The majority of participants considered the topic very important (94.5%) and called for stronger curricular integration (79.5%). Conclusions: The newly developed MediProf questionnaire provides, for the first time, a German-language self-assessment instrument with good psychometric properties for measuring medical professionalism among medical students. The participants’ expressed desire for stronger curricular integration highlights the importance of early and continuous promotion of professionalism throughout medical education.