Investigating the internal structure of multiple mini interviews—A perspective from Pakistan

BACKGROUND: Healthcare professionals require many personal attributes in addition to cognitive abilities and psychomotor skills for competent practice. Multiple Mini- Interviews are being employed globally to assess personality attributes of candidates for selection in health professions education at all level of entry; these attributes are namely, communication skills, critical thinking, honesty, responsibility, health advocacy, empathy and sanctity of life. Considering the high stakes involved for students, faculty, institutions and the society, rigorous quality assurance mechanisms similar to those used for student assessment must be employed for student selection, throughout the continuum of medical education. It is a difficult undertaking as these psychological constructs are difficult to define and measure. Though considered to yield reliable and valid scores, studies providing multiple evidences of internal structure especially dimensionality of Multiple Mini-Interviews are sparse giving rise to questions if they are measuring a single or multiple constructs and even if they are measuring what they are purported to be measuring. OBJECTIVE: The main objective is to provide statistical support of the multi-dimensional nature of our Multiple Mini Interviews, hypothesized a-priori, through CFA. Another objective is to provide multiple evidences for the internal structure. Our study highlights the link between content and internal structure evidences of the constructs, thus establishing that our Multiple Mini Interviews measure what they were intended to measure. METHOD: After securing permission from the Institutional review board, an a-priori seven factor-model was hypothesized based on the attributes considered most essential for the graduating student of the institution. After operationally defining the attributes through extensive literature search, scenarios were constructed to assess them. A 5-point rating scale was used to rate each item on the station. A total 259 students participated in the multiple mini interviews over a period of three days. A training workshop had been arranged for the participating faculty. RESULTS: The reliability coefficient using Cronbach's alpha were calculated (range from 0.73 to 0.94), Standard Error of Measurement (ranged from 0.80 to1.64), and item to station-total correlation ranged from 0.43-0.50 to 0.75-0.83. Inter-station correlation was also determined. Confirmatory factor analysis endorsed the results of Exploratory factor analysis in the study revealing a seven model fit with multiple indices of Goodness-of-fit statistics such as Root mean square error of approximation (RMSEA) value 0.05, Standardized root mean square residual (SRMR) value with less than 0.08. All these indices showed that model fit is good. The Confirmatory factor analysis confirmed the multi-dimensional nature of our MMIs and also confirmed that our stations measured the attributes that they were supposed to measure. CONCLUSION: This study adds to the validity evidence of Multiple Mini-Interviews, in selection of candidates, with required personality traits for healthcare profession. It provides the evidence for the multi-dimensional structure of Multiple Mini interviews administered with multiple evidences for its internal structure and demonstrates the independence of different constructs being measured.