Improving and validating a rating scale to assess student pharmacists' perception of professional identity

There are limited data on the psychometric properties of instruments evaluating professional identity (PI) among student pharmacists.

This study analyzed the psychometric properties of an instrument to assess student pharmacists' perception of their PI.

Data from a cross-sectional survey were used to establish validity and reliability evidence of student pharmacists' perception of PI using Rasch analysis. Linear regression was conducted to evaluate the association of students' characteristics with their perceived PI. Analyses were conducted in WINSTEPS (SWREG, Minnetonka, MN) and SAS (SAS, Cary, NC).

The analysis included 118 student pharmacists. Primary analysis suggested inadequate scale functionality; thus, some response categories were merged. With modified item anchors and the removal of the most misfitting item, the data fit the model as measured by student and item infit and outfit mean-squared values. The item-person map showed appropriate distribution of item difficulty, identifying medicine adviser and entrepreneur being the easiest and hardest items to agree with, respectively. Students' abilities initially mismatched with item difficulty and exhibited a ceiling effect, requiring addition of items reflecting students' higher perceptions of PIs. Although students' reliability coefficient (RC) and separation index were 0.98 and 1.73, respectively, RC of the items was 0.94. Students who reported receiving formal PI training were 0.3 times more likely to have high perception of PI than those who did not report training.

The instrument exhibited fair validity and reliability evidence for assessing the perception of PI among student pharmacists. Additional items to fill identified item gaps are needed to improve the instrument's content validity.