ObjectivesThis study aimed to assess whether male and female
Iranian medical students perceived the meaning of the items in the Depression
Anxiety Stress Scales-21 consistently.
MethodsA convenience sample of 783 preclinical medical students
from the first to sixth semester was invited to this cross-sectional study. Of
the 477 respondents, 238 were male and 239 were female. All participants
completed the Persian version of the Depression Anxiety Stress Scales-21. The
graded response model was used to assess measurement invariance of the instrument
across the gender groups. Categorical confirmatory factor analysis was used to
evaluate the construct validity of the measure. Moreover, internal consistency
was assessed via Cronbach's Alpha.
ResultsStatistically significant differential item functioning
was flagged for just item 6 in the depression subscales (c2=6.5,
df=1, p=0.011). However, removing or retaining the item 6 in the stress
subscale did not change our findings significantly, when we compared stress
scores across two genders. The results of categorical confirmatory factor
analysis supported the fit of the three-factor model of Depression Anxiety
Stress Scales-21. Moreover, Cronbach’s alpha was greater than 0.7 in
depression, anxiety and stress subscales.
ConclusionsThis study revealed that Depression Anxiety Stress
Scales-21 is an invariant measure across male and female medical students.
Hence, this reliable and valid instrument can be used for meaningful comparison
of distress scores between medical student genders. Gender comparisons of
medical students’ psychological profiles provide a better insight into gender
influences on the outcome of medical education and medical practice.