The Interaction with Disabled Persons Scale: evidencing construct validity with factor analysis and measurement invariance in Greek-speaking healthcare students

Purpose To explore the construct validity and reliability of the Greek version of the Interaction with Disabled Persons Scale (IDPS) amongst healthcare students. Methods Greek IDPS factors were extracted and confirmed by Analysis of Moment Structures. Measurement invariance for the group of students completing a clinical module with people with disabilities was also evaluated. The scale was distributed twice, 3 weeks apart (test-retest reliability) to sample. Greek IDPS scores amongst students with frequent contact with people with disabilities were compared with those with infrequent contact (discriminant validity). Results 327 healthcare students (21.25 +/- 4.3 years, 118 males) participated. Exploratory factor analysis extracted 6 factors explaining 55.66% of total variance. Confirmatory factor analysis showed a good fit of the model (AGFI = 0.95 > 0.90, RMSEA = 0.07 < 0.08, CFI = 0.95 >= 0.90, SRMR = 0.00 < 0.08). An adequate fit for the students completing a clinical practice module was observed. The scale's test-retest reliability and internal consistency were excellent; ICC(2,1)=0.86 (CIs:0.82-0.89) and Cronbach's alpha = 0.87, respectively. Statistically significant differences between the two student groups were yielded; students with frequent contact with people with disabilities had lower scores (mean difference: -4.5; CI: -6.6 to -2.4), suggesting that they were significantly more comfortable with people with disabilities than the students with infrequent contact. Conclusion The Greek IDPS provided sufficient validity and reliability evidence for evaluating healthcare students' perceptions and attitudes towards people with disabilities.