Evaluating the psychometric properties of HIV/AIDS stigma among postgraduate medical students in Southern India: a Rasch analysis approach

Abstract The burden of HIV/AIDS in India is high, yet there is a dearth of scales measuring HIV/AIDS stigma that have been validated in an Indian health care population. Thus, this study aimed to assess the psychometric properties of the Health Care Provider HIV/AIDS Stigma Scale (HPASS) among Indian medical students. Data were collected from post-graduate (PG) medical students at a South Indian tertiary hospital via a structured online survey (March 2023-May 2024) including HPASS items and sociodemographics. The psychometric properties of HPASS were assessed using the principles of Item Response Theory. Respondents had a mean age of 25.9 years (SD = 2.5); 52% were female. Stereotyping and Discrimination subscales had satisfactory fit statistics, but two items of the Discrimination subscale did not fit the unidimensional construct and were therefore excluded. The 6-point rating scale performed poorly across subscales. The Stereotyping measure ranged from − 1.2 to 0.8 logits, Prejudice ranged from − 3 to 3 logits, Discrimination ranged from − 4 to 1.5 logits, indicating that Stereotyping subscale exhibited a reasonable spread in terms of the person and item distributions overlapping while the items in the two other subscales of Discrimination and Prejudice showed bias towards measuring higher level of Discrimination or Prejudice. Person separation index and person separation reliability were satisfactory for all the subscales. Stereotyping and Discrimination subscale had satisfactory construct validity, but Prejudice subscales and rating scales require further updates. This study is an important step in the direction of assessing HIV stigma in Indian medical students.