Cross-cultural validation of the Internalized Scale of Mental Illness (ISMI) in leprosy-affected people and people with disabilites in Nepal.
Background: Although leprosy can now be easily cured, the stigma associated with leprosy remains a major problem. Also in Nepal, leprosy is a stigmatized disease and leprosy-associated stigma enforces the already existing inequalities in social class, gender, and age. Good instruments are essential to assess levels of stigma in society and to monitor and evaluate stigma reduction interventions. Recently, some studies have tested and/or validated stigma scales in a number of Asian countries. However, the Internalized Scale of Mental Illness (ISMI, measuring internalized stigma) has not yet been validated in Nepal.
Objective: To test and validate the ISMI scale in Nepal, in order to assess levels of internalized stigma in leprosy-affected people and people with (other) disabilities (PWD).
Methods: The study took place in collaboration with Partnership for Rehabilitation Programme (PFR), a community outreach and rehabilitation program of the International Nepal Fellowship (INF). Participants were interviewed at Green Pastures Hospital and Rehabilitation Centre (GPH&RC) and at people’s homes in Pokhara. More participants were recruited in the Terai area via INF and Disabled Rehabilitation Centre. Herdman’s six types of ‘equivalence’ were assessed in the cross-cultural adaptation process. Semi-structured interviews were conducted to revise the ISMI scale and quantitative methods were used to evaluate the reliability to distinguish between groups, internal consistency, construct validity and floor and ceiling effects of the ISMI scale.
Results: The domains and items of the ISMI scale were relevant to Nepali leprosy-affected and PWD. Seven out of all 27 statements were not correctly interpreted by the majority of respondents and were revised before commencing the quantitative part of the study. Especially two older, illiterate women had difficulty understanding the statements and answer categories. After revision, the statement-format of the scale remained difficult to comprehend for most respondents that participated in the quantitative research part. To retrieve unbiased results, it was necessary to change statements into questions when interviewing respondents who did not understand the statement-format. The quantitative results indicated the ability of the ISMI scale to discriminate between groups effectively. The scale presented good internal consistency for all subscales (Cronbach’s α between 0.71-0.89), except for the subscale Stereotype Endorsement (0.66). The construct validity was confirmed by a positive correlation of 0.65 between the ISMI and EMIC score. No floor or ceiling effects were found.
Conclusion: Conceptual, item, semantic, and measurement equivalence were achieved. To achieve operational equivalence, it is recommended to change the ISMI statements into questions and develop appropriate response categories that are understood in Nepali context.