Assessment of validity and reliability of the tuberculosis related stigma scale in Colombian patients

Abstract

Objective

To know the dimensionality and internal consistency of the Tuberculosis-Related Stigma Scale in patients living with tuberculosis in Santa Marta, Colombia.

Method

One hundred and twenty-two patients between the ages of 18 and 75 participated (M = 40.3, SD = 14.9), 63.9% were men, 44.3% were single, 69.7% had low income, 80.3% had pulmonary tuberculosis, and 13.1% had co-infection with HIV. The Tuberculosis-Related Stigma Scale was applied; it comprises perceived and internalised stigma subscales. The internal structure was explored by confirmatory factor analysis (EFA). Internal consistency was measured with Cronbach's alpha and McDonald's omega. Besides, the differential functioning of the scales according to gender was explored with Kendall's tau-b coefficient.

Results

CFA did not show excellent goodness-of-fit indicators for the perceived stigma scale (Satorra-Bentler's chi-square of 184.48, degree of freedom of 44, p = .001, RMSEA of 0.16, 95%CI 0.14–0.19, CFI of 0.77, TLI of 0.72, and SRMR of 0.08) and internalised (Satorra-Bentler's chi-square of 189.14, degree of freedom of 54, p = .001; RMSEA of 0.14, 95%CI 0.12–0.17, CFI of 0.82, TLI of 0.78, and SRMR of 0.07). The alpha and omega coefficients were 0.89 and 0.91 for both scales. Non-gender differential functioning was observed; Kendall's tau-b was between 0.00 and 0.15.

Conclusions

The Tuberculosis-Related Stigma Scale has an excellent internal consistency but poor goodness-of-fit indicators of unidimensionality. Evaluating the scale's psychometric performance is recommenced in future research.

Keywords:

• Tuberculosis
• validation study
• reproducibility of results
• Colombia

Transparency

Declaration of funding

The Universidad del Magdalena, Santa Marta, Colombia funded the research through VIN Resolution 0517, 2019.

Declaration of financial/other relationships

The authors have no conflicts of interest to declare. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.