Factorial validity of a substance-use stigma scale in methamphetamine-using adults in China

Background
Despite the large number of individuals who use substances of abuse and the stigma of such behaviors in China, scales have not been developed and validated for assessing substance-use stigma. Given its importance for targeting interventions, the aim of the present study was to validate a Chinese substance-use stigma measure including three dimensions of substance-use-disorder-related stigma (personal stigma, perceived stigma and social distance) by modifying a pre-existing scale measuring mental illness-related stigma and social distance.

Methods
A convenience sample of eight-hundred-and-twelve individuals with substance abuse (aged 18–68 years) from different drug rehabilitation centers completed a self-reported survey including their demographics and drug use, and the stigma and social distance scales. The adapted, translated from English to Chinese, and back-translated scales were an 18-items stigma scale including personal stigma and perceived stigma subscales and a 5-items one domain social distance scale. Confirmatory factor analysis and multigroup confirmatory factor analysis tested factorial validity and measurement invariance of the scales, respectively.

Results
For the stigma scale, by deleting one low correlation dimension (named “weak-not-sick”), personal stigma and perceived stigma showed acceptable fit indices and internal consistency with two dimensions (named “dangerous/unpredictable” and “social discrimination”), separately. The social distance scale showed good fit indices and internal consistency as a separate facet of stigma-related substance-use problems. Invariance of the model across drug-rehabilitation centers was found.

Conclusions
The Chinese substance-use stigma scale may serve as a valuable tool for better understanding substance-use stigma among adults in China who abuse substances.