Goffman's description of stigma is awesome but he never operationalized or measured it. Some people say there really isn't a theory of stigma and while LInk & Pehlan make claims about power and stigma they do not measure it. Any suggestions?
Have a look at Social Work and Disadvantage: Addressing the Roots of Stigma through association. Peter Burke and Jonathan Parker (Editors). It deals with stigma and disabilities. There are some excellent models which have used Gothman's work.