The development of an inventory to assess the structural barriers to clinic attendance and pill-taking amongst users of antiretroviral therapy.

In addition to personal and psychological factors, structural factors may reduce the likelihood of optimal adherence to antiretroviral therapy (ART) among persons living with HIV. In this mixed-method study we report on the development of a scale to assess the salience of various structural barriers to ART adherence. After following conventional guidelines for scale development, two scales measuring structural barriers to adherence to clinic attendance and pill-taking were administered to 291 patients receiving ART at a public hospital in South Africa. Both exploratory and higher order factor analysis indicated that a single underlying general factor was appropriate for both scales. The final scales consisted of 12 items for the structural barriers to clinic attendance scale and 13 items for the structural barriers to medication-taking scale. Both scales displayed excellent internal consistency with Cronbach alpha coefficients above 0.80. Research to determine the construct validity of the scales may be a next step in this line of research.