Assessment of the psychometric properties of HIV knowledge items across five countries.

HIV knowledge is commonly measured in HIV prevention research and program evaluations, but rigorous measurement standards are not always applied. Using item response theory methods, we examined the psychometric functioning of five commonly used HIV knowledge questions in five countries with varying HIV prevalence. We evaluated the internal consistency and measurement invariance of the items. The items performed poorly in all samples and the scale as a whole did not perform equally across samples. We conclude that current ways of measuring HIV knowledge are not adequate and recommend new items be developed, tested, and validated using psychometric methods.