This item relates to what diagnosis is being investigated in the systematic review. This may be a disease, injury, disability or any other pathological condition. In some cases (i.e. where the index or reference tests are only used for one purpose or the population specifies “patients suspected of…”) this factor may seem redundant. However, as a general rule, it is useful to explicitly specify the diagnosis of interest. An example diagnosis of interest is “swine flu (H1N1)”.