Figure 2. Reclassification of patients eligible for isoniazid preventive therapy.
If isoniazid preventive therapy (IPT) eligibility were determined by the WHO symptom screen, no patients with active TB but only 42 of 196 patients without active TB would have been considered eligible for IPT. If point-of-care C-reactive protein (POC-CRP) were used instead, one patient with active TB (reclassification of cases = -20%, p=0.32) and 129 patients without active TB (reclassification of non-cases = +66%, p<0.001) would have been reclassified as being eligible for IPT. Thus, TB screening with POC-CRP would have resulted in a net reclassification improvement (NRI) of 46% (95% CI: 2-87, p=0.03).