Background: The World Health Organization recommends tuberculin skin tests (TSTs) where feasible to identify individuals most likely to benefit from isoniazid preventive therapy (IPT). The requirement for TST reading after 48-72 h by a trained nurse is a barrier to implementation and increases loss to follow-up.
Methods: Patients with human immunodeficiency virus (HIV) infection were recruited from a primary care clinic in South Africa and trained by a lay counsellor to interpret their own TST. The TST was placed by a nurse, and the patient was asked to return 2 days later with their self-reading result, followed by blinded reading by a trained nurse (reference).
Results: Of 227 patients, 210 returned for TST reading; 78% interpreted their test correctly: those interpreting it as negative were more likely to be correct (negative predictive value 93%) than those interpreting it as positive (positive predictive value 42%); 10/36 (28%) positive TST results were read as negative by the patient.
Conclusions: Patients with HIV in low-resource settings can be trained to interpret their own TST. Those interpreting it as positive should return to the clinic within 48-72 h for confirmatory reading and IPT initiation; those with a negative interpretation can return at their next scheduled visit and initiate IPT at that time if appropriate.