An open-label cluster-randomised trial on TB preventive therapy for children

BACKGROUND: In a study on 9 months of isoniazid preventive therapy (IPT) in children in Guinea-Bissau, 76% of children exposed to TB at home completed 6 months of IPT. We aimed to test whether 4 months of rifampicin and isoniazid (RH) would improve adherence compared to 9 months of isoniazid (INH). METHODS: We conducted an open-label clusterrandomised superiority study in children aged,15 years living with a TB case. Children were randomised by house to receive 4 months of RH or 9 months of INH. RH was given as a fixed-combination pill. The primary outcome was adherence, defined as taking .80% of prescribed dosages per month, assessed by pill count. Our aim was 3 months of RH or 6 months of INH. RESULTS: A total of 752 children from 223 houses were included, 354 in the INH group and 398 in the RH group. Overall, 57% of the children took .80% of the prescribed pills. In the INH group, 68% completed 6 months of therapy, while 61% of the RH group completed 3 months (OR 1.32, 95% CI 0.90–1.95). The main reason for non-adherence in both groups was travel or relocation, accounting for 50% of missed doses. CONCLUSION: The shorter preventive therapy of 4 months of RH did not improve adherence in children in Guinea-Bissau. Travelling was the primary reason for non-adherence.