Using group norms to promote acceptance of HIV testing during household tuberculosis contact investigation: A household-randomized trial.

Background: HIV status awareness and linkage to care are critical for ending the HIV epidemic and preventing tuberculosis (TB). Among household contacts of persons with TB, HIV greatly increases the risk of incident TB and death. However, almost half of household contacts in routine settings decline HIV test offers during routine contact investigation. We evaluated a brief social-behavioral norming intervention to increase acceptance of HIV testing during household TB contact investigation.

Methods: We carried out a household-randomized, controlled trial to evaluate the effect of the norming strategy among household contacts of persons with pulmonary TB in Kampala, Uganda ( ClinicalTrials.gov # NCT05124665 ). Community health workers (CHW) visited homes of persons with TB to screen contacts for TB symptoms and offer free, optional, oral HIV testing. Households were randomized (1:1) to usual care or the norming strategy. Contacts were eligible if they were ≥ 15 years old, self-reported to be HIV-negative, and living in a multi-contact household. The primary outcome, the proportion of contacts accepting HIV testing, was analyzed using an intention-to-treat approach, using a mixed-effects model to account for clustering by household. We assessed HIV testing yield as a proportion of all contacts tested.

Results: We randomized 328 contacts in 99 index households to the norming strategy, of whom 285 (87%) contacts were eligible. We randomized 224 contacts in 86 index households to the usual strategy, of whom 187 (84%) contacts were eligible. Acceptance of HIV testing was higher in the intervention arm (98% versus 92%, difference +6%, 95%CI +2% to +10%, p=0.004). Yield of HIV testing was 2.1% in the intervention arm and 0.6% in the control arm (p=0.22).

Conclusion: A norming intervention significantly improved uptake of HIV testing among household contacts of persons with TB.

Funding/support: This work was supported by the Center for Interdisciplinary Research on AIDS (P30MH062294) and the Fogarty International Center of the National Institutes of Health (R21TW011270). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH or other sponsors.