EFFECTIVENESS OF INCENTIVES ON STI TESTING UPTAKE: A TRIAL AMONG ABORIGINAL AND TORRES STRAIT ISLANDER YOUNG PEOPLE IN REMOTE CENTRAL AUSTRALIA (2015-2020).

Background: Bacterial sexually transmissible infections (STIs) cause a substantial disease burden worldwide, and disproportionately impact young people. In Australia, Aboriginal and Torres Strait Islander people are a priority population in STI testing guidelines.

Methods: The More Options for STI Testing (MOST) trial evaluated whether providing an incentive impacted STI testing rates in select central Australian communities. Aboriginal and Torres Strait Islander people aged 16 to 29 years were eligible for a A$30 phone voucher if they had an STI test at a participating Aboriginal community-controlled primary health care clinic. An interrupted time series analysis examined monthly STI test counts for chlamydia, gonorrhoea or syphilis from 2015 to 2020, to determine whether testing increased during the incentives phase (2018-2020).

Results: There were a total of 10,457 visits to the clinic in which an STI test was conducted, 5,110 of which were during the incentives period. A total of 1,526 incentives were provided to eligible clients. The baseline and incentives periods were each divided into two phases to account for new clinic openings and the COVID-19 pandemic. Among men, average monthly visits for an STI test were 32.6 (baseline phase 1), 44.1 (baseline phase 2), 50.8 (incentives phase), and 35.4 (incentives/COVID-19 phase). Women had 93.5, 111.3, 118.8 and 113.4 visits respectively. No significant change in STI testing was observed during the incentives phase. The proportion of visits for an STI test where an incentive was paid (coverage) varied by month, from 36% to 76% of consultations.

Conclusions: The limited impact of incentives could be explained by low coverage, or that the incentive was not motivating enough to overcome STI testing barriers. Future studies should investigate alternative methods of increasing STI testing in remote central Australia, including through primary care clinics.