Methods, system errors, and demographic differences in participant errors using daily text message-based short message service computer-assisted self-interview (SMS-CASI) to measure sexual risk behavior in a RCT of HIV self-test use.

The SMS-CASI system was effective at confidentially collecting sexual risk behavior data on a daily basis, potentially contributing to reduced recall and social desirability bias. This study provides methodological examples and data demonstrating how SMS-CASI can be used for sexual health data collection.