The Sexual Health Myth-Conceptions Scale: Development and Psychometric Evaluation of the Scale with Emerging Adults in the USA.

Sexually transmitted infections (STIs) are most prevalent among emerging adults (ages 18-29) in the USA. Heightened risk of STIs is partly due to increased self-exploration and experimentation during this developmental period, compounded by sexual health misinformation that spreads through peer interactions and online media. Despite a well-documented impact of (false) beliefs on behavior, very little is known about sexual myths among emerging adults in the USA and the structure of these myths. In the current study, we introduce the Sexual Health Myth-Conceptions Scale (SHMCS) with two primary goals: (1) to identify common sexual health myth-conceptions (i.e., a fusion of myths and misconceptions) among US emerging adults and (2) to evaluate the scale's psychometric properties. A sample of 1,162 US-based emerging adults were recruited through Prolific, an online crowdsourcing platform, and completed the 34-item SHMCS. Item-level characteristics, exploratory factor analysis, exploratory structural equation modeling, and bifactor analysis were used to establish factorial validity. Item response theory (IRT) was used to examine item and scale performance. Results of factor analyses reinforce three persistent factors, including multi-topic or general, pornography use, and STIs/pregnancy. Results of a 2-PL IRT model reinforce good discrimination and moderate item difficulty across the spectrum of myth-conceptions. Although the SHMCS would benefit from further psychometric refinement, it shows promise as a tool for assessing general and domain-specific sexual health myth-conceptions and for advancing understanding their roles in sexual health among emerging adults.