LAUSR

BACKGROUND This study examined condom use and STI testing among unmarried, non-cohabiting women and men who had multiple past-year partnerships or perceived their partner's involvement in another sexual relationship. METHODS We identified 5,868 and 5,330 unmarried, non-cohabiting sexually active women and men aged 15-44 years using National Survey of Family Growth data for 2011-2017. To measure multiple partnerships, we created four dichotomous variables that included both past-year number of opposite-sex sex partners (one, two or more) and perceived partner non-monogamy (PPNM) (yes, no). Results were stratified by relationship type at last sex ("steady" vs. "casual"). RESULTS Overall, 39.4% of women and 48.3% of men reported multiple partnerships and 23.4% and 24.0% reported PPNM. Lower condom use was seen for women and men who had two or more partners in the past year and PPNM than those with only one partner and no PPNM (women: 28.5%; 95% confidence interval (CI): 24.1, 32.9 vs. 39.3%; 36.6, 41.9); (men: 37.7%; 33.5, 41.8 vs. 54.9%; 51.9, 57.9). STI testing was higher for groups with PPNM. Men with a steady sex partner had higher prevalence of past-year STI testing if they reported PPNM than not (aPR=2.00; CI: 1.63, 2.45). CONCLUSION Screening practices that include a standardized sexual risk assessment could identify those with multiple sex partners or PPNM and improve linkage to STI services. Availability of point-of-care tests and expedited partner therapy could provide targeted strategies that prioritize rapid diagnosis and effective partner treatment which may prevent further STI spread.