In Poisson multiple regression analyses , sex ( risk ratio -LSB- RR -RSB- , @ ; @ % confidence interval -LSB- CI -RSB- , @-@ @ ) , intimate partner violence ( RR , @ ; @ % CI , @-@ @ ) , unprotected sex ( RR , @ ; @ % CI , @-@ @ ) , and multiple partners ( RR , @ ; @ % CI , @-@ @ ) , but not partner 's age ( RR , @ ; @ % CI , @-@ @ ) were associated with incident STD , adjusting for @-month STD prevalence .