Table 1.

Study Outcome and Referent Group Definitions

	Nondual method use risk groups	Referent group
Outcome 1	Condom-only use: time-varying condom-only use (consistent or inconsistent) without modern contraceptive method use in the previous study interval	Consistent dual method use: time-varying modern contraceptive method use, with no indication of unprotected sex with the study partner in the previous study interval
Outcome 2	Modern contraceptive use with inconsistent condom use: time-varying modern contraceptive method use, with indication of condomless sex in the previous study interval