This overview of the oral contraceptive (OC) study shows the key variables and a timeline for when they are assessed. Women complete a set of questionnaires prior to starting the birth control pill (Pre-OC), including questions about one-time measures (OTM) and repeated measures (RM). They then fill out a questionnaire including questions about the repeated measures again after taking the pill for three, six, and twelve months. At these follow-up assessments, women are also asked to identify any physical or emotional changes that they attribute to the pill (side effects-SE). The attributes assessed by the one-time measures may influence how the woman reacts to pill-induced changes, and all of these factors may affect her decision to continue or discontinue taking the pill (C/D).