Final answer:
Lower effectiveness rates of hormonal birth control methods can occur in women with certain health conditions, those on interfering medications, and those not strictly adhering to birth control schedules. These factors can reduce the contraception's efficacy compared to perfect usage scenarios.
Step-by-step explanation:
Women who may experience lower effectiveness rates with hormonal methods of birth control include those with certain health conditions, those taking particular medications that can interact with the birth control hormones, and those who have difficulties with consistently taking the birth control pills as prescribed. For example, the effectiveness of hormonal contraceptives, such as the combined pill and the progesterone-only pill, may be reduced in women who are overweight, smokers over the age of 35, or have specific medical conditions like epilepsy which require medications that can diminish the pill's effectiveness. Additionally, perfect use versus typical use plays a critical role in the efficacy of hormonal birth control methods, as typical use often results in a higher failure rate due to missed pills or incorrect timing.