Efficacy
/EF-ih-kuh-see/
A measure of how well a medication or treatment works under ideal conditions, often expressed as a percentage.
Detailed Explanation
In the context of emergency contraception, efficacy refers to how well the medication prevents pregnancy when taken correctly. For example, levonorgestrel has 95% efficacy within 24 hours, meaning it prevents 95 out of 100 pregnancies that would have occurred without treatment. Efficacy decreases with time—this is why taking EC as soon as possible is so important. Real-world effectiveness may be slightly lower due to factors like incorrect use or timing.
Related Terms
Frequently Asked Questions
What is Efficacy?
A measure of how well a medication or treatment works under ideal conditions, often expressed as a percentage.
How does Efficacy work?
In the context of emergency contraception, efficacy refers to how well the medication prevents pregnancy when taken correctly. For example, levonorgestrel has 95% efficacy within 24 hours, meaning it prevents 95 out of 100 pregnancies that would have occurred without treatment.
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