Contraception

Typical use

Alsotypical-use effectivenessperfect usereal-world effectivenessperfect-use effectivenessfailure ratecontraceptive effectiveness

Not yet reviewed by a clinician. This health entry was written from the public-health sources listed below and is general information only. It is not medical advice.

Definition

Typical use describes how well a contraceptive works in everyday life, including human error, while perfect use describes how well it works when used exactly as directed every time.

At a glance

  • Typical use includes everyday human error such as missed or late doses.
  • Perfect use describes effectiveness when a method is used exactly as directed every time.
  • For the implant or an IUD, typical and perfect use are almost identical, above 99%.
  • For the pill the gap is roughly 99% versus 91%; for condoms roughly 98% versus 82%.
  • Typical-use figures are often the more useful guide when choosing a method.

In detail

The gap between the two numbers shows how much a method depends on the user. For the implant or an IUD the figures are almost identical, above 99%. For the pill, the gap is roughly 99% versus 91%, and for condoms roughly 98% versus 82%.

Researchers usually express these as the percentage of people who would become pregnant during the first year of using a method. Typical-use figures are often the more useful guide when choosing a method, because they reflect real routines, forgotten doses and imperfect timing.

In a sentence

  • The typical use figure for the pill surprised me, given how reliable it is with perfect use.
  • Look at the typical use numbers, because hardly anyone is perfect every day.

Not to be confused with

  • Pearl Index

    The Pearl Index is a specific statistical measure used in clinical trials, not a general effectiveness label.

Common questions

What is the difference between typical use and perfect use?

Perfect use is how well a method works when used exactly as directed every time; typical use is how well it works in real life, including forgotten doses and imperfect timing.

Why do some methods have a big gap between the two?

Methods that depend on the user remembering or acting each time, such as pills or condoms, have a bigger gap than methods such as the implant or IUD that need no regular action.

Related terms

Sources

  1. Contraception (peer-reviewed)Contraceptive failure in the United States
  2. NHSYour contraception guide