• Data reference period
• Place of residence (Portugal)

• RESIDENT POPULATION:  Set of persons who, regardless of being present or absent in a given housing unit at the moment of observation, have lived in the place of their usual residence for a continuous period of 12 months prior to the moment of observation, or have arrived to the place of their usual residence during the period of 12 months prior to the moment of observation, with the purpose of living there for a year, at least.
• CONTRACEPTION:  Use of means to prevent pregnancy through sexual relations.
• REFERENCE PERIOD:  Period to which the information refers and which may be a specific day or a time interval (month, fiscal year, calendar year, among others).
• CONTRACEPTIVE PILL:  Method of hormonal contraception that consists in the regular ingestion of a pill.

(Female resident population aged 15 to 49 years who used the contraceptive pill as the main contraception method/ Female resident population aged 15 to 49 years)*100