• Data reference period
• Geographic localization (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.
• ECONOMIC TERRITORY:  Territory that consists on: (a) the geographic territory administered by a government within which persons, goods, services and capital move freely; (b) any free zones, including bonded warehouses and factories under customs control; (c) the national air-space, territorial waters and the continental shelf lying in international waters, over which the country enjoys exclusive rights; (d) territorial enclaves (i.e. geographic territories situated in the rest of the world and used, under international treaties or agreements between States, by general government agencies of the country (embassies, consulates, military bases, scientific bases, etc.); (e) deposits of oil, natural gas, etc., in international waters outside the continental shelf of the country, worked by units resident in the territory as defined in the preceding subparagraphs.
• HEALTH PROFESSIONAL:  Qualified worker involved in the provision of health care.
• 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).

(Total number of health professionals registered in the end of the year/ Resident population estimated for the end of the year)*100 000