• Data reference period
• Place of residence (Portugal)
• Age group
• Mandatory notification diseases

• MANDATORY NOTIFICATION DISEASE:  Disease included in a list periodically reviewed and approved by law that must be notified to the competent authority by any medical doctor diagnosing it, in case of disease or death.
• 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).
• AGE GROUP:  The age interval in years to which a person belongs at the time of reference.
• MANDATORY NOTIFICATION DISEASE:  Infectious disease with impact on public health, as set out in specific legislation, being subject to mandatory declaration as soon as the diagnosis is made.
• AVERAGE POPULATION:  The average population during a calendar year, generally calculated as the arithmetic mean of the population on two consecutive years.

(Number of notified cases of mandatory notification diseases/ Resident population estimated for the middle of the year)*100 000