Table 2.

Protocol specificities between coordinating sites

Characteristic	Valencia, Spain	St. Petersburg, Russia	Moscow, Russia	Turkey	France
Hospitals	5 health care district general hospitals	1 infectious disease hospital, 1 children’s city hospital, 1 children’s infectious disease hospital	1 infectious disease hospital	7 general hospitals	5 university hospitals
Screening ward	Emergency	Emergency and 3 selected wards	Paediatric, mixed, pregnancy, adults	Emergency and 7 selected wards	Emergency and >20 selected wards
Screening diagnosis	Admission diagnosis associated with influenza infection; clinical symptoms of ILI	Clinical symptoms of ILI	Admission diagnosis associated with influenza inflection; clinical symptoms of ILI	Clinical symptoms of ILI	Signs of respiratory illness for <7 days
Recruited by	Full-time trained nurses	Doctors	Doctors, nurses, heads of wards	Doctors	Doctors, clinical researchers, nurses
Additional exclusion criteria	Outside catchment area	-	-	-	Not affiliated with social security
Study start criteria	2 consecutive weeks with ≥2 cases	Week with ≥5 laboratory-confirmed influenza cases using national surveillance data	Week with ≥5 laboratory-confirmed influenza cases using national surveillance data	Not defineda	Defined by the national surveillance system
Study end criteria	2 consecutive weeks with no cases	Week with no laboratory-confirmed influenza cases	Week with no laboratory-confirmed influenza cases	Not defineda	Defined by the national surveillance system
Actual study period (epidemiological weeks)	2013-01 – 2013-15	2013-03 – 2013-22	2013-02 – 2013-21	2013-01 – 2013-14	2012-51 – 2013-16

^aStudy period not defined because it was a pilot study. Cases of ILI were reported between epidemiological weeks 1 and 14 of 2013.

Dashes indicate no additional exclusion criteria.