Table 1:
Overview of the collection of data on laboratory-confirmed cases of pandemic (H1N1) influenza during the first wave (Apr. 12 to Aug. 29, 2009) and the second wave and post-peak period (Aug. 30, 2009, to Apr. 3, 2010) of the 2009 pandemic
| Variable | April to May 2009 | June 2009 | July 2009 | October 2009 | November 2009 to January 2010 |
|---|---|---|---|---|---|
| Frequency and type of reporting | Real-time detailed case-based reporting | Weekly abbreviated case-based reporting | Weekly abbreviated case-based reporting | Weekly abbreviated case-based reporting | Combination of weekly abbreviated case-based reporting and aggregate reporting (5 provinces and territories) |
| Type of cases collected | Community-based cases, hospital admissions and deaths | Community-based cases, hospital admissions and deaths | Hospital admissions and deaths | Hospital admissions and deaths | Hospital admissions and deaths |
| Information collected | Detailed case information: age, sex, province/territory, Aboriginal status,* Aboriginal group,† clinical presentation, underlying medical conditions, pregnancy status, severity of illness, vaccine history, antiviral treatment, exposure history | Core variables: age, sex, province/ territory, Aboriginal status,* Aboriginal group,† underlying medical conditions (including pregnancy), date of symptom onset, date of specimen collection, date of hospital admission, ICU admission (yes v. no), date of death | In addition to previous core variables: reserve status of Aboriginal patients, pregnancy trimester and post- partum period, need for ventilation, categorization of underlying conditions (chronic heart disease, chronic pulmonary disease [including asthma], diabetes, chronic renal disease, immunosuppression [including cancer]) | In addition to previous core variables: date data reported to PHAC, registered Indian, residence in isolated or remote community, asthma, chronic liver disease, anemia or hemoglobinopathy, chronic neurologic disease, weight, height, obesity, current smoker, discharged from hospital | Core variables and aggregate counts (some of the provinces and territories later sent core information on cases reported in aggregate) |
Note: ICU = intensive care unit, PHAC = Public Health Agency of Canada.
*
Aboriginal status (yes v. no) was self-reported or recorded by a health care provider in most cases.
†
In Canada, Aboriginal groups are First Nations, Inuit and Métis. Inuit status was assigned to all cases in Nunavut, because most of the people in this territory are Inuit.