CLINICAL DATA
RESEARCH DATA
The BQC19’s mission is to make biological samples and associated clinical data available to the scientific community. In a pandemic context that is sometimes restrictive, it has given priority to data collection even when no biological samples were available for certain visits.
Data collection is based on the compilation of case report forms (CRFs). It is carried out by the clinical teams at the sites, either by correlation with hospitalization data, or in real time. All clinical data is then stored on the RedCap platform.


Participant identification
The data collected in this section concerns participants’ consent and contact details. This information is internal and is not shared by the sites.
Demographic data available through the access process includes:
- Patient profile and type: COVID status, severe/poor disease, age, gender, weight, height, smoking status, drug use, healthcare workers, etc.
- Pediatric: birth weight, length of gestation.
- Obstetrics: post-partum, pregnancy outcome, COVID status of the baby, other infectious pathogens of the mother.
- Medical history.
- Reported COVID-19 symptoms, if present, and date of onset.
- COVID-19 test and severity of illness (WHO severity scale).
- Clinical frailty score.

Upon arrival
Certain data are collected on the participant’s arrival:
- Vital signs: temperature, blood pressure, respiratory/heart rate, room air oxygen saturation and oxygen therapy, if applicable.
- Laboratory results: routine tests requested by the physician.

During hospitalization
Data are collected at recruitment (day 0) and on days 2, 7, 14 and 30, if the patient is still admitted to hospital. They include:
- Description of visit and sampling for BQC19, including calculation of time from visit to recruitment and time from visit to symptom onset.
- Vital signs including, if available, AVPU scale, Glasgow score and 24-hour urine output.
- Arterial gas assessment data, if available.
- Data on respiratory support and adjuvant therapies, if available.
- Results of routine laboratory tests requested by the physician. Although the list of routine laboratory tests is available for data collection, only those actually requested by the attending physician are recorded.

On hospital leave
This section summarizes the data obtained during hospitalization:
- Hospitalization summary: ED visit, hospital admission (with length of stay), ICU admission (with duration), facility transfer, vital status at discharge, disposition (home, CHSLD, etc.), final diagnosis and last level of care.
- Complications observed.
- Treatments and interventions: medications administered and tests performed during hospitalization (without notation of results).
- Respiratory support and adjuvant therapies: summary of measures used and duration of respiratory support.
- Laboratory tests: summary of all routine tests performed during hospitalization.

During longitudinal follow-up
Follow-up is carried out at the following periods: 30, 90, 180, 365, 540 and 730 days post original infection..
Longitudinal follow-up data are identical for all cohorts. These follow-ups extend to 24 months after hospital discharge for participants who developed a severe form of the disease, or after PCR testing for SARS-CoV-2 for those with a mild or asymptomatic form. They include:
- Description of visit and sampling for BQC19, including calculation of time from visit to recruitment and time from visit to onset of symptoms.
- Essential follow-up: time from diagnosis to follow-up, continued consent status, vital status.
- Follow-up: new COVID-19 diagnosis, unscheduled hospital visits after discharge, current symptoms, functional status questionnaire.
- Post-COVID complications, including listing of symptoms associated with long COVID.
- Tests performed in a clinical setting.
- Routine laboratory tests performed in a clinical setting.
- Clinical frailty score.

At the end-of-study visit
These data will be collected during the 730-day visit, except for participants who choose to withdraw from the project before that date.
This section also includes participants’ vaccination data. The information collected includes:
- The type of vaccine received (Pfizer, Moderna, AstraZeneca, etc.)
- The number of doses received
- Reported side effects