. 2022 Jul 29;37(8):849–870. doi: 10.1007/s10654-022-00896-z

Table 3.

Case and control definitions for the NAPKON.

Case definition for SARS-CoV-2 infection (= inclusion criteria)	Control definition
Either: Positive polymerase chain reaction (PCR) for SARS-CoV-2 in either Oro/nasopharyngeal swab, BAL, sputum, tracheal secretions, stool, or blood^a Or (all of the following): Negative polymerase chain reaction (PCR) for SARS-CoV-2 of a swab or body fluid Definitive infection of the respiratory system Characteristic radiographic imagery A negative test for influenza Exclusion of other potential causes (like chronic diseases of the respiratory system)	Case definition for SARS-CoV-2 case not applicable Applicable control inclusion criteria for one of the three control strata (pool) Outpatient (e.g., respiratory viral infection) Inpatient (e.g., community-acquired pneumonia) Intensive care unit (e.g., acute respiratory distress syndrome) Capacity for control recruitment with sufficient positive cases in the respective pool over the past eight weeks

Case definition for SARS-CoV-2 infection (= inclusion criteria)

Control definition

Either:

Positive polymerase chain reaction (PCR) for SARS-CoV-2 in either Oro/nasopharyngeal swab, BAL, sputum, tracheal secretions, stool, or blood^a

Or (all of the following):

Negative polymerase chain reaction (PCR) for SARS-CoV-2 of a swab or body fluid

Definitive infection of the respiratory system

Characteristic radiographic imagery

A negative test for influenza

Exclusion of other potential causes (like chronic diseases of the respiratory system)

Case definition for SARS-CoV-2 case not applicable

Applicable control inclusion criteria for one of the three control strata (pool)

Outpatient (e.g., respiratory viral infection)

Inpatient (e.g., community-acquired pneumonia)

Intensive care unit (e.g., acute respiratory distress syndrome)

Capacity for control recruitment with sufficient positive cases in the respective pool over the past eight weeks

Additional case definitions exist for patients age < 18. No exclusion criteria exist, except for age < 18 for the POP and the HAP

^aAntibody testing or rapid tests are no viable alternatives