Table 1. Overview of included ICPC-1 codes per group
ICPC-1 codeInfluenza groupSARS-CoV-2 group
R74 Acute upper respiratory infectionYesYes
R75 Acute/chronic sinusitisYesYes
R77 Acute laryngitis/tracheitisYesYes
R78 Acute bronchitis/bronchiolitisYesYes
R80 InfluenzaYesYes
R81 PneumoniaYes, excluding R81.01 Legionella pneumonia
R83 Other respiratory infectionYes, excluding R83.01 Diphtheria and R83.02 Sarcoidosis
  • ICPC-1 = International Classification of Primary Care first edition. SARS-CoV-2 = severe acute respiratory syndrome coronavirus 2.