Table 1

Characteristics of patients in case–control analysis.

Case events (n = 192)Control events (n = 198 124)
Sex, male (%)48.438.0
Median age, years (interquartile range)27, 20–3623, 12–38
 0–20 (%)22.944.2
 21–40 (%)58.933.4
 41–60 (%)15.614.8
 ≥61(%)2.67.6
Smoking status (%)
 Yes38.518.4
 No40.664.9
 Missing20.816.6
Type of RTI event (%)
 Tonsillitis46.922.0
 Sore throat/pharyngitis53.178.0
Exposure to immuno-suppressant drugs (%)1.00.8
Exposure to antibiotics (%)88.084.7
With history of lung disease (%)6.314.9
  • RTI = respiratory tract infection.