Number and proportion of participants reporting primary outcomes, by mask versus no-mask groups (n=597)*
| CRI No (rate person-days) | RR | ILI No (rate person-days) | RR | Laboratory-confirmed viral respiratory infections No (rate person-days) | HR† | |
|---|---|---|---|---|---|---|
| Mask group | 3/2694 (1.11/1000) | 0.23 (0.06 to 0.88) | 1/2694 (0.37/1000) | 0.18 (0.02 to 1.71) | 0/2694 (0/1000) | 0.11 (0.01 to 4.40) |
| No-mask group | 7/1440 (4.86/1000) | Ref | 3/1440 (2.08/1000) | Ref | 2/1440 (0.70/1000) | Ref |
*Household members (mask group 387 and no-mask group 210).
†Calculated through Cox PH methods.
CRI, clinical respiratory illness; ILI, influenza-like illness; PH, proportional hazards; RR, relative risk.