Intention-to-treat analysis
| CRI N (%) | RR (95% CI) | ILI N (%) | RR (95% CI) | Laboratory- confirmed viruses N (%) | RR (95% CI) | |
|---|---|---|---|---|---|---|
| Medical mask* | 28/580 (4.83) | Ref | 1/580 (0.17) | Ref | 19/580 (3.28) | Ref |
| Cloth masks† | 43/569 (7.56) | 1.57 (0.99 to 2.48) | 13/569 (2.28) | 13.25 (1.74 to 100.97) | 31/569 (5.45) | 1.66 (0.95 to 2.91) |
| Control‡ | 32/458 (6.99) | 1.45 (0.88 to 2.37) | 3/458 (0.66) | 3.80 (0.40 to 36.40) | 18/458 (3.94) | 1.20 (0.64 to 2.26) |
Bold typeface indicates statistically significant. *p Value from cluster adjusted χ2 tests is 0.510 and intracluster correlation coefficients is 0.065.
†p Value from cluster adjusted χ2 tests is 0.028 and intracluster correlation coefficients is 0.029.
‡p Value from cluster adjusted χ2 tests is 0.561 and intracluster correlation coefficients is 0.068.
CRI, clinical respiratory illness; ILI, influenza-like illness; RR, relative risk.