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 χ

^{2}tests is 0.510 and intracluster correlation coefficients is 0.065.†p Value from cluster adjusted χ

^{2}tests is 0.028 and intracluster correlation coefficients is 0.029.‡p Value from cluster adjusted χ

^{2}tests is 0.561 and intracluster correlation coefficients is 0.068.CRI, clinical respiratory illness; ILI, influenza-like illness; RR, relative risk.