Volume 15, Number 2—February 2009
CME ACTIVITY - Research
Face Mask Use and Control of Respiratory Virus Transmission in Households
Table 4
Intention-to-treat analysis used in the study*
Data | Control group, no. (%) | All masks |
Surgical masks |
P2 masks |
||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
No. (%) | RR (95% CI)† | p value† | No. (%) | RR (95% CI)† | p value† | No. (%) | RR (95% CI)† | p value† | ||||
By house | n = 50 | n = 93 | n = 47 | n = 46 | ||||||||
ILI |
12 (24) |
25 (27) |
1.12
(0.62–2.03) |
0.84 |
15 (32) |
1.33
(0.70–2.54) |
0.50 |
10 (22) |
0.91
(0.43–1.89) |
0.81 |
||
By individual | n = 100 | n = 186 | n = 94 | n = 92 | ||||||||
ILI |
16 (16) |
33 (18) |
1.11
(0.64–1.91) |
0.75 |
19 (20) |
1.29
(0.69–2.31) |
0.46 |
14 (15) |
0.95
(0.49-1.84) |
1 |
||
Laboratory confirmed infections | ||||||||||||
Influenza A | 0 | 3 (2) | 1 (1) | 2 (2) | ||||||||
Influenza B | 0 | 1 (0.5) | 0 | 1 (1) | ||||||||
RSV | 1 (1) | 1 (0.5) | 0 | 0 | ||||||||
hMPV | 0 | 0 | 0 | 0 | ||||||||
Adenoviruses | 0 | 2 (1) | 0 | 2 (2) | ||||||||
PIV‡ | 1 (1) | 1 (0.5) | 1 (1) | 0 | ||||||||
Coronaviruses§ | 1 (1) | 0 | 0 | 0 | ||||||||
Rhinoviruses | 0 | 5 (3) | 3 (3) | 2 (2) | ||||||||
Enteroviruses | 0 | 0 | 0 | 0 | ||||||||
Picornoviruses | 0 | 1 (0.5) | 0 | 1 (1) | ||||||||
Total | 3 (3) | 14 (8) | 2.51 (0.74–8.5) | 0.19 | 6 (6) | 2.13 (0.55–8.26) | 0.32 | 8 (9) | 2.90 (0.79–10.6) | 0.12 |
*RR, relative risk; CI, confidence interval; ILI, influenza-like illness; RSV, respiratory syncytial virus; hMPV, human metapneumovirus; PIV, parainfluenza virus.
†Reference group is the control group.
‡Types 1–3; 229E/OC43.
§Types 1–3.