Table 1. Risk ratios of laboratory confirmed SARS-CoV-2 infection for participation in different rehearsals of choir 1, Berlin, March 2020.
| exposed | unexposed | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Rehearsal | cases n | total N | AR (%) | cases n | total N | AR (%) | RR | 95% CI | p-value |
| 09 March | 64 | 71 | 90 | 1 | 14 | 7.1 | 12.6 | 1.91–84 | <0.001 |
| 07 March, am | 51 | 61 | 84 | 14 | 24 | 58 | 1.4 | 1.00–2.1 | 0.01 |
| 07 March, pm | 49 | 60 | 82 | 14 | 23 | 61 | 1.3 | 0.95–1.9 | 0.05 |
| 02 March | 52 | 69 | 75 | 12 | 14 | 86 | 0.9 | 0.68–1.1 | 0.40 |
AR = attack rate; RR = risk ratio; CI = confidence interval; am = morning; pm = afternoon