Table 1. Likelihood Ratios Associated With Symptoms in, and Outside, Flu Seasona.
| Signs and Symptoms | COVID-19 Number/Total (Percent) | Flu Number/Total (Percent) | Flu-Like Illness Number/Total (Percent) | Likelihood Ratio for COVID-19 in Widespread Flu Season | Likelihood Ratio for COVID-19 in Sporadic Flu Season | |
|---|---|---|---|---|---|---|
| Ageb | 0-29 | 129/709 (18%) | 1480/2885 (51%) | 241/884 (27%) | 0.400 | 0.669 |
| 30-39 | 96/709 (14%) | 278/2885 (10%) | 146/884 (17%) | 1.208 | 0.821 | |
| 40-49 | 114/709 (16%) | 278/2885 (10%) | 146/884 (17%) | 1.431 | 0.973 | |
| 50-59 | 132/709 (19%) | 278/2885 (10%) | 138/884 (16%) | 1.688 | 1.194 | |
| 60-69 | 107/709 (15%) | 201/2885 (7%) | 89/884 (10%) | 1.968 | 1.497 | |
| 70-79 | 59/709 (8%) | 124/2885 (4%) | 41/884 (5%) | 1.907 | 1.792 | |
| 80c | 71/709 (10%) | 248/2885 (9%) | 82/884 (9%) | 1.141 | 1.072 | |
| Raceb | White | 169 737/326 828 (52%) | (78%) | 0.669 | ||
| Black | 95 850/326 828 (29%) | (13%) | 2.189 | |||
| Asian | 16 167/326 828 (5%) | (8%) | 0.651 | |||
| Other | 3135/326 828 (1%) | (1%) | 0.719 | |||
| Gender | Female | 316/704 (45%) | 328/1719 (19%) | 556/884 (63%) | 1.322 | 0.714 |
| Male | 388/704 (55%) | 1391/1719 (81%) | 328/884 (37%) | 0.835 | 1.485 | |
| Chest pain | No | 693/709 (98%) | 347/486 (71%) | 884/884 (100%) | 1.088 | 0.977 |
| Yes | 16/709 (2%) | 139/486 (29%) | 0/884 (0%) | 0.222 | 17.000 | |
| Chills | No | 685/709 (97%) | 484/1229 (39%) | 414/635 (65%) | 2.005 | 1.482 |
| Yes | 24/709 (3%) | 745/1229 (61%) | 221/635 (35%) | 0.065 | 0.097 | |
| Conjunctivitis | No | 704/709 (99%) | 734/932 (79%) | 53/190 (28%) | 1.416 | 3.560 |
| Yes | 5/709 (1%) | 198/932 (21%) | 137/190 (72%) | 0.024 | 0.010 | |
| Cough | No | 393/709 (55%) | 288/1548 (19%) | 369/695 (53%) | 1.892 | 1.044 |
| Yes | 316/709 (45%) | 1260/1548 (81%) | 326/695 (47%) | 0.630 | 0.950 | |
| Diarrhea | No | 564/588 (96%) | 12 885/13 658 (94%) | 0.983 | ||
| Yes | 23/588 (4%) | 772/13 658 (6%) | 1.415 | |||
| Fatigue | No | 615/709 (87%) | 594/1343 (44%) | 445/581 (77%) | 1.606 | 1.133 |
| Yes | 94/709 (13%) | 749/1343 (56%) | 136/581 (23%) | 0.288 | 0.566 | |
| Fever | No | 174/709 (25%) | 469/1583 (30%) | 517/776 (67%) | 0.587 | 0.368 |
| Yes | 535/709 (75%) | 1114/1583 (70%) | 259/776 (33%) | 1.296 | 2.261 | |
| Headache | No | 676/709 (95%) | 739/1416 (52%) | 390/560 (70%) | 1.669 | 1.369 |
| Yes | 33/709 (5%) | 677/1416 (48%) | 170/560 (30%) | 0.109 | 0.153 | |
| Nausea | No | 695/709 (98%) | 817/1159 (70%) | 501/596 (84%) | 1.305 | 1.166 |
| Yes | 14/709 (2%) | 342/1159 (30%) | 95/596 (16%) | 0.079 | 0.124 | |
| Runny nose | No | 684/709 (96%) | 583/1424 (41%) | 465/732 (64%) | 1.985 | 1.519 |
| Yes | 25/709 (4%) | 841/1424 (59%) | 267/732 (36%) | 0.069 | 0.097 | |
| Shortness of breath | No | 666/709 (94%) | 840/1160 (72%) | 501/589 (85%) | 1.225 | 1.104 |
| Yes | 43/709 (6%) | 320/1160 (28%) | 88/589 (15%) | 0.260 | 0.406 | |
| Vomiting | No | 702/709 (99%) | 960/1192 (81%) | 534/596 (90%) | 1.185 | 1.105 |
| Yes | 7/709 (1%) | 232/1192 (19%) | 62/596 (10%) | 0.060 | 0.095 | |
| Wheezing | No | 708/709 (100%) | 457/619 (74%) | 459/546 (84%) | 1.270 | 1.188 |
| Yes | 1/709 (0%) | 162/619 (26%) | 87/546 (16%) | 0.007 | 0.009 | |
| Diminished smell/taste | No | 263/272 (97%) | 14 678/14 695 (100%) | 0.968 | ||
| Yes | 9/272 (3%) | 17/14 695 (0.12%) | 28.602 | |||
| Excessive sweating | No | 241/272 (89%) | 13 870/14 695 (94%) | 0.939 | ||
| Yes | 31/272 (11%) | 825/14 695 (6%) | 2.030 | |||
| Change in appetite | No | 254/272 (93%) | 14 210/14 695 (97%) | 0.966 | ||
| Yes | 18/272 (7%) | 485/14 695 (3%) | 2.005 | |||
aTo score the odds ratio of COVID-19, multiply likelihood ratios associated with the features of the individual.
bBased on CDC data.
cMissing values were set to absence of symptom.