Patient characteristics
| Influenza (n=151) | Influenza-like (n=172) | P value | |
| Age, median (Q1–Q3) | |||
| Years | 61 (51–72) | 58 (47–72) | 0.2140* |
| Sex, n (%) | |||
| Female | 88 (58.3) | 91 (52.9) | 0.3326 |
| Race, n (%) | |||
| African-American | 96 (63.6) | 94 (54.7) | 0.1992† |
| Caucasian | 53 (35.1) | 72 (41.9) | |
| Other | 2 (1.3) | 6 (3.5) | |
| Social history, n (%) | |||
| Alcohol | 11 (7.3) | 26 (15.1) | 0.0275 |
| Smoke | 39 (25.8) | 63 (36.6) | 0.0372 |
| Any drug use | 13 (8.6) | 23 (13.4) | 0.1747 |
| Medical history, n(%) | |||
| Cardiovascular | 13 (8.6) | 25 (14.5) | 0.0009 |
| Respiratory | 60 (39.7) | 83 (48.3) | |
| Cardiovascular and respiratory | 12 (8.0) | 24 (14.0) | |
| None | 66 (43.7) | 40 (23.3) |
*Wilcoxon rank sum test.
†Fisher’s exact test; χ2 test.