Table 1.
Baseline sample characteristics.
| Covariates | CDC COVID cases | COVID population in UAS | Final sample | People with long COVID | People without long COVID | P values |
|---|---|---|---|---|---|---|
| n = 21,926,390 | n = 872 | n = 308 | n = 74 | n = 234 | n = 308 | |
| % | %/mean (SD) | %/mean (SD) | %/mean (SD) | %/mean (SD) | With vs without long COVID | |
| Age in years (18–110) | – |
45.9 (15.4) IQR = 24 |
46.0 (15.8) IQR = 26 |
44.9 (13.9) IQR = 21 |
46.4 (16.3) IQR = 28 |
0.555 |
| Age groups | ||||||
| 18–49 | 60.7 | 60.2 | 56.5 | 56.8 | 56.5 | 0.973 |
| 50–64 | 23.2 | 27.4 | 29.9 | 34.4 | 28.6 | 0.498 |
| 65 + | 16.1 | 12.4 | 13.6 | 8.9 | 14.9 | 0.209 |
| Gender | ||||||
| Male | 47.8 | 44.0 | 42.7 | 34.9 | 45.0 | 0.270 |
| Female | 52.2 | 56.0 | 57.3 | 65.1 | 55.0 | 0.270 |
| Race/ethnicity | ||||||
| Non-Hispanic white | 55.9 | 55.7 | 60.6 | 62.3 | 60.1 | 0.819 |
| Non-Hispanic black | 12.2 | 11.5 | 12.2 | 4.1 | 14.5 | 0.190 |
| Hispanic | 20.7 | 24.0 | 22.4 | 30.0 | 20.1 | 0.271 |
| Non-Hispanic others | 11.3 | 8.8 | 4.9 | 3.6 | 5.3 | 0.586 |
| Education | ||||||
| High school and less | – | 39.4 | 40.9 | 32.3 | 43.4 | 0.253 |
| Some college | – | 32.6 | 35.1 | 39.0 | 34.0 | 0.553 |
| College and more | – | 28.0 | 24.0 | 28.7 | 22.6 | 0.424 |
| Current smoker | – | 24.8 | 29.4 | 19.7 | 32.2 | 0.106 |
| Health conditions | ||||||
| Diabetes | – | 13.6 | 17.7 | 20.0 | 17.1 | 0.694 |
| Cancer | – | 4.8 | 5.2 | 1.1 | 6.4 | 0.059 |
| Heart disease | – | 6.7 | 9.2 | 7.2 | 9.8 | 0.540 |
| Hypertension | – | 30.7 | 28.6 | 33.3 | 27.2 | 0.468 |
| Asthma | – | 15.3 | 18.9 | 24.1 | 17.3 | 0.372 |
| Chronic lung disease | – | 4.2 | 4.6 | 6.8 | 4.0 | 0.850 |
| Kidney disease | – | 3.5 | 4.4 | 7.5 | 3.5 | 0.363 |
| Autoimmune disorder | – | 5.1 | 4.7 | 9.2 | 3.4 | 0.055 |
| Obesity | – | 20.1 | 24.2 | 42.4 | 18.9 | 0.004** |
| New-onset symptoms at infection stage | ||||||
| Body aches | – | – | 44.5 | 50.3 | 42.8 | 0.413 |
| Fatigue | – | – | 43.0 | 47.1 | 41.7 | 0.554 |
| Cough | – | – | 40.8 | 42.7 | 40.3 | 0.791 |
| Headache | – | – | 40.4 | 60.0 | 34.7 | 0.004** |
| Fever | – | – | 37.3 | 51.7 | 33.1 | 0.037* |
| Runny or stuffy nose | – | – | 34.8 | 49.3 | 30.6 | 0.034* |
| Loss of smell | – | – | 32.7 | 43.5 | 29.6 | 0.110 |
| Diarrhea | – | – | 28.5 | 37.7 | 25.9 | 0.168 |
| Sore throat | – | – | 28.0 | 40.1 | 24.5 | 0.061 |
| Shortness of breath | – | – | 26.0 | 34.9 | 23.4 | 0.177 |
| Chest congestion | – | – | 25.2 | 17.2 | 27.6 | 0.116 |
| Sneezing | – | – | 24.1 | 33.8 | 21.2 | 0.104 |
| > 100.4 °F | – | – | 22.7 | 19.6 | 23.6 | 0.616 |
| Abdominal discomfort | – | – | 22.3 | 30.1 | 20.0 | 0.187 |
| Dry skin | – | – | 11.2 | 15.6 | 10.0 | 0.327 |
| Vomiting | – | – | 7.8 | 13.7 | 6.1 | 0.167 |
| Skin rash | – | – | 4.0 | 3.7 | 4.1 | 0.903 |
| Hair loss | – | – | 2.6 | 6.3 | 1.5 | 0.100 |
| Symptomatic at infection | – | 83.2 | 80.3 | 100.0 | 74.6 | – |
| Symptom count at infection (0–18) | – |
5.8 (4.6) IQR = 8 |
6.0 (4.6) IQR = 9 |
7.9 (3.3) IQR = 5 |
5.4 (4.7) IQR = 9 |
0.000*** |
The CDC COVID cases information were from CDC COVID Data Tracker: https://covid.cdc.gov/covid-data-tracker/#demographics.
For the UAS sample, the time of COVID diagnosis is considered baseline, and all percentages and means are weighted to be nationally representative.
Significant values are in bold.
*p < 0.05, **p < 0.01, ***p < 0.001.