Table 3

ORs for prolonged symptom duration by age, acute COVID-19 severity, date of COVID-19 onset and comorbidities

OR (95% CI) for prolonged symptom duration 28 days or longer (CDC definition)OR (95% CI) for prolonged symptom duration 90 days or longer (WHO definition)
Age (per 10 years)1.25 (1.05 to 1.50)1.29 (1.00 to 1.68)
Age categories, years
 18–291.0 (ref)1.0 (ref)
 30–491.02 (0.44 to 2.69)1.55 (0.41 to 10.1)
 50–691.82 (0.80 to 4.73)2.16 (0.50 to 13.9)
 70+1.95 (0.49 to 7.47)4.04 (0.61 to 33.4)
Age-adjusted OR (95% CI)Age-adjusted OR (95% CI)
Acute COVID-19 severity
 Not hospitalised and no difficulties performing daily activities1.0 (ref)1.0 (ref)
 Not hospitalised but had difficulties performing daily activities4.02 (2.31 to 7.31)2.84 (1.34 to 6.60)
 Hospitalised6.49 (3.03 to 14.1)2.93 (0.92 to 8.72)
 Hospitalised and required ICU care7.28 (1.66 to 30.4)*
Date of COVID-19 onset
 December 2019 to June 20201.0 (ref)1.0 (ref)
 July 2020 to December 20201.05 (0.63 to 1.80)1.30 (0.61 to 2.95)
 January 2021 to July 20210.42 (0.21 to 0.81)0.46 (0.15 to 1.28)
 Comorbidity count (per comorbidity)1.11 (1.02 to 1.21)1.16 (1.02 to 1.33)
Individual comorbidities
 Hypertension (vs not)1.55 (0.96 to 2.48)2.23 (1.14 to 4.33)
 Lung disease† (vs not)1.52 (0.89 to 2.55)0.87 (0.34 to 1.94)
 Obesity (vs not)1.46 (0.89 to 2.36)1.33 (0.63 to 2.63)
 Diabetes (vs not)1.10 (0.45 to 2.43)0.62 (0.10 to 2.19)
 Cardiovascular disease (vs not)1.87 (0.68 to 4.74)3.62 (1.11 to 10.1)
 Osteoarthritis (vs not)2.11 (1.01 to 4.27)1.96 (0.69 to 4.80)
 Fibromyalgia (vs not)1.51 (0.79 to 2.79)2.33 (1.01 to 5.02)
 No comorbidity (vs any)0.60 (0.36 to 0.98)0.34 (0.13 to 0.78)
  • *Model did not converge due to few outcomes.

  • †Lung disease includes asthma, emphysema, chronic bronchitis, chronic obstructive pulmonary disease, pulmonary hypertension, interstitial lung disease, idiopathic pulmonary fibrosis and other lung diseases.

  • CDC, Centers for Disease Control and Prevention; ICU, intensive care unit; ref, reference.