Multivariable ordinal logistic regression models for factors associated with more severe PCR-positive SARS-CoV-2 infection on WHO COVID-19 Clinical Progression Scale, stratified according to age groups (children<1 year old; children<12 years old; children≥12 years old)
| Covariates | Model 1*: Children<1 year old (n=113) aOR (95% CI) | Model 2*: Children<1 year old (n=113) aOR (95% CI) | Model 3†: Children<12 years old (n=308) aOR (95% CI) | Model 4†: Children<12 years old (n=308) aOR (95% CI) | Model 5†: Children≥12 years old (n=93) aOR (95% CI) | Model 6†: Children≥12 years old (n=93) aOR (95% CI) |
| Number of comorbidities | ||||||
| None | – | Ref. | – | Ref. | – | Ref. |
| 1 comorbidity | – | 1.72 (0.62 to 4.78) | – | 1.82 (0.98 to 3.36) | – | 2.40 (0.79 to 7.30) |
| Multiple (>2) comorbidities | – | 2.16 (0.44 to 10.57) | – | 2.33 (1.18 to 4.63) | – | 2.35 (0.68 to 8.17) |
| Individual comorbidities | ||||||
| Obesity | 1.21 (0.14 to 10.70) | – | 2.87 (0.96 to 8.55) | – | 3.69 (1.45 to 9.40) | – |
| Pulmonary disorders | 4.55 (0.87 to 23.82) | 2.33 (1.20 4.51) | – | 0.84 (0.28 to 2.58) | – | |
| Non-asthma pulmonary disorders | 6.42 (0.95 to 43.18) | 3.07 (1.26 to 7.49) | 0.51 (0.09 to 2.96) | |||
| Asthma | N/A | 1.42 (0.62 to 3.25) | 1.14 (0.32 to 4.06) | |||
| Prematurity (<37 weeks’ gestational age) | 1.23 (0.36 to 4.20) | – | 1.13 (0.52 to 2.46) | – | 3.31 (0.35 to 31.24) | – |
| Immunosuppression | – | – | 0.45 (0.14 to 1.43) | – | 0.32 (0.05 to 2.05) | – |
| Anaemia or haemoglobinopathy | 1.51 (0.08 to 29.76) | – | 2.15 (0.61 to 7.52) | – | 1.37 (0.09 to 20.44) | – |
| Neurological disorders | 10.72 (1.01 to 113.35) | – | 1.86 (0.87 to 3.97) | – | 1.71 (0.63 to 4.58) | – |
| Cardiac disorders | 10.13 (1.69 to 60.54) | – | 2.90 (1.11 to 7.56) | – | -‡ | – |
| Metabolic disorders | –‡ | – | 1.24 (0.24 to 6.34) | – | 1.61 (0.11 to 22.59) | – |
| Renal disorders | –‡ | – | 2.87 (0.92 to 8.97) | – | –‡ | – |
| Hypertension | –§ | – | 3.04 (0.61 to 15.06) | – | 2.61 (0.23 to 29.36) | – |
| Chromosomal disorders | 13.70 (0.68 to 274.79) | – | 3.30 (0.84 to 12.95) | – | –‡ | – |
| Others | 3.48 (0.17 to 72.25) | – | 1.74 (0.68 to 4.45) | – | 0.82 (0.17 to 3.83) | – |
*Model 1 incorporates each individual comorbidity in a separate ordinal logistic regression model, and model 2 incorporates the number of comorbidities while excluding individual comorbidities. Both models are adjusted for coinfection and chest imaging results.
†Models 3 and 5 incorporate each individual comorbidity in a separate ordinal logistic regression model, and models 4 and 6 incorporate the number of comorbidities while excluding individual comorbidities. All models are adjusted for age, coinfection, chest imaging results and MIS-C.
‡Too few occurrences/observations of this individual comorbidity in this age group resulting in a model error.
§No occurrences/observations of this individual comorbidity in this age group (n=0).
aOR, adjusted OR; MIS-C, multisystem inflammatory syndrome in children; NA, not appropriate (a diagnosis of asthma should not be made in an infant <1 year of age).