Table 4.
Analyses on potential risk factors in the nested case-control study, Shenzhen, China (n = 572)
| Characteristics | Severe cases (n = 286) | Non-severe cases (n = 286) | OR (95% CI) | P |
|---|---|---|---|---|
| Sex ratio (male:female) | 1·70:1 | 1·91:1 | 1·113 (0·802–1·591) | 0·485 |
| Age, mean (s.d.) | 2·01 (2·165) | 2·48 (3·112) | n.a. | 0·029 |
| Migrant children, n (%) | 232 (81·1) | 191 (66·8) | 2·137 (1·454–3·141) | 0·000 |
| Clinical symptoms, n (%) | ||||
| Fever >39°C | 186 (65·0) | 71 (24·8) | 2·832 (2·421–3·313) | 0·000 |
| Skin or mucous membrane lesions within 48 h of onset | 42 (14·7) | 270 (94·4) | 0·010 (0·006–0·019) | 0·000 |
| Aseptic meningitis | 54 (18·9) | — | — | — |
| Encephalitis | 40 (14·0) | — | — | — |
| Myocarditis | 34 (11·9) | — | — | — |
| Neurogenic pulmonary oedema | 82 (28·7) | — | — | — |
| Healthcare services, first visit, n (%) | ||||
| Private clinic | 161 (56·3) | 52 (18·2) | 5·796 (3·961–8·481) | 0·000 |
| Community health centre | 70 (24·5) | 57 (19·9) | 1·302 (0·876–1·935) | 0·191 |
| District hospital | 46 (16·1) | 102 (35·7) | 0·346 (0·232–0·515) | 0·000 |
| City-level hospital/medical centre | 9 (3·1) | 75 (26·2) | 0·091 (0·045–0·187) | 0·000 |
| Time between onset and first visit, mean (s.d.) | 2·13 (1·564) | 1·02 (1·677) | n.a. | 0·001 |
| Time between onset and diagnosis, mean (s.d.) | 3·27 (1·702) | 1·77 (1·592) | n.a. | 0·018 |
| Has health insurance, n (%) | 56 (19·6) | 80 (28·0) | 0·627 (0·425–0·926) | 0·018 |
| Medication within 72 h, n (%) | ||||
| (1) Self-medication | 152 (53·2) | 147 (51·4) | 1·073 (0·773–1·489) | 0·676 |
| (2) Any antibiotic use | 141 (49·3) | 132 (46·2) | 1·134 (0·817–1·575) | 0·451 |
| (3) Any antiviral medicine use | 192 (67·1) | 181 (63·3) | 1·185 (0·840–1·672) | 0·334 |
| (4) Any oral antipyretics use | 183 (64·0) | 122 (42·7) | 2·388 (1·706–3·344) | 0·000 |
| (5) Any intramuscular pyrazolone use | 122 (42·7) | 50 (17·5) | 3·511 (2·390–5·159) | 0·000 |
| (6) Any intravenous glucocorticoid use | 120 (42·0) | 35 (12·2) | 5·184 (3·391–7·926) | 0·000 |
| (2)+(3) | 104 (36·4) | 91 (31·8) | 1·224 (0·866–1·731) | 0·252 |
| (2)+(4) | 94 (32·9) | 57 (19·9) | 1·967 (1·344–2·879) | 0·000 |
| (3)+(4) | 126 (65·6) | 79 (27·6) | 2·063 (1·456–2·925) | 0·000 |
| (2)+(3)+(4) | 74 (25·9) | 40 (14·0) | 2·147 (1·402–3·288) | 0·000 |
| (5)+(6) | 49 (17·1) | 4 (1·4) | 14·576 (5·184–40·981) | 0·000 |
OR, Odds ratio; CI, confidence interval; n.a., not available; s.d., standard deviation.