Table 2.

Association of clinical and demographic factors with mode of detection and severity at initial assessment

	Outcome: symptom-based surveillance						Outcome: moderate or severe assessment
	Univariate regression			Multivariate regression			Univariate regression			Multivariate regression
	OR	2·5%	97·5%	OR	2·5%	97·5%	OR	2·5%	97·5%	OR	2·5%	97·5%
Sex
Female	Ref	..	..	Ref	..	..	Ref	..	..	Ref	..	..
Male	3·23	1·93	5·53	3·06	1·77	5·44	1·30	0·82	2·07	1·37	0·85	2·22
Age
0–9 years	0·07	0·02	0·23	0·08	0·02	0·25	0·88	0·30	2·77	0·67	0·22	2·23
10–19 years	0·19	0·05	0·77	0·17	0·04	0·76	1·08	0·28	5·27	0·88	0·22	4·40
20–29 years	0·33	0·12	0·89	0·37	0·13	1·02	0·65	0·28	1·56	0·61	0·26	1·49
30–39 years	0·75	0·31	1·77	0·8	0·32	1·93	1·17	0·58	2·37	1·15	0·57	2·33
40–49 years	0·86	0·32	2·33	0·79	0·29	2·19	1·27	0·58	2·83	1·21	0·55	2·72
50–59 years	Ref	..	..	Ref	..	..	Ref	..	..	Ref	..	..
60–69 years	0·48	0·2	1·08	0·44	0·18	1·04	1·50	0·72	3·16	1·43	0·68	3·03
≥70 years	0·56	0·16	2·25	0·45	0·12	1·89	1·41	0·45	5·43	1·28	0·40	4·96
Severity
Mild	Ref	..	..	Ref	..	..	..	..	..	..	..	..
Moderate	0·6	0·33	1·05	0·51	0·26	0·94	..	..	..	..	..	..
Severe	2·2	0·68	9·84	1·51	0·42	7·23	..	..	..	..	..	..
Fever
No	Ref	..	..	..	..	..	Ref	..	..	..	..	..
Yes	3·06	1·69	5·49	..	..	..	0·94	0·49	1·75	..	..	..
Symptomatic
No	Ref	..	..	..	..	..	Ref	..	..	..	..	..
Yes	8·62	3·68	21·89	..	..	..	0·51	0·15	1·39	0·55	0·29	1·01
Surveillance method
Contact-based	..	..	..	..	..	..	Ref	..	..	..	..	..
Symptom-based	..	..	..	..	..	..	0·67	0·37	1·17	..	..	..

OR=odds ratio.