Skip to main content

Table 2 Bivariate regression analysis of laboratory-confirmed influenza versus seven demographic and clinical variables of interest

From: Determination of clinical and demographic predictors of laboratory-confirmed influenza with subtype analysis

Variable

Laboratory-confirmed influenza diagnosis

Total study population

Subjects ages 3–5 years

Subjects ages 6–49 years

Subjects ages 50–80 years

(n = 789)

(n = 65)

(n = 523)

(n = 201)

n/total (%)a

OR (95% CI)

n/total (%)a

OR (95% CI)

n/total (%)a

OR (95% CI)

n/total (%)a

OR (95% CI)

Continuous variable

        

Age (years)

 

1.00 (0.99–1.01)

 

0.47 (0.17–1.10)

 

0.99 (0.98–1.01)

 

1.01 (0.95–1.07)

Categorical variables

 

Sex

 

Female

141/494 (28.5)

1.09 (0.78–1.53)

5/30 (16.7)

0.80 (0.18–3.38)

109/357 (30.5)

1.08 (0.71–1.66)

27/107 (25.2)

0.98 (0.50–1.96)

Maleb

79/295 (26.8)

1.0

7/35 (20.0)

1.0

48/166 (28.9)

1.0

24/94 (25.5)

1.0

Acute onset

≤3 days

110/273 (40.3)

2.49 (1.78–3.48)

8/30 (26.7)

2.77 (0.65–14.21)

86/199 (43.2)

2.71 (1.81–4.06)

16/44 (36.4)

1.98 (0.90–4.31)

>3 daysb

110/516 (21.3)

1.0

4/35 (11.4)

1.0

71/324 (21.9)

1.0

35/157 (22.3)

1.0

Fever

> 38.0°C

65/126 (51.6)

3.49 (2.31–5.27)

1/11 (9.1)

0.40 (0.01–3.37)

51/91 (56.0)

3.91 (2.39–6.44)

13/24 (54.2)

4.28 (1.63–11.51)

≤ 38.0°Cb

155/663 (23.4)

1.0

11/54 (20.4)

1.0

106/432 (24.5)

1.0

38/177 (21.5)

1.0

Cough

Yes

219/736 (29.8)

22.99 (3.72–890.52)

12/63 (19.0)

0.55 (≥0.04) c

156/475 (32.8)

22.92 (3.84–932.74)

51/198 (25.8)

1.32 (≥0.14) c

Nob

1/53 (1.9)

1.0

0/2 (0.0)

1.0

1/48 (2.1)

1.0

0/3 (0.0)

1.0

Body achesd

Yes

177/581 (30.5)

1.67 (1.13–2.50)

8/27 (29.6)

3.40 (0.79–17.59)

127/388 (32.7)

1.70 (1.06–2.79)

42/166 (25.3)

0.98 (0.40–2.57)

Nob

43/207 (20.8)

1.0

4/37 (10.8)

1.0

30/135 (22.2)

1.0

9/35 (25.7)

1.0

Vaccinated

Yes

39/217 (18.0)

0.47 (0.31–0.71)

0/17 (0.0)

0.13 (≤0.89) c

16/112 (14.3)

0.32 (0.17–0.57)

23/88 (26.1)

1.07 (0.54–2.13)

Nob

181/572 (31.6)

1.0

12/48 (25.0)

1.0

141/411 (34.3)

1.0

28/113 (24.8)

1.0

  1. NOTE. Bivariate exact conditional logistic regression was performed in each age group. Bivariate results (OR, odds ratio; CI, confidence interval) are displayed here for all variables of interest (those that were retained in the final multivariate regression model in any age group) modeled against laboratory-confirmed influenza. aNumber of subjects meeting criteria at left who have laboratory-confirmed influenza/all subjects meeting criteria at left (percent). bReference category in regression model. cOR is a median unbiased estimate; one limit of CI is infinite or crosses zero due to cell size of zero. dData missing for 1 subject age 3–5 years.
Back to article page

BMC Infectious Diseases

ISSN: 1471-2334

Contact us