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Table 1 Descriptive statistics for laboratory-confirmed influenza outcomes and demographic and clinical variables

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

  

Subjects ages

Subjects ages

Subjects ages

Subjects ages

 

Total study population

3–5 years

6–17 years

18–49 years

50–80 years

Variable

(n = 789)

(n = 65)

(n = 197)

(n = 326)

(n = 201)

Outcome variables

n (%)

n (%)

n (%)

n (%)

n (%)

Influenza diagnosis

     

Positive

220 (27.9)

12 (18.5)

65 (33.0)

92 (28.2)

51 (25.4)

Negative

569 (72.1)

53 (81.5)

132 (67.0)

234 (71.8)

150 (74.6)

Influenza type

     

A

152 (69.1)

7 (58.3)

53 (81.5)

63 (68.5)

29 (56.9)

B

67 (30.5)

5 (41.7)

11 (16.9)

29 (31.5)

22 (43.1)

AB

1 (0.5)

0 (0.0)

1 (1.5)

0 (0.0)

0 (0.0)

Influenza A subtypea

     

H1

51 (44.0)

3 (42.9)

19 (44.2)

18 (38.3)

11 (57.9)

H3

46 (39.7)

1 (14.3)

21 (48.8)

17 (36.2)

7 (36.8)

Unsubtypeable

19 (16.4)

3 (42.9)

3 (7.0)

12 (25.5)

1 (5.3)

Continuous variables

Value (error)b

Value (error)b

Value (error)b

Value (error)b

Value (error)b

Age (years)

31.2 (19.4)

4.0 (0.8)

11.5 (3.6)

32.0 (9.9)

56.8 (5.3)

Symptom duration (days)

4.0 (1–90)

4.0 (1–30)

3.0 (1–60)

5.0 (1–60)

5.0 (1–90)

Temperature (°C)

36.9 (35.6–40.3)

36.8 (35.9–39.5)

37.1 (35.6–40.3)

36.9 (35.9–39.6)

36.8 (35.6–39.3)

Smoking history (pack-years)

0.0 (0–117.5)c

––d

––d

0.0 (0–51)c

0.0 (0–117.5)

Vaccine to Onset Time (Days)e

80 (0–365)

57 (0–198)

74 (6–348)

89 (3–342)

85.4 (8–365)

Categorical variables

n (%)

n (%)

n (%)

n (%)

n (%)

Enrollment site

     

Outpatient clinic 1

284 (36.0)

6 (9.2)

61 (31.0)

137 (42.0)

80 (39.8)

Outpatient clinic 2

203 (25.7)

15 (23.1)

55 (27.9)

63 (19.3)

70 (34.8)

Emergency room

246 (31.2)

24 (36.9)

47 (23.9)

124 (38.0)

51 (25.4)

Pediatric clinic

56 (7.1)

20 (30.8)

34 (17.3)

2 (0.6)

0 (0.0)

Sex

     

Female

494 (62.6)

30 (46.2)

87 (44.2)

270 (82.8)

107 (53.2)

Male

295 (37.4)

35 (53.8)

110 (55.8)

56 (17.2)

94 (46.8)

Acute onset

     

≤3 days

273 (34.6)

30 (46.2)

99 (50.3)

100 (30.7)

44 (21.9)

>3 days

516 (65.4)

35 (53.8)

98 (49.8)

226 (69.3)

157 (78.1)

Fever

     

>38.0°C

126 (16.0)

11 (16.9)

48 (24.4)

43 (13.2)

24 (11.9)

≤38.0°C

663 (84.0)

54 (83.1)

149 (75.6)

283 (86.8)

177 (88.1)

Cough

     

Yes

736 (93.3)

63 (96.9)

176 (89.3)

299 (91.7)

198 (98.5)

No

53 (6.7)

2 (3.1)

21 (10.7)

27 (8.3)

3 (1.5)

Sore throat

     

Yes

630 (79.8)

33 (50.8)

170 (86.3)

278 (85.3)

149 (74.1)

No

159 (20.2)

32 (49.2)

27 (13.7)

48 (14.7)

52 (25.9)

Shortness of breathe

     

Yes

346 (43.9)

20 (30.8)

73 (37.2)

166 (50.9)

87 (43.3)

No

442 (56.0)

45 (69.2)

123 (62.8)

160 (49.1)

114 (56.7)

Nasal congestion

     

Yes

650 (82.4)

51 (78.5)

155 (78.7)

271 (83.1)

173 (86.1)

No

139 (17.6)

14 (21.5)

42 (21.3)

55 (16.9)

28 (13.9)

Headache

     

Yes

619 (78.5)

31 (47.7)

134 (68.0)

286 (87.7)

168 (83.6)

No

170 (21.5)

34 (52.3)

63 (32.8)

40 (12.3)

33 (16.4)

Conjunctivitise

     

Yes

44 (5.6)

6 (9.2)

4 (2.0)

16 (4.9)

18 (9.0)

No

744 (94.3)

59 (90.8)

193 (98.0)

309 (94.8)

183 (91.0)

Body achese

     

Yes

581 (73.6)

27 (41.5)

99 (50.2)

289 (88.7)

166 (82.6)

No

207 (26.2)

37 (56.9)

98 (49.8)

37 (11.4)

35 (17.4)

Nausea/vomiting

     

Yes

347 (44.0)

19 (29.2)

107 (54.3)

155 (47.5)

66 (32.8)

No

442 (56.0)

46 (70.8)

90 (45.7)

171 (52.5)

135 (67.2)

Smoker

     

Yes

157 (19.9)

0 (0.0)

0 (0.0)

88 (27.0)

69 (34.3)

No

632 (80.1)

65 (100.0)

197 (100. 0)

238 (73.0)

132 (65.7)

Vaccinated

     

Yes

217 (27.5)

17 (26.2)

27 (13.7)

85 (26.1)

88 (43.8)

No

572 (72.5)

48 (73.9)

170 (86.3)

241 (73.9)

113 (56.2)

  1. NOTE. Percentages are rounded, thus may not add up to 100%. aDenominator is subjects with at least one specimen positive by culture for influenza A. bContinuous variable values reported as “mean (standard deviation)” if symmetric variable, or “median (low end–high end of range)” if nonsymmetric. cTwo subjects in age group reported history of smoking but datum for number of pack-years is missing. dIn this age group no subjects reported pack-years >0. eMedian (range) reported for subset of subjects who reported any influenza vaccine within the 12 months prior to presentation. fDatum missing for 1 subject in study population.