Skip to main content

Table 1 Demography of the study population

From: Influenza and other respiratory viral infections associated with absence from school among schoolchildren in Pittsburgh, Pennsylvania, USA: a cohort study

 

Total

Grade

K

1

2

3

4

5

6

7

8

9

10

11+

Total study population

2519

314

319

343

355

351

227

275

46

38

88

90

79

Observable for ILI (%)

 Yes

2077 (82)

279 (88)

267 (84)

300 (87)

301 (85)

304 (87)

185 (81)

216 (79)

34 (74)

30 (79)

61 (69)

50 (55)

50 (63)

 No

442 (18)

35 (22)

46 (26)

43 (23)

54 (15)

47 (23)

42 (19)

59 (21)

12 (26)

8 (21)

27 (31)

40 (45)

29 (37)

Observable population

 District

  A

647

54

53

62

56

66

62

69

34

30

61

50

50

  B

1430

225

214

238

245

238

123

147

 School

  A1

204

27

26

32

21

32

30

36

  A2

161

61

50

50

  A3

282

27

27

30

35

34

32

33

34

30

  B1

201

40

40

36

50

35

  B2

270

123

147

  B3

240

47

43

54

41

55

  B4

188

36

34

44

33

41

  B5

342

67

60

59

85

71

  B6

189

35

37

45

36

36

Sex

 Female

995

145

125

149

137

136

91

97

14

17

34

27

23

 Male

1082

134

142

151

164

168

94

119

20

13

27

23

27

Self-reported vaccination §

 No

850

133

111

131

118

122

74

63

17

10

22

25

24

 Yes

694

63

95

105

107

120

66

74

10

8

20

13

13

 Not reported

533

83

61

64

76

62

45

79

7

12

19

12

13

  1. § Of 2077 participants, we obtained a valid immunization response from 1544 children: we failed to interview 296 children regarding their vaccination status; of the children interviewed, 237 did not know their vaccination status or refused to provide a valid answer for any of the times they were questioned