Volume 19, Number 2—February 2013
Dispatch
Risk Factors for Influenza A(H1N1)pdm09 among Students, Beijing, China
Table 1
Bivariate analysis of potential factors associated with influenza A(H1N1)pdm09 infection among students ≤18 years, Beijing, China*
Variable | No. (%) case-patients, n = 304 | No. (%) controls, n = 608 | p value | OR (95%CI) |
---|---|---|---|---|
Vaccination against influenza A(H1N1)pdm09 | ||||
No | 276 (90.8) | 264 (43.4) | Referent | |
Yes | 28 (9.2) | 344 (56.6) | <0.001 | 0.08 (0.05–0.12) |
Vaccination with pneumococcal vaccine | ||||
No | 279 (91.8) | 542 (89.1) | Referent | |
Yes | 25 (8.2) | 66 (10.9) | 0.193 | 0.72 (0.43–1.18) |
Use of traditional Chinese medicine | ||||
No | 103 (33.9) | 175 (28.8) | Referent | |
Yes | 201 (66.1) | 433 (71.2) | 0.068 | 0.73 (0.51–1.02) |
Eye rubbing | ||||
No | 163 (53.6) | 395 (65.0) | Referent | |
Yes | 141 (46.4) | 213 (35.0) | 0.001 | 1.68 (1.25–2.26) |
Handwashing immediately after sneezing | ||||
No | 151 (49.7) | 205 (33.7) | Referent | |
Yes | 153 (50.3) | 403 (66.3) | <0.001 | 0.48 (0.36–0.65) |
Use of soap during handwashing | ||||
No | 37 (12.2) | 63 (10.4) | Referent | |
Yes | 267 (87.8) | 545 (89.6) | 0.402 | 0.83 (0.53–1.29) |
Handwashing after lessons in communal classrooms | ||||
No | 176 (57.9) | 285 (46.9) | Referent | |
Yes | 128 (42.1) | 323 (53.1) | 0.002 | 0.63 (0.48–0.84) |
Handwashing after participation in outdoor sports activities | ||||
No | 46 (15.1) | 69 (11.3) | Referent | |
Yes | 258 (84.9) | 539 (88.7) | 0.088 | 0.69 (0.45–1.06) |
Duration of handwashing, s | ||||
<20 | 176 (57.9) | 347 (57.1) | Referent | |
≥20 | 128 (42.1) | 261 (42.9) | 0.800 | 0.96 (0.71–1.30) |
Sleep time, h/day | ||||
<7 | 99 (32.6) | 162 (26.6) | Referent | |
≥7 | 205 (67.4) | 446 (73.4) | 0.030 | 0.67 (0.47–0.96) |
Sharing of tableware with classmates | ||||
No | 263 (86.5) | 534 (87.8) | Referent | |
Yes | 41 (13.5) | 74 (12.2) | 0.556 | 1.14 (0.74–1.75) |
Classroom space/student, m2 | ||||
<1.6 | 223 (73.4) | 412 (67.8) | Referent | |
≥1.6 | 81 (26.6) | 196 (32.2) | <0.001 | 0.17 (0.07–0.41) |
Participation in outdoor activities after class | ||||
No | 232 (76.3) | 411 (67.6) | Referent | |
Yes | 72 (23.7) | 197 (32.4) | 0.003 | 0.58 (0.40–0.83) |
Frequency of classroom ventilation | ||||
>1×/h | 109 (35.9) | 160 (26.3) | Referent | |
1×/h | 195 (64.1) | 448 (73.9) | 0.002 | 0.61 (0.44–0.83) |
Having meals in small restaurants near school | ||||
No | 232 (76.3) | 460 (75.7) | Referent | |
Yes | 72 (23.7) | 148 (24.3) | 0.808 | 0.96 (0.67–1.37) |
Modes of transportation to and from school | ||||
Closed (taxi, public transportation, school bus, car) | 188 (61.8) | 325 (53.5) | Referent | |
Open (walking, bicycle, motorcycle) | 116 (38.2) | 283 (46.5) | 0.009 | 0.66 (0.48–0.90) |
Participation in clustered social activities after school closure | ||||
No | 266 (87.5) | 559 (91.9) | Referent | |
Yes | 38 (12.5) | 49 (8.1) | 0.023 | 1.76 (1.08–2.86) |
*Bivariate conditional logistic regression was used to generate p values. OR, odds ratio.
1These authors contributed equally to this article.