Table 1.
Demographic characteristics-specific prevalence of IBS in children.
| Number of cases | (%) | Total surveyed n † | z/χ 2-value | P value | |
|---|---|---|---|---|---|
| Age (years) | |||||
| 8 | 50 | 13.40 | 374 | 2.796* | 0.0026 |
| 9 | 106 | 12.70 | 832 | ||
| 10 | 171 | 11.20 | 1533 | ||
| 11 | 191 | 10.17 | 1883 | ||
| 12 | 207 | 10.20 | 2025 | ||
| 13 | 74 | 9.40 | 784 | ||
| Sex | |||||
| Male | 403 | 10.30 | 3917 | 2.015 | 0.15 |
| Female | 402 | 11.30 | 3555 | ||
| Annual family income (RMB) | |||||
| ≤12,000 | 117 | 12.00 | 979 | 3.84 | 0.27 |
| 12,001–20,000 | 75 | 9.90 | 758 | ||
| 20,001–36,000 | 108 | 9.60 | 1129 | ||
| >36,000 | 64 | 11.30 | 567 | ||
| Gestational age (weeks) | |||||
| ≤35 | 25 | 10.30 | 244 | 0.712 | 0.87 |
| 35+1–37 | 68 | 10.50 | 651 | ||
| 37+1–40 | 214 | 11.20 | 1904 | ||
| >40 | 48 | 10.20 | 471 | ||
| Birth weight (kg) | |||||
| <2.5 | 86 | 11.20 | 765 | 4.77 | 0.09 |
| 2.5–4.0 | 537 | 11.50 | 4671 | ||
| >4.0 | 28 | 7.70 | 362 | ||
| Weight (kg) | |||||
| ≤30 | 250 | 11.59 | 2157 | 6.55 | 0.25 |
| 30.1–35 | 164 | 11.29 | 1453 | ||
| 35.1–40 | 121 | 10.34 | 1170 | ||
| >40 | 161 | 10.23 | 1574 |
*Cochran-Armitage trend test.
†Due to missing cases, the total number is less than 7472.