Table 2. Overall analyses on constipation (less than once every 2 days).
| Constipation % (95% CI) | Univariate OR (95% CI) | Multivariate OR (95% CI) | ||
| Sex | girl/boy | 5.1 (4.8–5.6)/2.8 (2.4–3.2) | 1.89 (1.50–2.39) | 1.97 (1.55–2.51) |
| Skipping breakfast | yes/no | 4.5 (4.0–5.0)/3.8 (3.3–4.2) | 1.19 (0.78–1.80) | 0.94 (0.61–1.45) |
| Physical activity | very often | 3.0 (2.6–3.4) | 1 | 1 |
| often | 3.9 (3.5–4.3) | 1.29 (0.96–1.73) | 1.17 (0.86–1.57) | |
| rarely | 5.0 (4.5–5.5) | 1.68 (1.22–2.31) | 1.41 (1.01–1.95) | |
| TV viewing, hours on weekdays | ||||
| <2 | 3.4 (3.0–3.8) | 1 | 1 | |
| 2 to <3 | 4.2 (3.8–4.6) | 1.24 (0.96–1.62) | 1.07 (0.82–1.40) | |
| ≥3 | 5.8 (5.2–6.3) | 1.73 (1.25–2.37) | 1.37 (0.99–1.95) | |
| Sleep duration | <8 h/≥8 h | 5.0 (4.5–5.5)/3.8 (3.4–4.2) | 1.32 (0.85–2.04) | 1.18 (0.75–1.85) |
| Food frequency (except school lunch) | ||||
| Fruit | almost every day | 2.5 (2.2–2.8) | 1 | 1 |
| 3 to 5 times per week | 4.3 (3.9–4.7) | 1.78 (1.33–2.39) | 1.68 (1.24–2.26) | |
| 0 to 2 times per week | 5.3 (4.8–5.7) | 2.23 (1.65–3.01) | 1.94 (1.42–2.66) | |
| Vegetables | almost every day | 3.0 (2.6–3.4) | 1 | 1 |
| 3 to 5 times per week | 5.2 (4.7–5.7) | 1.76 (1.37–2.27) | 1.53 (1.17–1.98) | |
| 0 to 2 times per week | 5.3 (4.8–5.8) | 1.80 (1.30–2.49) | 1.46 (1.03–2.05) | |
| Overweight | yes/no | 2.6 (2.3–2.9)/4.1 (3.7–4.5) | 0.63 (0.43–0.91) | 0.58 (0.40–0.85) |
| Psychological stress, family environment | ||||
| irritability | often | 6.6 (6.1–7.1) | 2.21 (1.60–3.06) | 1.76 (1.24–2.50) |
| sometimes | 3.6 (3.2–4.0) | 1.18 (0.87–1.60) | 1.07 (0.81–1.43) | |
| rarely | 3.1 (2.7–3.5) | 1 | 1 | |
| unwillingness to attend school | often | 6.9 (6.3–7.5) | 2.06 (1.44–2.93) | 1.66 (1.13–2.43) |
| sometimes | 4.0 (3.6–4.4) | 1.17 (0.91–1.51) | 1.02 (0.78–1.33) | |
| rarely | 3.5 (3.1–3.9) | 1 | 1 | |
| interaction with parents | often | 2.7 (2.3–3.1) | 1 | 1 |
| sometimes | 4.3 (3.9–4.7) | 1.61 (1.18–2.20) | 1.55 (1.13–2.13) | |
| rarely | 4.3 (3.9–4.7) | 1.63 (1.18–2.26) | 1.48 (1.06–2.07) | |
| mother’s employment | full-time | 3.9 (3.5–4.3) | 1 | 1 |
| part-time | 4.5 (4.0–5.0) | 1.17 (0.90–1.52) | 1.22 (0.93–1.59) | |
| unemployed | 3.3 (2.9–3.7) | 0.86 (0.65–1.14) | 0.92 (0.69–1.23) | |
| dinner | with both parents | 3.8 (3.4–4.2) | 1 | 1 |
| with either parent | 3.8 (3.4–4.2) | 1.00 (0.79–1.27) | 0.97 (0.76–1.24) | |
| without parent | 5.4 (4.9–5.9) | 1.44 (0.95–2.19) | 1.40 (0.91–2.15) | |
CI, confidence interval; OR, odds ratio.