Table 2.
Point prevalence of low back pain and extracurricular sports activities among girls by grade
| Variable | E4 | E5 | E6 | J1 | J2 | J3 |
|---|---|---|---|---|---|---|
| ECSA (−) | ||||||
| n (%) | 1126 (49.4) | 1322 (48.5) | 1422 (52.5) | 660 (23.2) | 746 (27.0) | 2437 (89.3) |
| LBP (+) /LBP (−) | 35/1091 | 42/1280 | 49/1373 | 42/618 | 55/691 | 196/2241 |
| LBP (+) /n (%) | 3.1 | 3.2 | 3.4 | 6.4 | 7.4 | 8.0 |
| ECSA (+) | ||||||
| n (%) | 1154 (50.6) | 1405 (51.5) | 1284 (47.5) | 2188 (76.8) | 2016 (73.0) | 292 (10.7) |
| LBP (+) /LBP (−) | 29/1125 | 65/1340 | 82/1202 | 163/2005 | 180/1836 | 40/252 |
| LBP (+) /n (%) | 2.5 | 4.6 | 6.4 | 7.5 | 8.9 | 13.7 |
| Odds ratio | 0.80 | 1.48 | 1.91 | 1.20 | 1.23 | 1.81 |
| (95% CI) | (0.49–1.32) | (1.00–2.20)† | (1.33–2.75)** | (0.84–1.70) | (0.90–1.69) | (1.26–2.61)** |
| PAF (%) | −10.7 | 19.0** | 28.8** | 12.2 | 13.3 | 7.0 |
Abbreviations: ECSA extracurricular sports activities, n number of students, LBP low back pain, PAF population attributable fraction, CI confidence interval. E4–E6 and J1–J3 refer to elementary school grades 4–6 and junior high school grades 1–3, respectively. The PAF among girls was compared with that among boys. †P = 0.05, **P < 0.01