Table 2.
Intention to treat analysis of warm-up exercise programme (intervention) in young female footballers. Values are numbers (percentages) of injured players
| Intervention group (n=1055) | Control group (n=837) | Intracluster correlation coefficient* | Inflation factor* | NNT | Rate ratio (95% CI)† | P value | |
|---|---|---|---|---|---|---|---|
| All injuries | 135 (13.0) | 166 (19.8) | 0.096 | 2.86 | 15 | 0.68 (0.48 to 0.98) | 0.041 |
| Match injuries | 96 (9.1) | 114 (13.6) | 0.045 | 1.87 | 22 | 0.72 (0.52 to 1.00) | 0.051 |
| Training injuries | 50 (4.7) | 63 (7.5) | 0.044 | 1.86 | 36 | 0.68 (0.41 to 1.11) | 0.120 |
| Lower extremity injuries | 121 (11.5) | 143 (17.1) | 0.088 | 2.70 | 18 | 0.71 (0.49 to 1.03) | 0.072 |
| Knee injuries | 33 (3.1) | 47 (5.6) | 0.028 | 1.54 | 40 | 0.62 (0.36 to 1.05) | 0.079 |
| Ankle injuries | 45 (4.3) | 49 (5.9) | 0.026 | 1.50 | 63 | 0.81 (0.50 to 1.30) | 0.378 |
| Acute injuries | 112 (10.6) | 130 (15.5) | 0.070 | 2.35 | 20 | 0.74 (0.51 to 1.08) | 0.110 |
| Overuse injuries | 27 (2.6) | 48 (5.7) | 0.040 | 1.76 | 32 | 0.47 (0.26 to 0.85) | 0.012 |
| Severe injuries | 45 (4.3) | 72 (8.6) | 0.028 | 1.54 | 23 | 0.55 (0.36 to 0.83) | 0.005 |
NNT=number needed to treat.
*Generalised estimating equation model with clubs as cluster unit.
†Cox model calculated according to method of Lin and Wei,25 which takes cluster randomisation into account.