Replacement of staff and the hamstring injury (HI) burden for team seasons with replacements compared with team seasons without replacements
| Replacement of staff | Frequency of replacements | HI burden for team seasons without replacements (mean, 95% CI) | HI burden for team seasons with replacements (mean, 95% CI) | HI burden change when replacements compared without replacements | HI burden increase when team season replacement compared with without replacement (95% CI) |
| Total number of replacements during the 42 team seasons | 49 | 24 (15 to 34) | 32 (23 to 40) | +33% | 8 (−6 to 21) |
| New head coach at the start of the season | 10/42=24% | 27 (20 to 31) | 35 (24 to 46) | +30% | 8 (−7 to 23) |
| Change of head coach during the season | 10/42=24% | 29 (20 to 37) | 29 (12 to 45) | ±0 | 0 (−16 to 14) |
| New head coach before or during the season | 20/42=48% | 27 (19 to 35) | 32 (22 to 42) | +19% | 5 (−8 to 18) |
| New head fitness/performance coach at the start of the season | 10/42=24% | 27 (19 to 34) | 38 (28 to 47) | +41% | 11 (−4 to 26) |
| Change of head fitness/performance coach during the season | 7/42=17% | 27 (20 to 33) | 40 (20 to 60) | +48% | 3 (−3 to 30) |
| New head fitness/performance coach before or during the season | 15/42=36% | 24 (17 to 31) | 39 (28 to 50) | +63% | 15 (3 to 28) |
| New head team doctor before or during the season | 7/42=17% | 26 (20 to 31) | 47 (23 to 70) | +81% | 21 (5 to 37) |
| New head physiotherapist before or during the season | 7/42=17% | 29 (22 to 35) | 32 (10 to 55) | +10% | 3 (-13 to 21) |
HI burden is expressed as the number of days lost per 1000 hours of exposure.