| Initial visit | 1 Year | 2 Years | 5 Years |
---|---|---|---|---|
Frequency | 13.4 ± 10.8 | 4.9 ± 7 (P < 0.001) | 4.7 ± 7.6 (P < 0.001) | 4.6 ± 7.6 (P < 0.001) |
Severity | 6.8 ± 1.8 | 5.2 ± 2.3 (P < 0.001) | 5.0 ± 2.4 (P < 0.001) | 4.6 ± 2.5 (P < 0.001) |
Duration | 17.3 ± 9.5 | 12.2 ± 18.6 (P < 0.01) | 9.4 ± 15.1 (P < 0.001) | 11.5 ± 16.5 (P = 0.02) |
School days missed | 4.5 ± 9.5 | 5 ± 12.2 (P = 0.35) | 2.7 ± 6 (P = 0.01) | 1.5 ± 2.8 (P < 0.001) |