Table 4 Symptom duration outcome intervals and prior concussion history
Study | Outcome coding | Result | p | Effect size | |
|---|---|---|---|---|---|
Mihalik et al. [24] | NR (~ 6 days) | Odds ratio reflects time to symptom resolution in those with prior concussion history relative to those without prior concussion. Median symptom resolution time for the overall sample was 6.1 days | NR | 1.13 [0.62, 2.04]a | |
Bruce and Echemendia [22] | 7 days | Percentage endorsing cognitive/balance symptoms Prior concussion group: 32% No prior concussion group: 8% | < 0.05 | NR | |
Guskiewicz et al. [23] | < 1 day; 1–7 days; > 7 days | Length of symptom recovery 0 Prior concussions: < 1 day: 30.3%; 1–7 days: 62.3%; > 7 days: 7.4% 1 Prior concussion: < 1 day: 39.0%; 1–7 days: 46.3%; > 7 days: 14.6% 2 Prior concussions: < 1 day: 33.3%; 1–7 days: 46.7%; > 7 days: 20.0% ≥ 3 Prior concussions: < 1 day: 0.0%; 1–7 days: 70.0%; > 7 days: 30.0% | 0.03 | NR | |
Slobounov et al. [21] | 10Â days | All participants were clinically asymptomatic on day 10 of testing | NR | NR | |
Pattinson et al. [32] | 14 days | The number of prior concussions did not differ between those who experienced symptom resolution at < 14 days and ≥ 14 days | 0.13 | NR | |
Churchill et al. [27] | RTP; 28 days | No difference between those with and without concussion history at any of the time points | ≥ 0.21 | NR | |
Post-RTP; 1Â year post-RTP | |||||
Meehan et al. [20] | 28 days | Symptom Resolution (days) ≤ 28 days: 66.6% of participants with prior SRCs; 50.0% of those without SRC > 28 days: 33.3% of participants with prior SRCs; 50.0% of those without SRC | 0.61 | NR | |
Wasserman et al. [3] | 28 days | 14.6% of athletes with recurrent SRCs symptoms lasted > 28 days 5.4% of athletes with no recurrent SRCs took symptoms lasted > 28 days | < 0.001 | NR | |
Zuckerman et al. [2] | 28 days | 13.3% of athletes with recurrent SRCs symptoms lasted > 28 days 6.5% of athletes with no recurrent SRCs took symptoms lasted > 28 days | < 0.001 | 2.08 [1.28–3.36] | |
Bretzin et al. [33] | Continuous (until recovery) | Median Days [IQR] | Median Days [IQR] | 0.104 | NR |
Men: | Women: | ||||
Gallagher et al. [28] | Continuous (until recovery) | No relationship between concussion history and time since injury to physician clearance date (assumes symptom resolution) | > 0.05 | NR | |
Lempke et al. [29]b | Continuous (until recovery) | ≥ 1 Prior concussion not associated with days to symptom recovery | 0.139 | 0.6 [− 0.2, 1.4]c | |
Putukian et al. [30] | Continuous (until recovery) | Days until symptom free was not significantly associated with concussion history | > 0.05 | NR | |