Concussion incidence is known to be highest in children and adolescents; however, there is conflicting evidence about the effect of age on concussion risk and recovery within the adolescent age range. The heterogeneity of results may be partially due to the use of age groupings based on convenience, making comparisons across studies difficult. This study evaluated the independent effect of age on concussion incidence, severity, and recovery in student-athletes aged 12–18 years using cluster analysis to define groupings.

Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) scores of 11,403 baseline tests and 4922 postinjury tests were used to calculate the incidence rates for adolescent student-athletes grouped into 3 age bands (12–13, 14–15, and 16–18 years of age) on the basis of clustering analysis. The recently created Severity Index was used to compare concussion severity between groups. Follow-up tests for subjects who sustained a concussion were used to evaluate recovery time. The chi-square test and 1-way ANOVA were used to compare differences in demographic characteristics and concussion incidence, severity, and recovery. Multivariable logistic and linear regressions were used to evaluate the independent effects of age on concussion incidence and severity, respectively. Multivariable Cox hazard regression was used to evaluate differences in recovery time. Further analyses were conducted to directly compare findings across studies on the basis of the age groupings used in prior studies.

Multivariable regression analyses demonstrated that the 14- to 15-year-old age group had a significantly higher concussion incidence than both the 12- to 13-year-old (14- to 15-year-old group vs 12- to 13-year-old group, OR 1.57, 95% CI 1.16–2.17, p = 0.005) and 16- to 18-year-old (16- to 18-year-old group vs 14- to 15-year-old group, OR 0.79, 95% CI 0.69–0.91, p = 0.0008) age groups. There was no difference in incidence between the 12- to 13-year-old and 16- to 18-year-old groups (16- to 18-year group vs 12- to 13-year group, OR 1.26, 95% CI 0.93–1.72, p = 0.15). There were also no differences in concussion severity or recovery between any groups.

This study found that concussion incidence was higher during mid-adolescence than early and late adolescence, suggesting a U-shaped relationship between age and concussion risk over the course of adolescence. Age had no independent effect on concussion severity or recovery in the 12- to 13-, 14- to 15-, and 16- to 18-year-old groups. Further analysis of the various age groups revealed that results may vary significantly with minor changes to groupings, which may explain the divergent results in the current literature on this topic. Thus, caution should be taken when interpreting the results of this and all similar studies, especially when groupings are based on convenience.

众所周知，儿童和青少年的脑震荡发病率最高；然而，在青少年年龄范围内，年龄对脑震荡风险和恢复的影响存在相互矛盾的证据。结果的异质性可能部分是由于使用基于方便的年龄分组，使得跨研究的比较变得困难。本研究使用聚类分析来定义分组，评估年龄对 12-18 岁学生运动员的脑震荡发病率、严重程度和恢复的独立影响。

使用 11,403 项基线测试和 4922 项伤后测试的即时脑震荡后评估和认知测试 (ImPACT) 分数来计算分为 3 个年龄段（12-13、14-15 和 16-18 岁）的青少年学生运动员的发病率岁）基于聚类分析。最近创建的严重程度指数用于比较组间的脑震荡严重程度。对遭受脑震荡的受试者进行的后续测试用于评估恢复时间。卡方检验和单因素方差分析用于比较人口统计学特征和脑震荡发生率、严重程度和恢复情况的差异。多变量逻辑回归和线性回归分别用于评估年龄对脑震荡发生率和严重程度的独立影响。多变量 Cox 风险回归用于评估恢复时间的差异。进行了进一步的分析，以根据先前研究中使用的年龄分组直接比较研究的结果。

多变量回归分析表明，14 至 15 岁年龄组的脑震荡发病率显着高于 12 至 13 岁（14 至 15 岁组 vs 12 至 13 岁） - 年龄组，OR 1.57，95% CI 1.16–2.17，p = 0.005）和 16 至 18 岁（16 至 18 岁组与 14 至 15 岁组，OR 0.79 , 95% CI 0.69–0.91, p = 0.0008) 年龄组。12 至 13 岁和 16 至 18 岁组之间的发病率没有差异（16 至 18 岁组 vs 12 至 13 岁组，OR 1.26，95% CI 0.93 –1.72，p = 0.15）。任何组之间的脑震荡严重程度或恢复情况也没有差异。

这项研究发现，青春期中期的脑震荡发病率高于青春期早期和晚期，这表明在青春期，年龄和脑震荡风险之间存在 U 型关系。年龄对 12 至 13 岁、14 至 15 岁和 16 至 18 岁组的脑震荡严重程度或恢复没有独立影响。对不同年龄组的进一步分析表明，随着分组的微小变化，结果可能会有很大差异，这可以解释当前有关该主题的文献中的不同结果。因此，在解释本研究和所有类似研究的结果时应谨慎，尤其是在基于方便的分组时。