Data extraction tool for studies using genetic testing
| Study design | Participants | Review of evidence | ||||||
| First author, year | Study type | Modality | Sport | Age/level (mean ± SD, range) | Gender (M/F) | n (control description) | Time from injury to examination | Risk of bias |
| McDevitt J, 201587 | PCS | VNTR/GRIN2A | Any | 19.5±6.0 years | M/F | 87 C+ | Recovery followed prospectively; ≤60 days postinjury | High |
| Gill J, 201685 | PCS | RNA | Any | Control: 18.5±0.4 years; concussed: 19.4±1.5 years | M/F | 15 C+, 16 C- | BL, within 6 hours and 7 days postinjury | Moderate |
| Madura SA, 201690 | PCS | SLC17A7 | Any | 20.0±6.3 years | M/F | 40 C+ | Recovery followed prospectively; ≤20 days postinjury | High |
| Merchant-Borna K, 201686 | PCS | mRNA | FB, IH, SCR, LX | Control: 18.5±0.4 years; concussed: 19.4±1.5 years | M/F | 16 C+, 16 C- teammate controls (253 C- at BL including C+ athletes) | BL, within 6 hours, and 7 days postinjury | Moderate |
| Merritt VC, 201689 | PCS | APOE | Any | 19.3±1.5 years | M/F | 45 C+, 43 C- | 10.0±14.3 days postinjury | Moderate |
| Merritt VC, 201688 | CS | APOE | Any | Positive ϵ4 allele group 19.9±1.4 years; negative ϵ4 allele group 20±1.6 years | M/F | 42 C+ | 9.8±14.6 days postinjury (range of 0–72 days) | Moderate |
Definitions and coding for Table 4: Author indicates last name of first author. Year refers to year of publication.
Study type coded as follows: CS, clinical series; PCS, prospective cohort study.
Modality refers to specific genetic marker(s) studied: VNTR, variable number tandem repeats; GRIN2A, N-methyl-D-aspartate receptor 2A; APOE, Apolipoprotein e; SLC17A7, Solute Carrier Family 17 Member 7.
Sports coded as follows: BX, boxing; FB, football; FH, field hockey; IH, ice hockey; LX, LaCrosse; OT, other; RB, rugby; SCR, soccer; WR, wrestling.
Age/Level coded as follows: Col, college; HS, high school; O, other; P, professional; Y, youth.
F/M indicates gender: F, female; M, male; list both if it applies.
Misc: BL, baseline.
Risk of bias: overall risk of bias rated as low, moderate, high or unclear, based on modified QUADAS-2 critical appraisal tool (see online supplementary appendix 2).