Table 1 Characteristics of included studies
Study | Design | Sample size (mTBI, healthy controls) | Percentage female | Nature of mTBI | Mean symptom duration (months) | Primary symptom domain | Diagnostic approach to PSaC | Primary clinical outcome measure | Cut-off score | Clinician rated or self-rated |
|---|---|---|---|---|---|---|---|---|---|---|
PCS+ studies | ||||||||||
Amir 2021 (ref. 40) | Cross-sectional | 53 (27, 26) | 70 | Civilian | 8.8 | Global | Cut-off score | RPQ | RPQ ≥ 30 | Self-rated |
Dumkrieger 2019 (ref. 37) | Case-control | 80 (44, 36) | 36 | Mixed | 108 | Headache | Headache specialist assessment | Numeric rating scale | ICDH-3 diagnostic criteria | Clinician rated |
Leung 2016 (ref. 41) | Cross-sectional | 30 (15, 15) | 26 | Veteran | 70 | Headache | Headache specialist assessment | Numeric rating scale, visual analog scale | ICDH-2 diagnostic criteria + visual analog scale score ≥ 3 out of 10 | Clinician + self-rated |
Rockswold 2019 (ref. 42) | Longitudinal | 19 (10 PCS+ and 9 PCS-) | 53 | Civilian | 3 | Vision | Vision testing by optometrist | Optometric testing | Determined to have substantial oculomotor dysfunction | Clinician rated |
Runyan 2022 (ref. 44) | Cross-sectional | 127 (46, 81) | 7 | Veteran | 11.6 | Cognition | Cut-off score | NSI | Score of ≥3 on any NSI cognitive symptoms | Clinician rated |
Shafi 2020 (ref. 27) | Cross-sectional | 111 (80, 31) | 33 | Civilian | 19 | Global | Diagnostic assessment | DSM-IV PCS diagnostic criteria | DSM-IV PCS diagnostic criteria | Clinician rated |
Sheth 2021 (ref. 43) | Cross-sectional | 74 (49, 25) | 10 | Veteran | 144 | Post-traumatic stress disorder | Cut-off score | Clinician-Administered Post-traumatic Stress Disorder Scale | CAPS cut-off (score of ≥2) | Self-rated |
Sours 2015 (ref. 45) | Longitudinal | 56 (28, 28) | 33 | Civilian | 6 | Global | Cut-off score | RPQ | ≥3 RPQ symptoms present at 3 months | Self-rated |
Stevens 2012 (ref. 46) | Cross-sectional | 60 (30, 30) | 33 | Civilian | 2 | Global | Total score, no cut-offa | Post-concussion symptoms checklist | No cut-off used; scores well above recognized threshold | Self-rated |
Trofimova 2021 (ref. 47) | Longitudinal | 22 (12, 10) | 92 | Mixed (civilian + sports) | 2 | Vestibular | Total score, no cut-offa | Post-Concussion Symptom Scale + Vestibular/Ocular Motor Screen | No cut-off used; scores well above recognized threshold | Clinician + self-rated |
Vedaei 2023 (ref. 38) | Cross-sectional | 100 (60, 40) | 62 | Civilian | 24 | Global | Diagnostic assessment | ICD-10 PCS diagnostic criteria | ICD-10 PCS diagnostic criteria | Clinician rated |
Wong 2023 (ref. 26) | Cross-sectional | 38 (17, 21) | 100 | Civilian | 21.5 | Global | Total score, no cut-offa | Composite score of Graded Symptom Scale Checklist severity and cognitive testing | No cut-off used | Clinician rated |
PCS− studies | ||||||||||
Chong 2019 (ref. 51) | Longitudinal | 30 (15, 15) | 87 | Civilian | 5 | Global | Total score, no cut-offa | Sport Concussion Assessment Tool 3 | No cut-off used | Self-rated |
Churchill 2019 (ref. 52) | Longitudinal | 146 (24, 122) | 50 | Sports | 12 | Global | Total score, no cut-offa | Sport Concussion Assessment Tool 3 | No cut-off used | Self-rated |
De Souza 2020 (ref. 53) | Longitudinal | 39 (39, 0) | 26 | Civilian | 18 | Global | Total score, no cut-off | Glasgow Outcome Scale–Extended | No cut-off used | Clinician rated |
D’Souza 2020 (ref. 48) | Longitudinal | 120 (60, 60) | 43 | Civilian | 6 | Global | Total score, no cut-off | RPQ | No cut-off used | Self-rated |
McCuddy 2018 (ref. 54) | Longitudinal | 94 (43, 51) | 21 | Sports | 1 | Mood | Total score | HAM-D | HAM-D cut-off scores | Clinician rated |
Studies that distinguished between high-symptom and low-symptom groups | ||||||||||
Flowers 2021 (ref. 59) | Cross-sectional | 64 (16 PCS+ and 16 PCS-, 32) | 0 | Veteran | 3 | Headache | Categorical cut-off score | NSI | Headache severity rating (mild (1), moderate (2), severe (3 or 4)) | Self-rated |
Sours 2013 (ref. 39) | Cross-sectional | 37 (13 PCS+ and 10 PCS–, 14) | 52 | Civilian | 1 | Cognition | Diagnostic assessment + categorical cut-off score | RPQ | ICD-10 PCS diagnostic criteria + presence of cognitive symptoms on RPQ (that is, yes/no) | Clinician + self-rated |
