Table 3

Sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio for visible signs predicting subsequent concussion diagnoses

SignSensitivitySpecificityPositive predictive valueNegative predictive valuePositive likelihood ratioNegative likelihood ratio
Loss of consciousness/motionless6%
(3.5% to 10.8%)
98%
(97.3% to 99.2%)
52%
(31.3% to 72.2%)
80%
(77.3% to 82.5%)
4.11
(1.9 to 8.9)
0.95
(0.9 to 1.0)
Slow to get up following a hit to the head40%
(32.8% to 46.7%)
7%
(5.7% to 9.5%)
10%
(8.1% to 12.4%)
32%
(25.1% to 39.2%)
0.43
(0.4 to 0.5)
8.13
(6.2 to 10.7)
Incoordination/balance problems17%
(12.4% to 23.3%)
90%
(87.6% to 92.0%)
31%
(22.8% to 40.7%)
81%
(77.7% to 83.1%)
1.73
(1.2 to 2.5)
0.92
(0.9 to 1.0)
Blank or vacant look2%
(0.5% to 6.0%)
100%
(99.1% to 100%)
67%
(22.3% to 95.7%)
79%
(76.8% to 82.0%)
7.59
(1.4 to 41.2)
0.98
(0.96 to 1.0)
Clutching of head after a hit8%
(4.6% to 12.5%)
86%
(83.7% to 88.7%)
13%
(7.8% to 20.6%)
78%
(75.1% to 80.8%)
0.58
(0.4 to 1.0)
1.07
(1.0 to 1.1)
Visible facial injury in combination5%
(2.4% to 8.9%)
80%
(77.3% to 83.1%)
6%
(3.1% to 11.1%)
76%
(73.2% to 79.1%)
0.25
(0.1 to 0.5)
1.18
(1.1to 1.2)
  • 95% CIs in parentheses.