Table 7.
Group comparisons, p-values and effect sizes [Cliff's delta (Cohen's d)].
| MTBI/trauma control/community control | Complicated | LOC | PTA | ||||||
|---|---|---|---|---|---|---|---|---|---|
| p | Effect sizes: MTBI vs. trauma controls | Effect sizes: MTBI vs. community controls | p | Effect sizes | p | Effect sizes | p | Effect sizes | |
| Paper-and-Pencil | |||||||||
| OTBM | 0.152 | 0.14 (0.30) | 0.12 (0.28) | 0.603 | 0.07 (0.24) | 0.685 | 0.05 (0.00) | 0.013 | 0.27 (0.48) |
| GDS | 0.655 | 0.06 (0.31) | 0.03 (0.23) | 0.221 | 0.16 (0.43) | 0.889 | −0.02 (−0.16) | 0.054 | 0.18 (0.39) |
| NDS-W | 0.295 | 0.12. (0.32) | 0.08 (0.24) | 0.593 | 0.08 (0.34) | 0.799 | 0.03 (−0.15) | 0.020 | 0.25 (0.49) |
| LSC | 0.316 | 0.12 (0.29) | 0.08 (0.24) | 0.625 | 0.07 (0.25) | 0.786 | 0.04 (−0.11) | 0.017 | 0.25 (0.46) |
| #≤ 5th %tile | 0.186 | 0.12 (0.31) | 0.06 (0.21) | 0.243 | 0.14 (0.35) | 0.671 | −0.05 (−0.13) | 0.071 | 0.16 (0.36) |
| #≤ 16th %tile | 0.471 | 0.09 (0.23) | 0.03 (0.10) | 0.710 | 0.05 (0.08) | 0.960 | −0.01 (−0.08) | 0.008 | 0.26 (0.49) |
| #< 50th %tile | 0.261 | 0.10 (0.18) | 0.12 (0.22) | 0.889 | −0.02 (−0.03) | 0.660 | 0.06 (0.08) | 0.006 | 0.29 (0.52) |
| CANTAB | |||||||||
| OTBM | 0.733 | 0.03 (0.11) | 0.07 (0.16) | 0.681 | −0.06 (−0.06) | 0.806 | −0.03 (−0.05) | 0.001 | 0.37 (0.53) |
| GDS | 0.582 | 0.08 (0.18) | 0.03 (0.13) | 0.780 | −0.04 (0.10) | 0.908 | 0.01 (−0.04) | 0.009 | 0.24 (0.34) |
| NDS-W | 0.468 | 0.06 (0.16) | 0.10 (0.18) | 0.314 | −0.15 (−0.01) | 0.728 | −0.05 (0.01) | 0.015 | 0.26 (0.41) |
| LSC | 0.458 | 0.06 (0.13) | 0.10 (0.16) | 0.370 | −0.13 (−0.05) | 0.819 | −0.03 (0.03) | 0.013 | 0.27 (0.43) |
| #≤ 5th %tile | 0.628 | 0.05 (0.14) | 0.05 (0.14) | 0.520 | −0.07 (−0.10) | 0.426 | −0.08 (−0.10) | 0.007 | 0.22 (0.41) |
| #≤ 16th %tile | 0.862 | 0.03 (0.03) | 0.04 (0.08) | 0.946 | −0.01 (0.05) | 0.752 | 0.04 (0.00) | 0.008 | 0.25 (0.49) |
| #< 50th %tile | 0.239 | 0.03 (0.05) | 0.14 (0.23) | 0.265 | −0.16 (−0.29) | 0.903 | −0.02 (−0.07) | 0.002 | 0.31 (0.58) |
| Combined | |||||||||
| OTBM | 0.259 | 0.11 (0.23) | 0.11 (0.30) | 0.757 | 0.04 (0.12) | 0.866 | 0.02 (−0.03) | 0.001 | 0.35 (0.57) |
| GDS | 0.541 | 0.08 (0.29) | 0.01 (0.23) | 0.469 | 0.10 (0.34) | 0.950 | −0.01 (−0.11) | 0.005 | 0.29 (0.42) |
| NDS-W | 0.407 | 0.11 (0.28) | 0.07 (0.26) | 0.861 | 0.03 (0.22) | 0.990 | 0.00 (−0.09) | 0.003 | 0.32 (0.48) |
| LSC | 0.426 | 0.10 (0.26) | 0.07 (0.24) | 0.916 | 0.02 (0.19) | 0.886 | 0.02 (−0.05) | 0.003 | 0.32 (0.50) |
| #≤ 5th %tile | 0.355 | 0.10 (0.27) | 0.04 (0.23) | 0.537 | 0.08 (0.20) | 0.518 | −0.08 (−0.14) | 0.007 | 0.26 (0.45) |
| #≤ 16th %tile | 0.610 | 0.08 (0.17) | 0.01 (0.11) | 0.841 | 0.03 (0.07) | 0.937 | 0.01 (−0.05) | 0.001 | 0.33 (0.59) |
| #< 50th %tile | 0.199 | 0.08 (0.14) | 0.15 (0.27) | 0.535 | −0.09 (−0.18) | 0.739 | 0.04 (0.02) | 0.001 | 0.36 (0.66) |
#, Number of scores; CANTAB, Cambridge Neuropsychological Test Automated Battery; Effect size, Cliff's delta (Cohen's d); GDS, Global Deficit Score; LOC, Loss of Consciousness; LSC, Low Score Composite; MTBI, Mild Traumatic Brain Injury; NDS-W, Neuropsychological Deficit Score-Weighted; OTBM, Overall Test Battery Mean; PTA, Posttraumatic Amnesia. P-values are from Kruskal-Wallis Tests for the three-group comparisons and Mann-Whitney U tests for the two-group comparisons. Cliff's delta is presented first followed by Cohen's d in parentheses. A positive effect sized indicates lower performance in the group assumed to have the greatest deficits (i.e., MTBI, Complicated; LOC, Long PTA). A Cliff's delta of 0.11 is considered a small effect size, 0.28 a moderate effect size, and 0.43 a large effect size. A Cohen's d of 0.2 is considered small, 0.5 moderate, and 0.8 large. Cohen's ds should be interpreted with caution because of the non-normal distribution characterizing most of the composite scores.