Table 3.
Multivariable analysis of the COMT Val158Met polymorphism and 6-month cognitive outcome following mild traumatic brain injury
| WAIS-PSI Composite Scorea | Mean±SE | B [95 % CI] | Sig. (p) |
|---|---|---|---|
| COMT Val158Met | 0.017 | ||
| Val158/Val158 | 93.8±3.0 | Reference | – |
| Met158 | 101.6±2.1 | 7.9 [1.4, 14.3] | |
| GCS | 0.013 | ||
| GCS=15 | 101.6±1.9 | Reference | – |
| GCS <15 | 93.8±3.0 | −7.9 [−14.1, −1.7] | |
| Race | 0.539 | ||
| Caucasian | 96.8±2.1 | Reference | – |
| African-American/African | 95.8±3.6 | −1.1 [−9.0, 6.9] | 0.790 |
| Other | 100.5±3.5 | 3.7 [−3.5, 10.9] | 0.312 |
| Education (years) | – | 1.4 [0.4, 2.3] | 0.005 |
| TMT Trail B minus A Timeb | Mean±SE | B [95 % CI] | Sig. (p) |
| COMT Val158Met | 0.318 | ||
| Val158/Val158 | 58.8±10.2 | Reference | – |
| Met158 | 47.7±7.1 | −11.1 [−33.0, 10.8] | |
| GCS | 0.284 | ||
| GCS=15 | 47.5±6.5 | Reference | – |
| GCS <15 | 59.0±10.3 | 11.5 [−9.7, 32.6] | |
| Race | 0.492 | ||
| Caucasian | 59.2±7.1 | Reference | – |
| African-American/African | 43.0±12.3 | −16.2 [−43.1, 10.7] | 0.235 |
| Other | 57.4±12.2 | −1.8 [−27.0, 23.4] | 0.888 |
| Education (years) | – | −5.2 [−8.4, −2.0] | 0.002 |
| Age (years) | – | 1.2 [0.6, 1.8] | <0.001 |
| CVLT-II Trial 1–5 Standard Scorea | Mean±SE | B [95 % CI] | Sig. (p) |
| COMT Val158Met | 0.771 | ||
| Val158/Val158 | 51.6±2.4 | Reference | – |
| Met158 | 50.9±1.6 | −0.7 [−5.8, 4.3] | |
| GCS | 0.044 | ||
| GCS =15 | 53.7±1.5 | Reference | – |
| GCS <15 | 48.7±2.4 | −5.0 [−9.9, −0.1] | |
| Race | 0.068 | ||
| Caucasian | 54.7±1.6 | Reference | – |
| African-American | 50.1±2.8 | −4.7 [−10.9, 1.5] | 0.139 |
| Other | 48.9±2.8 | −5.9 [−11.5, −0.2] | 0.042 |
| Education (years) | – | 0.6 [−0.1, 1.4] | 0.098 |
The WAIS Processing Speed Index (WAIS-PSI) Composite Score and the CVLT-II Trial 1–5 Standard Score are adjusted for education years, race (Caucasian, African-American/African, other races), and GCS (15 vs. less than 15). The TMT Trail B minus ATime is adjusted for age, education years, race, and GCS. Distributions are reported as adjusted mean±standard error. The mean difference (B) between COMT Met158 and COMT Val158 /Val158 and associated 95 % CI is reported for each outcome measure CVLT-II, California Verbal Learning Test, Second Edition; TMT, Trail Making Test; WAIS, Wechsler Adult Intelligence Scale, Fourth Edition.
CI confidence interval, COMT catechol-O-methyltransferase, CVLT-II California Verbal Learning Test, second edition, GCS Glasgow Coma Scale, TMT Trail Making Test, WAIS Wechsler Adult Intelligence Test
Higher scores suggest improved performance
Lower scores suggest improved performance