Table 4.
The relationship between OSRC classes and neurobehavioral outcome scores. Each oil spill and response (OSRC) class is compared to administrative workers, n=223. Confidence intervals are shown in parentheses.
| Neurobehavioral Outcomes† | Cleanup on land (n=405)‡ | Decontamination Work (n=558)‡ | Cleanup on water (n=469)‡ | Operations (n=658)‡ | Response work (n=506)‡ |
|---|---|---|---|---|---|
| CPT correct response fraction | 0 (−0.02, 0.01) | 0 (−0.01, 0.02) | −0.01 (−0.02, 0.01) | 0 (−0.02, 0.01) | 0 (−0.02, 0.01) |
| CPT d prime | −0.08 (−0.29, 0.14) | −0.07 (−0.28, 0.14) | −0.11 (−0.34, 0.11) | −0.16 (−0.36, 0.04) | −0.12 (−0.32, 0.08) |
| CPT false alarm fraction§ | 0 (−0.02, 0.01) | 0 (−0.01, 0.02) | −0.01 (−0.02, 0.01) | −0.002 (−0.02, 0.01) | 0 (−0.02, 0.01) |
| CPT false latency (msec)§ | −14.68 (−58.67, 29.3) | −23.06 (−65.16, 19.04) | −4.11 (−49.08, 40.86) | −12.31 (−53.79, 29.18) | −11.70 (−53.04, 29.64) |
| CPT hit fraction | −0.01 (−0.04, 0.01) | −0.02 (−0.04, 0.01) | −0.01 (−0.04, 0.02) | −0.02 (−0.05, 0) | −0.02 (−0.05, 0) |
| DST forward count | −0.58 (−0.98, −0.17)* | −0.51 (−0.90, −0.12)* | −0.6 (−1.01, −0.18)* | −0.40 (−0.78, −0.01)* | −0.68 (−1.06, −0.30)* |
| DST reverse count | −0.17 (−0.54, 0.21) | −0.17 (−0.53, 0.19) | 0.04 (−0.35, 0.42) | −0.33 (−0.69, 0.02) | −0.28 (−0.63, 0.07) |
| MTS ave correct latency (msec)§ | −97.24 (−242.63, 48.15) | −22.84 (−161.94, 116.25) | −42.95 (−191.48, 105.57) | −100.66 (−237.76, 36.45) | −107.95 (−244.61, 28.7) |
| MTS no. of correct responses | 0.03 (−0.47, 0.53) | 0.24 (−0.24, 0.72) | 0.18 (−0.33, 0.69) | 0.10 (−0.38, 0.57) | −0.08 (−0.55, 0.39) |
| SDT ave correct latency (msec)§ | −159.92 (−335.6, 15.76) | −95.77 (−263.79, 72.25) | −94.06 (−273.53, 85.41) | −189.38 (−355.05, −23.72)* | −149.06 (−314.18, 16.06) |
| SDT total errors§ | −0.02 (−0.79, 0.74) | −0.37 (−1.10, 0.36) | −0.54 (−1.32, 0.24) | −0.40 (−1.12, 0.32) | −0.58 (−1.30, 0.14) |
| SRT ave correct latency (msec)§ | −18.12 (−39.99, 3.74) | −14.46 (−35.37, 6.46) | −0.22 (−22.56, 22.12) | −20.41 (−41.03, 0.21) | −13.10 (−33.66, 7.45) |
| SRT total no. of errors§ | −0.78 (−1.82, 0.26) | −0.26 (−1.26, 0.73) | 0.01 (−1.05, 1.07) | −0.68 (−1.66, 0.3) | −0.80 (−1.77, 0.18) |
| Ave # taps, alternating hands | −5.07 (−9.49, −0.64)* | −2.73 (−6.96, 1.50) | −3.96 (−8.47, 0.56) | −2.66 (−6.84, 1.51) | −0.33 (−4.49, 3.83) |
| Ave # taps, preferred hand | −3.58 (−7.23, 0.07) | −1.98 (−5.47, 1.51) | −2.87 (−6.60, 0.85) | −2.66 (−6.10, 0.78) | −0.50 (−3.93, 2.93) |
| PRT total taps | −20.38 (−39.15, −1.60)* | −5.81 (−23.78, 12.17) | −10.30 (−29.50, 8.89) | −21.66 (−39.37, −3.94)* | −6.09 (−23.78, 11.60) |
| All BARS tests completed^ | 0 (−0.03, 0.03) | 0 (−0.02, 0.03) | 0 (−0.03, 0.02) | 0 (−0.02, 0.03) | −0.01 (−0.04, 0.01) |
| % of BARS tests completed^ | 0 (−0.01, 0.01) | 0 (−0.01, 0.01) | 0 (−0.01, 0.01) | 0 (−0.01, 0.01) | 0 (−0.01, 0.01) |
Indicates statistical significance of adverse effect (p<0.05).
CPT=continuous performance test (measures sustained visual attention); DST=digit span test (measured attention and memory); MTS=match-to-sample test (measures visual memory); SDT=symbol-digit test (measures executive function and coding); SRT=simple reaction time test (measures response speed); PRT=progressive ratio test (measures effort-related motivation); taps measure response speed and coordination; ave=average; no.=number (see Table 1 for more test details).
Models are adjusted for age, sex, race (white, black, other), education (less than high school, high school diploma or equivalent, some college, college graduate), tobacco use (current, former, never), binge drinking (reported ≥5 drinks on one occasion ≥12 times during the year before the clinical exam; yes/no), and passive smoking (lived with smoker, yes/no). Confidence intervals are shown in parentheses.
These neurobehavioral test measures were negated so that negative results always indicate an adverse effect of THC exposure compared to <0.30 ppm THC.
These measures assess the proportion of BARS tests completed by each participant and whether all of the BARS tests were completed. These results indicate that there was no relationship between participants’ ability to complete the BARS tests and their OSRC class.