Table 4.
Cognitive performance by class.
| Older, Less Educated Polysubstance |
Older Crack Smoke / Nasal Heroin |
Less Educated Heroin Injectors |
More Educated Nasal Heroin |
Younger Multi- injectors |
Published Norms |
|
|---|---|---|---|---|---|---|
|
| ||||||
| M (SE) | M (SE) | M (SE) | M (SE) | M (SE) | M (SE) | |
| Intelligence (Shipley) | ||||||
| Verbal *** | 36.42 (1.62) a | 36.42 (0.91) a | 37.40 (1.05) a,b | 41.50 (1.81) c | 41.84 (0.91) b,c | -- |
| Abstract *** | 44.57 (1.35) a | 46.55 (0.73) a | 45.77 (0.83) a | 49.89 (1.35) b | 49.18 (0.84)b | --- |
| Predicted IQ *** | 83.57 (1.94) a | 85.22 (1.06) a | 84.54 (1.27) a | 91.53 (2.13) b | 90.07 (1.24) b | 102.5 (0.92) |
| Memory (Digit Span Task) | ||||||
| Forward | 9.63 (0.30) | 9.71 (0.19) | 9.68 (0.22) | 10.10 (0.37) | 10.01 (0.20) | 10.2 (0.52) |
| Backward * | 5.20 (0.29) a | 5.55 (0.19) a,b | 5.41 (0.20) a | 6.38 (0.38) b | 5.78 (0.20) a,b | 7.20 (0.45) |
| Total † | 14.73 (0.51) a | 15.18 (0.33) a,b | 15.08 (0.35) a,b | 16.48 (0.66) b | 15.80 (0.35) a,b | --- |
| Attention (Trail Making) | ||||||
| Trails A (seconds) | 27.29 (1.53) | 27.55 (0.92) | 28.72 (1.15) | 27.15 (1.66) | 25.95 (0.92) | 24.40 (1.52) |
| Trails B (seconds)* | 92.92 (6.95) a,b | 87.99 (3.89) a,b | 92.91 (4.73) b | 80.64 (6.00) a,b | 78.24 (4.00) a | 50.68 (2.15) |
| Beh Inhibition (Stroop) | ||||||
| Word Score | 41.26 (1.21) | 41.50 (0.69) | 40.89 (0.76) | 42.21 (1.39) | 42.74 (0.77) | --- |
| Color Score | 43.72 (1.24) | 42.36 (0.70) | 42.27 (0.77) | 43.13 (1.24) | 43.56 (0.75) | --- |
| Interference Score † | 45.95 (1.33) a | 46.55 (0.66) a | 49.30 (0.73) b | 48.83 (1.31) a,b | 49.73 (0.76) b | 50.7 (1.0) |
| Cog Flexibility (WCST) | ||||||
| Categories Completed * | 3.75 (0.33) a | 4.29 (0.17) a | 4.38 (0.20) a,b | 4.47 (0.29) a,b | 4.87 (0.20) b | 5.0 (0.2) |
| Non-perseverative Errors*** | 82.35 (2.82) a | 87.74 (1.33) a,b | 89.92 (1.69) b,d | 88.05 (2.04) a,d | 95.60 (1.80) c | --- |
| Perseverative Errors*** | 90.98 (3.78) a,b | 91.55 (1.80) a | 98.37 (2.44) b | 90.41 (3.10) a,b | 106.58 (2.79) c | --- |
†
Omnibus test (degrees of freedom = 4), p < .1
*
Omnibus test (df = 4), p < .05
**
Omnibus test (df = 4), p < .01
***
Omnibus test (df = 4), p < .001
Subscripts with same letter are not significantly different at p < .05, as revealed by post-hoc pairwise tests (df = 1).
If at least one class is significantly worse than another, class(es) with worst performance on variable shown in italics.
If at least one additional class is significantly better than another, class(es) with best number on variable shown in bold.
Note: Higher scores on all tasks, except for Trail Making Task, indicate better performance