Table 3.
Means and standard deviations (in parentheses) for parent self-report on outcome measures in placebo and omega-3 groups for the three time periods, together with statistical comparisons and effect sizes.
| Placebo Mean 0 Months (SD) | Omega-3 Mean 0 Months (SD) | Placebo Mean 6 Months (SD) | Omega-3 Mean 6 Months (SD) | Placebo Mean 12 Months (SD) | Omega-3 Mean 12 Months (SD) | Effect size for mean group difference at 12 Months, Cohen’s d (95% C.I.) | Main group effect, F (df = 1) | Group × time interaction, F (df = 2) | Effect Size for Group × Time interaction, partial eta2 | |
|---|---|---|---|---|---|---|---|---|---|---|
| Parent Self-Report | ||||||||||
| Psychopathic Personality Inventory (PPI) | ||||||||||
| PPI Total | 116.55 (11.36) | 116.95 (9.68) | 113.16 (12.67)a | 108.44 (11.60)a | 117.07 (12.14)b | 108.11 (12.81) | -.72 (-1.00, -.43) | 11.38** | 13.97** | .07 |
| PPI Social Potency | 19.32 (3.79) | 19.42 (3.77) | 17.13 (4.29)a | 17.67 (4.85)a | 18.31 (4.70)b | 17.08 (4.43) | -.27 (-.55, .01) | .14 | 5.98** | .03 |
| PPI Coldheartedness | 15.04 (3.84) | 15.66 (3.08) | 13.76 (3.76)a | 14.27 (4.02)a | 15.52 (4.28)b | 15.39 (4.23)b | -.03 (-.31, .25) | .51 | 1.32 | .01 |
| PPI Carefree Nonplanfulness | 11.30 (3.33) | 12.93 (3.17) | 10.16 (3.12)a | 10.22 (2.89)a | 11.57 (4.03)b | 10.46 (3.18) | -.31 (-.58, -.03) | .30 | 13.29** | .06 |
| PPI Fearlessness | 12.17 (3.94) | 12.07 (3.12) | 12.54 (5.32) | 9.90 (3.33)a | 12.95 (3.38) | 11.07 (3.14)b | -.58 (-.86, -.29) | 11.40** | 14.43** | .07 |
| PPI Blame Externalization | 16.15 (6.70) | 15.78 (6.07) | 15.67 (7.25) | 16.21 (6.70) | 15.69 (6.73) | 14.03 (6.82)b | -.25 (-.52, .03) | .32 | 7.21** | .04 |
| PPI Stress Immunity | 18.30 (3.37) | 17.72 (2.67) | 19.57 (3.89)a | 17.60 (3.61)a | 19.06 (3.46) | 18.58 (3.26)b | -.14 (-.42, .13) | 6.57* | 6.13** | .03 |
| PPI Impulsive Nonconformity | 11.92 (3.17) | 11.51 (2.84) | 11.26 (3.42)a | 10.14 (3.07)a | 11.84 (3.28) | 10.07 (3.09) | -.56 (-.84, -.27) | 9.39** | 4.41* | .02 |
| PPI Machiavellian Egocentricity | 12.35 (3.80) | 11.89 (3.30) | 13.07 (4.28) | 12.43 (3.93) | 12.12 (3.97)b | 11.43 (3.40)b | -.19 (-.46, .09) | 1.70 | .12 | .00 |
| Reactive-Proactive Aggression Questionnaire | ||||||||||
| RPQ Proactive | .68 (1.41) | .54 (1.03) | .66 (1.26) | .39 (1.13) | .54 (2.08) | .37 (.65) | -.11 (-.39, .17) | 1.52 | .28 | .00 |
| RPQ Reactive | 4.45 (3.62) | 5.25 (3.60) | 4.17 (3.22) | 4.84 (3.21) | 3.82 (3.55) | 3.72 (2.73)b | -.03 (-.31, .25) | 1.21 | 3.15* | .02 |
| RPQ Total | 5.13 (4.48) | 5.79 (4.18) | 4.83 (4.13) | 5.23 (3.81)a | 4.36 (5.11) | 4.09 (3.09)b | -.06 (-.03, .21) | .25 | 2.21 | .01 |
a
indicates within group behavior change from 0 to 6 months was statistically significant (p< .05).
b
indicates within group behavior change from 6 to 12 months was statistically significant (p< .05).