Table 2.
Means and standard deviations on child behavior outcome measures in placebo and omega-3 groups for the three assessment 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 Report | ||||||||||
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| Child Behavior Checklist | ||||||||||
| CBC Externalizing | 8.78 (8.44) | 8.33 (9.01) | 6.97 (8.79)a | 7.79 (8.17)a | 7.79 (8.95) | 5.05 (6.75) | -.35 (-.62, -.07) | .54 | 8.74** | .04 |
| CBC Internalizing | 8.88 (8.48) | 7.45 (7.84) | 5.22 (6.22)a | 4.94 (5.90)a | 6.72 (7.88)b | 3.14 (4.76)b | -.55 (-.83, -.27) | 4.59* | 6.33** | .03 |
| CBC Rule-Breaking | 1.58 (1.97) | 1.32 (2.27) | 1.29 (2.24)a | 1.36 (1.77) | 1.71 (2.41)b | .64 (1.67)b | -.52 (-.80, -.23) | 2.73 | 10.85** | .05 |
| CBC Aggression | 7.20 (6.93) | 7.01 (7.07) | 5.68 (6.90)a | 6.43 (6.82) | 6.08 (6.96) | 4.41 (5.45)b | -.33 (-.71, -.05) | .19 | 6.18** | .03 |
| CBC Attention Problems | 3.54 (3.72) | 3.53 (3.29) | 2.29 (3.00)a | 2.64 (2.95)a | 3.13 (3.09)b | 1.57 (1.93)b | -.61 (-.90, -.32) | 1.29 | 12.01** | .06 |
| CBC Withdrawn | 3.00 (2.84) | 2.28 (2.71) | 1.54 (1.96)a | 1.54 (2.07)a | 2.40 (2.70)b | 1.01 (1.67)b | -.62 (-.90, -.34) | 6.74* | 8.37** | .04 |
| CBC Somatic | 2.09 (2.69) | 1.60 (2.14) | 1.52 (2.34)a | 1.15 (2.00) | 1.07 (1.87) | .69 (1.43)b | -.23 (-.51, .05) | 3.05 | .09 | .00 |
| CBC Anxious/ Depressed | 3.97 (4.41) | 3.66 (4.47) | 2.27 (3.03)a | 2.30 (3.22)a | 3.26 (4.26)b | 1.44 (2.68)b | -.51 (-.79, -.23) | 2.58 | 7.10** | .04 |
| CBC Social Problems | 2.06 (2.41) | 1.80 (2.00) | 1.13 (1.79)a | 1.23 (1.63)a | 1.84 (2.11)b | .77 (1.34)b | -.61 (-.89, -.32) | 3.78 | 8.37** | .04 |
| CBC Thought Problems | .69 (1.22) | .75 (1.32) | .44 (1.02) | .36 (.80)a | .64 (1.26) | .13 (.51)b | -.53 (-.81, -.25) | 2.46 | 6.01** | .03 |
| CBC Other Problems | 5.13 (4.67) | 4.23 (4.35) | 3.35 (3.82)a | 3.30 (3.56)a | 4.02 (4.66) | 2.29 (2.62) | -.46 (-.74, -.18) | 3.41 | 5.37** | .03 |
| Antisocial Process Screening Device | ||||||||||
| APSD Callous-Unemotional | 4.60 (2.25) | 4.68 (2.22) | 3.06 (2.32)a | 3.55 (2.32)a | 3.96 (2.39)b | 2.58 (2.37)b | -.58 (-.86,-.30) | 1.22 | 13.69** | .07 |
| APSD Narcissism | 2.44 (2.84) | 2.70 (2.62) | 3.03 (3.36)a | 2.76 (3.12) | 2.39 (2.91)b | 2.38 (2.86) | -.00 (-.28, .28) | .00 | 1.05 | .01 |
| APSD Impulsivity | 2.68 (2.16) | 2.37 (1.98) | 2.98 (2.61) | 2.57 (2.27) | 2.24 (2.29)b | 1.99 (2.33)b | -.11 (-.39, .17) | 1.35 | .16 | .00 |
| APSD Total | 9.83 (5.53) | 9.75 (5.08) | 9.07 (7.04) | 8.88 (6.17) | 8.59 (6.14) | 6.95 (5.75)b | -.28 (-.55, .00) | .74 | 2.97 | .02 |
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| Child Report | ||||||||||
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| Youth Self-Report | ||||||||||
| YSR Externalizing | 8.81 (7.23) | 11.47 (6.49) | 7.59 (7.10)a | 10.17 (6.68)a | 7.60 (7.77) | 9.82 (6.87) | .30 (.02, .58) | .54 | .34 | .00 |
| YSR Internalizing | 13.70 (11.05) | 13.80 (10.45) | 12.38 (11.77) | 14.33 (11.37) | 10.62 (9.08)b | 13.27 (12.30) | .25 (-.03, .52) | 3.94* | 2.30 | .01 |
| YSR Rule-Breaking | 1.64 (1.97) | 2.65 (2.02) | 1.64 (2.01) | 1.89 (2.02)a | 1.63 (1.93) | 2.05 (2.12) | .21 (-.07, .49) | 1.39 | 1.24 | .01 |
| YSR Aggression | 7.17 (5.76) | 8.82 (5.19) | 5.95 (5.65)a | 8.28 (5.26) | 5.97 (6.31) | 7.77 (5.54) | .30 (.02, .58) | 7.29** | .68 | .00 |
| YSR Attention Problems | 3.38 (3.07) | 4.38 (2.61) | 2.91 (2.93) | 3.81 (2.74)a | 2.58 (2.83) | 3.77 (3.26) | .39 (.11, .67) | 2.30 | 1.48 | .01 |
| YSR Withdrawn | 2.60 (2.19) | 2.73 (2.10) | 2.54 (2.46) | 2.41 (1.97) | 2.06 (1.90) b | 2.46 (2.18) | .20 (-.08, .47) | .12 | 1.97 | .01 |
| YSR Somatic | 1.16 (1.33) | 1.25 (1.75) | .90 (1.31) | 1.26 (1.56) | .98 (1.59) | 1.18 (1.67) | .12 (-.15, .40) | 2.20 | 1.24 | .01 |
| YSR Anxious/ Depressed | 4.97 (4.49) | 4.91 (4.05) | 4.47 (4.48) | 5.33 (4.65) | 3.79 (3.51) b | 4.80 (4.93) | .24 (-.04, .51) | 4.40* | 2.48 | .01 |
| YSR Social Problems | 3.32 (2.42) | 3.09 (2.03) | 2.86 (2.32)a | 3.62 (2.52) | 2.30 (1.97)b | 3.07 (2.28)b | .36 (.08, .64) | 11.79** | 5.55** | .03 |
| YSR Thought Problems | 1.47 (2.14) | 1.25 (1.56) | 1.47 (1.91) | 1.71 (2.07)a | 1.52 (1.89) | 1.82 (2.18) | .15 (-.13, .42) | 3.64 | 1.77 | .01 |
| YSR Other Problems | 7.17 (5.76) | 8.82 (5.19) | 5.44 (4.72)a | 5.98 (3.16)a | 5.15 (3.93) | 6.48 (3.94) | .33 (.06, .62) | 5.03* | 1.59 | .01 |
| Reactive-Proactive Aggression Questionnaire | ||||||||||
| RPQ Proactive Aggression | .67 (1.28) | 1.52 (2.12) | .96 (2.09) | .67 (1.30)a | .83 (2.03) | 1.27 (2.37)b | .20 (-.08, .48) | 2.81 | 4.02* | .02 |
| RPQ Reactive Aggression | 3.91 (3.85) | 6.05 (3.40) | 4.61 (4.34) | 3.96 (3.02)a | 4.17 (4.14) | 5.13 (3.35) b | .25 (-.02, .53) | 4.58* | 7.88** | .04 |
| RPQ Total Aggression | 4.58 (4.67) | 7.57 (4.95) | 5.57 (5.99) | 4.63 (3.87)a | 5.00 (5.72) | 6.40 (5.16)b | .26 (-.02, .54) | 5.76* | 8.58** | .04 |
a
indicates statistically significant (p < .05) within group behavior change from 0 to 6 months.
b
indicates statistically significant (p < .05) within group behavior change from 6 to 12 months.