5. Comparison 3: phenytoin/diphenylhydantoin versus placebo: aggression, observer‐reported (skewed data).
| Study | Outcome | n(Exp) | Mean(Exp) | SD(Exp) | n(Cntrl) | Mean(Cntrl) | SD(Cntrl) | Statistic | Notes |
|
Stanford 2005 300 mg/day |
OAS aggression score, at 2 wks | 7 | 2.17 | 1.95 | 8 | 4.38 | 1.86 |
F1,13 = 19.84 (repeated measures ANOVA; P = 0.001; partial eta2 = 0.60; power = 0.98); treatment OAS aggression score significantly lower compared with the placebo group Significant main effect by time (3 interventions of which phenytoin was one; baseline, 2, 4, 6 wks); F3,75 = 3.41; P = 0.02; partial eta2 = 0.12; power = 0.78) |
Favours phenytoin Completer analysis (see note 1) |
|
Stanford 2005 300 mg/day |
OAS aggression score, at 4 wks | 7 | 1.28 | 2.30 | 8 | 4.49 | 2.14 |
F1,13 = 19.84 (repeated measures ANOVA; P = 0.001; partial eta2 = 0.60; power = 0.98); treatment OAS aggression score significantly lower compared with the placebo group Significant main effect by time (3 interventions of which phenytoin was one; baseline, 2, 4, 6 wks); F3,75 = 3.41; P = 0.02; partial eta2 = 0.12; power = 0.78). |
Favours phenytoin Completer analysis (see note 1) |
|
Stanford 2005 300 mg/day |
OAS aggression score, at 6 wks | 7 | 2.38 | 1.99 | 8 | 5.40 | 1.86 |
F1,13 = 19.84 (repeated measures ANOVA; P = 0.001; partial eta2 = 0.60; power = 0.98); treatment OAS aggression score significantly lower compared with the placebo group Significant main effect by time (3 interventions of which phenytoin was one; baseline, 2, 4, 6 wks); F3,75 = 3.41; P = 0.02; partial eta2 = 0.12; power = 0.78) |
Favours phenytoin Completer analysis (see note 1) |
|
Barratt 1991 100 mg/day |
Frequency of aggressive acts, change from baseline, at 4 wks | 13 |
No data | 13 |
No data | Frequency of aggressive acts not significantly reduced from baseline during either treatment or placebo conditions (Wilcoxon’s signed ranks test) | Favours neither condition Completer analysis (no data available) |
||
|
Barratt 1991 300 mg/day |
Frequency of aggressive acts, change from baseline, at 4 wks | 13 |
No data | 13 |
No data | Frequency of aggressive acts significantly reduced from baseline (Wilcoxon’s signed ranks test; P < 0.001) during treatment but not placebo condition |
Favours phenytoin Completer analysis (no data available) |
||
|
Barratt 1997 300 mg/day |
Frequency of aggressive acts per wk, mean, at 6 wks | 60 | 0.33 | No data | 60 | 0.51 | No data | F1,58 = 9.64 (repeated measure ANOVA, Geissner‐Greenhouse adjusted; P < 0.001) |
Favours phenytoin (see below for subgroup analysis) |
|
Barratt 1997 300 mg/day |
Intensity of aggressive acts, mean, at 6 wks | 60 | 2.61 | No data | 60 | 3.96 | No data | F1,58 = 8.23 (repeated measure ANOVA, Geissner‐Greenhouse adjusted; P < 0.01) |
Favours phenytoin (see below for subgroup analysis) |
|
Barratt 1997 300 mg/day |
Frequency of aggressive acts per wk, mean, impulsive subgroup, at 6 wks | 30 | 0.20 | 0.19 | 30 | 0.52 | 0.46 | Subgroup effect (impulsive vs. non‐impulsive) F1,58 = 9.21 (repeated measure ANOVA, Geissner‐Greenhouse adjusted; P < 0.01) Subgroup by drug‐placebo effect F1,58 = 9.50 (repeated measure ANOVA, Geissner‐Greenhouse adjusted; P < 0.01) |
Favours phenytoin (impulsive aggression subgroup) |
|
Barratt 1997 300 mg/day |
Intensity of aggressive acts, mean, impulsive subgroup, at 6 wks | 30 | 2.11 | 1.20 | 30 | 4.16 | 1.92 | Subgroup effect (impulsive vs. non‐impulsive) F1,58 = 4.78 (repeated measure ANOVA, Geissner‐Greenhouse adjusted; P < 0.05) Subgroup by drug‐placebo effect F1,58 = 9.74 (repeated measure ANOVA, Geissner‐Greenhouse adjusted; p<0.01). |
Favours phenytoin (impulsive aggression subgroup) |
|
Barratt 1997 300 mg/day |
Frequency of aggressive acts per week, mean, non‐impulsive subgroup, at 6 wks | 30 | 0.42 | 0.24 | 30 | 0.51 | 0.48 | Subgroup effect (impulsive vs. non‐impulsive) F1,58 = 9.21 (repeated measure ANOVA, Geissner‐Greenhouse adjusted; P < 0.01) Subgroup by drug‐placebo effect F1,58 = 9.50 (repeated measure ANOVA, Geissner‐Greenhouse adjusted; P < 0.01) |
Favours neither condition (non‐impulsive aggression subgroup) |
|
Barratt 1997 300 mg/day |
Intensity of aggressive acts, mean, non‐impulsive subgroup, at 6 wks | 30 | 3.40 | 1.29 | 30 | 3.76 | 1.59 | Subgroup effect (impulsive vs. non‐impulsive) F1,58 = 4.78 (repeated measure ANOVA, Geissner‐Greenhouse adjusted; P < 0.05) Subgroup by drug‐placebo effect F1,58 = 9.74 (repeated measure ANOVA, Geissner‐Greenhouse adjusted; P < 0.01) |
Favours neither condition (non‐impulsive aggression subgroup) |
|
Stanford 2001 300 mg/day |
Frequency of impulsive‐aggressive outbursts, from OAS, mean no outbursts/week, over 6 wks | 23 | 0.60 | 0.41 | 23 | 0.97 | 0.68 |
F1,21 = 8.44 (repeated measures ANOVA; P = 0.008) Frequency of impulsive‐aggressive outbursts significantly reduced from baseline for phenytoin (F1,21 = 9.37; P = 0.006) |
Favours phenytoin Completer analysis (see note 2) |
1. Data presented here extracted from graph provided as figure 1 in study paper and confirmed by inspection of original Excel file supplied by lead author (email to J. Dennis 22 January 2009); statistics from study paper.
2. Data presented here extracted from graph provided as figure 1 in study paper; statistics from study paper.
OAS = Overt Aggression Scale; wks = weeks