To examine the intensity of CSA psychological effects or correlates, we first meta-analyzed the sample-level effect sizes from the 54 samples for which these could be computed (sample-level effect sizes are listed in the Appendix ). [*3]
unbiased effect size estimate, based on 15,912 participants, was
A chi-square test of the homogeneity of the sample-level effect sizes revealed
that they were not homogeneous,
In an attempt to achieve homogeneity, we examined the distribution of sample-level effect sizes to determine whether outliers existed. We defined outliers to be effect sizes that were at least 1.96 standard deviations away from the unweighted mean effect size (i.e., falling in the extreme 5% of the distribution).
Three outliers were found ( r = .36 in Jackson et al., 1990 ; r = .40 in Roland et al., 1989 ; r = -.25 in Silliman, 1993 ) with z scores of 2.71, 3.16, and -3.60, respectively.
The Jackson et al. study included only incest cases in the CSA group, and the Roland et al. study included a large proportion of incest cases. Moreover, Neumann et al. (1996) also found the Roland et al. result to be an outlier.
Measures used in these studies from which effect sizes were computed included:
These measures were all
used in other studies whose effect sizes were not outliers, implying that the outlying
results were not a function of these measures. Removing these outliers resulted in
The recalculated unbiased effect size estimate (
95% confidence interval for ru
|Alcohol||8||1,645||.07||.02 to .12||2.97|
|Anxiety||16 (18)||6,870 (7,365)||.13 (.13)||.10 to .15||4.62 (28.72*)|
|Depression||22 (23)||7,778 (7,949)||.12 (.13)||.10n to .14||25.71 (49.72*)|
|Dissociation||8||1,342||.09||.04 to .15||1.86|
|Eating disorders||10||2,998||.06||.02 to .10||9.92|
|Hostility2||5||1,497||.11||.06 to .16||11.22*|
|Interpersonal sensivity||7||1,934||.10||.06 to .15||11.78|
|Locus of control||6||1,354||.04||-.02 to .09||1.65|
|Obsessive-compulsive||7||1,934||.10||.06 to .15||5.01|
|Paranoia||9 (10)||1,881 (2,052)||.11 (.13)||.07 to .16||10.34 (20.07*)|
|Phobia||5||1,497||.12||.07 to .17||8.08|
|Psychotic symptoms||10 (11)||2,009 (2,180)||.11 (.13)||.06 to .15||10.13 (23.84*)|
|Self-esteem2||16||3,630||.04||.01 to .07||51.31*|
|Sexual adjustment2||20||7,723||.09||.07 to .11||39.49*|
|Social adjustment||15 (17)||3,782 (4,332)||.07 (.09)||.04 to .10||20.37 (40.62*)|
|Somatization||18 (19)||4,205 (4,376)||.09 (.10)||.06 to .12||15.20 (33.21*)|
|Suicide||9||5,425||.09||.06 to .12||10.94|
|Wide adjustment||14 (15)||3,620 (3,768)||.12 (.11)||.08 to .15||18.77 (24.25*)|
k represents the number of effect sizes (samples);
N is the total number of participants in the k samples;
ru is the unbiased effect size estimate (positive values indicate better adjustment for control subjects);
H is the within-group homogeneity statistic (chi square based on df = k - 1).
Cutting or trimming outliers was performed when effect sizes were heterogeneous in an attempt to reach homogeneity. Original numbers, before cuttinng ore trimming, are shown in parentheses. 95% confidence intervals are based on final (cut or trimmed) distributions.
2 Cutting or trimming outliers failed to produce homogeneity; thus, only original numbers are shown.
* p < .05 in chi-square test.