Measures
Self-reported effects
Psychological or sexual adjustment
Sample of StudiesTo obtain studies using national probability samples in which researchers examined self-reported effects or psychological correlates of CSA, several strategies were employed. Studies using national probability samples already known to the authors were included. Computer searches of Dissertation Abstracts International, Sociofile, PsycLII, and ERIC were made to locate additional studies. The keywords and phrases entered were
Finally,
obtained articles were examined for mentions of additional studies. These strategies yielded 17 studies, of which 7 were included for analysis in the current article. The remaining 10 studies were eliminated
These criteria were
The inclusion of both male and female respondents and the separate reporting of their results were required so as to be able to address the question of whether the CSA experiences of males and females are equivalent. Most obtained studies were not retained because they contained no outcome data. Self-reported
effects refers to asking respondents whether they thought their experience
of CSA had an effect (i.e., impact on psychological or sexual adjustment) upon
their lives that could be classified into the two mutually exclusive and
exhaustive categories of negative and nonnegative. Nonnegative effects could
include perceptions of neutral or positive impact. Finally,
quantitative presentation of the self-reported effects or adjustment data was
required so as to be able to compare and combine the results across studies via
meta-analysis. Four of the seven included studies came from the United States, and one each came from Great Britain, Canada, and Spain. Table
1 lists the seven studies along with the populations of inference,
methods of gathering data, definitions of CSA, sample sizes reported for males
and females, prevalence rates of CSA, and response rates.
sample
size refers to the number of respondents who were included in data
analysis. The
sampling frames (i.e., method for selecting a representative sample) in these
studies generally consisted of area probability sampling from nearly all
households throughout the countries in which the studies were conducted.
Two studies with face-to-face interviews also included a self-administered questionnaire. Definitions
of CSA varied from study to study. In all studies but one, child included
both children and adolescents -- i.e., young persons aged younger than 19,
18,17, or 16 years, depending on the study. In one study (Laumann et al., 1994),
child referred to prepubescent persons. classified
as CSA included both contact and noncontact sexual experiences. Total
sample sizes of respondents who actually participated in these studies ranged
from 314 to 3,432. This variability in prevalence rates is attributable to differing definitions of CSA. Two studies employed widely inclusive definitions of CSA. In addition to defining older-younger sexual experiences to be CSA, Bigler (1992) defined CSA to include all sexual experiences persons under 18 years had with family members, regardless of their age. Badgley et al. (1984) included persons over 18 years of age if this was the earliest age at which they had their first unwanted sexual experience. As
will be discussed later, most unwanted sexual experiences first occurred when
respondents in this study were under 18, thus qualifying as CSA. Measures
Self-reported effectsIn three studies researchers collected and reported data on self-reported effects (Badgley et al., 1984; Baker & Duncan, 1985; Laumann et al., 1994), Badgley et al. (1984) asked their Canadian respondents whether they had experienced sex with someone when they "didn't want this." If they answered affirmatively, they were then asked to indicate at what age or ages this occurred and whether they had been physically injured or emotionally or psychologically harmed by the first such incident of this type at the time it occurred. Baker and Duncan (1985) asked their British respondents with a history of CSA to indicate the effect on them of this experience by choosing one of four options:
Laumann
et al. (1994) asked their U.S. respondents with a history of CSA whether this
experience had affected their lives since it happened. Psychological or sexual adjustmentIn five studies researchers used various measures to assess psychological or sexual adjustment among their control and CSA respondents
Bigler (1992) measured sexual functioning in his sample of U.S. respondents with two instruments:
Bigler also used the Impact of Event Scale (Horowitz, Wilner, & Alvarez, 1979) to measure the level of trauma associated with CSA. Boney-McCoy and Finkelhor (1995) created an instrument to measure trauma related to posttraumatic stress disorder (PI'SD), which contained [Page
243] items
asking their sample of U.S. children and adolescents how often they experienced
in the past week each of 10 symptoms. These symptoms were all associated with PT'SD
and were modified from the SCL-90-R. In
López et al.'s (1995) study conducted on a national Spanish sample, the Self
Reporting Questionnaire was used to assess current psychological adjustment. Finkelhor
et al. (1989) reviewed the results of the Los Angeles Times Poll, which
was conducted by telephone on a national sample of U.S. residents, asking them
to respond to a series of items about CSA.
Finkelhor
et al. argued that this last item was a valid indicator of long-term harm
because "Russell ... found that victimized women were more disillusioned
with religion than were non-victimized peers" (p. 393). We analyzed the 89 attitude items presented by Finkelhor et al. ( 1989) to determine which items were face-valid indicators of long-term negative impact. Four judges (the two authors and two other sex researchers, all of whom are familiar with the CSA literature and are currently involved in CSA research) judged the validity of each item by answering two questions.
If
the judge decided that the difference was most likely caused by the SA
experience, then the judge considered the attitude item to be a valid measure of
long-term harm. Each judge rated the items independently. The mean pair-wise
inter-judge agreement across all items was 74%. In
Laumann et al.'s (1994) study using a U .S. sample, respondents were asked a
series of questions relevant to their current psychological and sexual
adjustment, as well as to their level of sexual activity. ProcedureFor
the self-reported effects data, the percentages of males and females with a
history of CSA who reported negative effects resulting from their CSA
experiences were tabulated.
The effect size used for these comparisons was Pearson's T. Formulas for calculating T were taken from Rosenthal (1984, 1995). Positive Ts indicated that males reported fewer negative effects, or more neutral or positive effects, than females. The effect sizes comparing the genders were then meta-analyzed using formulas from Rosenthal (1984) and Shadish and Haddock (1994). The meta-analysis involved several steps. First, the effect sizes were combined by
The
resulting T represents the mean weighted effect size and is referred to
as the unbiased effect size estimate ( ru ). The
unbiased effect size estimate is used to estimate the effect size in the
population and is considered to be unbiased because it weights more heavily
larger samples whose effect sizes are generally considered to be more precise
population estimates. In
addition to combining the effect sizes, they were compared as well. Comparing
a set of effect sizes is achieved by summing the products of each sample's
degrees of freedom (N-3) times the square of the difference between a
sample's Fisher's z and the mean Fisher z across all samples. [Page
244] distributed
as Chi-square with k-1 degrees of freedom, where k represents
the number of samples. Next,
a 95% confidence interval around the unbiased effect size estimate was computed
using the formula presented by Shadish and Haddock (1994). For the adjustment data, the statistics assessing the difference between the CSA and control groups in terms of psychological or sexual adjustment were converted to effect sizes (Pearson rs). Positive rs indicated that CSA was associated with poorer adjustment, whereas negative rs indicated the reverse relation. In
most studies reporting adjustment data, more than one measure comparing the CSA
and control respondents in terms of their adjustment was used. Meta-analysis consisted of combining and comparing effect sizes, as well as computing 95% confidence intervals. |