Chrld Abuse & N&ec~. Vol. 16. pp. 285-295, Printed in the U.S.A. All rights reserved.
1992
0145-2134192 $5.00 + .w Copyfight 0 1992 Pergamon Press Ltd.
CHILDHOOD SEXUAL ABUSE: IMPACT ON A COMMUNITY’S MENTAL HEALTH STATUS UTHRYN
D.
SCOTT
School of Public Health, University of California, Los Angeles
A~t~ct-EpidemioIo~sts have used impact fractions (e.g., att~b~tabie fractions} to study the influence of various risk factors on the rates of physical diseases within the community. In this study, impact fractions are applied to a psychiatric epidemiologic problem in order to examine the impact of childhood sexual abuse (CSA) on the mental health status of a community. Analysis of the Los Angeles Epidemiologic Catchment Area (LAECA) data indicate that a history of CSA significantly increases an individual’s odds of developing eight psychiatric disorders in adulthood. On the community level, however, it is estimated that 74% of the exposed psychiatric cases (i.e., those with a history of GA), and 3.9% of all psychiatric cases within the population can be attributed to childhood sexual abuse. Intervention implications are discussed. Key ~~~~~-Child
sexual abuse, Epidemiolo~,
Impact fractions, Att~bu~ble
fractions, Intervention.
INTRODUCTION THE PAST DECADE of child abuse research has seen the birth and evolution of several studies designed to measure long-term psycholo~cal outcomes to childhood sexual assaults. Many population studies have begun to delineate the etiologic role of childhood sexual abuse (CSA) in the development of mental distress and disorder, and have demonstrated the psychological toll CSA takes on its victims (Bagley & Ramsay, 1986; Burnam et al., 1988; Finkelhor, Hotaling, Lewis, & Smith, 1989; Mullen, Romans-Clarkson, Walton, & Herbison, 1988; Murphy et al., 1988; Peters, 1988; Russell, 1986; Stein, Golding, Siegel, Bumam, & Sorenson, 1988). Given the evidence of CSA’s impact on an ~nd~v~d~~l’~psychological well-being, a logical research extension is to assess the impact of CSA on the c~~~~~~~~~~ mental health status. Epidemiologic methods designed traditionally to assess the impact of physical disease risk factors on the public’s health can address this issue and, in addition, provide direction for CSA intervention studies. The term “impact fractions” refers to two types of measures reflecting either the causal risk or protective risk of an exposure. Att~butable fractions of the exposed, preventive fractions, and preventive fractions of the exposed are additional examples of impact fractions (Kleinbaum, Kupper, & Morgenstern, 1982). In this paper, epidemiologic impact fractions (e.g., attributable fractions) are applied to data from the Los Angeles Epidemiologic Catchment Area (LAECA) project to demonstrate their use in assessing the mental health status of a community. Specifically, this study asks two questions. How much of the psychological distress within a community results from CSA and to what degree would a community’s mental Supported by the Epidemiologic Catchment Area Program (ECA), supplemental funds from the National Center for the Prevention and Control of Rape, and an NIMH Psychiatric Epidemiologic Training grant to the UCLA School of Public Health. Received for publication January 30, 199 1; final revision received April 15, 199 I ; accepted April 17, 199 1. Requests for reprints may be sent to Kathryn D. Scott, M. P. II., 2356 Moonli~t 285
Way, Santa Rosa, CA 95403.
286
Kathryn D. Scott
health status improve if CSA did not occur? The first question is answered by estimating the percentage of mental health disorders attributable to CSA within a community. The second question is answered by estimating the potential reduction in occurrence of psychological disorders given the hypothetical elimination of CSA from the community. LITERATURE
REVIEW
Epidemiologic measures have had widespread public health applications. Odds ratios have been used extensively in both physical disease and psychiatric epidemiology. This measure has described such associations as that between sexual activity and cervical cancer (Slattery et al., 1989), and the relationship of psychiatric disorders to mortality (Bruce & Leaf, 1989). For instance, in a case-control study examining risk factors for cervical cancer, having had many sexual partners increased a woman’s odds of developing cervical cancer by a factor of 8.99. If a woman’s current mate had a history of numerous sex partners then her odds of developing cervical cancer increase by a factor of 8.62 (Slattery et al., 1989). Population attributable fractions, which estimate the number of cases attributable to an exposure, have received less attention in impact analyses by psychiatric epidemiologists but are often used in physical disease epidemiology. In a classic study on the relationship between tobacco smoking and lung cancer, Levin (1953) noted that between 56% and 92% of lung cancer cases can be attributed to smoking. In other words, eliminating tobacco smoking would eliminate between 56% and 92% of all lung cancer cases if, indeed, smoking is a causative agent for the disease. One of the few examples of the use of population att~bu~ble fractions in psychiatry arises from a study of the association between chronic exposure to neuroleptic medication and the development of tardive dyskinesia (TD), an abnormal involuntary movement disorder (Morgenstern, Glazer, Niedzwiecki, & Nourjah, 1987). In this study, the authors estimated that 65% of exposed cases (i.e., those with TD who had used neuroleptic medications chronically) and 5 1% of all cases of TD were caused by long-term use of neuroleptic medications. The application of epidemiologic impact fractions to CSA is timely since previous research has shown that childhood sexual abuse is associated with a variety of mental and behavioral problems, including: (a) depression (Bagley & McDonald, 1984; Briere & Runtz, 1988), (b) substance abuse (Briere, 1988), (c) sexual dysfunctions (Bagley & McDonald, 1984; Becker, Skinner, Abel, Axelrod, & Cichon, 1986; Dimock, 1988; Johnson & Shrier, 1985; Tsai, Feldman-summers, & Edgar, 1979), fd) posttraumati~ stress disorder (Briere & Runtz, 1987; Lindberg & Distad, 1985), (e) low self-esteem (Bagley & McDonald, 1984), (f) anxiety (Briere & Runtz, 1988; Fromuth, 1986), (g) suicide ideation and attempts (Briere, 1988), (h) prostitution (James & Meyerding, 1977; Silbert & Pines, 198 l), (i) bulimia (Root & Fallon, 1988), and (j) somatization (Briere & Runtz, 1987; Cunningham, Pearce, & Pearce, 1988). Seven community studies have corroborated many of these clinical findings, particularly for anxiety, depression, substance abuse, low self-esteem and interpersonal difficulties (Bagley & Ramsay, 1986; Burnam et al., 1988; Finkelhor et al., 1989; Mullen et al., 1988; Murphy et al., 1988; Peters, 1988; Russell, 1986; Stein et al., 1988). These studies have displayed the impact of CSA on the individual’s psychological well-being. The following study examines the impact of CSA on the community’s mental health status.
The Los Angeles E~idemi~~~gi~ ~at~~m~~t Area (LAECA) ~~rn~le The sample was comprised of 3,13 1 individuals, 18 years of age or older, from two catchment areas. One catchment area was located in East Los Angeles and contained predomi-
Childhood sexual abuse
287
nantly Hispanic Ame~cans (83%). The other catchment area was located in the Venice/ Culver City area of Los Angeles and was composed predominantly of non-Hispanic whites (63%). Eighty-seven percent of the Hispanic population in these two catchment areas are of Mexican cultural or ethnic origin. Households were selected using a two-stage probability sampling technique and stratified by catchment area. The primary sampling units were census blocks while households made up the secondary sampling units. Each household had an equal probability of selection for the study. The Kish ( 1965) procedure was used to randomly select one adult from each household when more than one person was eligible for inclusion into the study. Interviews were conducted in either Spanish or English according to each respondent’s preference. Interviewers were not matched to the respondent by gender although interviewer gender was recorded. The overall completion rate for the study was 68%, a rate comparable to other large-scale mental health surveys (Frerichs, Aneshensel, & Clark, 198 1). The LAECA study was one of five sites nationwide comprising the Epidemiologic Catchment Area research program. The primary goal of the ECA program was to estimate the prevalence and incidence of specific psychiatric disorders in addition to examining the utilization patterns of health services. Further description of the ECA methodology can be found elsewhere (Eaton & Kessler, 1985); the LAECA methods will be reviewed briefly here.
The NIMH Diagnostic Interview Schedule (DIS) was used to assess twelve psychiatric disorders. The DIS is designed to be administered by lay interviewers and is based on diagnostic criteria from the DSM-III. The validity of the DIS in regard to DSM-III diagnosis is reflected through a mean kappa of 0.69, a mean sensitivity of 75%, and a mean specificity of 94% (Robins, Helzer, Croughan, & Ratcliff, 198 1f. The present study evaluated the following live individual diagnoses for lifetime prevalence (at or after 18 years ofage): (a) drug abuse or dependence, (b) alcohol abuse or dependence, (c) phobia, (d) major depression, and (e) obsessive-compulsive disorder. In addition, three composite diagnoses of any disorder except cognitive impairment (i.e., schizophrenia, general affective disorders, general substance abuse or dependence, somatization, panic, anorexia), any affective disorder (i.e., mania, depression, depression with grief, dysthymia), and substance abuse or dependence (i.e., drug and/or alcohol abuse or dependence) were assessed. Dysthymia was excluded from analyses because the DIS does not assess age of onset for this diagnosis. Antisocial personality and panic disorder were not evaluated because there was an insufficient number of cases for the type of statistical analyses conducted in this paper. Appended to the Los Angeles survey was an instrument developed at the LAECA site, in collaboration with NIMH, to estimate lifetime prevalence of sexual assault and the circumstances su~ounding the most recent assault. Sexual assaults occurring both in childhood and adulthood were assessed with the question, “In your lifetime, has anyone ever tried to pressure or force you to have sexual contact? By sexual contact, I mean their touching your sexual parts, your touching their sexual parts, or sexual intercourse?” For the LAECA study, CSA is considered to have occurred at or prior to the age of 15.
Estimated population attributable fractions (PAF) were calculated from the 2 X 2 contingency table (Figure 1). In the table, E = exposure to CSA, E = no exposure to CSA, D = presence of a specilic DIS disorder (e.g., major depression), and D = absence of that specific DIS disorder. The estimated population attributable fraction is calculated as PAF = a/M, (POR - l/POR) where
KathrynD. Scott
288
Disorder
CSA
E j2
Figure 1. 2
X
D
is
a
b
N1
C
d
%
Ml
%
83
2 contingency table.
POR = the estimated prevalence odds ratio = ad/be, and a/M, is the proportion of cases exposed in the base ~puiation. The equation AFE = (POR - l/POR) computes the estimated att~butabl~ fraction of the exposed group ~~einbaum et al., 1982). Population attributable fractions are a function of both the odds ratio and the prevalence of the exposure variable while AFEs are a function of the odds ratio alone (Kleinbaum et al., 1982). Therefore, PAFs and AFEs were calculated only when abused respondents showed statistically significantly higher odds of developing a disorder than their nonabused counterparts. The PAF can be thought of as the proportion of all cases in the population which hypothetically are at~butable to the exposure. For example, the study on tobacco smoking and lung cancer mentioned earlier found PAF values to range from 56 to .92 for a population of lung cancer cases which included both smokers and nonsmokers (Levin, 1953). These PAF values indicate that smoking accounts for 56% to 92% of the lung cancer cases with the remaining lung cancer cases arising from causes other than tobacco smoking. The AFE is interpreted in a similar manner but only among the exposed cases. In a hypothetical smoking and lung cancer example, an AFE value of .95 indicates that 95% of the lung cancer cases among persons with a history of tobacco smoking were caused by the smoking while the remaining 5% of the cases resulted from other causes. Finally, the POR is simply the odds of developing the disease in the exposed group (e.g., smokers) over the odds of developing the disease in the unexposed group (e.g., nonsmokers) (Kleinbaum et al., 1982). FINDINGS
Prevalence qf CS’Aand Associated Disorders Siegel, Sorenson, Golding, Burnam, & Stein ( 1987) presented findings on the prevalence of CSA in this sample. Women and men, respectively, comprised 53% and 47% of the sample. Fifty-nine percent of the respondents were between the ages of 18 and 39 years, and 4 1% of the sample was 40 years of age or older. Forty percent of the respondents considered themselves Mexican Americans, 42% of the respondents were non-Hispanic whites and the remainder were of other ethnic origins. The overall prevalence of CSA was 5.3% (Siegel et al., 1987) with 177 respondents reporting a childhood assault. Females were twice as likely as males to have reported at least one sexual assault in childhood and non-Hispanic whites were nearly 3 times as likely as Hispanics to report such assaults. Both non-Hispanic white males and females had significantly higher prevalence rates than their Hispanic counterparts. Persons under the age of 40 and those with some college education or beyond were more likely to report childhood sexual assaults than older persons or those with less education.
Childhood sexual abuse
289
CSA and Epidemiologic Impact Fractions Table 1 presents the statistically significant POR’s for ever experiencing a DIS/DSM-III psychiatric disorder at or after the age of 18 for persons who experienced at least one childhood sexual assault. As shown, a history of CSA increases one’s odds of developing these disorders from two to nearly sixfold in most instances. Childhood sexual abuse survivors appear to be at greatest risk for substance abuse or dependence and drug abuse or dependence in comparison to nonabused respondents. All of the groups, with the exception of Hispanics and Hispanic women, displayed increased odds ratios for both disorders. Including the latter two groups, a history of childhood sexual abuse significantly increases the odds for developing any disorder. However, the broad 95% confidence intervals around the values for Hispanics and Hispanic females indicate the need for interpretive caution regarding their respective results. In the POR analyses, abused respondents were not found to have statistic~ly signifi~nt higher odds than their nonabused counterparts for panic disorder and only women showed increased odds for obsessive-compulsive disorder. Interestingly, abused women show statistically significant higher odds for alcohol abuse or dependence than their nonabused counterparts. Abused men display only a marginally significant result (p = .048) for this disorder even though it is the most common disorder among men in this population (Burnam et al., 1987). Overall, a history of CSA increases an individual’s odds of developing any affective disorder and phobia disorder. Statistically significant odds ratios for depression were also seen in the overall sample. However, it may be that non-Hispanic white women account for the overall increase as no other groups display significant PORs for the two disorders. Table 2 displays the PAFs and the AFEs. As stated earlier, PAFs and AFEs are reported only for measures showing statistically significant differences in odds between the abused and nonabused respondents. As seen in column 1, a total of 3.6% to 11.2% of the psychiatric disorders assessed for the overall study population can be attributed to childhood sexual assaults. Stated another way, 3.6% to 11.2% of the psychiatric cases in the general population hy~thetically can be prevented if childho~ sexual abuse is eliminated from the community. Among persons with a history of CSA (i.e., the exposed group), no fewer than 50% of the psychiatric disorders they experienced as adults could have been prevented had they not been sexually abused as children. These findings are based on the assumptions that (a) the randomly selected nonassaulted respondents are representative of the base population, (b) the assaulted respondents are representative of all assaulted respondents in the population, and (c) the assaulted and nonassaulted respondents have the same risk for developing psychiatric disorders regardless of CSA exposure (Kleinbaum et al., 1982). Across all of the groups in Table 2, CSA consistently accounts for the development of at least 2% of any disorder in the general population, and at least 50% of any disorder in the exposed population. This indicates that a broad range of psychiatric outcomes can be attributed to childhood sexual abuse. However, as seen with the prevalence odds ratios, CSA appears to have its greatest impact on the development of drug abuse or dependence. Across all groups displaying statistically significant PORs, from 6% to 19% of the drug abuse or dependence cases in the general population, and over 70% of the cases in the exposed population potentially can be prevented if CSA is eliminated as a risk factor in the community. In general, results for substance abuse or dependence follow a pattern similar to that of drug abuse or dependence. For any affective disorder and phobia disorder, a history of CSA accounts for the occurrence of at least 4% of the cases in the overall population and 57% of the cases in the exposed population. In addition, over 6.9% of the depression cases in the general population can be attributed to childhood sexual abuse.
Note. The
Depression
.OOl
3.2 (l&5.8) p < ,001
by the Mantel-Haenszel
p = ,001
3.4 (3.0, 5.8) p < .OOl
pi .OOl
2.5 (1.1, 5.7) p = ,036 3.3 (1.8, 6.1)
ns
ns
2.2 (1.3, 3.7) p < .002 ns
2.0 (1.0,4.0) p = .048 ns
significant.
ns
p= .Ol
5.7 (1.8, 17.8)
ns
ns
2.8 (1.4, 5.6) p = .003
ns
p < ,001
p = ,001
ns
3.4 (1.3, 6.5) p < ,001 2.8 (1.4, 5.8) p = ,004 ns
6.9 (2.1, 23.2) p = .007 ns
ns
ns
10.5 (3.1, 36) p = ,002 ns
3.2 (1.8, 5.8)
p < .OOl
19.0 (3.5, 99) p18 years of age) Prevalance Odds Ratios of Assaulted
G+
4.1
5.7
I I.2
Any Affective Disorder
Substance Abuse or Dependence
Drug Abuse or Dependence
ns
6.9
6.9
Phobia
Depression
9 8.3
71
I4
14
19
17
4.8
8
PAF
71
-
52
81
68
59
74
AFE
Women
69
71
75
79
85
84
57
84
AFE
ns
ns
ns
2
6
2.6
ns
2
PAF
Men
-
-
50
78
63
-
60
AFE
II
70
60
1
55
13
66
61
69
AFE
ns
6.3
12
8.2
7
5.8
PAF
NH-Whites
6.1 ns
ns
ns
ns
ns
ns
2.7
PAF
83 -
-
-
-
-
-
88
AFE
Hispanics
Notr. PAF = population attributable fraction; AFE = attributable fraction of the exposed group; ns = not statistically significant.
3.6
Dependence
ObsessiveCompulsive Disorder
Of
Alcohol Abuse
3.9
Any disorder
PAF
Overall
Attributable Fractions
ns 12
ns
12
15
13.3
ns
8.2
64
-
64
71
69
-
71
AFE
NH White Females PAF
Table 2. Percentage of Lifetime (218 yrs of age) Cases Attributable to Childhood Sexual Assaults
9.2 ns
ns
ns
ns
14
ns
1.4
PAF
86 -
-
-
-
90
-
95
AFE
Hispanic Females
Kathryn D. Scott
292
Table 3. Impact Fractions for Experiencing One and One or More Diagnoses Diagnosis for Assaulted Versus Nonassaulted Respondents Number of Lifetime Diagnoses
POR
95% CI
1 1 or more
2.8* 3.2*
(i&5.3) (1.8, 5.6)
Versus No
PAF
AFE
1.O%
64% 69%
1.1%
*p < ,001. Note. POR = estimated prevalence odds ratio; CI = confidence interval; PAF = population attributable fraction: AFE = attributable fraction of the exposed group.
Finally, a count was taken of the number of diagnoses experienced by an individual in his or her lifetime since the age of 18. This count included all of the individual diagnoses assessed in this study (i.e., major depression, alcohol abuse or dependence, drug abuse or dependence, ob~ssive-compulsive disorder, panic disorder, and phobia). Table 3 displays the PORs and attributable fractions for the results of this count. As seen, a sexually abused respondent’s lifetime odds of experiencing one diagnosis as opposed to no diagnosis are increased by a factor of 2.8. A history of CSA increases one’s odds to 3.2 for experiencing one or more lifetime diagnoses in adulthood. In the general population, 1.O% and 1.1% of the cases with a history of one diagnosis, and one or more diagnoses, respectively, can be attributed to the presence of CSA in the community. For the exposed group (i.e., persons with a history of CSA), 64% of the cases with one lifetime diagnosis, and 69% of the cases with two or more lifetime diagnoses can be attributed to CSA experiences.
SUMMARY,
CONCLUSIONS,
AND IMPLICATIONS
This paper has illustrated the profitable application of epidemiologic impact fractions as a means of delineating the repercussions of childhood sexual abuse on the mental health status of a community. Results indicate that continued prevention efforts aimed at eliminating CSA from the community hold extensive beneficial potential for improving the public’s quality of life. Generally, the POR results in this paper are in agreement with previous findings concerning the lifetime prevalence of psychiatric disorders associated with CSA (Stein et al., 1988). However, the present study found fewer ethnic differences. The discrepancy between the two studies most likely results from the greater number of cases required to conduct odds ratio analyses in compa~son to prevalence analyses for the odds ratio is a function of the risk factor’s prevalence within the population (Kleinbaum et al., 1982). In this sample, only 45 Hispanic respondents, as compared to 118 non-Hispanic white respondents, reported a history of CSA. Therefore, future studies may find it beneficial to oversample populations with low CSA prevalence rates in order to correctly assess the associated odds of developing psychiatric disorders. Additional studies might also consider utilizing attributable fractions extended to multiple exposure categories (Kleinbaum et al., 1982). For example, this study examined CSA alone as a risk factor for the development of psychiatric disorders in adulthood. It is conceivable, however, that CSA serves as a proxy variable for one or more additonal variables associated with the development of psychiatric disorders (e.g., physical violence or emotional neglect
Childhood sexual abuse
293
within the family). This possibility is underscored by Burnam et al. (1988) findings that respondents assaulted sexually in either childhood or adulthood are at greater risk than nonassaulted respondents for the onset of psychiatric disorders prior to the age of first assault; a finding which threatens this study’s assumption that nonassaulted respondents and assaulted respondents are at equal risk for the onset of psychiatric disorders. Attributable fractions extended to multiple exposure categories (e.g., CSA alone, CSA with physical abuse, no CSA) would be able to test a proxy variable hypothesis showing that it is either a single non-CSA proxy variable (e.g., emotional neglect) which is associated with the development of psychiatric disorders or that multiple exposure variables (e.g., emotional neglect and CSA) are associated with the onset of disorders. Such analyses were not performed in this study due to small cell sizes. An underestimation of the true prevalence of CSA would threaten the assumption that the assaulted respondents are representative of all CSA survivors in the population. This also threatens the validity of the study findings. The LAECA study’s prevalence estimate of 5.3% is the lowest reported in eight U.S. (Ageton, 1983; Essock-Vitale & McGuire, 1985; Hall & Flannery, 1984; Kercher & McShane, 1984; Murphy et al., 1988; Russell, 1983; Siegel et al., 1987; Wyatt, 1985; ) and 2 Canadian (Bagley & Ramsay, 1986; Brickman & Briere, 1984) surveys. This low estimate may result from the study’s use of a single prompt or question on pressured or forced sexual contact (Kleinbaum et al., 1982) and the use of a more restricted definition of childhood sexual abuse in this study (Wyatt & Peters, 1986). The true relationship between CSA and psychiatric disorder would be attenuated if disordered survivors reported their history of abuse at greater rates than nondisordered survivors. The true relationship may be strengthened if disordered persons reported abuse at lower rates than their nondisordered counterparts. The sensitive nature of the topic makes it more likely that CSA survivors, whether disordered or not, will underreport their assaults. Therefore, the true relationship between CSA and psychiatric disorders may be stronger than that found in this study. Clinical studies have frequently noted posttraumatic stress disorder (PTSD) as an outcome to CSA (Briere & Runtz, 1987; Lindberg & Distao, 1985). One of PTSD’s dimensions involves psychic numbing as a direct attempt to repress the intrusive or invasive images of the traumatic experience (Horowitz, 1976). Substance abuse or dependence disorders, often found to be comorbidly associated with PTSD (Centers for Disease Control Vietnam Experience Study, 1988; Kulka et al., 1990; Sierles, Chen, McFarland, & Taylor, 1983) can be seen as a direct means of achieving psychic numbing. The large percentage of substance abuse or dependence cases att~buted to CSA in this study lends credence to hypotheses suggesting that this disorder stems from maladaptive attempts to cope with the sexual assault trauma (Sierles et al., 1983). Female survivors of CSA appear to be more prone to alcohol abuse or dependence than male survivors. Increased odds ratios for this disorder were found among women, but not among men, even though alcohol abuse is more common to males in this population (Burnam et al., 1987). Men with a history of CSA show no statistically significant increase in odds over nonassaulted males for the disorder. Rather, the difference between assaulted and nonassaulted males is seen in drug abuse or dependence. This suggests that CSA may play a stronger etiologic role in the development of alcohol abuse or dependence for women while other etiologic factors may account for its development in men. An important focus for substance abuse intervention may be programs which contain a childhood sexual abuse assessment component. This paper has approached the repercussions of CSA from the viewpoint of the community’s health. It was found that much of the mental distress within the community is attributable to CSA barring further research on muitiple exposures or hidden proxy variables. It was
294
Kathryn D. Scott
also shown that much of this psychological distress potentially can be alleviated through efforts aimed at eliminating childhood sexual abuse from the community. Acknowledgemenf-The author acknowledges the support and comments of Drs. Carol Aneshensel, Linda Bourque, Judy Siegel, and Susan Sorenson.
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Levin, M. ( 1953). The occurrence of lung cancer in man. ACTA Unio ~nternationai~s Contra Cancrum, 9,53 l-54 1. Lindberg, F., & Distad, L. (1985). Post-traumatic stress disorders in women who experienced childhood incest. Child Abuse and Neglect, 9, 329-334. Mo~enstem, H., Glazer, W., Niedzwiecki, D., & Noujah, P. (1987). The impact of neuroleptic medication on tardive dyskinesia: A mew-analysis of p~blish~ studies. American Journal of~b~~~ wealth, 77,7 17-724. Mullen, P., Roman+Clarkson, S., Walton, V., & Herbison, G. (1988). Impact of sexual and physical abuse on women’s mental health. The Lancet, 1, 841-845. Murphy, S. M., Kilpatrick, D. G., Amick-McMullan, A., Veronen, L. J., Paduhovich, J., Best, C. L., Villeponteaux, L. A., & Saunders, B. E. (I 988). Current psychological functioning of child sexual assault survivors. Journal of Interpersona[ Violence. 3, 55-79. Peters, S. (1988). Child sexual abuse and later psychological problems.ln G. E. Wyatt & G. 3. Powell (Eds.), Lasting effectsofchild sexual abuse (101-l 17). Beverly Hills, CA: Sage. Robins, L. N., Helzer, J. E., Croughan, J., & Ratcliff, K. (1981). National Institute of Mental Health Diagnostic Interview Schedule: Its history, characteristics, and validity. Archives of General Psychiatry. 38, 381-389. Root, M., & Fallon, P. (1988). The incidence of victimization experiences in a bulimic sample. Journal ~~~nterpersonal Violence, 3, 16 l- 173. Russell, D. (1986). The secret Irauma: Incest in the lives of girls and women. Basic Books. Russell, D. E. H. (1983). The incidence and prevalence of intrafamilial and extrafamilial sexual abuse of female children. Child Abuse and Neglect, 7, 133- 146. Siegel, J., Sorenson, S., Golding, J., Burnam, M., & Stein, J. (1987). The prevalence ofchildho~ sexual assault: The Los Angeles Epidemiologic Catchment Area Project. American Journal ofEpidemiology, 126, 1141-l 153. Sierles, F., Chen, J., McFarland, R., & Taylor, M. (1983). Post-traumatic stress disorder and concurrent psychiatric illness: a preliminary report. American Journal of Psychiatry, 41, 177- 179. Silbert, M., & Pines, A. (198 1). Sexual child abuse as an antecedent to prostitution. Child Abuse and Neglect, 5, 407-4 11. Slattery, M., Overall, J., Abbott, T., French, T., Robinson, L., & Gardner, J. (1989). Sexual activity, contraception, genital infections, and cervical cancer: Support for a sexually transmitted disease hypothesis. American Journal of Epidemiology, 130,248-2X% Stein, J., Gelding, J., Siegel, J., Bumam, M., & Sorenson, S. (1988). Long-term psychological sequelae ofchild sexual abuse: The Los Angeles Epidemiologic Catchment Area Study. In G. E. Wyatt and G. J. Powell (Eds.) Child sexuaf abuse and fater ~syc~lolog~~alproblems ( 135- 154). Beverly Hills, CA: Sage. Tsai, M., Feldman-Summers, S., & Edgar, M. (1979). Childhood molestation variables related to differential impact of psychosexual functioning in adult women. Journal ofAbnormal Psychology, S&407-417. Wyatt, G. E. ( 1985). The sexual abuse of Afro-American and white-American women in childhood. Child Abuseand Neglect, 9. 507-5 19. Wyatt, G. E., & Peters, S. D. (1986). Issues in the definition of child sexual abuse in prevalence research. Child Abuse and Neglect, 10,23 l-240.
R&urn&-Les ~pid~miolo~stes ont utilise les fractions d’impact (par ex. les fractions attribuables) pour etudier l’influence de divers facteurs de risque sur les incidences de maladies organiques dans la population. Dans cette etude-& les fractions d’impact sont appliquees I un probleme epidemiologique psychiatrique pour examiner I’impact des abus sexuels dans l’enfance (CSA) surf&at de sante mentale dans la population. L’analyse des donnees du “Los Angeles Epidemiologic Catchment Area” (LAECA) indique que des antecedents d’abus sexuel au tours de l’enfance augmente signi~~tivement la pro~bilit~ de developper huit maladies mentales Ztl’age adulte. Par contre, au niveau de la pop~ation g&n&ale, on estime que 74% des personnes qui ont 6th agressees sexuellement au tours de leur enfance et qui so&rent dune maladie psychiatrique et 3, 9% de tous les cas psychiatriques dans la population g&&ale peuvent &tre attribues aux abus sexuels dans l’enfance. Les implications de ces don&es au niveau des interventions sont discutees. Resumen-Los epidemiologos han usado fracciones de impact0 (i.e. indice de probabilidad y fmcciones de atribucibn) para estudiar la influencia de varios factores de riesgo sobre las tasas de enfermedades fisicas dentro de la comunidad. En este estudio, se aplican las fracciones de impact0 a un problema psiquiatrico epidemiol6gico para examinar el impact0 de1 abuso sexual en la niez (ASN) en el status de la salud mental de una comunidad. El analisis de 10s datos de1 “Los Angeles Epidemiologic Catchment Area” (LAECA) indican que una historia de ASN aumenta significat~vamente las probabilidad~ de desarrollar echo desodenes psiquiatricos en la adultez. Sin embargo, en el nivel de la comunidad, se estima que el77% de 10s cases psiquiatricos expuestos (i.e., aquellos con una historia de ASN), y el47% de todos 10s cases psiquiatricos en una poblacion, pueden atribuirse al abuso sexual en !a infancia. Se discuten las implicaciones para la intervention.
1992
0145-2134192 $5.00 + .w Copyfight 0 1992 Pergamon Press Ltd.
CHILDHOOD SEXUAL ABUSE: IMPACT ON A COMMUNITY’S MENTAL HEALTH STATUS UTHRYN
D.
SCOTT
School of Public Health, University of California, Los Angeles
A~t~ct-EpidemioIo~sts have used impact fractions (e.g., att~b~tabie fractions} to study the influence of various risk factors on the rates of physical diseases within the community. In this study, impact fractions are applied to a psychiatric epidemiologic problem in order to examine the impact of childhood sexual abuse (CSA) on the mental health status of a community. Analysis of the Los Angeles Epidemiologic Catchment Area (LAECA) data indicate that a history of CSA significantly increases an individual’s odds of developing eight psychiatric disorders in adulthood. On the community level, however, it is estimated that 74% of the exposed psychiatric cases (i.e., those with a history of GA), and 3.9% of all psychiatric cases within the population can be attributed to childhood sexual abuse. Intervention implications are discussed. Key ~~~~~-Child
sexual abuse, Epidemiolo~,
Impact fractions, Att~bu~ble
fractions, Intervention.
INTRODUCTION THE PAST DECADE of child abuse research has seen the birth and evolution of several studies designed to measure long-term psycholo~cal outcomes to childhood sexual assaults. Many population studies have begun to delineate the etiologic role of childhood sexual abuse (CSA) in the development of mental distress and disorder, and have demonstrated the psychological toll CSA takes on its victims (Bagley & Ramsay, 1986; Burnam et al., 1988; Finkelhor, Hotaling, Lewis, & Smith, 1989; Mullen, Romans-Clarkson, Walton, & Herbison, 1988; Murphy et al., 1988; Peters, 1988; Russell, 1986; Stein, Golding, Siegel, Bumam, & Sorenson, 1988). Given the evidence of CSA’s impact on an ~nd~v~d~~l’~psychological well-being, a logical research extension is to assess the impact of CSA on the c~~~~~~~~~~ mental health status. Epidemiologic methods designed traditionally to assess the impact of physical disease risk factors on the public’s health can address this issue and, in addition, provide direction for CSA intervention studies. The term “impact fractions” refers to two types of measures reflecting either the causal risk or protective risk of an exposure. Att~butable fractions of the exposed, preventive fractions, and preventive fractions of the exposed are additional examples of impact fractions (Kleinbaum, Kupper, & Morgenstern, 1982). In this paper, epidemiologic impact fractions (e.g., attributable fractions) are applied to data from the Los Angeles Epidemiologic Catchment Area (LAECA) project to demonstrate their use in assessing the mental health status of a community. Specifically, this study asks two questions. How much of the psychological distress within a community results from CSA and to what degree would a community’s mental Supported by the Epidemiologic Catchment Area Program (ECA), supplemental funds from the National Center for the Prevention and Control of Rape, and an NIMH Psychiatric Epidemiologic Training grant to the UCLA School of Public Health. Received for publication January 30, 199 1; final revision received April 15, 199 I ; accepted April 17, 199 1. Requests for reprints may be sent to Kathryn D. Scott, M. P. II., 2356 Moonli~t 285
Way, Santa Rosa, CA 95403.
286
Kathryn D. Scott
health status improve if CSA did not occur? The first question is answered by estimating the percentage of mental health disorders attributable to CSA within a community. The second question is answered by estimating the potential reduction in occurrence of psychological disorders given the hypothetical elimination of CSA from the community. LITERATURE
REVIEW
Epidemiologic measures have had widespread public health applications. Odds ratios have been used extensively in both physical disease and psychiatric epidemiology. This measure has described such associations as that between sexual activity and cervical cancer (Slattery et al., 1989), and the relationship of psychiatric disorders to mortality (Bruce & Leaf, 1989). For instance, in a case-control study examining risk factors for cervical cancer, having had many sexual partners increased a woman’s odds of developing cervical cancer by a factor of 8.99. If a woman’s current mate had a history of numerous sex partners then her odds of developing cervical cancer increase by a factor of 8.62 (Slattery et al., 1989). Population attributable fractions, which estimate the number of cases attributable to an exposure, have received less attention in impact analyses by psychiatric epidemiologists but are often used in physical disease epidemiology. In a classic study on the relationship between tobacco smoking and lung cancer, Levin (1953) noted that between 56% and 92% of lung cancer cases can be attributed to smoking. In other words, eliminating tobacco smoking would eliminate between 56% and 92% of all lung cancer cases if, indeed, smoking is a causative agent for the disease. One of the few examples of the use of population att~bu~ble fractions in psychiatry arises from a study of the association between chronic exposure to neuroleptic medication and the development of tardive dyskinesia (TD), an abnormal involuntary movement disorder (Morgenstern, Glazer, Niedzwiecki, & Nourjah, 1987). In this study, the authors estimated that 65% of exposed cases (i.e., those with TD who had used neuroleptic medications chronically) and 5 1% of all cases of TD were caused by long-term use of neuroleptic medications. The application of epidemiologic impact fractions to CSA is timely since previous research has shown that childhood sexual abuse is associated with a variety of mental and behavioral problems, including: (a) depression (Bagley & McDonald, 1984; Briere & Runtz, 1988), (b) substance abuse (Briere, 1988), (c) sexual dysfunctions (Bagley & McDonald, 1984; Becker, Skinner, Abel, Axelrod, & Cichon, 1986; Dimock, 1988; Johnson & Shrier, 1985; Tsai, Feldman-summers, & Edgar, 1979), fd) posttraumati~ stress disorder (Briere & Runtz, 1987; Lindberg & Distad, 1985), (e) low self-esteem (Bagley & McDonald, 1984), (f) anxiety (Briere & Runtz, 1988; Fromuth, 1986), (g) suicide ideation and attempts (Briere, 1988), (h) prostitution (James & Meyerding, 1977; Silbert & Pines, 198 l), (i) bulimia (Root & Fallon, 1988), and (j) somatization (Briere & Runtz, 1987; Cunningham, Pearce, & Pearce, 1988). Seven community studies have corroborated many of these clinical findings, particularly for anxiety, depression, substance abuse, low self-esteem and interpersonal difficulties (Bagley & Ramsay, 1986; Burnam et al., 1988; Finkelhor et al., 1989; Mullen et al., 1988; Murphy et al., 1988; Peters, 1988; Russell, 1986; Stein et al., 1988). These studies have displayed the impact of CSA on the individual’s psychological well-being. The following study examines the impact of CSA on the community’s mental health status.
The Los Angeles E~idemi~~~gi~ ~at~~m~~t Area (LAECA) ~~rn~le The sample was comprised of 3,13 1 individuals, 18 years of age or older, from two catchment areas. One catchment area was located in East Los Angeles and contained predomi-
Childhood sexual abuse
287
nantly Hispanic Ame~cans (83%). The other catchment area was located in the Venice/ Culver City area of Los Angeles and was composed predominantly of non-Hispanic whites (63%). Eighty-seven percent of the Hispanic population in these two catchment areas are of Mexican cultural or ethnic origin. Households were selected using a two-stage probability sampling technique and stratified by catchment area. The primary sampling units were census blocks while households made up the secondary sampling units. Each household had an equal probability of selection for the study. The Kish ( 1965) procedure was used to randomly select one adult from each household when more than one person was eligible for inclusion into the study. Interviews were conducted in either Spanish or English according to each respondent’s preference. Interviewers were not matched to the respondent by gender although interviewer gender was recorded. The overall completion rate for the study was 68%, a rate comparable to other large-scale mental health surveys (Frerichs, Aneshensel, & Clark, 198 1). The LAECA study was one of five sites nationwide comprising the Epidemiologic Catchment Area research program. The primary goal of the ECA program was to estimate the prevalence and incidence of specific psychiatric disorders in addition to examining the utilization patterns of health services. Further description of the ECA methodology can be found elsewhere (Eaton & Kessler, 1985); the LAECA methods will be reviewed briefly here.
The NIMH Diagnostic Interview Schedule (DIS) was used to assess twelve psychiatric disorders. The DIS is designed to be administered by lay interviewers and is based on diagnostic criteria from the DSM-III. The validity of the DIS in regard to DSM-III diagnosis is reflected through a mean kappa of 0.69, a mean sensitivity of 75%, and a mean specificity of 94% (Robins, Helzer, Croughan, & Ratcliff, 198 1f. The present study evaluated the following live individual diagnoses for lifetime prevalence (at or after 18 years ofage): (a) drug abuse or dependence, (b) alcohol abuse or dependence, (c) phobia, (d) major depression, and (e) obsessive-compulsive disorder. In addition, three composite diagnoses of any disorder except cognitive impairment (i.e., schizophrenia, general affective disorders, general substance abuse or dependence, somatization, panic, anorexia), any affective disorder (i.e., mania, depression, depression with grief, dysthymia), and substance abuse or dependence (i.e., drug and/or alcohol abuse or dependence) were assessed. Dysthymia was excluded from analyses because the DIS does not assess age of onset for this diagnosis. Antisocial personality and panic disorder were not evaluated because there was an insufficient number of cases for the type of statistical analyses conducted in this paper. Appended to the Los Angeles survey was an instrument developed at the LAECA site, in collaboration with NIMH, to estimate lifetime prevalence of sexual assault and the circumstances su~ounding the most recent assault. Sexual assaults occurring both in childhood and adulthood were assessed with the question, “In your lifetime, has anyone ever tried to pressure or force you to have sexual contact? By sexual contact, I mean their touching your sexual parts, your touching their sexual parts, or sexual intercourse?” For the LAECA study, CSA is considered to have occurred at or prior to the age of 15.
Estimated population attributable fractions (PAF) were calculated from the 2 X 2 contingency table (Figure 1). In the table, E = exposure to CSA, E = no exposure to CSA, D = presence of a specilic DIS disorder (e.g., major depression), and D = absence of that specific DIS disorder. The estimated population attributable fraction is calculated as PAF = a/M, (POR - l/POR) where
KathrynD. Scott
288
Disorder
CSA
E j2
Figure 1. 2
X
D
is
a
b
N1
C
d
%
Ml
%
83
2 contingency table.
POR = the estimated prevalence odds ratio = ad/be, and a/M, is the proportion of cases exposed in the base ~puiation. The equation AFE = (POR - l/POR) computes the estimated att~butabl~ fraction of the exposed group ~~einbaum et al., 1982). Population attributable fractions are a function of both the odds ratio and the prevalence of the exposure variable while AFEs are a function of the odds ratio alone (Kleinbaum et al., 1982). Therefore, PAFs and AFEs were calculated only when abused respondents showed statistically significantly higher odds of developing a disorder than their nonabused counterparts. The PAF can be thought of as the proportion of all cases in the population which hypothetically are at~butable to the exposure. For example, the study on tobacco smoking and lung cancer mentioned earlier found PAF values to range from 56 to .92 for a population of lung cancer cases which included both smokers and nonsmokers (Levin, 1953). These PAF values indicate that smoking accounts for 56% to 92% of the lung cancer cases with the remaining lung cancer cases arising from causes other than tobacco smoking. The AFE is interpreted in a similar manner but only among the exposed cases. In a hypothetical smoking and lung cancer example, an AFE value of .95 indicates that 95% of the lung cancer cases among persons with a history of tobacco smoking were caused by the smoking while the remaining 5% of the cases resulted from other causes. Finally, the POR is simply the odds of developing the disease in the exposed group (e.g., smokers) over the odds of developing the disease in the unexposed group (e.g., nonsmokers) (Kleinbaum et al., 1982). FINDINGS
Prevalence qf CS’Aand Associated Disorders Siegel, Sorenson, Golding, Burnam, & Stein ( 1987) presented findings on the prevalence of CSA in this sample. Women and men, respectively, comprised 53% and 47% of the sample. Fifty-nine percent of the respondents were between the ages of 18 and 39 years, and 4 1% of the sample was 40 years of age or older. Forty percent of the respondents considered themselves Mexican Americans, 42% of the respondents were non-Hispanic whites and the remainder were of other ethnic origins. The overall prevalence of CSA was 5.3% (Siegel et al., 1987) with 177 respondents reporting a childhood assault. Females were twice as likely as males to have reported at least one sexual assault in childhood and non-Hispanic whites were nearly 3 times as likely as Hispanics to report such assaults. Both non-Hispanic white males and females had significantly higher prevalence rates than their Hispanic counterparts. Persons under the age of 40 and those with some college education or beyond were more likely to report childhood sexual assaults than older persons or those with less education.
Childhood sexual abuse
289
CSA and Epidemiologic Impact Fractions Table 1 presents the statistically significant POR’s for ever experiencing a DIS/DSM-III psychiatric disorder at or after the age of 18 for persons who experienced at least one childhood sexual assault. As shown, a history of CSA increases one’s odds of developing these disorders from two to nearly sixfold in most instances. Childhood sexual abuse survivors appear to be at greatest risk for substance abuse or dependence and drug abuse or dependence in comparison to nonabused respondents. All of the groups, with the exception of Hispanics and Hispanic women, displayed increased odds ratios for both disorders. Including the latter two groups, a history of childhood sexual abuse significantly increases the odds for developing any disorder. However, the broad 95% confidence intervals around the values for Hispanics and Hispanic females indicate the need for interpretive caution regarding their respective results. In the POR analyses, abused respondents were not found to have statistic~ly signifi~nt higher odds than their nonabused counterparts for panic disorder and only women showed increased odds for obsessive-compulsive disorder. Interestingly, abused women show statistically significant higher odds for alcohol abuse or dependence than their nonabused counterparts. Abused men display only a marginally significant result (p = .048) for this disorder even though it is the most common disorder among men in this population (Burnam et al., 1987). Overall, a history of CSA increases an individual’s odds of developing any affective disorder and phobia disorder. Statistically significant odds ratios for depression were also seen in the overall sample. However, it may be that non-Hispanic white women account for the overall increase as no other groups display significant PORs for the two disorders. Table 2 displays the PAFs and the AFEs. As stated earlier, PAFs and AFEs are reported only for measures showing statistically significant differences in odds between the abused and nonabused respondents. As seen in column 1, a total of 3.6% to 11.2% of the psychiatric disorders assessed for the overall study population can be attributed to childhood sexual assaults. Stated another way, 3.6% to 11.2% of the psychiatric cases in the general population hy~thetically can be prevented if childho~ sexual abuse is eliminated from the community. Among persons with a history of CSA (i.e., the exposed group), no fewer than 50% of the psychiatric disorders they experienced as adults could have been prevented had they not been sexually abused as children. These findings are based on the assumptions that (a) the randomly selected nonassaulted respondents are representative of the base population, (b) the assaulted respondents are representative of all assaulted respondents in the population, and (c) the assaulted and nonassaulted respondents have the same risk for developing psychiatric disorders regardless of CSA exposure (Kleinbaum et al., 1982). Across all of the groups in Table 2, CSA consistently accounts for the development of at least 2% of any disorder in the general population, and at least 50% of any disorder in the exposed population. This indicates that a broad range of psychiatric outcomes can be attributed to childhood sexual abuse. However, as seen with the prevalence odds ratios, CSA appears to have its greatest impact on the development of drug abuse or dependence. Across all groups displaying statistically significant PORs, from 6% to 19% of the drug abuse or dependence cases in the general population, and over 70% of the cases in the exposed population potentially can be prevented if CSA is eliminated as a risk factor in the community. In general, results for substance abuse or dependence follow a pattern similar to that of drug abuse or dependence. For any affective disorder and phobia disorder, a history of CSA accounts for the occurrence of at least 4% of the cases in the overall population and 57% of the cases in the exposed population. In addition, over 6.9% of the depression cases in the general population can be attributed to childhood sexual abuse.
Note. The
Depression
.OOl
3.2 (l&5.8) p < ,001
by the Mantel-Haenszel
p = ,001
3.4 (3.0, 5.8) p < .OOl
pi .OOl
2.5 (1.1, 5.7) p = ,036 3.3 (1.8, 6.1)
ns
ns
2.2 (1.3, 3.7) p < .002 ns
2.0 (1.0,4.0) p = .048 ns
significant.
ns
p= .Ol
5.7 (1.8, 17.8)
ns
ns
2.8 (1.4, 5.6) p = .003
ns
p < ,001
p = ,001
ns
3.4 (1.3, 6.5) p < ,001 2.8 (1.4, 5.8) p = ,004 ns
6.9 (2.1, 23.2) p = .007 ns
ns
ns
10.5 (3.1, 36) p = ,002 ns
3.2 (1.8, 5.8)
p < .OOl
19.0 (3.5, 99) p18 years of age) Prevalance Odds Ratios of Assaulted
G+
4.1
5.7
I I.2
Any Affective Disorder
Substance Abuse or Dependence
Drug Abuse or Dependence
ns
6.9
6.9
Phobia
Depression
9 8.3
71
I4
14
19
17
4.8
8
PAF
71
-
52
81
68
59
74
AFE
Women
69
71
75
79
85
84
57
84
AFE
ns
ns
ns
2
6
2.6
ns
2
PAF
Men
-
-
50
78
63
-
60
AFE
II
70
60
1
55
13
66
61
69
AFE
ns
6.3
12
8.2
7
5.8
PAF
NH-Whites
6.1 ns
ns
ns
ns
ns
ns
2.7
PAF
83 -
-
-
-
-
-
88
AFE
Hispanics
Notr. PAF = population attributable fraction; AFE = attributable fraction of the exposed group; ns = not statistically significant.
3.6
Dependence
ObsessiveCompulsive Disorder
Of
Alcohol Abuse
3.9
Any disorder
PAF
Overall
Attributable Fractions
ns 12
ns
12
15
13.3
ns
8.2
64
-
64
71
69
-
71
AFE
NH White Females PAF
Table 2. Percentage of Lifetime (218 yrs of age) Cases Attributable to Childhood Sexual Assaults
9.2 ns
ns
ns
ns
14
ns
1.4
PAF
86 -
-
-
-
90
-
95
AFE
Hispanic Females
Kathryn D. Scott
292
Table 3. Impact Fractions for Experiencing One and One or More Diagnoses Diagnosis for Assaulted Versus Nonassaulted Respondents Number of Lifetime Diagnoses
POR
95% CI
1 1 or more
2.8* 3.2*
(i&5.3) (1.8, 5.6)
Versus No
PAF
AFE
1.O%
64% 69%
1.1%
*p < ,001. Note. POR = estimated prevalence odds ratio; CI = confidence interval; PAF = population attributable fraction: AFE = attributable fraction of the exposed group.
Finally, a count was taken of the number of diagnoses experienced by an individual in his or her lifetime since the age of 18. This count included all of the individual diagnoses assessed in this study (i.e., major depression, alcohol abuse or dependence, drug abuse or dependence, ob~ssive-compulsive disorder, panic disorder, and phobia). Table 3 displays the PORs and attributable fractions for the results of this count. As seen, a sexually abused respondent’s lifetime odds of experiencing one diagnosis as opposed to no diagnosis are increased by a factor of 2.8. A history of CSA increases one’s odds to 3.2 for experiencing one or more lifetime diagnoses in adulthood. In the general population, 1.O% and 1.1% of the cases with a history of one diagnosis, and one or more diagnoses, respectively, can be attributed to the presence of CSA in the community. For the exposed group (i.e., persons with a history of CSA), 64% of the cases with one lifetime diagnosis, and 69% of the cases with two or more lifetime diagnoses can be attributed to CSA experiences.
SUMMARY,
CONCLUSIONS,
AND IMPLICATIONS
This paper has illustrated the profitable application of epidemiologic impact fractions as a means of delineating the repercussions of childhood sexual abuse on the mental health status of a community. Results indicate that continued prevention efforts aimed at eliminating CSA from the community hold extensive beneficial potential for improving the public’s quality of life. Generally, the POR results in this paper are in agreement with previous findings concerning the lifetime prevalence of psychiatric disorders associated with CSA (Stein et al., 1988). However, the present study found fewer ethnic differences. The discrepancy between the two studies most likely results from the greater number of cases required to conduct odds ratio analyses in compa~son to prevalence analyses for the odds ratio is a function of the risk factor’s prevalence within the population (Kleinbaum et al., 1982). In this sample, only 45 Hispanic respondents, as compared to 118 non-Hispanic white respondents, reported a history of CSA. Therefore, future studies may find it beneficial to oversample populations with low CSA prevalence rates in order to correctly assess the associated odds of developing psychiatric disorders. Additional studies might also consider utilizing attributable fractions extended to multiple exposure categories (Kleinbaum et al., 1982). For example, this study examined CSA alone as a risk factor for the development of psychiatric disorders in adulthood. It is conceivable, however, that CSA serves as a proxy variable for one or more additonal variables associated with the development of psychiatric disorders (e.g., physical violence or emotional neglect
Childhood sexual abuse
293
within the family). This possibility is underscored by Burnam et al. (1988) findings that respondents assaulted sexually in either childhood or adulthood are at greater risk than nonassaulted respondents for the onset of psychiatric disorders prior to the age of first assault; a finding which threatens this study’s assumption that nonassaulted respondents and assaulted respondents are at equal risk for the onset of psychiatric disorders. Attributable fractions extended to multiple exposure categories (e.g., CSA alone, CSA with physical abuse, no CSA) would be able to test a proxy variable hypothesis showing that it is either a single non-CSA proxy variable (e.g., emotional neglect) which is associated with the development of psychiatric disorders or that multiple exposure variables (e.g., emotional neglect and CSA) are associated with the onset of disorders. Such analyses were not performed in this study due to small cell sizes. An underestimation of the true prevalence of CSA would threaten the assumption that the assaulted respondents are representative of all CSA survivors in the population. This also threatens the validity of the study findings. The LAECA study’s prevalence estimate of 5.3% is the lowest reported in eight U.S. (Ageton, 1983; Essock-Vitale & McGuire, 1985; Hall & Flannery, 1984; Kercher & McShane, 1984; Murphy et al., 1988; Russell, 1983; Siegel et al., 1987; Wyatt, 1985; ) and 2 Canadian (Bagley & Ramsay, 1986; Brickman & Briere, 1984) surveys. This low estimate may result from the study’s use of a single prompt or question on pressured or forced sexual contact (Kleinbaum et al., 1982) and the use of a more restricted definition of childhood sexual abuse in this study (Wyatt & Peters, 1986). The true relationship between CSA and psychiatric disorder would be attenuated if disordered survivors reported their history of abuse at greater rates than nondisordered survivors. The true relationship may be strengthened if disordered persons reported abuse at lower rates than their nondisordered counterparts. The sensitive nature of the topic makes it more likely that CSA survivors, whether disordered or not, will underreport their assaults. Therefore, the true relationship between CSA and psychiatric disorders may be stronger than that found in this study. Clinical studies have frequently noted posttraumatic stress disorder (PTSD) as an outcome to CSA (Briere & Runtz, 1987; Lindberg & Distao, 1985). One of PTSD’s dimensions involves psychic numbing as a direct attempt to repress the intrusive or invasive images of the traumatic experience (Horowitz, 1976). Substance abuse or dependence disorders, often found to be comorbidly associated with PTSD (Centers for Disease Control Vietnam Experience Study, 1988; Kulka et al., 1990; Sierles, Chen, McFarland, & Taylor, 1983) can be seen as a direct means of achieving psychic numbing. The large percentage of substance abuse or dependence cases att~buted to CSA in this study lends credence to hypotheses suggesting that this disorder stems from maladaptive attempts to cope with the sexual assault trauma (Sierles et al., 1983). Female survivors of CSA appear to be more prone to alcohol abuse or dependence than male survivors. Increased odds ratios for this disorder were found among women, but not among men, even though alcohol abuse is more common to males in this population (Burnam et al., 1987). Men with a history of CSA show no statistically significant increase in odds over nonassaulted males for the disorder. Rather, the difference between assaulted and nonassaulted males is seen in drug abuse or dependence. This suggests that CSA may play a stronger etiologic role in the development of alcohol abuse or dependence for women while other etiologic factors may account for its development in men. An important focus for substance abuse intervention may be programs which contain a childhood sexual abuse assessment component. This paper has approached the repercussions of CSA from the viewpoint of the community’s health. It was found that much of the mental distress within the community is attributable to CSA barring further research on muitiple exposures or hidden proxy variables. It was
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Kathryn D. Scott
also shown that much of this psychological distress potentially can be alleviated through efforts aimed at eliminating childhood sexual abuse from the community. Acknowledgemenf-The author acknowledges the support and comments of Drs. Carol Aneshensel, Linda Bourque, Judy Siegel, and Susan Sorenson.
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R&urn&-Les ~pid~miolo~stes ont utilise les fractions d’impact (par ex. les fractions attribuables) pour etudier l’influence de divers facteurs de risque sur les incidences de maladies organiques dans la population. Dans cette etude-& les fractions d’impact sont appliquees I un probleme epidemiologique psychiatrique pour examiner I’impact des abus sexuels dans l’enfance (CSA) surf&at de sante mentale dans la population. L’analyse des donnees du “Los Angeles Epidemiologic Catchment Area” (LAECA) indique que des antecedents d’abus sexuel au tours de l’enfance augmente signi~~tivement la pro~bilit~ de developper huit maladies mentales Ztl’age adulte. Par contre, au niveau de la pop~ation g&n&ale, on estime que 74% des personnes qui ont 6th agressees sexuellement au tours de leur enfance et qui so&rent dune maladie psychiatrique et 3, 9% de tous les cas psychiatriques dans la population g&&ale peuvent &tre attribues aux abus sexuels dans l’enfance. Les implications de ces don&es au niveau des interventions sont discutees. Resumen-Los epidemiologos han usado fracciones de impact0 (i.e. indice de probabilidad y fmcciones de atribucibn) para estudiar la influencia de varios factores de riesgo sobre las tasas de enfermedades fisicas dentro de la comunidad. En este estudio, se aplican las fracciones de impact0 a un problema psiquiatrico epidemiol6gico para examinar el impact0 de1 abuso sexual en la niez (ASN) en el status de la salud mental de una comunidad. El analisis de 10s datos de1 “Los Angeles Epidemiologic Catchment Area” (LAECA) indican que una historia de ASN aumenta significat~vamente las probabilidad~ de desarrollar echo desodenes psiquiatricos en la adultez. Sin embargo, en el nivel de la comunidad, se estima que el77% de 10s cases psiquiatricos expuestos (i.e., aquellos con una historia de ASN), y el47% de todos 10s cases psiquiatricos en una poblacion, pueden atribuirse al abuso sexual en !a infancia. Se discuten las implicaciones para la intervention.
