Child Sexual Abuse Victimization Amongst Detained Adolescents and Incarcerated Young Adults: Findings from an Australian Population-Based Birth Cohort Study

ABSTRACT

To guide prevention and intervention efforts, the prevalence and impact of child sexual abuse (CSA) victimization among detained and incarcerated populations requires further examination, particularly with consideration of multi-type maltreatment experiences and sex-based variations. This longitudinal population-based study explores these relationships in an Australian birth cohort comprising all individuals born in Queensland in 1983 and 1984 (n = 82,409; 48.68% female). Data include all notified and substantiated harm(s) from child protection services (0 to 17 years), and sentences to youth detention and/or adult incarceration between ages 10 and 30. Findings indicate greater prevalence of CSA amongst detained/incarcerated individuals compared to the general population but emphasize the impact of cooccurring maltreatment (particularly neglect) on the likelihood of custodial outcomes. Important sex-based differences were noted in the intersection of CSA victimization and detention/incarceration. Findings reinforce the need for trauma-informed practices when working with custodial populations, particularly females, and highlight opportunities for prevention of detention/incarceration in at-risk populations, in line with a broader public health approach to child protection.

KEYWORDS:

• Incarceration
• youth detention
• custodial
• sexual abuse
• maltreatment
• adverse childhood experiences
• administrative data
• linkage

Introduction

While relationships between child sexual abuse (CSA) victimization, later offending and custody are well acknowledged in the research literature, the complexity and heterogeneity of this phenomenon has become evident. There is considerable variability in reported rates of CSA among custodial populations, partly attributable to variations in methodology and data sources. Furthermore, it is increasingly clear that CSA frequently occurs alongside other harms, creating challenges in determining its unique, shared, and interactive impacts. Understanding these nuances has important implications for development of prevention and intervention efforts.

This study draws on longitudinal population-based linked administrative data across child protection, youth justice, and criminal justice systems for the state of Queensland (Australia). We explore the population prevalence of notified and substantiated CSA and multi-type maltreatment (including physical abuse, emotional abuse and/or neglect) within custodial (youth detention and adult custodial corrections) and non-custodial subgroups as well as variations across sex. In doing so, this study provides a rare opportunity to examine prospective links between CSA and custody at the population level. To aid clarity, we henceforth use the terms “detained” and “detention” to refer to young people in custody, and the terms “incarcerated” and “incarceration” to refer to adults in custody.

Child sexual abuse (CSA) victimization in custodial populations

Evidence indicates that rates of CSA in incarcerated adult populations far exceed those in the general population (e.g., de Jong & Dennison, 2017; Debowska & Boduszek, 2017), with females in custody more often reporting CSA than males, as is the case in the general population (Mathews et al., 2023; Stoltenborgh et al., 2015). US studies have found self-reported CSA rates of 59% for adult male prisoners (R. J. Johnson et al., 2006) and 64% for adult female prisoners (K. A. Johnson & Lynch, 2013). This greatly surpasses estimates in the general US population of 25% for females and 5–10% for males from self-report data (National Center for Victims of Crime, 2023). In a recent Australian study, 28.5% of the general population self-reported CSA victimization (Mathews et al., 2023), while the prevalence of self-reported sexual abuse experiences prior to incarceration (although not restricted to CSA) has been found to be as high as 89% in some Australian incarcerated adult samples (Stathopoulos, 2012).

Prevalence rates vary however, depending on study design and operationalization of CSA. For example, C. G. Malvaso et al. (2022) systematic review found that CSA prevalence ranged from 1% to 94% across studies of individuals under youth justice supervision (pooled prevalence 12.2%; n = 362,163). The use of self-report data can itself be problematic for establishing prevalence, due to recall issues, social desirability biases, and underestimation of CSA that occurred early in childhood (Mills et al., 2016), particularly for male victims who are less likely to disclose their victimization experiences (Cashmore & Shackel, 2013). At the same time, custodial populations may also overreport CSA to explain and/or excuse offenses, evoke sympathetic responses, or to obtain leniency in treatment and/or sentencing (Papalia et al., 2018). While official data only captures a proportion of sexual abuse occurring (see Mills et al., 2016; Negriff et al., 2017), exploring prevalence using official records of maltreatment overcomes some limitations of self-report studies, and provides the ability to identify opportunities to intervene early (i.e. at points of official contact) before pathways to custody become entrenched, thus also having important policy and practice implications.

Prospective research examining CSA victimization–incarceration relationships

Prospective research is crucial for delineating pathways from CSA victimization that do not include detention/incarceration, as well as for understanding nuances in relationships between CSA and custody. It is well known that CSA victimization can lead to deleterious psychosocial consequences, including depression, suicidal ideation, post-traumatic stress disorder, and low self-esteem, which are often associated with an increased risk of later offending and detention/incarceration (e.g., de Jong & Dennison, 2017; Debowska & Boduszek, 2017; K. A. Johnson & Lynch, 2013; R. J. Johnson et al., 2006; Ogloff et al., 2012). To our knowledge, no research prospectively examines pathways from CSA victimization to detention/incarceration specifically, although prospective research demonstrates the relationship between CSA and offending more broadly.

In a study utilizing official records of CSA, de Jong and Dennison (2017) found that victimization was a significant predictor of general offending for both males and females compared to random controls. Similarly, in Ogloff et al. (2012) prospective, longitudinal study, individuals who experienced CSA victimization were 4.97 times more likely than individuals from the general population to be convicted of an offense, with the association between CSA victimization and subsequent offending stronger for females than males. While CSA and other victimization experiences appear to be salient predictors of later offending, not all individuals who experience sexual victimization go on to offend (Ogloff et al., 2012; Widom, 2017). Further prospective examination of the relationship between victimization and custodial outcomes drawing from large, representative samples and including victims of CSA who do not offend or experience custodial sentences is needed, particularly to inform opportune timing and targets for interventions that divert pathways.

The complexity and heterogeneity of childhood harms

It is well-established that custodial populations experience adversity in childhood at a disproportionately higher rate than the general population (Ford et al., 2019; Stensrud et al., 2019; Widom, 2017). However, there are complex nuances in experiences of and exposure to victimization. For instance, detained/incarcerated females are more likely than males to report childhood trauma (Stathopoulos, 2012; Widom, 2017). Further, Dong et al. (2003) found that females who had experienced CSA were 2 to 3.4 times more likely than those who had not experienced sexual victimization to experience each other category of adverse childhood experiences (ACEs), while males were 1.6 to 2.5 times more likely.

Research increasingly identifies the importance of multi-type maltreatment (i.e. overlapping experiences of sexual abuse, physical abuse, emotional abuse, or neglect) and cumulative risks (i.e. multiple victimization types or events) for our understanding of adverse developmental outcomes, including offending and detention/incarceration. Accordingly, Debowska and Boduszek (2017) found that those who experienced multiple maltreatment (including sexual abuse) had higher odds of violent offending than other classes of maltreatment, including a high physical and emotional abuse group, and a low abuse group. Similarly, in a prospective birth cohort study of 38,282 males, Leach et al. (2016) found that multi-type maltreatment was significantly associated with sexual, violent, and general offending, and that CSA victimization impacts may be secondary to the impacts of multi-type maltreatment on offending outcomes. These findings emphasize the need to examine links between CSA and detention/incarceration with consideration of other childhood maltreatment for improved understanding of the unique, shared, and interactive impacts of CSA.

Current study

The current study uses a prospective population-based longitudinal research design to explore the prevalence of notified and substantiated CSA victimization in a whole-population birth cohort, including amongst those who are later detained during adolescence and/or incarcerated in adulthood. We extend this examination to the impact of multi-type maltreatment (CSA co-occurring with other maltreatment types) on later detention/incarceration. Our population-based data provides a rare opportunity to compare the prevalence of CSA victimization, and its impacts on detention/incarceration, across sex. Specifically, we aim to determine (1) the prevalence of officially recorded CSA amongst individuals with histories of youth detention/early adult imprisonment; and (2) the proportion of individuals with histories of CSA who subsequently experience custody. In addition, we examine (3) the role of co-occurring maltreatment in the relationship between CSA and later detention/incarceration; and (4) sex-based differences in both the prevalence of CSA and pathways from CSA to detention/incarceration.

Method

Data source and sample

This study utilized an existing dataset from the Queensland Cross-sector Research Collaboration (QCRC) repository, which consists of linked administrative government data for all individuals born in the state of Queensland, Australia, during 1983 and 1984 (see Stewart et al., 2021for further details). These QCRC data holdings include all Queensland system contacts for all individuals in the cohorts from birth to 30 years of age. For the current study, data were utilized from datasets of (a) births into the cohort, (b) deaths from the cohort, (c) contacts with the child protection system in childhood (0 to 17 years of age), and (d) offending contacts across youth justice and children and adult courts (from ages 10 to 30 years).

The 1983/1984 QCRC cohort includes a total of 83,362 individuals born in the state of Queensland (48.5% female; 5.8% Aboriginal and/or Torres Strait Islander). Individuals who passed away before the age of 30 (n = 947) were excluded (noting that 33.2% of these died at or prior to age 10), as were individuals recorded as having experienced CSA after detention (n = 6). This resulted in a final sample of 82,409 (48.7% female; 5.7% Aboriginal and/or Torres Strait Islander). This study was approved by the Griffith University Human Research Ethics Committee (2021/404), and by all relevant Queensland Government data custodians.

Measures

Sex was computed as a binary variable; female (1) or male (2), with individuals classified based on what was most recorded across all QCRC databases.

Child Protection System (CPS) contacts included all contacts as a victim of childhood maltreatment (0–17 years of age) as obtained from Queensland CPS. As child protection agency data, maltreatment in this study relates to harm perpetrated within the family, including commissions, omissions, and failure to protect a child from harm by another. We utilized both notifications (where concerns have been reported and assessed as requiring investigation) and substantiations (where an investigation has found confirming evidence of harm) of maltreatment. Research indicates that reliance on substantiated outcomes alone may underrepresent harm due to evidentiary challenges, statutory thresholds, and resource availability (Fallon et al., 2019; Font & Kennedy, 2022); however, maltreatment based on notifications may potentially be unfounded. By utilizing both measures, comparisons can be made across these operationalizations. It is important to note that from 2000s onwards, Queensland child protection legislation changed from the Childrens Services Act (1965) to the Child Protection Act (1999). Therefore, thresholds for determining “child in need of protection” may not be consistent across these periods.

Notified and substantiated child sexual abuse (CSA) were each coded 0 (absence of any notified/substantiated sexual harm) or 1 (at least one recorded notification/substantiation, where the event occurred before detention/incarceration). Notified and substantiated physical abuse, emotional abuse and neglect were coded separately in the same manner (0 = absence; 1 = presence). Where individuals experienced one or more of these types of maltreatment in addition to CSA, they were flagged as having experienced multi-type maltreatment, with the number of different harm types between 1 (i.e. CSA only) and 4 recorded.

Detention/Incarceration was measured using sentencing data from Queensland Court records, with youth detention sentences derived from Youth Justice data and adult incarceration sentences obtained from adult courts data (provided by the Department of Justice and Attorney General). The minimum age of criminal responsibility in Queensland is 10 and until 2018, individuals in Queensland could be charged as an adult from 17 years of age. Further information on offenses committed by individuals in the cohort is found in Kuluk et al. (2024).

This study explores experiences of detention (between 1993/94 and 1999/2000) and incarceration (between 2000/01 and 2013/14) related to sentenced offenses between the ages of 10 to 30 years. Detention or incarceration experiences purely associated with remand are not captured. Youth Justice Detention and Adult Incarceration were computed as binary variables that captured whether individuals had ever been sentenced to a Youth Justice detention order/imprisonment respectively (yes; no). Dual custody was a binary variable that captured whether individuals had been sentenced to both a Youth Justice detention order AND adult imprisonment during the observation period (yes; no). While our data captures individuals sentenced to custody, we acknowledge that not all those sentenced to detention/incarceration will experience it.

Analyses

A series of univariate and bivariate analyses were conducted to explore prevalence of CSA and the rate and nature of multi-type maltreatment amongst detained/incarcerated and non-detained/non-incarcerated individuals, with Chi-square tests conducted to determine significant differences based on custody experiences and sex. The effects of CSA experiences on likelihood of subsequent detention/incarceration during youth and adulthood to age 30 was examined using a series of binary logistic regressions, with consideration given to other maltreatment harm types.

Results

Overall prevalence of system contact

Both CSA victimization and detention/incarceration were rare in this cohort (see Table 1). Of all 82,409 individuals, just 1.6% received notifications for suspected CSA. Sexual abuse was substantiated for 67.8% of these notifications (1.1% of the total cohort). CSA was more prevalent amongst females, with approximately three quarters of CSA notifications (73.4%) and substantiations (77.1%) for female children.

Table 1. Prevalence of CSA victimization across custody settings, stratified by sex.

	Female (%)	Male (%)	Total (%)
Full Cohort: n	40,116	42,293	82,409
Notified CSA	957 (2.39)	347 (0.82)	1,304 (1.58)
Substantiated CSA	682 (1.70)	202 (0.48)	884 (1.07)
Custody status:
Youth detention	75 (0.19)	368 (0.87)	443 (0.54)
Adult imprisonment	313 (0.78)	1,611 (3.81)	1,924 (2.33)
Dual custody	45 (0.11)	299 (0.71)	344 (0.42)
Any custody	343 (0.86)	1680 (4.0)	2023 (2.45)

Youth detention and adult incarceration were similarly rare, with 0.5% sentenced to a period of youth detention and 2.3% sentenced to adult prison by the age of 30. Males were more likely to have been sentenced to custody than females, comprising 83.1% of youths sentenced to detention and 83.7% of those sentenced to adult incarceration. Just over three-quarters (77.7%) of youth sentenced to detention were also sentenced to incarceration as adults by 30 years of age (0.4% of the total cohort), with this group making up 17.9% of incarcerated adults overall. Most individuals with dual custody histories were male (86.9%).

Prevalence of CSA for in-custody individuals

Individuals with histories of any detention/incarceration (youth and/or adult) were significantly more likely to have had a notification (8.9% v.1.5%; χ² = 287.46, p < .001, Cramer’s V [φ_c] = .059) or substantiation for CSA prior to custody (3.7% v. 1.0%; χ² = 135.66, p < .001, φ_c = .041) compared to the general (no custody) population (see Table 2).

Table 2. Prevalence of childhood sexual abuse notifications and substantiations.

	Females	Males	Total
	n (%)	n (%)	n (%)
No custody	39,773	40,613	80,386
Notified	911 (2.29)	267 (0.66)	1,178 (1.47)
Substantiated	651 (1.64)	158 (0.39)	809 (1.01)
Youth detention	75	368	443
Notified	19 (25.33)	23 (6.25)	42 (9.48)
Substantiated	11 (14.67)	13 (3.53)	24 (5.42)
Adult incarceration	313	1,611	1,924
Notified	38 (12.14)	78 (4.84)	116 (6.03)
Substantiated	26 (8.31)	43 (2.67)	69 (3.59)
Dual custody	45	299	344
Notified	11 (24.44)	21 (7.02)	32 (9.30)
Substantiated	6 (13.33)	12 (4.01)	18 (5.23)
Any custody	343	1,680	2023
Notified	46 (13.41)	80 (4.76)	126 (8.85)
Substantiated	31 (9.04)	44 (2.62)	75 (3.71)

Prevalence of CSA amongst individuals with histories of youth justice detention

Individuals with youth detention histories were 6.4 times more likely to have a notification for suspected CSA (9.5%), and 5.3 times more likely to have experienced substantiated CSA (5.4%), than the general population (1.5% and 1.0%, respectively). Moreover, CSA was around four times as prevalent amongst females who served detention than males, when measured using both notifications (25.3% of females versus 6.3% of males; χ² = 26.44, p < .001, φ_c = .244) and substantiations (14.7% of females versus 3.5% of males; χ² = 15.07, p < .001, φ_c = .184).

Prevalence of CSA amongst individuals with histories of adult incarceration by age 30

Rates of CSA amongst individuals sentenced to adult incarceration were lower than for those sentenced to youth detention but remained substantially higher than the general (no-custody) population. Of the 1,924 individuals sentenced to adult incarceration, around 1 in 17 (6.0%) had been the subject of a notification for suspected CSA, and sexual harm had been substantiated for 1 in 28 (3.6%), making them 4.1 times more likely to have a notification for suspected CSA, and 3.6 times more likely to have experienced substantiated CSA than the general population. As was the case with youth sentenced to detention, incarcerated females were significantly more likely to have experienced both notified (χ² = 24.64, p < .001, φ_c = .113; prevalence 2.5 times greater for females) and substantiated (χ² = 24.09, p < .001, φ_c = .112; prevalence 3.1 times greater for females) sexual harm than males, although the effect sizes were smaller.

Prevalence of CSA amongst individuals with histories of dual custody

Rates of CSA notifications (9.3%) and substantiations (5.2%) for individuals with dual custody histories were comparable to those with youth justice detention only – this was unsurprising given that 77.7% of youth detainees were also sentenced to incarceration in adulthood. When compared to individuals who had never experienced custody, the dual-custody cohort were 6.3 times more likely to have a CSA notification, and 5.2 times more likely to have experienced substantiated CSA. Consistent with the other custodial cohorts, prevalence of CSA victimization (both notified and substantiated) was greater for females than males (notifications: χ² = 14.07, p < .001, φ_c = .202; and substantiations: χ² = 6.85, p < .001, φ_c = .141).

Multi-type maltreatment amongst in-custody individuals with histories of CSA

For individuals with notifications of CSA, notifications of other suspected harm were found for 95.2% of youth sentenced to detention, 86.9% of those sentenced to adult prison, and 93.7% of those with dual custody histories (see Table 3). Similar patterns were identified amongst those with substantiated CSA. While rates were considerably lower than in detained/incarcerated populations, 68.3% and 57.7% of the general (no custody) population with histories of sexual abuse had also experienced additional notified and substantiated harm, respectively.

Table 3. Prevalence of cooccurring maltreatment for individuals with experiences of CSA.

	Youth detention n (%)	Adult Prison n (%)	Dual Custody n (%)	No Custody n (%)
Notifications for CSA	N = 42	N = 116	N = 32	N = 1,178
Number of notified harm types
1 (i.e. CSA only)	n < 5	16 (13.1)	n < 5	373 (31.7)
2	n < 10	25 (20.5)	6 (18.8)	263 (22.3)
3	10 (23.8)	24 (20.7)	n < 5	268 (22.8)
4	24 (57.1)	51 (44.0)	21 (65.6)	274 (23.3)
Prevalence of other notified harm
Physical abuse	31 (73.8)	75 (64.7)	25 (78.1)	500 (42.4)
Emotional abuse	29 (69.0)	70 (60.3)	22 (68.6)	552 (46.9)
Neglect	38 (90.5)	81 (69.8)	28 (87.5)	569 (48.3)
Substantiated CSA	N = 24	N = 69	N = 18	N = 809
Number of substantiated harm types
1 (i.e. CSA only)	n < 5	17 (24.6)	n < 5	342 (42.3)
2	n < 5	14 (20.3)	n < 5	173 (21.4)
3	n < 5	11 (15.9)	n < 5	152 (18.8)
4	17 (70.8)	27 (39.1)	14 (77.8)	142 (17.6)
Prevalence of other substantiated harm
Physical abuse	19 (79.2)	40 (58.9)	15 (83.3)	259 (32.0)
Emotional abuse	19 (79.2)	40 (57.5)	14 (77.8)	336 (41.5)
Neglect	22 (91.7)	37 (54.8)	16 (88.9)	308 (38.1)

Cells with less than five individuals are presented as n < 5 to preserve the anonymity of the individuals (Cell presented as n < 10 is to maintain suppressed cell).

Multi-type maltreatment was particularly prominent amongst youth sentenced to detention, with nine out of 10 youths subjected to notified/substantiated CSA also experiencing notifications/substantiations for neglect. Moreover, most youths sentenced to detention with notified/substantiated CSA experienced all forms of notified/substantiated harm types (physical abuse, emotional abuse, and neglect) in addition to sexual abuse. Similar patterns emerged for those who experienced dual custody and CSA. While some form of multi-type maltreatment was also common amongst those with CSA notifications/substantiations who were sentenced to incarceration as adults, the number of cooccurring maltreatment types were typically fewer than was the case amongst the dual-custody population. Still, 44% and 39% experienced all three harm types in addition to notified/substantiated CSA.

Custodial outcomes for individuals with histories of CSA

While understanding rates of CSA within detained/incarcerated populations is critical for informing tertiary prevention, prospective exploration reveals how many individuals with histories of CSA in the birth cohort are subsequently detained/incarcerated. As illustrated in Table 4, 9.7% of individuals with notifications of CSA and 8.5% with substantiations for CSA were subsequently sentenced to detention and/or incarceration by age 30. This rate far exceeds custody rates amongst individuals with no notified (2.3%) or no substantiated CSA (2.4%). Elevated patterns of detention/incarceration were observed for both males and females across both notified and substantiated CSA. For example, 4.8% of females with notified CSA were subsequently detained and/or incarcerated, compared with 0.8% of females with no CSA notifications. Comparatively, 23.1% of males with notified CSA were subsequently detained and/or incarcerated, compared with just 3.8% of males with no CSA notifications.

Table 4. Custodial outcomes by sex and CSA notifications/substantiations.

	Youth detention	Adult Prison	Dual custody	No custody	Total
	n (%)	n (%)	n (%)	n (%)	n
Females
CSA notification	19 (1.99)	38 (3.97)	11 (1.15)	911 (95.19)	957
No CSA notification	56 (0.14)	275 (0.70)	34 (0.09)	38,862 (99.24)	39,159
Total females	75 (0.19)	313 (0.78)	45 (0.11)	39,773 (99.14)	40,116
Males
CSA notification	23 (6.63)	78 (22.48)	21 (6.05)	267 (76.95)	347
No CSA notification	345 (0.82)	1533 (3.65)	278 (0.66)	40,346 (96.19)	41,946
Total males	368 (0.87)	1,611 (3.81)	299 (0.71)	40,613 (96.03)	42,293
TOTAL
CSA notification	42 (3.22)	116 (8.90)	32 (2.45)	1,178 (90.34)	1,304
No CSA notification	401 (0.49)	1,808 (2.23)	312 (0.38)	79,208 (97.66)	81,105
Total	443 (0.54)	1,924 (2.33)	344 (0.42)	80,386 (97.55)	82,409
Females
CSA substantiation	11 (1.61)	26 (3.81)	6 (0.88)	651 (95.45)	682
No CSA substantiation	64 (0.16)	287 (0.73)	39 (0.10)	39,122 (99.21)	39,434
Total females	75 (0.19)	313 (0.78)	45 (0.11)	39,773 (99.14)	40,116
Males
CSA substantiation	13 (6.44)	43 (21.29)	12 (5.94)	158 (78.22)	202
No CSA substantiation	355 (0.84)	1,568 (3.73)	287 (0.68)	40,455 (96.11)	42,091
Total males	368 (0.87)	1,611 (3.81)	299 (0.71)	40,613 (96.03)	42,293
TOTAL
CSA substantiation	24 (2.71)	69 (7.81)	18 (2.04)	809 (91.52)	884
No CSA substantiation	419 (0.51)	1,855 (2.28)	326 (0.40)	79,577 (97.61)	81,525
Total	443 (0.54)	1,924 (2.33)	344 (0.42)	80,386 (97.55)	82,409

A series of bivariate logistic regressions (see Table 5) confirmed the magnitude of the relationship between CSA and later custody, with the likelihood of youth detention increasing by 8 times for males and by 10 (substantiated) and 14 (notified) times for females. Similarly, males were around 7 times more likely to be incarcerated as young adults than individuals in the birth cohort without notified/substantiated CSA. Comparatively, females with notified/substantiated CSA were around 5 times more likely to be sentenced to incarceration as adults.

Table 5. Impact of maltreatment on custody outcomes by sex.

	Females n = 40,116				Males n = 42,293
	Youth detention		Adult prison		Youth detention		Adult prison
	Odds ratio		Odds ratio		Odds ratio		Odds ratio
	BV	MV	BV	MV	BV	MV	BV	MV
Notified harm
Sexual abuse	14.14*	1.24	5.85*	0.81	8.56*	0.96	7.64*	1.82*
Physical abuse	24.42*	2.57**	12.03*	2.79*	20.73*	4.73*	8.32*	2.80*
Emotional abuse	20.95*	1.18	9.67*	0.99	14.21*	0.77	7.11*	0.97
Neglect	37.84*	18.08*	15.28*	9.00*	24.78*	11.00*	9.73*	5.10*
Intercept		0.001*		0.01*		0.01*		0.03*
Nagelkerke R^2		.185		.104		.167		.075
Substantiated harm
Sexual abuse	10.09*	.777	5.41*	0.85	8.09*	0.93	6.99*	1.77**
Physical abuse	25.60*	2.81**	11.66*	3.04*	20.29*	4.34*	8.63*	2.81*
Emotional abuse	22.82*	1.21	10.08*	1.24	14.79*	0.74	7.87*	1.14
Neglect	43.08*	23.48*	14.49*	7.30*	28.44*	14.66*	11.07	5.77*
Intercept		0.001*		0.01*		0.01*		0.03*
Nagelkerke R^2		.185		.104		.167		.075

BV = Bivariate; MV = Multivariable.

*p < .001; ** p < .01.

Relationships between CSA, other maltreatment types, and later custody

Bivariate logistic regressions indicated that CSA had the lowest effect sizes of all harm types (see Table 5). However, while lowest in comparison to physical and emotional abuse, and neglect, the effect of CSA on later custody was still large. All four harm types were subsequently included in a series of multivariable logistic regressions to explore the unique effect of CSA over and above these other maltreatment types on detention/incarceration. Relationships between maltreatment and detention/incarceration were examined for both notified and substantiated harm, with analyses conducted separately across sex. In almost all these models, CSA lost significance after controlling for other types of harm. The exception to this was when predicting early adult imprisonment amongst males. In this case, notified and substantiated CSA increased the likelihood of incarceration by 1.8 times in both models, when the effects of other harms were considered. In all other multivariable models, the only significant predictors of later detention/incarceration over and above other harm types were physical abuse and neglect.

Discussion

Using a population-based linked administrative dataset, this study advanced current knowledge of the extent of notifications/substantiations of CSA among detained and/or incarcerated individuals compared to the general (no-custody) population. We examined important aspects of heterogeneity, including multi-type maltreatment and variations across males and females. Findings highlight the heightened prevalence of CPS contacts for CSA (and multi-type maltreatment) among those detained during adolescence, incarcerated during early adulthood, or both (dual-custody histories). Prospective analyses demonstrated that these harms were important precursors to detention/incarceration across the life-course.

Within the overall cohort, both CSA notifications/substantiations and custodial histories were rare, at around 1–2%. While these rates are much lower than those typically documented in self-report studies, they reflect prevalence rates based on child protection contacts reported elsewhere (e.g., 2% to 2.5%; Mills et al., 2016). CPS-based CSA contacts provide an important counterpoint to self-report data which can itself suffer from underreporting (e.g., early life experiences; Mills et al., 2016) and/or overreporting (e.g., in custodial situations; Papalia et al., 2018). Moreover, CPS contacts for CSA provide clear opportunities for targeted intervention to divert individuals most at risk of problematic pathways.

Detained and incarcerated individuals experienced both notified and substantiated CSA at far greater rates than those not detained/incarcerated, demonstrating links between CSA and later custody. Specifically, those incarcerated as young adults were around four times more likely than the general population to have histories of notified or substantiated CSA, with rates even higher among detained adolescents. Consistent with prior research (e.g., K. A. Johnson & Lynch, 2013; C. G. Malvaso et al., 2022), these findings highlight the vulnerability of custodial populations, particularly adolescents, for whom CSA appears to be an especially salient risk factor.

CSA rarely occurred in isolation. Detained/incarcerated individuals with histories of CSA had often experienced multi-faceted maltreatment, and co-occurrence of CSA with all three other harm types was common. While such multi-type maltreatment was most pronounced among CSA victims sentenced to youth detention and those with dual custody histories, cooccurring harm was also high among incarcerated adults. Consequently, while our findings support a strong link between CSA and detention/incarceration, this is situated within a broader experience of multi-type harm, reflecting the complex trauma histories that precede custody, particularly during adolescence.

Examination of prospective links between CSA and later custody confirmed the impact of multi-type maltreatment. While the relationship between CSA and detention/incarceration was strong, effect sizes were even stronger for physical and emotional abuse, and neglect. In fact, once other maltreatment was considered in multivariate models, the unique contribution of CSA substantially diminished, often becoming non-significant. While prospective studies have yet to establish a direct causal relationship between adverse childhood experiences (ACEs) and onset and persistence of offending (C. Malvaso et al., 2023), the proportion of young people in contact with CPS in our study who were later detained or incarcerated supports the hypothesis that ACEs are a significant risk factor associated with more serious offending behavior (Ford et al., 2019; Stensrud et al., 2019). It also highlights potentially missed opportunities for assessment of these criminogenic needs during adolescence to inform effective intervention at an individual and ecological level.

Sex differences in prevalence and pathways

CSA (both notified and substantiated) was strongly associated with detention/incarceration for both males and females across youth detention, adult prison, and dual custody, making it an important consideration in pathways to custody regardless of sex. Likewise, the co-occurrence of CSA with other maltreatment held across sex, highlighting the importance of the broader context within which CSA occurs. Beneath these broad similarities, however, lie important sex-based differences in patterns of CSA, detention/incarceration, and their intersection.

Reinforcing well-established findings on the gendered nature of CSA (Mathews et al., 2023), females in the birth cohort had significantly higher rates of CSA victimization. Coupled with the strong link between CSA and custody upheld across sex, this translated into higher rates of CSA amongst females in custody, whereby one quarter of females sentenced to youth detention had a CSA notification (compared to 6% of males) and nearly 1 in 8 females sentenced to adult prison had a CSA notification (compared to 1 in 20 males). Moreover, this only reflects those with official contact with the CPS for CSA within the family and does not encapsulate other forms of abuse known to be common amongst incarcerated females (Broidy & Thompson, 2018). These findings confirm the significance of sexual victimization in the lives of females in custody and support ongoing calls for trauma-informed approaches to intervention and treatment (Papalia et al., 2018).

Consistent with evidence (Stewart et al., 2021), males more often experienced custody than females. As a result, despite a stronger bivariate association between CSA and youth detention among females, far more males with histories of CSA were sentenced to youth detention (6–7% versus 2% of females). Differences were even greater for adult prison (21–22% versus 4% for females), whereby males had a stronger CSA-incarceration link than females. These sex-based differences likely reflect varying exposure to risk factors associated with detention/incarceration beyond CSA, as well as gendered mediation processes that result in the differential salience of the same risk factors for males and females (Broidy & Thompson, 2018). Regardless, the finding that 1 in 4 males with CSA notifications (and 1 in 5 with CSA substantiations) are subsequently detained in adolescence and/or incarcerated in adulthood, identifies a clear opportunity for early intervention to redirect pathways and improve the lives of these young people.

While few females with CSA were subsequently detained/incarcerated, the impact of CSA on female custody rates produced high effect sizes of similar magnitude to males. Moreover, detention/incarceration is just one adverse outcome of CSA. There is substantial evidence that female experiences of CSA are associated with other adverse outcomes such as poor mental health (Papalia et al., 2018), intergenerational cycles of maltreatment (e.g., Leifer et al., 2004), and other poor health outcomes (Coles et al., 2015). Indeed, a similarly broad array of adversity is also reported amongst male victims of CSA (Cashmore & Shackel, 2013). Consequently, it is pertinent to support both male and female victims of CSA to improve a wide range of health and wellbeing outcomes.

Implications for research, policy, and practice

Our results have important implications for policy and practice that align with a public health approach to child protection to address risk factors that increase likelihood of further system involvement at different points in one’s life trajectory (McKillop, 2019). Indeed, the present findings underscore the importance of a multipronged approach to prevention that recognizes the importance of early intervention and support for vulnerable young people when CSA (or other maltreatment) is identified or disclosed, to mitigate the adverse impacts of victimization and forestall potential later offending (Cant et al., 2022). Our prospective analyses showed elevated risk of detention/incarceration (particularly during adolescence) following CSA, especially when occurring in the context of multi-type maltreatment. Given the nature and extent of prior CPS contact in pathways to custody, there appears to have been missed “targeted” opportunities to address these concerns earlier in individuals’ lives. Within child protection, secondary or “targeted” interventions usually revolve around the family. Certainly, our findings suggest that more investment into early intervention for at-risk individuals and families to divert them from engagement in antisocial and offending behavior is warranted to reduce the likelihood of incarceration and re-incarceration (C. Malvaso et al., 2023).

Importantly, the increased risk of custody for individuals with CSA notifications, separate from substantiations, is consistent with other research indicating the need for some form of intervention for these young people, even if statutory intervention by CPS is not enabled with substantiation status (He et al., 2021). In this sense, referral pathways and service provision for those deemed beneath statutory threshold is a potentially valuable avenue for further investigation in relation to effective prevention and early intervention (He et al., 2021), although this approach could have a net-widening impact.

Consistent with a public health approach, calls to de-silo prevention initiatives are pertinent here (Cant et al., 2022). Our results show that young people who experience CSA are highly likely to experience multi-type maltreatment and are subsequently at elevated risk of later custody, indicating a subgroup of the population with multiple and complex needs. The existing evidence base suggests that these individuals are similarly at risk for other negative outcomes such as mental illness (C. Malvaso et al., 2023; McKenzie et al., 2023). Hence, it is likely that these individuals could have contact with multiple service systems across their life-course, and these systems could theoretically provide holistic cross-institutional care (C. Malvaso et al., 2023; McKenzie et al., 2023), best served via a public health prevention approach. However, this would be contingent on requisite larger system changes.

Clearly, our findings suggest that the need for early intervention is greatest amongst those experiencing multiple harms. Particularly for those with adolescent or dual histories of custody, our findings speak to the chronicity of victimization, and to the psychosocial impacts of such experiences, that may increase the likelihood of earlier involvement in, and persistence of, offending across the life-course. Importantly, the overrepresentation of CSA and multi-type maltreatment among custodial populations justifies existing calls for trauma-informed care models for those in custodial environments (Day et al., 2023); the purpose being to “offer a more compassionate approach that reduces risk by helping young people to feel safer, to better understand their experiences of maltreatment and adversity and, thereby, to recover, heal, and to strengthen their overall wellbeing” (Day et al., 2023, p. 2). Such approaches to service delivery should be reflected in staff education, training, and resources (Zettler, 2021), however, a “reshaping” of current policies and systems may be required to accommodate the implementation of such practice models (Vaswani & Paul, 2019).

Limitations and future directions

Our data likely underrepresents the actual prevalence of CSA victimization, given official reports include only CSA that has been disclosed by the child or that has come to the attention of a notifier. In addition, child protection agencies only substantiate harm where CSA occurs within the family unit, including where the abuser resides in the household, or where a caregiver is deemed to have failed to protect a child from harm caused by sexual abuse. However, as mentioned, system contacts for CSA provide clear opportunities for intervention to redirect problematic pathways and overcome some limitations of self-report data (Papalia et al., 2018).

While a limitation of our dataset is that individuals detained/incarcerated outside of Queensland have not been recorded, our results show that a significant proportion of those with CPS contact for notified and substantiated CSA and multi-type maltreatment were not subsequently detained/incarcerated by the age of 30 years. There is value in conducting additional research with this group to improve understanding of protective factors and post-traumatic growth, which could guide future intervention efforts for those most at risk. Findings also highlight the need to further explore the mechanisms underlying CSA, multi-type maltreatment, and detention/incarceration links. As noted by C. G. Malvaso et al (2022, 2023). there is growing awareness of the correlations between these factors, but clarification of their potential mechanisms is still needed, which may have even greater implications for guiding intervention and treatment efforts. While our initial focus was determining prevalence of CSA, our results show considerable overlaps between CSA and multi-type maltreatment suggesting the complex nature of victimization experiences within these vulnerable groups should be considered. Our results highlight the need for additional research that can incorporate a wider range of poly-victimization experiences beyond maltreatment. In addition, inclusion of adversity related to sociodemographic disadvantage, which was not possible to include in this study due to limitations of the dataset, would provide important contextual information about the settings in which risk of victimization is heightened.

Conclusions

This study provided a rare opportunity to explore the links between CSA victimization and custody at the population level, with consideration of both multi-type maltreatment and variations across sex. CSA was strongly associated with detention/incarceration for both males and females. This finding was upheld across notified and substantiated CSA as well as youth, adult, and dual-custody histories. However, CSA was almost always part of a broader experience of multi-type harm for individuals in custody, reflecting the complex histories that precede detention/incarceration, particularly during adolescence. Together, our findings underscore the value of adopting a public health approach to CSA prevention (and child protection more broadly), creating opportunities for early intervention for those at-risk of detention and imprisonment to redirect problematic pathways, and for trauma-informed practices to be embedded within both early intervention (secondary prevention) and tertiary prevention strategies to improve wellbeing and justice outcomes for this vulnerable population.

Availability of data and materials

Linked administrative data used in this study is held in the SAL at GU and owned by the respective Queensland Government agencies, with access managed by the Queensland Government Statistician’s Office. The data is not publicly available and cannot be made available to third parties by the authors, but can be made available upon reasonable request and with permission of relevant data custodians and the Queensland Government Statistician’s Office. Researchers can apply to SAL management committee ([email protected])) with the relevant support and approvals.

Ethical declarations

Ethical approval was obtained from the Griffith University Human Research Ethics Committee (HREC 2021/404), and approval was granted by all relevant Queensland Government data custodians. The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national and institutional committees on human experimentation, and with the Helsinki Declaration of 1975, as revised in 2008.

Acknowledgments

We sincerely thank the representatives from the Queensland Government Statistician’s Office; Queensland Department of Youth Justice, Employment, Small Business and Training; Queensland Department of Child Safety, Seniors and Disability Services; Queensland Department of Justice and Attorney-General; and Queensland Registry of Births, Deaths and Marriages for the support they provided for this project. The authors gratefully acknowledge use of the facilities of the Griffith Criminology Institute’s (GCI) Social Analytics Lab (SAL) at Griffith University (GU)). The views expressed are not those of the departments or agencies, and any errors of omission or commission are the responsibility of the authors.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was funded by a GCI Strategic Development Grant (CT, JO, TA, EH). The funder had no role in study design, collection, analysis and interpretation of data, writing of the report or the decision to submit for publication.

Notes on contributors

Lisa Thomsen

Lisa Thomsen, Griffith Criminology Institute, Griffith University, Mount Gravatt, Queensland, Australia

Carleen Thompson

Carleen Thompson, School of Criminology and Criminal Justice, Griffith University, Griffith Criminology Institute, Griffith University, Mount Gravatt, Queensland, Australia,

James Ogilvie

James Ogilvie, School of Criminology and Criminal Justice, Griffith University, Griffith Criminology Institute, Griffith University, Mount Gravatt, Queensland, Australia,

Nadine McKillop

Nadine McKillop, Sexual Violence Research and Prevention Unit, University of the Sunshine Coast, Sippy Downs, Queensland, Australia

Emily Hurren

Emily Hurren, School of Criminology and Criminal Justice, Griffith University, Griffith Criminology Institute, Griffith University, Mount Gravatt, Queensland, Australia

Timea Molnar

Timea Molnar, Griffith Criminology Institute, Griffith University, Mount Gravatt, Queensland, Australia

Troy Allard

Troy Allard, School of Criminology and Criminal Justice, Griffith University, Griffith Criminology Institute, Griffith University, Mount Gravatt, Queensland, Australia