The Association of Childhood Abuse with Physical Illness

1. The Association of Childhood Abuse with Physical Illness Kevin Chu

2. Introduction • Sexual and physical abuse during childhood has been associated with diverse negative mental health outcomes • Less work has been done exploring the effect of child sexual and physical abuse as a risk factor for physical illness

3. Sample • The young adult cohort (Cohort II) of the Australian Twin Register maintained by the Australian National Health and Medical Research Council (NHMRC) • Twins born from 1964-1971 (Heath et al. 2001) • Data was collected via telephone interview from 1996-2000

4. Sample (cont.) • Current sample includes 6051 individuals for whom data was available for child abuse • Sample is 55.2% female, 44.8% male with a mean age of 29.9 years (SD of 2.5 years) • Educational background did not suggest any social class bias

5. Assessment of health-related outcomes • One section of the interview focused on health problems • Respondents were directed to a list of twenty-two health problems and asked whether they experienced each • Four of these health problems only applied to females

6. Childhood Sexual Abuse • There were five component questions in three different sections of the interview • A composite variable was created (as noted in Nelson et al. 2002) to represent endorsement of any of these constructs as happening before the age of 18

7. Childhood Physical Abuse • There were four component questions in two different sections of the interview • A composite variable was created (as noted in Nelson et al. 2002) to represent endorsement of any of these constructs as happening before the age of 18

8. Assessment of Child Abuse (CA) • Initially, tried out models separating childhood sexual abuse and physical abuse • We opted to use a single child abuse variable representing experience of either physical or sexual abuse, because of the high correlation found between abuse types, as well as the greater power this approach offered

9. Data Analysis • SAS version 9.1.3 (SAS Institute, 2002) was used • An α-level of 0.05 was required for significance • SURVEYLOGISTIC procedure was utilized for logistic regression analyses; robust variance estimators were used to adjust for presence of multiple members of individual families

10. Data analysis (cont.) • Initial models were constructed using logistic regression analysis to analyze CA as a risk factor for each disease, controlling for parental education (using the highest level of education, university and above, as comparison group) and gender • Additional models were constructed for diseases in which CA was a significant risk factor, controlling for a lifetime DSM-IV diagnosis of major depressive disorder • Final models were constructed for each disease in which CA was a significant risk factor, additionally controlling for a lifetime DSM-IV diagnosis of nicotine, alcohol, and illicit drug dependence

11. Results • The prevalence of CA in our sample was 18.9% overall including 22.9% of women and 13.9% of men • Child abuse was found to be a significant risk in eight of the twenty-two diseases in our initial models

12. Child abuse & health problems (controlling for gender and SES)

13. *Females only

14. Abuse-related Risk Additionally Controlling for Depression, Sex, and Parental Education

15. Abuse-related Risk Additionally Controlling for Nicotine, Alcohol, and Illicit Drug dependence *Controlling for Maternal and Paternal Smoking History as well

16. Discussion Child abuse was found to be a significant risk for eight of twenty-two diseases in initial models ORs changed, but significant CA-associated risk remained for all diseases after controlling for depression Controlling for substance dependence, hepatitis was the only disease in which CA risk ceased to be significant This is understandable, since a common method via which hepatitis is spread is through unsafe drug injection (Illicit drug dependence was the largest risk factor for hepatitis, OR = 2.4)

17. Discussion (cont. II) The seven diseases for which CA was a significant risk factor are all non-surprising There are previously-published articles supporting an association of CA with risk for each of these diseases Depression has been associated with inflammation, weakened endocrine system, enhanced pain sensitivity, etc. It was interesting that there was little attenuation of the effects of CA on health outcomes after controlling for depression

18. Discussion (cont. III) • The strongest observed effects were for liver disease and pancreatitis, both diseases associated with alcoholism, despite our control for alcohol dependence • However, our sample’s very low prevalence of pancreatitis suggests results from our survey will require replication

19. Discussion (cont. IV) • Bone fractures are a likely result of physical trauma • It is believed that childhood trauma places a burden on the homeostatic systems such as neural, endocrine, and immune systems, increasing risk for chronic diseases such as arthritis and asthma (Korff et al.) • Physical abuse has also been linked to epilepsy (Chen et al.) and endometriosis in women (Tietjen et al.)

20. Limitations • Since all subjects were Australian, we cannot be sure findings will generalize to other populations • The assessment of health outcomes was a “quick and dirty” self-report measure; medical records might be a more reliable source • There may be other variables that were not accounted for in analyses that could be risk factors for both CA and outcomes examined

21. Looking Forward • It would be nice to have more data from another large sample, to see if we can tease out the effects of physical abuse and sexual abuse individually • Would also be nice to also see a non-AU data set (not that there is anything wrong with Australians… • Go Aussie’s!

22. Looking Forward (cont. II) • Another possible thing to look into is if early environments that foster childhood abuse may in fact be a risk factor for the diseases • Such factors could include poverty, parental alcoholism, neighborhood cleanliness, etc.

23. Looking Forward (cont. III) • Possible data sets to look at: Missouri Adolescent Female Twin Study (MOAFTS) and the Missouri Family Study (MOFAM) • Would be interesting to do a study on CA’s association on liver disease (previous studies have indicated only alcohol use disorder as a significant risk and not CA)

24. Acknowledgments • Elliot C. Nelson, M.D. • Vivia McCutcheon, Ph.D • Julia D. Grant, Ph.D • Andrew C. Heath, D. Phil • Pamela A.F. Madden, Ph.D • Kathleen K. Bucholz, Ph.D • Nick G. Martin, Ph.D • Marc ARTSS Program