Funded by the National Institute on Alcohol Abuse and Alcoholism (R37- AA10908 )

1. Population Attributable Risk, Intimate Partner Violence and Drinking Raul Caetano, M.D., Ph.D. Susie Mikler, M.P.H., Ph.D. University of Texas School of Public Health Funded by the National Institute on Alcohol Abuse and Alcoholism (R37- AA10908)

2. Objectives of this Presentation • Briefly discuss the application of the population attributable risk in assessing population level alcohol control policies to prevent intimate partner violence.

3. Prevalence of IPV

4. Prevalence of Violence: 1995 National Study of Couples

5. Violence, drinking and alcohol policy • As suggested by Room and Rossow (2000) it is important to consider different types of violence: domestic, bar and street, collective (e.g., war atrocities). • The association between alcohol and IPV in general population data are not strong and not always consistent. • This is probably due to the nature of IPV (mostly moderate) and drinking (mostly light) in these data. • The effect of alcohol-related policies on IPV is difficult to estimate because the Population Attributable Risk (PAR) is dependent on the definition of exposure.

6. Population Attributable Risk Rate of disease in the total population that is attributable to the exposure PAR = It – Io/It x 100 It: Incidence among the exposed Io: Incidence among the non-exposed

7. Estimates in the Literature • 33% of assaults (Lenke) • 50% of convicted assaults (Skog & Bjorks, 1988) • 69% of homicides, 47% of assaults (Norstrom, 1998) • Positive relationship with per capita consumption in aggregate studies

8. Population Attributable Risk %

9. If Exposure Is Drinking in the Event • Alcohol exposed IPV cases are those among drinkers drinking in the event. • IPV cases among drinkers not drinking in the event are not exposed. In U.S. data, about 70% of MFPV and 80% of FMPV events by drinkers had no drinking in the event.

10. Other Considerations • Violence literature has not considered a measure such as “drink 6 hours before” the event, which has been used in the injury field. • Consider culture: expectancies about alcohol effects. • Consider drinking patterns: how much binge and intoxication? • Consider population assumptions about the relationship between drinking and intimate partner violence. • Consider then the scientific and political uses of the PAR.

11. Other Considerations • Consider that PAR may vary across population subgroups because strength of association alcohol/IPV varies. • There are no specific alcohol-control policies to prevent intimate partner violence (or domestic violence). • Policies should not be justified by IPV prevention alone, but should based on the general prevention of violence and other problems. • Policy effectiveness may have to be assessed by aggregate-level studies.

12. The End

13. Alcohol and Intimate Partner Violence • Issues for consideration: • Is this association causal and if so which mechanisms underlie it. • Many aggressive events are not associated with alcohol. • It is difficult to establish a temporal relationship between drinking and aggression. • Alcohol and aggression may be both associated with a third factor (e.g., Impulsivity). • The association may be due to expectancies about the effect of alcohol.

14. Overall Design 1635 Couples Interviewed 1995 National Survey of Couples 555 Whites, 358 Black, 527 Hispanics 85% Response rate 1392 couples reinterviewed, 1136 intact couples. 2000 Follow-up National Survey of Couples 406 White, 232 Black and 387 Hispanic couples 72% Response rate

15. Other Methodological Features • Multistage area household probability sample. • Both partners interviewed separately. • Male-to-Female-Partner Violence (MFPV) and female-to-male partner violence (FMPV) measured with the Conflict Tactics Scale. • Upper-bound estimate used; violence considered to have occurred if either partner reports event.

16. Other Methodological Features • 1995: Interviews of about 1 hour with main respondents and of about 20 minutes with partner. 2000: Interviews of about 1 hour with both • Interviews conducted by trained interviewers. • Standardized questionnaire used (close ended). • Bilingual interviewers (Spanish/English) available on request. • Spanish questionnaire available on request.

17. Items in the Conflict Tactics Scale • Threw something (at him/her) (moderate) • Pushed, grabbed or shoved (moderate) • Slapped (moderate) • Kicked, bit or hit (severe) • Hit or tried to hit with something (severe) • Beat up (severe) • Choked (severe) • Burned or scalded (severe) • Forced sex (severe) • Threatened with a knife or gun (severe) • Used a knife or gun (severe)

18. Data Coverage • Alcohol consumption was assessed with a series of questions covering quantity and frequency of drinking wine, beer and spirits in the past 12 months. • Sociodemographic factors: Gender, age, income, education, marital status, place of birth, religion, employment status, occupation, number of children <17 at home, relationship length.

19. Data Coverage • Psychosocial factors: Childhood history of parent-perpetrated violence, witnessing violence between parents, approval of marital aggression, impulsivity, risk taking. • Acculturation. • Drug use. • Residential addresses matched to Census Tract number. 1990 Census data appended to the geocoded sample in 1995.

20. Cross-Sectional Results

21. Overall Rates of Male to Female Partner Violence * * Chi-square across ethnic groups: * p < .01

22. Type of Male to Female Partner Violence Moderate 10% Severe 4% * * * * Push Slap Kick Hit With Beat Choke Burn Sex Threat/ Knife or Gun Use/ Knife or Gun Throw * Chi-square across ethic groups: p < .05

23. Type of Female to Male Partner Violence Moderate 11% Severe 7% * * * * * Push Slap Kick Hit With Beat Choke Burn Sex Threat/ Knife or Gun Use/ Knife or Gun Throw * Chi-square across ethnic groups: p < .05

24. Unidirectional and Bidirectional Intimate Partner Violence

25. Male to Female Partner Violenceby Drinking Patterns Chi-square: p:ns

26. Female to Male Partner Violenceby Drinking Patterns Chi-square: Black - p<.001, Hispanic - p<.05

27. Odds Ratios from Multiple Logistic Regression on Male to Female Partner Violence

28. Odds Ratios from Multiple Logistic Regression on Female to Male Partner Violence

29. Other factors associated with Intimate Partner Violence • Risk factors for MFPV: Young age, lower income, unemployment, childhood physical abuse, approval of aggression, alcohol problems, neighborhood poverty. • Risk factors for FMPV: Young age, childhood physical abuse, alcohol, number of children, approval of aggression, alcohol problems, neighborhood poverty.

30. Longitudinal Results

31. Initial Research Questions • What is the prevalence of IPV across ethnic groups in 1995 and 2000? • What is the stability, remission and incidence of IPV across ethnic groups? • What is the course of IPV (no violence to moderate to severe violence) across ethnic groups? • What are the predictors of stability, remission and incidence?

32. Non-Response Analysis • Non-respondents were more likely to be: Younger men (18-29), unemployed men, women 40 to 49. • Women who experienced abuse during their childhood were less (OR=0.6) likely to be among non-respondents. • Gender-specific multivariate logistic regression models accounted for only 5% of the variance in survey participation.

33. Prevalence of Intimate Partner Violence: 1995 and 2000 (1) * * * Chi-square: p>.01 (1) Intact Couples Only

34. Stability and Incidence of Intimate Partner Violence (1) * ** • *Chi-square: Hispanic vs. White, p>.01 • **chi-square: p>.01 (1) Intact Couples Only

35. Odds Ratios from Multinomial Logistic Regression: Alcohol Problems a * Significant at p<.05 a Also controlling for: drug use, childhood victim., parental violence, impulsivity, attit. toward violence, age, income, education, emplm. status, marital status, length of relationship, ethnicity, weekly N drks, 5 or +.

36. 2000 Status of 1995 Non-Violent Couples

37. 2000 Status of 1995 Couples with Moderate Violence

38. 2000 Status of 1995 Couples with Severe Violence * *chi-square: p>.03

39. Odds Ratios from Logistic Regression: 1995 Alcohol-Related Predictors of 2000 MFPV * p<.05; **variable failed criteria for inclusion: p=.25 Also controlling for: childhood victim., parental violence, impulsivity, attit. toward violence, age, income, education, marital status, MFPV and FMPV in 95.

40. Odds Ratios from Logistic Regression: 1995 Alcohol-Related Predictors of 2000 FMPV. a * p<.05; ** variable failed criteria for inclusion: p =.25 aAlso controlling for: childhood victim., parental violence, impulsivity, attit. toward violence, age, income, education, marital status, MFPV and FMPV in 95.

41. Goodness of fit indices Hu and Bentler (1999) • Comparative Fit Index (CFI) • Between .90 and .95< : Acceptable fit • >.95 : Goodfit • Root Mean Square Error of Approximation (RMSEA) • RMSEA < 0.05 Close fit • RMSEA > .05 ≤ 0.08 Reasonablefit • RMSEA > 0.1 Poor fit • Ratio of chi-square to degrees of freedom (χ2 / df) = 2

42. 1995 Figure 1. Paths for the core set of associations in the model – WHITES 2000 0.66 * 0.42 * 0.27 * 049 * Male 5 plus drinks Male Alc. volume Male Alc. volume Male 5 plus drinks 0.32 * 0.10 * 0.15 * 0.42 * Male Alcohol Problems 0.14 Male Alcohol Problems 0.13 * 0.05 0.06 0.01 CFI = .879 χ 2 = 462.2 df = 238, p=.0000 RMSEA = 0.051 0.35 * IPV 1995 IPV 2000 0.48 * 0.13 * 0.09 0.12 * 0.07 - 0.14 * Female Alcohol Problems 0.38 * Female Alcohol Problems 0.39 * 0.16 * 0.06 0.31 * 0.41 * Female Alc. Vol. Female 5 plus drinks Female 5 plus drinks Female Alc. Vol. 0.39 * 0.71 * 0.19 *

43. 1995 Figure 2. Paths for the core set of associations in the model – BLACKS 2000 0.63 * 0.48 * 0.27 * 0.38* Male 5 plus drinks Male Alc. volume Male Alc. volume Male 5 plus drinks 0.23 * 0.16 0.22 * 0.51 * Male Alcohol Problems 0.13 Male Alcohol Problems - 0.06 0.03 0.21* 0.09 CFI = .766 χ 2 = 592.3 df = 238, p=.0000 RMSEA = 0.089 0.42 * IPV 1995 IPV 2000 0.39 * 0.08 * 0.29 * - 0.07 0.18 * 0.04 Female Alcohol Problems 0.66* Female Alcohol Problems 0.43 0.19 0.11 0.08 0.36 * Female Alc. Vol. Female 5 plus drinks Female 5 plus drinks Female Alc. Vol. 0.43 * 0.66 * 0.34 *

44. 1995 Figure 3. Paths for the core set of associations in the model – HISPANICS 2000 0.32 * 0.46 * 0.62 * 0.31* Male 5 plus drinks Male Alc. volume Male Alc. volume Male 5 plus drinks 0.27 * 0.11 0.19 * 0.49 * Male Alcohol Problems 0.29 * Male Alcohol Problems 0.06 -0.07 0.20* 0.01 CFI = .888, χ 2 = 430.6 df = 238, p=.0000 RMSEA= 0.049 0.46 * IPV 1995 IPV 2000 0.40 * 0.10 * - 0.045 0.01 0.11 0.025 Female Alcohol Problems 0.17 Female Alcohol Problems 0.33 * 0.26 0.11 0.12 0.36 * Female Alc. Vol. Female 5 plus drinks Female 5 plus drinks Female Alc. Vol. 0.43 * 0.43 * 0.44 *

45. Cross-sectional Associations

46. Summary of Longitudinal Results • Most couples reporting IPV at baseline do not report IPV five years later. • The likelihood of reporting IPV five years later is related to the severity of IPV at baseline. This is equally true of MFPV and FMPV.

47. Summary of Longitudinal Results • Male weekly N. of drinks is associated with incidence. • Male and female (Blacks only) alcohol problems associated with IPV. • Hispanics are more likely than Whites to report incident IPV (OR=2.9, 1.2-7.1). • Blacks are 3 times more likely than Whites to report IPV in both 1995 and 2000 (OR=2.9, 1.2-6.9).

48. Predictors of Intimate Partner Violence Moderate Sociodem. Char. Personality Char. Relationship Char. Personal History Situational Factors Contextual Factors Cultural Factors V I O L E N C E Alcohol Problems Psychiatric Diagnoses Alcohol Dependence Drug Dependence Severe

49. Intimate Partner Violence: A Longitudinal Perspective No Violence Time Violence Continuum Moderate Severe

50. Couple’s Level of Agreement in Reporting Intimate Partner Violence (Kappa)