Population Attributable Risk Intimate Partner Violence and Drinking
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 (R 37 - AA 10908)
Objectives of this Presentation Ø Briefly discuss the application of the population attributable risk in assessing population level alcohol control policies to prevent intimate partner violence.
Prevalence of IPV Male to Female Partner Violence (MFPV) 1975: 12% Female to Male Partner Violence (FMPV) 1975: 11. 6% 1985: 12. 4% 1992: 9% (minor) 1992: 2% (severe) 1992: 4. 5% (severe)
Prevalence of Violence: 1995 National Study of Couples
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.
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
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
Population Attributable Risk % Drinking Perp/Victim Perp Binge Perp/Victim Perp IPV MFPV FMPV 19 25 28 0 0 27 32 27 17 4
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.
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.
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.
The End
Alcohol and Intimate Partner Violence Ø Issues for consideration: ü Is this association causal and if so which mechanisms underlie it. ü Many aggressive events are not associated with alcohol. ü It is difficult to establish a temporal relationship between drinking and aggression. ü Alcohol and aggression may be both associated with a third factor (e. g. , Impulsivity). ü The association may be due to expectancies about the effect of alcohol.
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
Other Methodological Features Ø Multistage area household probability sample. Ø Both partners interviewed separately. Ø Male-to-Female-Partner Violence (MFPV) and female-to-male partner violence (FMPV) measured with the Conflict Tactics Scale. Ø Upper-bound estimate used; violence considered to have occurred if either partner reports event.
Other Methodological Features Ø 1995: Interviews of about 1 hour with main respondents and of about 20 minutes with partner. 2000: Interviews of about 1 hour with both Ø Interviews conducted by trained interviewers. Ø Standardized questionnaire used (close ended). Ø Bilingual interviewers (Spanish/English) available on request. Ø Spanish questionnaire available on request.
Items in the Conflict Tactics Scale Ø Ø Ø 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)
Data Coverage Ø Alcohol consumption was assessed with a series of questions covering quantity and frequency of drinking wine, beer and spirits in the past 12 months. Ø Sociodemographic factors: Gender, age, income, education, marital status, place of birth, religion, employment status, occupation, number of children <17 at home, relationship length.
Data Coverage Ø Psychosocial factors: Childhood history of parentperpetrated violence, witnessing violence between parents, approval of marital aggression, impulsivity, risk taking. Ø Acculturation. Ø Drug use. Ø Residential addresses matched to Census Tract number. 1990 Census data appended to the geocoded sample in 1995.
Cross-Sectional Results
Overall Rates of Male to Female Partner Violence * * Chi-square across ethnic groups: * p <. 01
Type of Male to Female Partner Violence Moderate 10% Severe 4% * * * Throw Push Slap Kick * Hit With Beat * Chi-square across ethic groups: p <. 05 Choke Burn Sex Threat/ Use/ Knife or Gun
Type of Female to Male Partner Violence Moderate 11% * Severe 7% * * * Throw Push Slap Kick Hit With Beat * Chi-square across ethnic groups: p <. 05 Choke Burn Sex * Threat/ Use/ Knife or Gun
Unidirectional and Bidirectional Intimate Partner Violence
Male to Female Partner Violence by Drinking Patterns Chi-square: p: ns
Female to Male Partner Violence by Drinking Patterns Chi-square: Black - p<. 001, Hispanic - p<. 05
Odds Ratios from Multiple Logistic Regression on Male to Female Partner Violence
Odds Ratios from Multiple Logistic Regression on Female to Male Partner Violence
Other factors associated with Intimate Partner Violence Ø Risk factors for MFPV: Young age, lower income, unemployment, childhood physical abuse, approval of aggression, alcohol problems, neighborhood poverty. Ø Risk factors for FMPV: Young age, childhood physical abuse, alcohol, number of children, approval of aggression, alcohol problems, neighborhood poverty.
Longitudinal Results
Initial Research Questions Ø What is the prevalence of IPV across ethnic groups in 1995 and 2000? Ø What is the stability, remission and incidence of IPV across ethnic groups? Ø What is the course of IPV (no violence to moderate to severe violence) across ethnic groups? Ø What are the predictors of stability, remission and incidence?
Non-Response Analysis Ø Non-respondents were more likely to be: Younger men (18 -29), unemployed men, women 40 to 49. Ø Women who experienced abuse during their childhood were less (OR=0. 6) likely to be among non-respondents. Ø Gender-specific multivariate logistic regression models accounted for only 5% of the variance in survey participation.
Prevalence of Intimate Partner Violence: 1995 and 2000 (1) * * Chi-square: p>. 01 * (1) Intact Couples Only
Stability and Incidence of Intimate Partner Violence (1) * ** • *Chi-square: Hispanic vs. White, p>. 01 • **chi-square: p>. 01 (1) Intact Couples Only
Odds Ratios from Multinomial Logistic Regression: Alcohol Problems a Incidence Recurrence Re: No violence Male Alcohol Problems 1. 2 (0. 2 -5. 4) 1. 8 (0. 6 -5. 9) Female Alcohol Problems 0. 1 (0. 01 -. 6)* 1. 7 (0. 6 -5. 2) * 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 +.
2000 Status of 1995 Non-Violent Couples
2000 Status of 1995 Couples with Moderate Violence
2000 Status of 1995 Couples with Severe Violence * *chi-square: p>. 03
Odds Ratios from Logistic Regression: 1995 Alcohol-Related Predictors of 2000 MFPV White Men N drinks ** Black. 9 (. 8 - 1. 1) Hispanic 1. 0 (. 9 - 1. 2) Women N drinks . 3 (. 1 -. 7)* 1. 1 (. 9 - 1. 4) Men 5+ . 4 (. 1 – 1. 3) . 6 (. 2 – 1. 8) Women 5+ 3. 6 (1. 1 – 12. 1)* 2. 7 (. 5 – 15. 7) . 6 (. 3 – 1. 5) Men’s Problems 3. 0 (. 7 – 12. 4) 2. 9 (. 4 – 20. 2) 1. 2 (. 5 – 3. 3) 3. 6 (. 6 – 21. 1) 2. 0 (. 4 – 10. 5) Women’s Problems ** ** 1. 2 (. 6 – 2. 7) * 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.
Odds Ratios from Logistic Regression: 1995 Alcohol-Related Predictors of 2000 FMPV. a Men N drinks Women N drinks White Black Hispanic 1. 2 (1. 1 – 1. 3)* ** ** ** Men 5+ . 2 (. 1 – 1. 2) 2. 6 (. 7 – 10. 0) . 9 (. 4 – 1. 8) Women 5+ 3. 3 (. 6 – 18. 3) 1. 9 (. 4 – 9. 7) 1. 3 (. 6 – 2. 6) Men’s Problems . 9 (. 3 – 3. 0) 1. 7 (. 3 – 8. 4) 1. 1 (. 4 – 2. 9) 3. 0 (. 4 – 25. 5) 1. 7 (. 4 – 7. 0) Women’s Problems ** * p<. 05; ** variable failed criteria for inclusion: p =. 25 a Also controlling for: childhood victim. , parental violence, impulsivity, attit. toward violence, age, income, education, marital status, MFPV and FMPV in 95.
Goodness of fit indices Hu and Bentler (1999) • Comparative Fit Index (CFI) – Between. 90 and. 95< : Acceptable fit – >. 95 : Good fit • Root Mean Square Error of Approximation (RMSEA) – RMSEA < 0. 05 Close fit – RMSEA >. 05 ≤ 0. 08 Reasonable fit – RMSEA > 0. 1 Poor fit • Ratio of chi-square to degrees of freedom (χ2 / df) = 2
Figure 1. Paths for the core set of associations in the model – WHITES 1995 2000 0. 66 * 0. 42 * 049 * Male Alc. volume Male 5 plus drinks 0. 27 * Male 5 plus drinks Male Alc. volume 0. 32 * 0. 10 * 0. 15 * 0. 42 * Male Alcohol Problems 0. 14 Male Alcohol Problems 0. 05 0. 06 IPV 1995 0. 48 * 0. 09 0. 35 * 0. 12 * CFI =. 879 χ 2 = 462. 2 df = 238, p=. 0000 RMSEA = 0. 051 IPV 2000 - 0. 14 * 0. 38 * Female Alcohol Problems 0. 13 * 0. 01 0. 07 Female Alcohol Problems 0. 39 * 0. 16 * 0. 31 * 0. 41 * Female 5 plus drinks Female Alc. Vol. 0. 39 * Female Alc. Vol. Female 5 plus drinks 0. 71 * 0. 06 0. 19 * 0. 13 *
Figure 2. Paths for the core set of associations in the model – BLACKS 1995 2000 0. 63 * 0. 48 * 0. 38* Male Alc. volume Male 5 plus drinks 0. 27 * Male 5 plus drinks Male Alc. volume 0. 23 * 0. 16 0. 22 * 0. 51 * Male Alcohol Problems 0. 13 Male Alcohol Problems - 0. 06 0. 03 0. 21* 0. 09 IPV 1995 0. 39 * 0. 42 * CFI =. 766 χ 2 = 592. 3 df = 238, p=. 0000 RMSEA = 0. 089 IPV 2000 0. 29 * - 0. 07 0. 04 0. 66* Female Alcohol Problems 0. 18 * Female Alcohol Problems 0. 43 0. 19 0. 11 0. 08 0. 36 * Female 5 plus drinks Female Alc. Vol. 0. 43 * Female Alc. Vol. Female 5 plus drinks 0. 66 * 0. 34 * 0. 08 *
1995 Figure 3. Paths for the core set of associations in the model – HISPANICS 2000 0. 32 * 0. 46 * 0. 31* Male Alc. volume Male 5 plus drinks 0. 62 * Male 5 plus drinks Male Alc. volume 0. 27 * 0. 11 0. 19 * 0. 49 * Male Alcohol Problems 0. 29 * Male Alcohol Problems 0. 06 -0. 07 0. 20* 0. 01 IPV 1995 0. 40 * 0. 46 * CFI =. 888, χ 2 = 430. 6 df = 238, p=. 0000 RMSEA= 0. 049 IPV 2000 - 0. 045 0. 01 0. 025 0. 17 Female Alcohol Problems 0. 11 Female Alcohol Problems 0. 33 * 0. 26 0. 11 0. 12 0. 36 * Female 5 plus drinks Female Alc. Vol. 0. 43 * Female Alc. Vol. Female 5 plus drinks 0. 43 * 0. 44 * 0. 10 *
Cross-sectional Associations White (n=366) Paths Estimated Black (n=190) Hispanic (n=344) 1995 2000 Male Volume Alc Problems * * NS * Male Binge Alc Problems * * * IPV NS * * NS NS Male Alc Problems Male Binge IPV Female Volume Alc Problems * NS NS NS Female Binge Alc Problems * * NS NS NS * * NS NS * Negative * NS NS Male Volume & Binge * * * Female Volume & Binge * * * Male and Female Volume * * * Female Alc Problems Female Binge IPV Correlations
Summary of Longitudinal Results Ø Most couples reporting IPV at baseline do not report IPV five years later. Ø 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.
Summary of Longitudinal Results Ø Male weekly N. of drinks is associated with incidence. Ø Male and female (Blacks only) alcohol problems associated with IPV. Ø Hispanics are more likely than Whites to report incident IPV (OR=2. 9, 1. 2 -7. 1). Ø Blacks are 3 times more likely than Whites to report IPV in both 1995 and 2000 (OR=2. 9, 1. 26. 9).
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 Severe Alcohol Problems Psychiatric Diagnoses Alcohol Dependence Drug Dependence
Intimate Partner Violence: A Longitudinal Perspective No Violence Time Moderate Violence Continuum Severe
Couple’s Level of Agreement in Reporting Intimate Partner Violence (Kappa)
Rates of Intimate Partner Violence in the U. S. : Lower and Upper Bound Estimates
Two Different Ways to Report the Prevalence of Intimate Partner Violence FMPV Only No No FMPV Both MFPV Only
Proportional Representation of MFPV Only, FMPV Only and Bidirectional Violence Among IPV Cases
Overall Rates of Intimate Partner Violence Among U. S. Hispanics by Acculturation * * Chi-square: p <. 01
Odds ratios and from Multiple Logistic Regression: Acculturation and IPV.
Association Between IPV and Expectancies How likely to be Violence aggressive? No/not much 16% chance Strong/very 19% strong chance No violence 13% 7% OR (Strong/very strong vs. no: 3. 2 (1. 3 -7. 9). Controlling for gender, age, ethnicity, income, attitudes towards IPV, impulsivity, excuses.
Hispanic (including birth place and acculturation) * 58 4. 8 * 0. 284 malcprob 1995 * * 0. 0 07 0. 117 9 0. 00 malcvol 1995 -0. 379 0. 822 * 0. 238 * 4 malcvol 2000 7 0. 0 2 00 0. 410 * ipv 1995 ipv 2000 0. 0 04 -0. 0 16 * faccult 2000 0. 045 -0 62 2 08 0. 839 * faccult 1995 maccult 2000 0. 00 mchildabuse (0. 042) fchildabuse(0. 128) * mattitudes (0. 183) * fattitudes (0. 010) mimpul (0. 128) * fimpul (0. 075) freqrelig (0. 045) * relength (-0. 093) * falcvol 2000 0. 379 * 0. 032 0. 173 0. 1 27 . 1 income femploy 0. 04 5 * marry -0 9 07 -0. 99 falcprob 1995 55 fedu * * 19 14 0. 0 0. 7 fhispus 0. 0 falcvol 1995 008 -0. 3 3 0. 05 maccult 1995 malcprob 2000 * 0. 370 * 84 mimpul * . 3 5 memploy. 4 -6 0. 26 4. 640 income 10 marry -0 medu 3. 091 * mhispus falcprob 2000 fimpul
Potential Courses for Violence Type: 1995 to 2000 1995 FMPV No Both MFPV 2000
Number of Respondents Eligible for Reinterview in 2000 Follow up Eligible Individuals for 2000 Follow-up Survey N = 3, 270 Dead or Incapacitated N = 124 Capable of Re-interview N = 3, 146 Interviewed N = 2, 577 Excluded from the Analysis N = 35 Final Respondents included in the Analysis N = 2, 542 Not Interviewed N = 569 Excluded from the Analysis N = 5 Final Non-Respondents in the Analysis N = 564
Proportion of Incident and Stable Cases of IPV in 2000 among All IPV Cases by Ethnicity Hispanic Black White
Prevalence of MFPV and FMPV in 1995 and 2000
Odds Ratios from Multinomial Logistic Regression: Drinking Variables a Incidence Re: No violence Recurrence Re: No violence 1. 1 (1. 0 -1. 2)* 1. 1 (1. 0 -1. 2) Female 5+ less once a month 1. 5 (0. 3 -7. 7) 3. 8 (1. 3 -10. 6)* Female 5+ at least once a month 1. 5 (0. 1 -29. 7) . 7 (0. 1 -5. 2) Male weekly N. of drinks (5) * p<0. 05, **p<0. 01 a Also controlling for: female and male alc. prob, drug use, childhood victim. , parental violence, impulsivity, attit. toward violence, age, income, education, emplm. status, marital status, length of relationship, ethnicity.
Stability and Incidence of MFPV and FMPV 1995 - 2000
2000 Status of 1995 Non-Violent Couples
2000 Status of 1995 Couples with Moderate Violence
2000 Status of 1995 Couples with Severe Violence
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