Descriptive Analyses of Drinking Patterns
Men reported drinking alcohol more frequently than women, with approximately 21% of women reported drinking alcohol in the year before couples testing and study enrollment, compared to 69% of men: 17% of men and 2% of women reported drinking alcohol ≥4 times a week, and 8% of men and 1% of women reported being drunk daily or almost daily. Approximately 6% of women, and 33% of men reported that in the past year, a relative, friend or health care provider suggested that they cut down on drinking (not tabled) (Fig. 1).
In M+F− couples, 37% of men reported getting drunk weekly, and 13% reported getting drunk daily or almost daily (n = 402), whereas 2% of women reported getting drunk weekly, and 1% getting drunk daily or almost daily (n = 24). Similarly, in M−F+ couples, 41% of men reported getting drunk weekly, and 13% reported getting drunk daily or almost daily (n = 608), whereas 5% of women reported getting drunk weekly, and 1% getting drunk daily or almost daily (n = 73).
Demographic and Behavioral Characteristics by Heavy Alcohol Use
Overall, 57% of couples had at least 1 year of follow-up, 35% had ≥2 years, and 22% had ≥3 years (mean follow-up was 616 days or 1.7 years per couple) and did not differ by reported alcohol use. Women who reported being drunk weekly or more were slightly older (30.5 vs. 29.2 mean years old), were closer in age to their partners (5.6 vs. 6.7-years’ difference), had a greater proportion of partners who also reported heavy drinking (defined as drunk weekly or more in 12-months before enrollment) (75 vs. 51%), had fewer live children (1.1 vs. 1.8) and were more often HIV+ than moderate/non-drinkers (75 vs. 57%). Women self-reporting having a STI in the last year was higher among heavy drinkers (38 vs. 27%). Heavy drinkers had about the same proportion of intervals in which they reported condomless sex during follow-up (31 vs. 30%), and reported having an outside partner slightly more than moderate/non-drinkers (2 vs. 1%) (Table 1).
Table 1 Demographic and behavioral characteristics by women’s alcohol use, 2002–2012
Men who were heavy drinkers were slightly younger (35.1 vs. 36.1 mean years old), were closer in age with their partners (6.2 vs. 7.1 years’ difference), had a greater proportion had female partners who reported heavy drinking (12 vs. 5%), reported more STIs in the past year (33 vs. 29%), and had more sex partners in the past year (1.7 vs. 1.6). Heavy drinkers had about the same proportion of intervals in which they reported condomless sex during follow-up (30 vs. 29%), and reported the same proportion of having an outside partner (6 vs. 5%) (Table 2).
Table 2 Demographic and behavioral characteristics by men’s alcohol use, 2002–2012
Factors Independently Associated with Women Reporting Heavy Alcohol Use
Women’s older age (adjusted prevalence odds ratio [aPOR] = 1.04, 95% CI = 1.00, 1.09), partner who reported heavy drinking (aPOR = 3.93, 95% CI = 1.94, 7.17), HIV status (woman HIV+ at baseline aPOR = 2.03, 95% CI = 1.12, 3.67) were associated with heavy alcohol consumption adjusting for age disparity with partner, and number of live children.
Factors Independently Associated With Men Reporting Heavy Alcohol Use
Lower age disparity with partner (aPOR = 0.97, 95% CI = 0.94, 0.99) and having a partner who reported heavy drinking (aPOR = 1.63, 95% CI = 1.35, 1.96) were associated with men’s heavy drinking adjusting for men’s age, years cohabiting, literacy, number of sex partner and self-reported STI in the past year (Table 3).
Table 3 Baseline factors associated with women’s and men’s heavy drinking (reporting being drunk weekly or more frequently vs. drunk less than weekly or never in year prior to baseline) in the Zambia cohort study (n = 1929 couples), 2002–2012
Alcohol Association With Condomless Sex With Partner
Given the lack of association between weekly drunkenness, outside partners and condomless sex in the bivariate analysis, we used a categorical variable to examine possible dose–response relationships in a multivariate analysis. Controlling for age, years cohabiting, months since baseline, and HIV status, men who reported being drunk daily or almost daily had increased odds of having condomless sex with their study partner (aOR = 1.18, 95% CI = 1.06, 1.32) compared to men who reported never being drunk in the past year, and being drunk monthly or less vs. never was also associated with increased condomless sex (aOR = 1.28, 95% CI = 1.10, 1.49). Overall, men reporting ever being drunk vs. never drinkers in the past year had increased odds of reporting condomless sex with study partner (aOR = 1.34, 95% CI = 1.26, 1.43; not tabled). Men being HIV− at baseline (aOR = 1.43, 95% CI = 1.33, 1.53) was also associated with increased odds of reporting condomless sex during the study compared with HIV+ men at baseline, adjusting for man’s heavy drinking, age, months since baseline, and years cohabiting.
Women who reported getting drunk less than monthly in the past year also had a higher odds of reporting condomless sex with study partner (aOR = 1.39, 95% CI = 1.23, 1.56) compared to women who reported never being drunk in the past year adjusting for woman’s age, HIV status, months since baseline and years cohabiting. As in the bivariate analyses, reporting being drunk monthly or weekly was not associated with condomless sex (aOR for monthly vs. never = 1.10, 95% CI = 0.91, 1.33; aOR for weekly vs. never = 1.05, 95% CI = 0.87, 1.26). The finding that being drunk daily was protective (aOR = 0.63) was likely due to small numbers in that category (n = 24 women). Overall, women being drunk vs. never drinkers was associated with condomless sex in the past 3-months with study partner (aOR = 1.20, 95% CI = 1.09, 1.31; not tabled). The woman being HIV+ at baseline was associated with increased condomless sex during the study (aOR = 1.45, 95% CI = 1.35, 1.56) compared to the woman being HIV− controlling for woman’s age, months since baseline, woman’s heavy drinking and years cohabiting (Table 4).
Table 4 Association between alcohol consumption in previous year at baseline and condomless sex with main partner and ≥1 outside partner in past 3 months during study stratified by gender
Alcohol Association With Outside Sex Partners
Men who reported being drunk daily or almost daily at baseline were more likely to report 1 or more outside sex partners during the study (aOR for drunk vs. never drunk = 1.68, 95% CI = 1.41, 2.01 [not tabled]; aOR for being drunk daily or almost daily = 1.91 (95% CI = 1.50, 2.43); aOR for being drunk weekly vs. never = 1.32 (95% CI = 1.08, 1.62); and aOR 2.03 (95% CI = 1.57, 2.62) for being drunk monthly vs. never), adjusting for age, years cohabiting, months since baseline and HIV status. Men being HIV− was also associated with having outside partners during the study (aOR = 1.45, 95% CI = 1.23, 1.71) adjusting for age, months since baseline, years cohabiting, and man’s heavy drinking.
Women who reported ever being drunk at baseline vs. never drinkers had increased odds of reporting 1 or more outside sex partners during the study compared to women who were never drunk (aOR = 1.90, 95% CI = 1.34, 2.68; not tabled), adjusted for women’s age, HIV status, months since baseline and years cohabiting. Women reporting being drunk monthly vs. never was associated with outside partners (aOR = 2.75, (95% CI = 1.56, 4.75) (Table 4).
Alcohol Association With ART Initiation
Overall, 17% of HIV infected individuals started ART during the study (n = 316 couples). After restricting analyses to individuals in the cohort 2007 or later (when ART first became available in government clinics), women who were HIV+ and reported being drunk monthly or more frequently in the past year had decreased odds of initiating ART during the study (aOR = 0.83, 95% CI = 0.70, 0.99) adjusting for age, months since baseline and number of previous pregnancies, compared to women who reported never being drunk in the past year. For men, there was no association between delayed ART initiation and alcohol use (data not tabled).
Baseline Alcohol Use Association With Women’s HIV Acquisition
There were 131 seroconversions in initially HIV− women. After controlling for woman’s age, literacy, years cohabiting and previous pregnancies, men’s heavy drinking was associated with trends of increased HIV transmission to their partners (adjusted hazard ratio [aHR] = drunk weekly or more frequently = 1.42, 95% CI = 0.97, 2.10) compared to men who reported being drunk less than weekly or never in the past year. Women’s reporting of being drunk weekly, daily or almost daily at baseline was marginally associated with increased HIV acquisition (aHR = 3.71, 95% CI = 0.90, 15.25), adjusting for age, literacy, years cohabiting and number of previous pregnancies compared to women who never reported being drunk in the past year. In both cases, the 95% CI included 1 (Table 5).
Table 5 Time to seroconversion stratified by gender of seroconverter as estimated by Cox regression models
Baseline Alcohol Use Association With Men’s HIV Acquisition
There were 137 seroconversions in initially HIV− men. Men reporting being drunk weekly, daily or almost daily at baseline was significantly associated with increased HIV acquisition (aHR = 1.72, 95% CI = 1.01, 2.93) adjusting for men’s age, literacy, years cohabiting, and male circumcision compared to men who drank less than weekly or never reported being drunk in the past year. Women’s drinking was not associated with increased HIV transmission to male partners (aHR = 1.70, 95% CI = 0.42, 6.93) (Table 5).