Multiple health behavior change (MHBC) intervention trials to date have only considered behaviors that were directly targeted. Research has yet to consider how untargeted behaviors can affect change in behaviors directly targeted by an intervention or how changes in targeted behaviors might lead to changes in other, untargeted behaviors. This study addresses these gaps with a secondary analysis of change in risk drinking (targeted behavior) and smoking (behavior that was not addressed) in the efficacy trial of CHOICES, an intervention for the prevention of alcohol-exposed pregnancies. Measures included the Timeline Followback for daily alcohol consumption and questions about smoking behavior. Participants were women of childbearing age who were at risk of alcohol-exposed pregnancy at baseline. Baseline smokers were less likely to change their drinking behavior than baseline non-smokers at nine months (n = 579) with Odds Ratio (OR) of 0.681 (95% CI = 0.471-0.985); 41.1% of smokers vs 50.6% of non-smokers reduced drinking to below risk levels (<5 drinks/day and < 8 drinks per week). Meanwhile, smokers who had changed their drinking behavior were more likely than smokers who had not changed their drinking behavior to have also quit smoking at nine months (OR = 2.769; 95% CI = 1.533-5.000); 19.5% vs. 8.1%, respectively. Together, these findings suggest a natural tendency towards change of multiple related behaviors and indicate that while the presence of unaddressed risk behaviors may make a targeted behavior change more difficult, change in one behavior may facilitate change in related behaviors, even when they are not addressed.
Keywords: Drinking behavior; Health risk behaviors; Smoking cessation; Women's health.