Processes of Change in Preventing Alcohol-Exposed Pregnancy: Mediation of the Choices Intervention

Background and Purpose: The processes of change for alcohol and contraception were tested as mediators of the CHOICES intervention for reducing the risk of an alcohol-exposed pregnancy (AEP). Data from two randomized clinical trials, CHOICES and CHOICES Plus, were used to test the mediation of CHOICES, an intervention to reduce the risk of alcohol-exposed pregnancy. The analyses examined the experiential and behavioral processes of change for alcohol and contraception, targeted in the intervention, as mediators of the CHOICES Plus intervention on risk drinking, ineffective contraception, and risk of AEP. It was hypothesized that each of the targeted treatment outcomes at 9-month follow-up would be mediated by the experiential processes of change at 3-months, and that these would then be mediated by the behavioral processes of change at 9-months.

Methods: In both studies, women participants were 18-45, fertile, sexually active, not using effective contraception (at risk of pregnancy) and drinking at risk levels (>4 drinks/day or >7 drinks/week in CHOICES and >3 drinks/day or >7 drinks/week in CHOICES Plus). The CHOICES intervention is a brief motivational interviewing-based intervention. In the CHOICES trial, participants were randomized to receive the CHOICES intervention (n=416) or to receive information only (n=414). In CHOICES Plus, women were randomized to receive the CHOICES intervention (n=131) or Brief Advice (n=130). Mediation models were first tested in the CHOICES data and then tested in the CHOICES Plus data for replication analyses, Mediation was tested with path analyses using maximum likelihood estimation in Mplus Version 8.

Data: CHOICES and CHOICES Plus study data were collected at 9-months post-intake. Primary outcomes included risk drinking, ineffective contraception, and risk of AEP. All outcome variables were dichotomous and measured using the Timeline Followback (TLFB) calendar assessment. Alcohol consumption was measured in standard drinks. Ineffective use of contraception was defined as not using any form of contraception or use that was inconsistent with accepted guidelines when having vaginal intercourse. Processes of change measures assessed the experiential and behavioral processes for each target behavior, drinking and contraception use.

Results: The mediation of the CHOICES Plus intervention by the processes of change for alcohol and the processes of change for contraception, completely replicated what was found in the mediation using the data from the CHOICES study. Model fit indices indicated good fit and the indirect effect of treatment on outcome via the processes of change for alcohol and the processes of change for contraception was significant for hypothesized models predicting risky drinking and ineffective contraception in both studies. The indirect effect of treatment on AEP risk through the processes of change for contraception was significant, but the indirect effect of processes of change for alcohol was not in both studies.

Conclusions and Implications: The CHOICES and CHOICES Plus interventions were associated with increased use of the processes of change for alcohol and for contraception which were related to a decrease in targeted risk behaviors. Promoting the use of the processes of change in interventions may increase the likelihood of positive outcomes.