Evaluation of an extended alcohol intervention ‘Drinktest’ to reduce excessive drinking among young adults

Excessive alcohol use is associated with short- and long-term health damaging consequences. The prevalence of excessive drinking, both binge drinking and the frequent consumption of large quantities is especially large among young adults: 1 in 5 drinks excessively. Hence, it is essential to target excessive drinking among young adults in order to reduce it. Although interventions usually target intentions, research based on dual-process models has shown that (risk) behavior is not always intentional, but may result of two systems: an explicit, planful system (intentional) and an implicit, associative system. The implicit system has shown to play a prominent role in the context of excessive alcohol and young adults, where behavior is often induced by a social context. The intervention aims to test two strategies that could successfully address the implicit route: drinker prototype alteration and cue reminders. Prototypes are (1) perceptions of a stereotypical person (‘a typical drinker of your age’), with identifiable, distinct characteristics (e.g., ‘cool’, ‘reckless’), which can be considered without the need to be personally experienced, and (2) ideas a person has of the kind of person he/she desires to become or fears of becoming in the future. Prototypes can be important predictors of health behavior (change), and affect behavior via implicit processes. Prototype alteration is aimed at changing the favorability of typical heavy drinking peers (heavy drinking prototypes) and promoting perceived similarity of the self-image to and favorability of the moderate drinker (moderate drinker prototype). Cue reminders can be defined as potential situations or materials that can function as a cue to remind people of their goals, values (i.e. (un)desirable images that are attainable/avoidable) in a specific (risk) situation. Cue reminders will be used to remind people in risk situations of the content of the intervention. The project objective is to decrease alcohol consumption among excessive (young) adults. In order to reach our aim we will develop, implement and evaluate modules including these two strategies to be added to the already existing online tailored intervention Drinktest.nl. The original drinktest.nl is compared with three experimental interventions (prototype vs. cue reminder vs. combined). Excessive drinkers of 18 years and older are targeted. The intervention should (1) raise awareness of health-risks, (2) promoting self-monitoring, (3) help people identify difficult situations, (4) for 2 study arms help people remember action plans and the intervention content by means of a cue reminder, and (5) for 2 study arms help people identify desired characteristics and achieve similarity to a moderate drinker prototype. Primary outcome is a difference between the conditions in reduced alcohol consumption, secondary outcomes are differences in contemplation of intervention content, intention and attempts to change alcohol consumption, and reduced willingness to drink more than planned. The final evaluation will be based on a RCT where excessive drinkers are randomized among the four conditions. Effects will be examined at 1- and 6-month follow-up.

Excessive drinking respondents exposed to the newly developed intervention modules, especially the cue reminder combined with feedback based on drinker prototypes, will show more reduction in their drinking behavior than those exposed to the original drinktest.

Baseline, 1 and 6 months

We developed extra modules to be added to the already existing program of "Drinktest.nl". We aimed to reduce alcohol consumption among excessive drinking respondents by making respondents more aware of their drinking behavior, promoting self monitoring, and identifying and coping with potentially tempting situations. Important methods for change are awareness and planning, among others.
The intervention, which consists of the orgininal drinktest and extra modules developed by us, is based on the Prototype/Willingness Model.

Respondents are provided with tailored feedback based on their gender and drinking behavior. The intervention includes four conditions. All four will participate in the modules that were present in the orgininal Drinktest. This part takes approximately 10-15 minutes and aims at giving the person more insights into his/her drinking behavior, raising awareness about health-risks, identifying tempting or difficult drinking situations.
The control group will only receive the original Drinktest.
The prototype module received by respondents in the prototype condition aims at providing additional feedback, besides the original Drinktest modules, regarding drinker prototypes. Respondents ideal selves are identified and are encouraged to achieve positive prototypical characteristics of a moderate drinker (moderate drinker prototype). They are shown how the characteristics attributed to heavy drinking (heavy drinker prototype) are not really valued by peers. They can then formulate action plans. This module takes about 5 minutes.
The cue reminder module received additional to the original drinktest by respondents in the cue condition aims at reminding respondents of the content of the intervention and/or the action plans they have formulated during the intervention by means of a sililcon bracelet as a cue. This module takes about 5 minutes.
The combination condition will receive the cue reminder module and prototype module besides the original Drinktest. These respondents are reminded of the content of the positive characteristics they can achieve by reducing their alcohol consumption and of the content of the intervention.