JMIR Publications

ABSTRACT

Background:

The alcohol-attributable burden of disease is high among socially disadvantaged individuals. Interventional efforts intending to have public health impact should also address the reduction of social inequalities due to alcohol.

Objective:

The aim was to test the moderating role of education on the efficacy of a computer-based brief intervention addressing the full spectrum of alcohol use (BAI).

Methods:

1,646 adults from the general population aged 18 to 64 years (56% women, M = 31 years, 35% with less than 12 years of school education) reporting alcohol use in the past year were randomized to BAI or assessment-only (participation rate: 67%). Recruitment took place in a municipal registry office in one German city. All participants filled out a self-administered, tablet-based survey during the recruitment process and were assessed 3, 6 and 12 months later by study assistants via computer-assisted telephone interviews. The BAI consisted of three computer-generated and individualized feedback letters that were sent per mail at baseline, month 3 and month 6. The intervention was based on the Transtheoretical Model of Behavior Change and expert system software that generated the feedback letters automatically according to previously defined decision rules. The outcome was self-reported change in number of alcoholic drinks per week over 12 months. Moderator was school education according to highest general educational degree (less than 12 years of education vs. 12 years or more). Covariates were gender, age, employment, smoking and alcohol-related risk level.

Results:

Latent growth modeling revealed that the intervention effect after 12 months was moderated by school education (Incidence Rate Ratio, IRR = 1.38, 95% Confidence Interval, CI = 1.08-1.76). Individuals with less than 12 years of school education increased their weekly alcohol use to a lesser extent when they received the intervention compared to assessment-only (IRR = 1.30, 95% CI = 1.05-1.62, Bayes Factor, BF = 3.82). No difference was found between groups (IRR = 0.95, 95% CI = 0.84-1.07, BF = 0.30) among those with 12 or more years of school education.

Conclusions:

The efficacy of an individualized brief alcohol intervention was moderated by the participants’ educational background. Alcohol users with less than 12 years of school education benefitted, whereas those with 12 or more years did not. People with lower levels of education might be more receptive to the behavior change mechanisms applied by BAIs. The intervention approach may support the reduction of health inequalities in the population at large if individuals with low or medium education can be reached. Clinical Trial: The trial has been prospectively registered at the German Clinical Trials Register (DRKS00014274, date of registration: 12th March 2018).