Supplementary Material for: Feasibility and Acceptability of an Intervention Providing Computer-Generated Tailored Feedback to Target Alcohol Consumption and Depressive Symptoms in Proactively Recruited Health Care Patients and Reactively Recruited Media Volunteers: Results of a Pilot Study

Background: A pre-post pilot study was conducted to test the feasibility, acceptability, and potential effectiveness of a fully automatized computer-based intervention targeting hazardous drinking and depressiveness in proactively recruited health care patients (HCPs). To address the importance of the sample selection when testing interventions, HCPs were compared to media recruited volunteers (MVs). Method: In a multicenter screening program 2,773 HCPs were screened for hazardous drinking and depressive symptoms. MVs were recruited via media solicitation. Over a period of 6 months, study participants received 6 individualized counseling letters and weekly short messages. Pre-post data were analyzed for 30 participants (15 HCPs, 15 MVs). Intervention acceptability was assessed in post-intervention interviews conducted with 32 study participants. Results: MVs showed higher problem severity and motivation to change than HCPs. Over the course of the intervention both subsamples reduced regular binge drinking (HCPs: p = 0.016; MVs: p = 0.031) and depressiveness (HCPs: p = 0.020; MVs: p < 0.001). MVs further reduced average daily alcohol consumption (p = 0.034). The intervention received positive ratings from both subsamples, the alcohol module was rated more favorably by MVs than by HCPs (p = 0.012). Subsamples further differed in terms of intervention usage (p = 0.013). Conclusion: The intervention was technically and logistically feasible, well accepted, and may have the potential to reduce hazardous drinking and depressive symptoms in different populations. Subsamples differed in terms of problem severity, motivation to change, intervention usage, pre-post changes, and attitudes toward the intervention, showing that intervention development should involve the intended target populations to avoid biased conclusions on intervention effectiveness and acceptability.