The effect of a brief intervention video on gambling advertising resistance: Results of a randomized, on-line experimental study.

Background And Aims: Gambling advertising is nowadays prevalent in multiple jurisdictions and can take multiple forms, such as TV adverts and social media promotions. However, few independently designed interventions for gambling advertising have been empirically tested. We aimed to measure the effectiveness of an inoculative intervention video for gambling advertising, which was developed based on previous interventions for alcohol and tobacco, and which used input from academics and experts by experience.

Design: Between-participants randomised online experiment.

Setting: UK.

Participants: UK-based gamblers aged 18-29 years (n = 1200) were recruited via Prolific.

Intervention: Participants either saw a novel inoculative intervention video (7.2 mins) aimed at increasing resistance against gambling advertising strategies (n = 595) or a neutral control video (7.2 mins) on healthy eating (n = 605).

Measurements: Participants completed pre- and post-test measures of gambling advertising scepticism and persuasion knowledge immediately before and after video exposure. They also answered the Problem Gambling Severity Index (PGSI) and reported their past-month engagement with gambling promotional offers. A random subset of participants (n = 797) recompleted these measures at one-month follow-up.

Findings: The intervention group's post-test scores were statistically significantly higher than control for scepticism [estimated marginal means (EMM) = 40.32 vs. EMM = 34.72; P < 0.001, 95% confidence interval (CI) = 4.90-6.29, ηp2 = 0.17] and persuasion knowledge (EMM = 20.77 vs. EMM = 16.71; P < 0.001, 95%CI = 3.61-4.50, ηp2 = 0.21). One-month follow-up scores also remained statistically significantly higher in the intervention group compared with control for both scepticism (EMM = 38.26 vs. EMM = 34.73; P < 0.001, 95%CI = 2.70-4.36, ηp2 = 0.08) and persuasion knowledge (EMM = 18.63 vs. EMM = 17.21; P < 0.001, 95%CI = 0.88-1.95, ηp2 = 0.03). Within the intervention group, 21% of participants had stopped engaging with gambling promotional offers at one-month follow-up, reflective of a statistically significant reduction compared with control (EMM = 0.48 vs. EMM = 0.87; P < 0.001, 95%CI = -0.53 to -0.26, ηp2 = 0.04). Overall, the control group showed no statistically significant changes in any of their scores throughout the study period.

Conclusions: An inoculative intervention video appears to increase young gamblers' resistance to gambling advertising and reduce their self-reported engagement with promotional offers.