Reaching out to big losers: Exploring intervention effects using individualized follow-up

Previous research suggests that a brief duty-of-care telephone call to high expenditure customers was associated with lower gambling over the subsequent year. The current aim was to assess effects on individual trajectories rather than overall group effects reported previously. The objective was to identify different patterns of individual change over the follow-up year and explore differential responses of subgroups of individuals.

A matched pair design contrasting the outcome for telephone intervention with a no-intervention control condition. Five hundred and ninety-six statistical pairs randomly drawn from the top 0.5% of customers based upon annual expenditure at Norsk Tipping, Norway. Primary outcome measure was gambling theoretical loss (TL), derived from the Norsk Tipping gambling data warehouse. Player trajectories across time were identified using growth mixture modeling to assess differential intervention effects on homogenous subgroups of individuals.

Relatively low, medium, and high TL subgroups were identified. The telephone intervention was associated with greater reductions than the control condition for all three subgroups but showed the strongest effect for the subgroup with the highest TL. The intervention was most effective for casino and sport gamblers, male, young, and middle-aged.

A brief duty of care telephone contact with high expenditure customers showed sustained effects over 12 months, in particular for individuals showing the highest level of TL. Examining trajectories using advanced statistical models identified customer characteristics most strongly associated with reduced TL. These findings can guide prevention strategies with evidence-based knowledge about differential effects. (PsycInfo Database Record (c) 2023 APA, all rights reserved).