The current study analyzed the impact of a telephone intervention introduced by the Norwegian state-owned gambling company, Norsk Tipping. The researchers wanted to know whether the telephone intervention influenced a person’s theoretical loss over the next year. Theoretical loss is the amount of money someone is expected to lose over the long time due to the gambling provider’s profit. Participants were people who lost the most money (top 0.5%) at Norsk Tipping in the past year. A total of 596 pairs of people were matched based on sex, age, and net losses. One person received the telephone intervention and the other received no intervention (i.e., control condition). The researchers identified three subgroups of participants based on their TL. One subgroup had a relatively high TL, while one subgroup had medium TL, and the last subgroup had a relatively low TL. Over time, all subgroups decreased in TL. But the telephone intervention was more effective than the control condition. The telephone intervention was most effective for those who had a high level of spending prior to the intervention. It was also most effective for people who gambled on sports and in casinos, and those who were male and young or middle-aged.
