Impact of Survey Description, Administration Format, and Exclusionary Criteria on Population Prevalence Rates of Problem Gambling

The present study investigated the impact of survey administration format, survey description, and gambling behaviour thresholds on obtained population prevalence rates of problem gambling. A total of 3,028 adults were surveyed about their gambling behaviour, with half of these surveys administered face-to-face and half over the phone, and half of the surveys being described as a „gambling survey‟ and half as a „health and recreation‟ survey. Population prevalence rates of problem gambling using the CPGI were 133% higher in „gambling‟ versus „health and recreation‟ surveys and 55% higher in face-to-face administration compared to telephone administration. If people with less than $300 in annual gambling expenditures are not asked questions about problem gambling, then the obtained problem gambling prevalence rate is 42% lower. When all of these elements are aligned they result in markedly different problem gambling prevalence rates (4.1% versus 0.8%). The mechanisms for these effects and recommended procedures for future prevalence studies are discussed.