Differences in Pathological Gambling Prevalence Estimates: Facts or Artefacts?

The paper aims at investigating whether survey methodology has recently converged to justify the common practice of comparing prevalence estimates and interpreting differences within and between countries. To this end, prevalence studies of problem (PrG) and pathological gambling (PG) published in peer-reviewed journals between 2000 and 2010 were critically reviewed. A systematic computer-based literature search was conducted within various databases and major gambling journals. In a two-step search process, a total of 39 studies reporting current prevalence data of non-clinical national samples from different countries were identified. Analyses revealed wide ranges in estimated PrG/PG rates for adults, adolescents, and college students, whereas similar estimates were reported in two studies on PrG/PG in seniors. Despite the discussion on methodological consistency in the field of gambling research, comparability of the reported estimates was found to be still highly limited by major variation between studies with regard to survey description, administration format, exclusion criteria, assessment instrument, cut-off scores, sample frame, and reference period. The interpretation of differences in PrG and PG prevalence estimates within and between countries may be improved by using valid and reliable instruments and by applying comparable survey methodology in well-defined populations.