title: Temporal stability of pathological scratchcard gambling among adult scratchcard buyers two years later.
abstract: OBJECTIVE
  To estimate the 2-year cumulative incidence of pathological scratchcard gambling (PSG) among a representative sample of high-risk scratchcard buyers, to assess the 2-year temporal stability of PSG and scratchcard-related problems and to estimate the adjusted 1-year prevalence for PSG taking into account the temporal dynamics of this diagnosis.
  
  
  METHODS
  A prospective study with two assessments was applied to a non-proportional stratified random sample of 12,222 adult scratchcard buyers in the Netherlands. A cost-effective design was used and only those scratchcard buyers (n=201) who had already experienced some scratchcard-related problems at initial assessment were followed-up 2 years later.
  
  
  METHODS
  Two independent cohorts of buyers with scratchcard-related problems were followed-up: a cohort of 173 potential problematic scratchcard gamblers (PPSG) at increased risk for PSG and a cohort of 28 pathological scratchcard gamblers. Incidence and prevalence estimates were calculated for the total sample of adult scratchcard buyers and for the Dutch adult population.
  
  
  RESULTS
  Of the PPSG group 6.72% (95% CI 2.30-8.90%) became addicted to scratchcards during the 2-year period. The 2-year cumulative incidence of PSG among Dutch adult scratchcard players was 0.24% (95% CI 0.16-0.34%). The stability of the Diagnostic and Statistical Manual 4th edition (DSM-IV) diagnosis of PSG ranged from 11.1% to 42.9%, depending on whether or not those lost to follow-up were considered to be cases of PSG. Taking into account the dynamics of this disorder, using the most conservative assumption, the adjusted 1-year prevalence of PSG for the total sample of adult scratchcard buyers was 0.33% (95% CI 0.23-0.45%).
  
  
  CONCLUSIONS
  PSG proves to be a rare phenomenon among adult scratchcard buyers in the Netherlands. Both incidence and prevalence of the DSM-IV diagnosis PSG were low. Stability of the DSM-IV diagnosis PSG, DSM-IV criteria and South Oaks Gambling Screening-S (SOGS-S) problems were low. Prevalence was stable over the time because incidence and recovery rates were very similar.
authors.affiliation: The Amsterdam Institute for Addiction Research, The Netherlands. merillas@aiar.nl
authors.forename: Laura
authors.initials: L
authors.lastname: DeFuentes-Merillas
authors.forename: Maarten W J
authors.initials: MW
authors.lastname: Koeter
authors.forename: Gerard M
authors.initials: GM
authors.lastname: Schippers
authors.forename: Wim
authors.initials: W
authors.lastname: van den Brink
mesh_terms: D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D005715:Gambling; D006801:Humans; D015994:Incidence; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies