Prevalence of problem gambling in Iowa: revisiting Shaffer's adaptation hypothesis

Pathological gambling (PG) is an important public health problem. We assessed the prevalence of PG and problem (at-risk) gambling in a random sample of Iowa adults and compared the results to survey data collected in 1989 and 1995. The goal of this study was to examine whether continued expansion of gambling venues is associated with increased rates of problematic gambling behavior.

A random digit dialing telephone screening was conducted in eastern Iowa of men and women age ≥18. Respondents were administered the South Oaks Gambling Screen (SOGS) to assess lifetime gambling behavior. Demographic and clinical variables were collected.

A total of 356 respondents (147 men, 209 women) completed the SOGS, and all reported lifetime gambling participation. PG (SOGS ≥5) was found in 5 (1.4%) and problem gambling (SOGS = 3, 4) in 8 (2.2%) respondents. Disordered gambling (SOGS ≥3) was found in 13 (3.6%) respondents. Risk factors for disordered gambling included age (odds ratio [OR] = 0.64 per 10-year age increase), income (OR = 0.82 per $10,000 increase), minority group status (OR = 5.75), number of lifetime gambling activities (OR = 1.27), and having ever gambled ≥$100 (OR = 13.3). Overall gambling participation was significantly less in the current sample, compared with data collected in 1995.

Recent gambling participation was less than in 1995, despite the continued expansion of gaming opportunities. Disordered gambling was associated with younger age, lower income, and minority group status. The results are consistent with Shaffer's "adaptation" hypothesis, which posits that following an initial increase in gambling participation, problematic gambling stabilizes at a lower level.