The NCRG awarded its first grant in 1996 to Harvard Medical School’s Division on Addictions for this meta-analysis, led by Howard Shaffer, Ph.D., director of Harvard’s Division on Addictions. The study examined 120 prevalence studies and produced the first reliable national estimates of the problem. According to the study, between 1.14 percent and 1.60 percent of the adult population could be classified as having pathological problems incident to gambling. The National Research Council of the National Academy of Sciences praised the meta-analysis for providing “the best current estimates of pathological and problem gambling among the general adult U.S. population and selected subpopulations” in Pathological Gambling: A Critical Review (1999).
The study was published in the American Journal of Public Health in 1999 and an updated version was released in 2001 in the Canadian Journal of Public Health.