In a recent study published in the Lancet Public Health, a group of researchers estimated the prevalence of any gambling activity, specific gambling activities, risk gambling, and problematic gambling among adults and adolescents globally.
Study: The prevalence of gambling and problematic gambling: a systematic review and meta-analysis. Image Credit: SeventyFour/Shutterstock.com
Background
The global gambling industry is projected to reach a yield of $531 billion by 2025, underscoring gambling as a public health issue.
Defined as a disorder in the International Classification of Diseases (ICD) since 1977 and in the Diagnostic and Statistical Manual of Mental Disorders, third edition (DSM-III), gambling disorder involves persistent behaviors causing significant distress or impairment.
Harms include physical, financial, relational, employment, psychological, and educational impacts.
Previous reviews on problem gambling prevalence vary by region and have not fully explored the spectrum of gambling risks or overall prevalence across activities. Further research is needed to understand the diverse behaviors and risks associated with gambling.
About the study
In the present study, searches were performed on June 21, 2021, and updated on March 4, 2024, using Excerpta Medica Database (Embase), Medical Literature Analysis and Retrieval System Online (MEDLINE), and Psychological Information Database (PsycInfo databases), alongside grey literature sources.
Quantitative studies published since 2010 were eligible if they reported prevalence estimates of gambling, risk gambling, or problematic gambling.
Non-original research, case-control studies, clinical trials, and studies with fewer than 40 participants were excluded. Studies were screened for inclusion, and data were extracted into a Microsoft Access database checked for accuracy.
The risk of bias was assessed using the Joanna Briggs Institute checklist. Publication bias testing was not conducted. Only representative studies reporting past 12-month gambling behaviors were included in pooled analyses using STATA 18.
Random effects meta-analyses estimated prevalence and 95% CIs for any risk gambling, gambling, and problematic gambling by country, with global and regional estimates also calculated.
Measures and scales included in analyses are detailed in the appendix. Meta-regressions explored heterogeneity sources, such as gender, age, substance use disorder, and country.
Individual gambling activity prevalence was also estimated, with a post-hoc stratification of online gambling prevalence by publication year. Adult and adolescent samples were analyzed separately, with subgroup comparisons being descriptive.
Study results
The systematic review identified 3,692 papers published since 2010. Of these, 580 reports met the inclusion criteria, with 380 unique representative samples from 68 countries, encompassing 3,441,720 individuals. The samples were predominantly male, with a mean age of 29.72 years, and mostly from high-income countries.
Data were lacking from central Asia, Pacific Island states, the Caribbean, and with only one sample from the Middle East, yet spanned countries containing 43% of the global population. Adult samples represented 41% of the global adult population from 43 countries, while adolescent samples represented 50% from 56 countries.
Of the samples, 366 were involved in the meta-analysis, covering 67 countries: 209 on any risk gambling activity, 299 reported on any gambling activity, and 166 on problematic gambling in the past 12 months.
Various methods were used to measure risk and problematic gambling, the most common being DSM criteria, the Canadian Problem Gambling Index, and South Oaks Gambling Screen.
The study estimated that 46.2% of adults globally engaged in gambling in the past 12 months, equating to approximately 2.3 billion adults. Men (49.1%) had higher rates than women (37.4%). Australasia had the highest prevalence (70%), while Latin America had the lowest (31.7%).
Among adults, 8.7% engaged in any risk gambling, with the highest rate in North America (13.8%). Problematic gambling was estimated at 1.4%, or 71.7 million people, with the highest rates in North America (1.6%).
For adolescents, 17.9% had gambled in the past 12 months, with higher rates in North America (33.7%) and lower in Australasia (9.4%). Data on adolescent risk and problematic gambling were sparse, but North America had the highest estimates for any risk gambling (27.8%) and problematic gambling (10.4%). Boys were more likely than girls to engage in both risk and problematic gambling.
Conditional estimates showed that 14.2% of adults who gambled engaged in risk gambling and 2.8% in problematic gambling. The highest rates of risk gambling were in Eastern Europe and North America, and problematic gambling in North America and Eastern Europe.
Among adolescents who gambled, risk gambling rates were higher in North America and Australasia, while problematic gambling was highest in Australasia.
Meta-regressions indicated that the country of study significantly influenced gambling estimates. Higher estimates of any gambling activity were associated with New Zealand, Australia, the United Kingdom (UK), Canada, and the United States of America (USA). US samples showed higher risk gambling estimates, while UK and Canadian samples showed lower risk gambling estimates.
The most common gambling activities among adults were lottery or raffle tickets (44.7%) and instant lottery or win games (23.9%). Among adolescents, the highest estimates were for instant lottery or win games (13.2%) and lottery (11.0%). Online gambling increased from 5.5% before 2016 to 10.0% after 2020.
Risk of bias varied, with most studies scoring 7 or higher, indicating low to moderate risk of bias. Higher risk of bias was associated with lower estimates of any risk gambling among adults who gambled.
Conclusions
This study assesses global gambling prevalence, showing 46.2% of adults (2.3 billion) and 17.9% of adolescents (159.6 million) gambled in the past 12 months. Online gambling is rapidly growing, with 7.8% of adults and 10.3% of adolescents participating.
An estimated 8.7% of adults engage in risk gambling, and 1.41% experience problematic gambling, especially in online formats.
Given the industry's expansion, the study highlights the need for stronger public health measures and regulations to address gambling harms.
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