Viewpoints: Where are all the gay guys? Using Google Trends to Inform the Population Size Estimation and Spatial Distribution and of Gay, Bisexual, and Other Men Who Have Sex with Men (Preprint)

BACKGROUND We must triangulate data sources to understand best the spatial distribution and population size of marginalized populations to empower public health leaders to address population-specific needs. Existing population size estimation techniques are difficult and limited. Passive surveillance strategies that utilize internet and social media could enhance, validate, and triangulate these estimates. OBJECTIVE We explored the Google Trends platform to approximate an estimate of the spatial heterogeneity of the population distribution of gay, bisexual, and other men who have sex with men (gbMSM). METHODS This was done by comparing the prevalence of the “gay porn” search term to the “porn” search term. RESULTS Our results suggest that most cities have a gbMSM population size between 2% and 4% of their total population, with large urban centres having higher estimates relative to rural or suburban areas. CONCLUSIONS This represents nearly a doubling of sample size estimates compared to other methods, which typically find that between 2% and 4% of the male population are gbMSM. However, we note that this method is limited by unequal coverage in internet usage across Canada and differences in the frequency of porn use by gender and sexual orientation. Nevertheless, we argue that Google Trends estimates provides, for most public health planning purposes, adequate city-level estimates of gbMSM population size in regions with a high prevalence of internet access and for purposes in which a precise or narrow estimate of the population size is not required. Furthermore, it does so in less than a minute, at no cost – making it extremely timely and cost effective relative to more precise (and complex)