Background Vape shops have been spreading rapidly in the USA since 2008, catering to the fast-growing market for electronic cigarettes. Little is known about the geographic density and proximity of vape shops near colleges.

Methods Names and addresses of vape shops were collected from 3 online directories: Yelp.com, Yellowpages.com and Guidetovaping.com. We identified the prevalence of US-based vape shops and their density and proximity to colleges using a geographic information system. General linear model and negative binomial regression were performed to examine the factors associated with proximity and density of vape shops near colleges.

Results We identified 9945 vape shops in the USA as of December 2015, a nearly threefold increase from 2013. Among the 2755 colleges included in this study, 66.5% had at least 1 vape shop within a 3-mile radius. The median proximity of the nearest vape shop to each college/university was 1.8 miles. Proximity increased by student population, private as compared to public institutions, and location (city vs rural). Within a 1-mile radius, colleges with smoke-free campus policies had a lower density of vape shops (RR=0.6, p=0.002) than those without smoke-free campus policies. Private institutions had a higher density of vape shops (RR=7.8, p<0.0001) than did public institutions. Colleges with campus housing had a lower density of vape shops (RR=0.4, p<0.0001) than those without campus housing, and colleges located in cities had a much higher density of vape shops than those located in rural areas (RR=6.6, p<0.0001). Smoke-free and e-cigarette-free campus policies had significant interactions with college type (private vs public) and campus housing in reducing vape shop density.

Conclusions Vape shops are more likely to be located near private institutions and colleges in cities as opposed to rural areas. Smoke-free and e-cigarette-free campus policies have had significant effects in reducing the density of vape shops but have not reduced the proximity of vape shops to colleges. Regulations on the sale and advertisement of e-cigarettes to youth and young adults are critically needed.