Substance use off and on school grounds: A California statewide comparison between different groups of homeless students and nonhomeless students.

About 1.3 million homeless students attend schools across the US, yet little is known about their substance use patterns, especially substance use on school grounds. The objectives of this study were to examine differences in substance use on and off school grounds between nonsheltered homeless, sheltered homeless, and nonhomeless public school students, and to examine the relationship between homelessness and substance use in school. Data were from a statewide representative sample from the California Healthy Kids Survey collected in 2011-2013, (n = 390,028). Bivariate and multivariate analyses were applied. Findings show that compared to nonhomeless students, homeless students, both sheltered and nonsheltered, reported higher rates of age at first time of use under the age of 10, and recent substance use, for an array of substances, indulging alcohol, cigarettes, marijuana and other illegal drugs. Additionally about 50% of nonsheltered homeless students, and 15% of sheltered homeless students reported having used substances in school in the past 30 days. Results from logistic regressions indicate that homelessness is associated with substance use in school. Particularly, nonsheltered homeless students were 17.41, 12.09, 11.36 and 17.59 times more likely to report smoking cigarettes, drinking alcohol, using marijuana and using other illegal drugs (respectively) in school in the past 30 days, compared to nonhomeless students. Sheltered homeless students were also more likely to use substances in school compared to nonhomeless students, but less likely compared to nonsheltered students. Findings highlight the need to develop differentiated school-based responses to each homeless subgroup and have conceptual, scientific and policy implications.