Areas of disadvantage: a systematic review of effects of area-level socioeconomic status on substance use outcomes.

ISSUES: This review examines whether area-level disadvantage is associated with increased substance use and whether study results are impacted by the size of the area examined, definition of socioeconomic status (SES), age or ethnicity of participants, outcome variables or analytic techniques. APPROACH: Five electronic databases and the reference sections of identified papers were searched to locate studies of the effects of area-level SES on substance use published through the end of 2007 in English-language, peer-reviewed journals or books. The 41 studies that met inclusion criteria included 238 effects, with a subsample of 34 studies (180 effects) used for the main analyses. Study findings were stratified by methodological characteristics and synthesised using generalised estimating equations to account for clustering of effects within studies. KEY
FINDINGS: There was strong evidence that substance use outcomes cluster by geographic area, but there was limited and conflicting support for the hypothesis that area-level disadvantage is associated with increased substance use. Support for the disadvantage hypothesis appeared to vary by sample age and ethnicity, size of area examined, type of SES measure, specific outcome considered and analysis techniques. IMPLICATIONS: Future studies should use rigorous methods to yield more definitive conclusions about the effects of area-level SES on alcohol and drug outcomes, including composite measures of SES and both bivariate and multivariate analyses.
CONCLUSION: Further research is needed to identify confounds of the relationship between area-level SES and substance use and to explain why the effects of area-level SES vary by outcome and residents' age.