Association of area socioeconomic status and breast, cervical, and colorectal cancer screening: a systematic review

BACKGROUND: Although numerous studies have examined the association of area socioeconomic status (SES) and cancer screening after controlling for individual SES, findings have been inconsistent. A systematic review of existing studies is timely to identify conceptual and methodologic limitations and to provide a basis for future research directions and policy. OBJECTIVE: The objectives were to (a) describe the study designs, constructs, methods, and measures; (b) describe the independent association of area SES and cancer screening; and (c) identify neglected areas of research. METHODS: We searched six electronic databases and manually searched cited and citing articles. Eligible studies were published before 2008 in peer-reviewed journals in English, represented primary data on individuals ages > or = 18 years from developed countries, and measured the association of area and individual SES with breast, cervical, or colorectal cancer screening. RESULTS: Of 19 eligible studies, most measured breast cancer screening. Studies varied widely in research design, definitions, and measures of SES, cancer screening behaviors, and covariates. Eight employed multilevel logistic regression, whereas the remainder analyzed data with standard single-level logistic regression. The majority measured one or two indicators of area and individual SES; common indicators at both levels were poverty, income, and education. There was no consistent pattern in the association between area SES and cancer screening. DISCUSSION: The gaps and conceptual and methodologic heterogeneity in the literature to date limit definitive conclusions about an underlying association between area SES and cancer screening. We identify five areas of research deserving greater attention in the literature