Methodological challenges and limitations of research on alcohol consumption and effect on common clinical conditions: Evidence from six systematic reviews

BACKGROUND: Despite the high prevalence of alcohol consumption in the US, 'mainstream' physicians generally consider it to be peripheral to most patient care. This may be due in part to a dearth of rigorous research on alcohol's effect on common diseases. METHODS: To evaluate this issue, we examined six systematic reviews, four of which were conducted as part of a research initiative supported by the Robert Wood Johnson Foundation, the Program of Research to Integrate Substance Use Information into Mainstream Healthcare (PRISM). PRISM aimed to assimilate and improve the evidence on the medical impact of alcohol (and other drugs of abuse) on common chronic conditions. RESULTS: From these reviews, we summarize the methodological limitations of research on alcohol's impact on development and/or clinical course of depression, hypertension, diabetes, bone disease, dementia, and sexually transmitted diseases. The studies included in these reviews were largely fair to good quality, and few were in primary care settings. Syntheses were hampered by the myriad of definitions of alcohol consumption from any/none to seven levels and a plethora of types of alcohol use disorders. CONCLUSION: We recommend more high-quality observational and experimental studies in primary care settings as well as a more standard approach to quantifying alcohol use and to defining alcohol use disorders.