Thørrisen MM, et al. - Through a systematic review of observational studies, the researchers examined the notion of alcohol-related presenteeism ie, whether the evidence in the research literature supported a correlation between employee alcohol consumption (a significant risk factor for disease, disability, and mortality and has been recognized as a causal agent in more than 200 disease and injury conditions) and impaired work performance. Twenty-six studies were involved with 132 tested correlations. The vast majority of associations showed that higher levels of alcohol consumption were correlated with higher levels of impaired work performance, and these positive relations were considerably more likely in comparison with negative correlations to be statistically important. Among important positive correlations of moderate and high quality, alcohol exposure estimated by hangover episodes and composite instruments were over-represented. Overall, 61% of the associations were identified as of low quality. Hence, the results gave some support for the idea of alcohol-related presenteeism. However, evidence should be considered as somewhat inconclusive because of low research quality and lack of longitudinal designs. More strong and less heterogeneous research is needed. Nonetheless, this review gave support for targeting alcohol consumption within the frame of workplace interventions targeted at advancing employee health and productivity.