BackgroundAlcohol consumption estimates in public health predominantly rely on self-reported survey data which is likely to underestimate consumption volume. Surveys tend to ask specifically about standard drinks and provide a definition or guide in an effort to gather accurate estimates. This study aimed to investigate whether the inclusion of the term standard drinks with pictorial guide is associated with an adjustment in self-reported alcohol volume.MethodsA web-based survey was administered with AUDIT-C questions repeated at the beginning and end of the survey with and without the standard drink term and guide. The order in which respondents were presented with the different question types was randomised. Two cohorts of university/college students in NSW Australia (n = 122) and the US Pacific Northwest (n = 285) completed the survey online.ResultsAustralian students did not adjust their responses to questions with and without the standard drink term and pictorial guide. The US students were more likely to adjust their responses based on the detail of the question asked. Those US students who drank more frequently and in greater volume were less likely to adjust/apply a conversion to their consumption.ConclusionsThis study supports previous findings of the inaccuracy of alcohol consumption volume in surveys, but also demonstrates that an assumption of underestimation cannot be applied to all individual reports of consumption. Using additional questions to better understand drink types and serving sizes is a potential approach to enable accurate calculation of underestimation in survey data.

The brain changes associated with Alzheimer's disease (AD) develop slowly over many years before the onset of dementia. Biomarkers for AD that allow its detection during this clinically silent phase will be hugely important when disease-modifying treatments that halt or slow its progression become available. Early detection, leading to early treatment, may in some cases avert dementia. Biomarkers aid our understanding of the presymptomatic stages of the disease and enable the identification of individuals with early disease who, by participating in clinical trials of investigational treatments with disease-modifying potential, contribute unique and vital information necessary to evaluate novel therapies. Most currently available AD biomarkers are expensive and not widely available and there are major efforts underway to find cheaper, simpler options. The olfactory system is affected by AD and the results from simple and inexpensive tests of the sense of smell, especially when paired with other information, can help identify individuals early in the disease. We review recent literature relevant to the use of simple olfactory tests, including some novel approaches, as aids to the early detection of AD. We consider their possible role in the design and conduct of clinical trials and suggest how in the future, when more effective treatments become available, they might be integrated into screening programs for early AD detection.