Are alcohol outlet densities strongly associated with alcohol-related outcomes? A critical review of recent evidence.

ISSUES: There have been reviews on the association between density of alcohol outlets and harm including studies published up to December 2008. Since then the number of publications has increased dramatically. The study reviews the more recent studies with regard to their utility to inform policy. APPROACH: A systematic review found more than 160 relevant studies (published between January 2009 and October 2014). The review focused on: (i) outlet density and assaultive or intimate partner violence; (ii) studies including individual level data; or (iii) 'natural experiments'. KEY FINDINGS: Despite overall evidence for an association between density and harm, there is little evidence on causal direction (i.e. whether demand leads to more supply or increased availability increases alcohol use and harm). When outlet types (e.g. bars, supermarkets) are analysed separately, studies are too methodologically diverse and partly contradictory to permit firm conclusions besides those pertaining to high outlet densities in areas such as entertainment districts. Outlet density commonly had little effect on individual-level alcohol use, and the few 'natural experiments' on restricting densities showed little or no effects. IMPLICATIONS AND CONCLUSIONS: Although outlet densities are likely to be positively related to alcohol use and harm, few policy recommendations can be given as effects vary across study areas, outlet types and outlet cluster size. Future studies should examine in detail outlet types, compare different outcomes associated with different strengths of association with alcohol, analyse non-linear effects and compare different methodologies. Purely aggregate-level studies examining total outlet density only should be abandoned. [Gmel G, Holmes J, Studer J. Are alcohol outlet densities strongly associated with alcohol-related outcomes? A critical review of recent evidence. Drug Alcohol Rev 2015].

Equating accelerometer estimates among youth: The Rosetta Stone 2.

OBJECTIVES: Different accelerometer cutpoints used by different researchers often yields vastly different estimates of moderate-to-vigorous intensity physical activity (MVPA). This is recognized as cutpoint non-equivalence (CNE), which reduces the ability to accurately compare youth MVPA across studies. The objective of this research is to develop a cutpoint conversion system that standardizes minutes of MVPA for six different sets of published cutpoints. DESIGN: Secondary data analysis. METHODS: Data from the International Children's Accelerometer Database (ICAD; Spring 2014) consisting of 43,112 Actigraph accelerometer data files from 21 worldwide studies (children 3-18 years, 61.5% female) were used to develop prediction equations for six sets of published cutpoints. Linear and non-linear modeling, using a leave one out cross-validation technique, was employed to develop equations to convert MVPA from one set of cutpoints into another. Bland Altman plots illustrate the agreement between actual MVPA and predicted MVPA values. RESULTS: Across the total sample, mean MVPA ranged from 29.7MVPAmind(-1) (Puyau) to 126.1MVPAmind(-1) (Freedson 3 METs). Across conversion equations, median absolute percent error was 12.6% (range: 1.3 to 30.1) and the proportion of variance explained ranged from 66.7% to 99.8%. Mean difference for the best performing prediction equation (VC from EV) was -0.110mind(-1) (limits of agreement (LOA), -2.623 to 2.402). The mean difference for the worst performing prediction equation (FR3 from PY) was 34.76mind(-1) (LOA, -60.392 to 129.910). CONCLUSIONS: For six different sets of published cutpoints, the use of this equating system can assist individuals attempting to synthesize the growing body of literature on Actigraph, accelerometry-derived MVPA.