Geographical distribution of alcohol-attributable mortality in Chile: A Bayesian spatial analysis

Highlights

• Small-area alcohol mortality can be estimated combining data and methodologies.

• Local policies should use small-area estimates to identify populations at risk.

• More than 90% of alcohol related deaths are not attributable solely to alcohol.

• We obtain stable local estimates, while including partially attributable causes.

• Municipalities with excess mortality risk were most common in south central regions.

Abstract

Objective

To describe the distribution of alcohol-attributable mortality (AAM) at the local level (345 municipalities) in Chile, including fully and partially attributable causes in 2009.

Methods

AAM was estimated for the population 15 years of age and older using per capita alcohol consumption combined with survey estimates. The effect of alcohol on each cause of death was extracted from the published scientific literature. We used Bayesian hierarchical models to smooth the Standardized Mortality Ratio for each municipality for six groups of causes related to alcohol consumption (total, neuro-psychiatric, cardiovascular, cancer, injuries and other causes).

Results

The percentage of municipalities with high risk for any group of causes in each region ranges from 0% to 87.0%. Municipalities with high risk were concentrated in south-central and southern Chile for all groups of causes related to alcohol.

Conclusions

AAM risk shows marked geographic concentrations, mainly in south-central and southern regions of Chile. This combination of methods for small-area estimates of AAM is a powerful tool to identify high risk regions and associated factors, and may be used to inform local policies and programs.

Introduction

The impact of alcohol consumption on health has been analyzed in different studies and contexts and is recognized as a global public health problem (Rehm et al., 2004). In Chile, the first study of burden of disease was published in 2008, showing the extent of the problem at the national level (9.7% of all deaths were attributable to alcohol consumption in 2004) (Ministerio de Salud y Pontificia Universidad Católica de Chile, 2008). Recently, a new study estimated deaths due to alcohol in 2009 in the population aged 15 and over and found similar results (Castillo-Carniglia, Kaufman, & Pino, 2013). However, at present no studies have yet estimated the impact of alcohol across smaller geographic areas, such as regional or municipal levels. This makes it difficult to design policies with local approaches that take account of the particular expression of the problem, as has been highlighted in the National Strategy on Drug and Alcohol and the Chilean Alcohol Strategy (Ministerio de Salud, 2010, Servicio Nacional para la Prevención y Rehabilitación de Drogas y Alcohol, 2011).

Chile is a developing country that in the last decades has experienced pronounced economic growth, with a current GDP per capita of around US$15,000 (World Bank, 2011). The economy is based primarily on mining (mostly in the northern regions), forestry, agriculture and fisheries (OECD, 2012). Chile is also a producer of wine and pisco (a distilled spirit made from grapes that contains 35–42% alcohol) that together constitute a market of more than 2.5 billion US dollars annually (Oficina de Estudios y Políticas Agrarias, 2012).

Previous studies had shown that general and cause-specific mortality is not homogeneous across the country (Icaza et al., 2006, Icaza et al., 2007, Icaza et al., 2013). The volume and patterns of alcohol consumption as well as its consequences are no exception, which make it necessary to identify regions and municipalities with excess risk to facilitate targeted policy formation. The presentation in maps of the spatial distribution of health and related indicators is useful for this purpose and to identify possible hypotheses to explain the varying incidence rates and for the broad dissemination of this information (Barceló et al., 2008). This approach has been applied extensively through the elaboration of mortality atlases for various causes and geographic areas with different sizes around the world (Casper et al., 2003, Ocaña-Riola et al., 2008). However, no previous studies in developing countries have examined the distribution of alcohol-attributable mortality at regional or municipal levels. Furthermore, of the studies in different parts of the world that have analyzed mortality attributable to alcohol, only a few included partially attributable causes (attributable fractions < 1) or cases in which alcohol explains only a fraction of the events, such as some types of cancer (New Mexico Department of Health, 2013, New South Wales Ministry of Health, 2013). The inclusion of partially attributable causes is of great importance since they represent, in some contexts, over 90% of all deaths due to alcohol (Castillo-Carniglia et al., 2013).

The objective of this study is to describe the distribution of alcohol-attributable mortality at the local level (345 municipalities), including fully and partially attributable causes, for the year 2009 in Chile.