Life expectancy in Scotland is markedly lower compared to other European nations and the UK as a whole [1]. But what are the reasons for this higher mortality? An explanatory framework, synthesising the evidence is published this month in Public Health.

Higher mortality in Scotland is often attributed to higher rates of deprivation, smoking, alcohol consumption and poor diet. However such explanations are not sufficient to understand why Scotland is so very different compared to other areas. A group of researchers found that no single cause was likely to explain the higher mortality, but the authors assert, as a result of their research, that it may be attributable to a range of factors influenced by the political direction of past decades.

In synthesising this evidence the group of researchers identified candidate hypotheses based on a literature review and a series of research dissemination events. Each hypothesis was described and critically evaluated by a set of epidemiological criteria.

Hypotheses identified and tested included: artefactual explanations (e.g. migration); 'downstream explanations' (e.g. genetics, individual values), midstream explanations (e.g. substance misuse, family, gender relations) and; upstream explanations (e.g. climate, inequalities, de-industrialisation and 'political attack').

The results showed that between 1950 and 1980 Scotland started to diverge from elsewhere in Europe and this may be linked to higher deprivation associated with particular industrial employment patterns, housing and urban environments, particular community and family dynamics, and negative health behaviour cultures.

The authors suggest that from 1980 onwards the higher mortality can be best explained by considering the political direction taken by the government of the day, and the consequent hopelessness and community disruption that may have been experienced. Other factors, such as alcohol, smoking, unemployment, housing and inequality are all important, but require an explanation as to why Scotland was disproportionately affected.

"It is increasingly recognised that it is insufficient to try to explain health trends by simply looking at the proximal causes such as smoking or alcohol. Income inequality, welfare policy and unemployment do not occur by accident, but as a product of the politics pursued by the government of the day. In this study we looked at the 'causes of the causes' of Scotland's health problems," said Dr Gerry McCartney, lead author of the study and consultant in public health at NHS Health Scotland.