Increase in mortality in Russia in the 1990s

Editor—Plavinski et al found that in two cohorts in St Petersburg mortality increased over the past decades in men without a university education but remained unchanged in those with one.¹ In a subanalysis, mortality increased substantially over time in consumer groups with both high and low alcohol consumption while differences in mortality between the groups were much smaller. Therefore, the authors conclude, alcohol accounts only partly for the recent rise in Russian mortality.

I doubt that the study design is appropriate to detect differences in alcohol related mortality. Alcohol consumption was asked for only on recruitment, 1975-7 and 1986-8, respectively. This is of special importance for the later cohort since its recruitment coincided with Michail Gorbachev's anti-alcohol campaign, which caused a considerable decline in alcohol consumption in Russia.² This decline, however, was shortlived, and alcohol consumption rose again quickly after the campaign's end. Therefore, many people classified as consumers of low quantities of alcohol on recruitment might have consumed considerably higher amounts during follow up and consequently been misclassified.

Alcohol consumption, in contrast to, for example, smoking or hypercholesterolaemia, seems to be, at least for cardiovascular diseases, a risk factor with a close temporal relation to the event.³ Therefore it is of special importance to assess it continuously in prospective studies.

An additional limitation of the study is that it did not account for drinking patterns, which might be crucial to the effects of alcohol on cardiovascular mortality.³