Critique 038: Effects of a large reduction in alcohol prices on mortality in Finland – 7 April 2011
Herttua K, Mäkelä P, Martikainen P. An evaluation of the impact of a large reduction in alcohol prices on alcohol-related and all-cause mortality: time series analysis of a population-based natural experiment. Int J Epidemiol 2011;40:441-454; doi:10.1093/ije/dyp336.
Background We examined the effect of a large reduction in the price of alcohol that occurred in Finland in 2004 on alcohol-related and all-cause mortality, and mortality due to cardiovascular diseases (CVDs) from which alcohol-attributable cases were excluded.
Methods Time series intervention analysis modelling was applied to the monthly aggregations of deaths in Finland for the period 1996–2006 to assess the impact of the reduction in alcohol prices. Alcohol-related mortality was defined using information on both underlying and contributory causes of death. Analyses were carried out for men and women aged 15–39, 40–49, 50–69 and >69 years.
Results Alcohol-related deaths increased in men aged 40–49 years, and in men and women aged 50–69 years, after the price reduction when trends and seasonal variation were taken into account: the mean rate of alcohol-related mortality increased by 17% [95% confidence interval (CI) 1.5, 33.7], 14% (95% CI 1.1, 28.0) and 40% (95% CI) 7.1, 81.7), respectively, which implies 2.5, 2.9 and 1.6 additional monthly deaths per 100,000 person-years following the price reduction. In contrast to alcohol-related mortality, CVD and all-cause mortality decreased: among men and women aged >69 years a decrease of 7 and 10%, respectively, in CVD mortality implied 19 and 25 fewer monthly deaths per 100,000 person-years, and a decrease of 7 and 14%, respectively, in all-cause mortality similarly implied 42 and 69 fewer monthly deaths.
Conclusion These results obtained from the time series analyses suggest that the reduction in alcohol prices led to an increase in alcohol-related mortality, except in persons <40 years of age. However, it appears that beneficial effects in older age, when CVD deaths are prevalent, counter-balance these adverse effects, at least to some extent.
Background: An increase in prices (from added taxes) is one of the key recommendations of many groups dealing with a reduction in alcohol abuse. Some studies,1-3 but not all,4 have reported that alcohol-related deaths have responded to increases or decreases in the cost of alcohol in the expected way: an increase in deaths with lowering of costs, a decrease with increasing costs. This paper is particularly interesting as it not only reports the effects of reducing costs of alcohol on alcohol-related mortality, but it also reports the effects of such changes on cardiovascular and all-cause mortality.
As described by the authors, the abolition of import quotas by the EU in 2004 made it possible to import from other member countries unlimited amounts of alcoholic beverages for personal use, and this led to an increase of approximately 10% in alcohol use in Finland. The authors reviewed death certificates for all underlying causes of death; they state that Finland reports alcohol intoxication on death certificates more accurately than in most other countries5 and that medico-legal autopsies were carried out for the large majority of accidental and violent deaths. The investigators used appropriate analytical methods, controlling for seasonal differences in mortality and adjusting for time trends and the autocorrelation inherent in the series of observations. They found that the effects of changes in alcohol best fit a model as having “abrupt and permanent” effects on mortality. A large number of outcomes that could be considered “attributable” to alcohol use, at least partially, were included in their analyses.
Key results of paper: The key results of the analyses were that for subjects over the age of 50 years, the decrease in the cost of alcohol was associated with an increase in rates of alcohol-related mortality. For men aged 40-49 years and men and women aged 50-69 years, these increases in risk estimated 1.6 to 2.9 additional monthly deaths per 100,000 person-years. On the other hand, the trend was very different for cardiovascular and all-cause mortality rates. For men and women aged 40-49 years and those >69 years, there were clear decreases in mortality from cardiovascular disease, with estimated 19 fewer monthly deaths per 100,000 person-years for men and 25 for women. For ischemic heart disease deaths among subjects >69 years of age, many fewer deaths were estimated. These effects were not different when the investigators included numbers of coronary operations as a control series in the models.
For all-cause mortality, the estimates implied 42 and 69 fewer monthly deaths in the oldest group. The lower all-cause mortality rates relate not only to decreases in CVD deaths but to fewer deaths from pulmonary disease, dementia, and diabetes; there were no changes in cancer death rates. The authors state: “the negative, i.e., beneficial, point estimates found in the current study suggest that cheaper alcohol may . . . have fostered moderate consumption and its beneficial effects in at least some part of the population.” They quote recent surveys showing that “alcohol consumption in the 2000s has increased among persons aged >65 years and those aged 50-69 years, whose drinking is reported to be primarily low to moderate.6,7
Comments from Forum reviewers: One Forum reviewer commented that the Finnish people consume more spirits than most other countries. The reduction in price of spirits in 2004 was approximately 30%, while for wine it was only about 3%. We must assume (although data are not given) that the consumption of spirits increased more than that of wine. The most surprising conclusion would be that it seems to be possible to have a significant reduction of the price of spirits in a binge-drinking population with very little change in all-cause mortality among persons below 70 years of age. It is also surprising that mortality due to COPD decreased by 14.9% (95% CI 27.2, 0.4) in men and 17.9% (95% CI 31.9, 0.9) in women in a society where the borders were also opened for the personal importation of cheap cigarettes.
While the results of this study suggest that lowering alcohol taxes is not going to cause a public health emergency, can we say anything about how raising taxes on alcohol relates to the overall public health of the population? In fact, if the elderly react in a complementary manner to price rises, then raising taxes on alcohol might be seen as a way to shorten their life span. One could therefore argue that raising alcohol prices is a way to deprive the low-income elderly from the life-extending benefit of moderate alcohol consumption, as suggested by the present study.
One Forum reviewer was “. . . surprised that the investigators do not show data on total mortality for the entire population. Further, specific data on the change in consumption associated with the change in prices are not given, either overall or by type of beverage. Given than many studies have shown lower risk of mortality from moderate drinking in the elderly, the observations are not all that surprising, but some reviewers thought it unusual that there was not a measurable change in mortality among the youngest group. It may have been preferable to divide up this group, say into 15-25 and 26-39 year groups, to explore these relations more clearly. It would have been interesting to see the contribution of beer, wine, and spirits to the 10% increase in alcohol consumption during 2003 to 2004, from 9.4 to 10.3 liters per inhabitant. The authors state that the fact that the decreases in CVD deaths occurred even when they controlled for trends in cardiac surgery make the results unlikely to be related to confounding from an increasing number of surgical procedures for heart disease.
It seems that the way to deal with such data such as these is to look at the global effect (total mortality) and then parse out the varying effects on subpopulations. In the discussion, the authors seem to accept the harmful effects as fact, and tend to equivocate in the attribution of the positive effects of alcohol consumption, stating: “The negative, i.e., beneficial point estimates found in the current study suggest that cheaper alcohol may, in addition to its harmful effects, also have fostered moderate consumption and its beneficial effects, in at least some parts of the population.”
Is the decrease in CVD due only to the change in alcohol intake? The extent to which the reductions in CVD and all-cause mortality can be attributed just to the changes in alcohol prices is unclear, as decreases in rates were occurring prior to the change in alcohol costs (presumably related to improvements in other risk factors and treatments). In western countries life expectancy has been increasing by 2-2.5 years per decade for many decades, due in large part to declining cardiovascular mortality rates. This is especially true for age groups above 65 years of age. While Finland once had among the highest mortality rates of CVD in the world, in recent decades Finland has made miraculous progress and has reduced cardiovascular mortality from 1970 to 2000 by 70-80 percent. Given that cardiovascular and total mortality have been declining in Finland for a long time, it is difficult to see an abrupt change in the downward trend of CVD and total mortality after the introduction of lower-priced alcohol; in other words, it is hard to notice an obvious acceleration from 2003 of the steady reduction of CVD mortality that has been taking place in Finland for years. The increase of “alcohol-related” deaths is so small, in terms of absolute numbers, that this increase does not have an impact on the long term downward trends of cardiovascular and total mortality in Finland.
Implications: Forum members agreed with the final “key message” of the authors: “Future comprehensive analysis of reductions in the price of alcohol should examine both the detrimental and beneficial consequences.” One Forum reviewer stated that “the increase in alcohol-related deaths from a reduction in alcohol costs will undoubtedly be used by some to support quasi-prohibition from price manipulation of alcohol. Investigators and, in particular, advocates of either encouraging moderate consumption or decreasing any use of alcohol must maintain the humility and patience to perceive the whole picture.”
Note: In the same journal issue is a paper by Gustafsson and Ramstedt8 on changes in alcohol-related harm in Sweden after similar changes in costs; it concluded that “the findings were not consistent with respect to whether alcohol-related harm increased in southern Sweden” after importation from Denmark increased. Also in the same issue is a Commentary by Mark Petticrew9 that points out the known problems in interpreting data from observational studies (such as the present two). He concludes that despite problems setting policy based on observational studies, “. . . evaluations of natural experiments have an essential role to play, not just in understanding impacts but also assessing impacts within different contexts, settings, and populations subgroups.”
References from Forum Review:
1. Herttua K, Mäkelä P, Martikainen P. Changes in alcohol related mortality and its socioeconomic differences after a large reduction in alcohol prices: a natural experiment based on register data. Am J Epidemiol 2008;168:1110–1118.
2. Cook PJ, Tauchen G. The effect of liquor taxes on heavy drinking. Bell J Econ 1982;13:379–390.
3. Wagenaar AC, Maldonado-Molina MM, Wagenaar BH. Effects of alcohol tax increases on alcohol-related disease mortality in Alaska: time-series analyses from 1976 to 2004. Am J Public Health 2008;99:1464–1470.
4. Sloan FA, Reilly BA, Schenzler C. Effects of prices, civil and criminal sanctions, and law enforcement on alcohol-related mortality. J Stud Alcohol 1994;55:454–465.
5. Lahti RA, Penttilä A. The validity of death certificates: routine validation of death certification and its effects on mortality statistics. Forensic Sci Int 2001;115:15–32.
6. Sulander T, Helakorpi S, Nissinen A, Uutela A. Health Behaviour and Health among Finnish Elderly, Spring 2005, with trends 1993–2005. Helsinki: KTL-National Public Health Institute, 2006 (in Finnish).
7. Mäkelä P, Mustonen H, Huhtanen P. Changes in Finnish alcohol consumption patterns in the early 2000s. Yhteiskuntapolitiikka 2009;74:268–288 (in Finnish).
8. Gustafsson N-K J, Ramstedt MR. Changes in alcohol-related harm in Sweden after increasing alcohol import quotas and a Danish tax decrease — an interrupted time-series analysis for 2000-2007. Int J Epidemiol 2011;40:432-440; doi:10.1093/ije/dyq153.
9. Petticrew M. Commentary: Sinners, preachers and natural experiments. Int J Epidemiol 2011;40:454-456; doi:10.1093/ije/dyr023.
Summary: Time series intervention analysis modelling was applied to the monthly aggregations of deaths in Finland for the period 1996–2006 to assess the impact of a reduction in alcohol prices in 2004. The authors report that alcohol-related deaths increased in men aged 40–49 years, and in men and women aged 50–69 years: the mean rate of alcohol-related mortality increased by 17%, 14%, and 40%, respectively, which implies 2.5, 2.9 and 1.6 additional monthly deaths per 100,000 person-years following the price reduction. In contrast to alcohol-related mortality, CVD and all-cause mortality decreased among men and women in the highest age category. The changes were consistent with 19 and 25 fewer monthly deaths per 100,000 person-years for CVD and 42 and 69 fewer monthly deaths for all-cause mortality. Forum members agreed that both potentially harmful and beneficial effects resulting from changes in alcohol intake should be considered when estimating population effects. They were unsure whether all of the reported effects in the elderly should be attributed to changes in alcohol intake, as decreases in CVD and all-cause mortality rates were occurring prior to the change in alcohol intake.
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Comments on the present paper was provided by the following members of the International Scientific Forum on Alcohol Research:
Andrew L. Waterhouse, PhD, Marvin Sands Professor, Department of Viticulture and Enology, University of California, Davis.
Gordon Troup, MSc, DSc, School of Physics, Monash University, Victoria, Australia.
Arne Svilaas, MD, PhD, general practice and lipidology, Oslo University Hospital, Oslo, Norway.
Creina Stockley, clinical pharmacology, Health and Regulatory Information Manager, Australian Wine Research Institute, Glen Osmond, South Australia, Australia.
Erik Skovenborg, MD, Scandinavian Medical Alcohol Board, Practitioner, Aarhus, Denmark.
Ross McCormick PhD, MSC, MBChB, Associate Dean, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
Ulrich Keil, MD, PhD, Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany.
Harvey Finkel, MD, Hematology/Oncology, Boston University Medical Center, Boston, MA, USA.
R. Curtis Ellison, MD, Section of Preventive Medicine & Epidemiology, Boston University School of Medicine, Boston, MA, USA.