Reasons for Decreases in Cirrhosis Death Rates

by National Institute of Health

(Page 3 of 4)

Changes in Per Capita Alcohol Consumption

Changes in per capita consumption of alcohol must be considered a leading candidate for the cause of recent reductions in cirrhosis mortality rates. Research demonstrates that, over a long period, changes in per capita consumption are broadly consistent with changes in cirrhosis mortality rates. However, cirrhosis mortality in the United States, Canada, and some other regions began to decline in the mid-1970s, before per capita consumption rates began to go down. This is the opposite of what would be expected based on the hypothesized lagged relationship between per capita consumption and cirrhosis mortality rates. Thus, researchers are considering whether other factors also have influenced cirrhosis mortality rates in recent years.

Beverage-Specific Effects

The relationship between cirrhosis mortality and alcohol consumption may vary depending on the type of alcoholic beverage - beer, wine, or spirits - consumed. Any such beverage-specific effects could help explain why cirrhosis mortality began to decline in the 1970s despite the continued rise in total alcohol consumption.

Researchers over the past four decades have investigated this question. Recently, Roizen and colleagues and Kerr and colleagues have proposed that cirrhosis mortality is more strongly associated with consumption of spirits than with other alcoholic beverages, and that this relationship accounts for the apparent discrepancy between per capita alcohol consumption measures and cirrhosis mortality rates. Roizen and colleagues examined U.S. cirrhosis mortality data from 1949 to 1994 and observed that consumption of spirits was more strongly related to cirrhosis mortality than was total alcohol consumption, a finding that is consistent with earlier observations of U.S. data. Kerr and colleagues extended this analysis to several other countries, with similar results. The relationship between spirits consumption and cirrhosis mortality during the 1970s, when cirrhosis mortality rates began to decline in the United States, suggests that the discrepancy between cirrhosis rates and per capita alcohol consumption observed at that time arose because research did not focus on spirits, the beverage most strongly related to cirrhosis mortality.

The stronger association between cirrhosis mortality and consumption of spirits may be attributable to biological and sociobehavioral mechanisms. Some types of alcoholic beverage may be more toxic to the liver than others. In addition, consumption of certain alcoholic beverages may be associated with different drinking styles - that is, people who tend to drink frequently and heavily, and thus are at greatest risk for developing cirrhosis, also may tend to drink spirits rather than beer or wine. Thus, drinking style may collude with biological mechanisms to significantly raise some drinkers' risk of liver disease. This interesting and important issue is the subject of ongoing investigation.

Increased Participation in Treatment and Alcoholics Anonymous Programs

Another possible reason for declines in cirrhosis mortality has been increased participation in treatment for alcohol abuse and in Alcoholics Anonymous meetings. Specifically, cirrhosis morbidity and mortality rates could be influenced if participation in alcoholism treatment and AA are in some degree effective in reducing excessive drinking among heavy or abusive drinkers, if sufficient treatment occurs, and if enough alcoholics become members of AA or receive other treatment services. The 1970s and 1980s saw large increases in AA participation and in the number of people who received alcoholism treatment services. Smart and Mann examined whether these increases in treatment and AA participation could affect cirrhosis morbidity and mortality rates. According to estimates derived from the research: alcoholics seeking treatment drink an average of 160 g of undiluted alcohol per day. About 14 percent of alcoholics will develop cirrhosis if they drink this quantity for a period of 8 years. About 50 percent of alcoholics receiving treatment or attending AA meetings improve sufficiently to postpone the development of cirrhosis or avoid death if they already have cirrhosis.

The authors applied these figures to the actual number of people who were AA members or were receiving alcohol abuse treatment in 1975 and 1986 in Ontario and the United States. Based on this analysis, between 25 percent and 100 percent of the actual reduction in cirrhosis deaths and hospital discharges during the period could be predicted, depending on the degree of overlap between treatment and AA membership that was assumed.

Other studies of the relationship between cirrhosis mortality rates and aggregate, or population, levels of treatment and AA membership rates support the hypothesis that increases in treatment and AA membership helped reduce cirrhosis mortality rates, both in the United States and elsewhere. Several studies have found an association between reductions in cirrhosis morbidity and mortality and increased levels of treatment and AA membership in Canada, the United States and Sweden. Examining monthly cirrhosis mortality data from North Carolina, Holder and Parker found that alcohol abuse treatment had a significant short-term lagged relationship with cirrhosis mortality, with an increase in treatment being followed 3 months later by a decline in cirrhosis mortality. Finally, Smart and colleagues found that increased funding for alcoholism treatment was associated with cirrhosis mortality reductions across the United States. Thus, the data so far provide strong support for the proposition that if a large enough portion of the population participates, AA membership and alcohol abuse treatment can influence cirrhosis morbidity and mortality rates at the population level.

About the Author

NIH is the nation's medical research agency - making important medical discoveries that improve health and save lives. The National Institutes of Health (NIH), a part of the U.S. Department of Health and Human Services, is the primary Federal agency for conducting and supporting medical research.