Alcohol as a risk factor for liver cirrhosis: a systematic review and meta-analysis.
OBJECTIVE
Alcohol is an established risk factor for liver cirrhosis. It remains unclear, however, whether this relationship follows a continuous dose-response pattern or has a threshold. Also, the influences of sex and end-point (i.e. mortality vs. morbidity) on the association are not known. To address these questions and to provide a quantitative assessment of the association between alcohol intake and risk of liver cirrhosis, we conducted a systematic review and meta-analysis of cohort and case-control studies.


METHODS
Studies were identified by a literature search of Ovid MEDLINE, EMBASE, Web of Science, CINAHL, PsychINFO, ETOH and Google Scholar from January 1980 to January 2008 and by searching the references of retrieved articles. Studies were included if quantifiable information on risk and related confidence intervals with respect to at least three different levels of average alcohol intake were reported. Both categorical and continuous meta-analytic techniques were used to model the dose-response relationship.


RESULTS
Seventeen studies met the inclusion criteria. We found some indications for threshold effects. Alcohol consumption had a significantly larger impact on mortality of liver cirrhosis compared with morbidity. Also, the same amount of average consumption was related to a higher risk of liver cirrhosis in women than in men.


CONCLUSIONS
Overall, end-point was an important source of heterogeneity among study results. This result has important implications not only for studies in which the burden of disease attributable to alcohol consumption is estimated, but also for prevention.
Rehm
Jürgen
J
Centre for Addiction and Mental Health, 33 Russell Street, Toronto, Ontario, Canada. jtrehm@aol.com
Taylor
Benjamin
B
Mohapatra
Satya
S
Irving
Hyacinth
H
Baliunas
Dolly
D
Patra
Jayadeep
J
Roerecke
Michael
M
D000428:Alcohol Drinking / Q000009:adverse effects* / Q000453:epidemiology* / Q000628:therapy; D000437:Alcoholism / Q000150:complications / Q000453:epidemiology / Q000628:therapy; D000818:Animals; D016022:Case-Control Studies; D015331:Cohort Studies; D023381:Endpoint Determination; D005260:Female; D006801:Humans; D008103:Liver Cirrhosis / Q000453:epidemiology* / Q000209:etiology* / Q000628:therapy; D008104:Liver Cirrhosis, Alcoholic / Q000453:epidemiology / Q000209:etiology / Q000628:therapy; D008297:Male; D012307:Risk Factors