Premature mortality attributable to smoking and hazardous drinking in Canada.

All causes of death related to the two risk factors, smoking and hazardous drinking, have been reviewed followed by a selection of those causes of death for which the causal role of the risk factor appears to be quasi-certain. For each cause, existing epidemiologic data were reviewed and used to determine the fraction of premature mortality which could be attributed to each factor (called the attributable fraction). This fraction was then multiplied by the corresponding Canadian premature mortality measured in terms of deaths between ages one and 70 and potential years of life lost (PYLL) between ages one and 70, which gives a higher weight to younger deaths. Of the 73,440 deaths between ages one and 70 in Canada in 1974, 12% (or 8718 deaths) were found to be attributable to current smoking and 6% (4716) to hazardous drinking. In terms of PYLL between ages one and 70, hazardous drinking ranks ahead of current smoking with 10% (or 132,044 PYLL) of the total PYLL, whereas current smoking represents 8% (105,085 PYLL) of the total . Regardless of whether premature mortality is expressed in terms of deaths or PYLL, about 18% of Canadian premature mortality is attributable to current smoking and/or drinking (with the range of possible values being 14-22%).