We next examined the association between AUD and mortality by age group in the general population and in half-siblings, full-siblings, and MZ twin pairs discordant for AUD. Our model, which predicted the mHR as a function of degree of genetic association among the relative pairs, fit the data well (AIC of model vs raw data: 4 090 815.9 vs 4 090 817.2). Parameter estimates are seen in Figure 2. In early adulthood, the mHR in close relatives discordant for AUD exposure was much lower than that seen in the general population. In particular, the estimated mHR conditional on AUD in discordant MZ twins did not differ significantly from 1 for ages 15 to 24 years and 25 to 29 years. By age 40 years, the estimated mHRs for the general population and for discordant close relative pairs were less discrepant. In MZ pairs, the mHR in the twin with AUD was more than 4 times greater than the unaffected twin. However, the mHR in discordant MZ twins was still much less than the mHR of nearly 8 seen in the
