Chunk #17 — RESULTS — Predicting Use of Alcohol, Cigarettes, and Cannabis with CSA History: Results of Cox Proportional Hazards Regression Analyses — Alcohol
As seen in Table 3, in Model 1, CSA was associated with a greater than 4-fold increase in risk for initiation of alcohol use before age 10 (HR=4.59; CI: 1.96–10.74) that dropped to a 76% increase in risk for use between ages 10 and 14 (HR=1.76; CI: 1.46–2.14) and 15% for ages 15–19. The addition of co-twin early age at first drink and co-twin early use x zygosity in Model 2 did not reduce the HR for use before 10 but HR estimates for the later periods of risk were slightly attenuated, significantly at ages 10–14 (i.e., the HR did not fall within the Model 1 confidence intervals) and at the trend level for 15–19. There was evidence as well for a peak period in risk associated with co-twin early use: HR=4.51 (CI:3.62–5.62) for ages 10–14. The HR for co-twin early use by zygosity (1.25; CI:1.04–1.51) is suggestive of a modest degree of genetic influence on the timing of first drink.
