Chunk #19 — RESULTS — Predicting Use of Alcohol, Cigarettes, and Cannabis with CSA History: Results of Cox Proportional Hazards Regression Analyses — Cannabis
As seen in Table 5, in Model 1, CSA was associated with a three and a half fold increase in risk for cannabis use at ages 5–13 (HR=3.56; CI: 2.44–5.20), an 80% increase for ages 14–17, and a marginally significant increase at ages 18–21. The HRs remained significant following the addition of co-twin early use and its interaction with zygosity. The estimates differed little for ages 14–17 and 18–21, but the drop to 2.34 (CI=1.57–3.48) was statistically significant for the youngest group (5–13). Co-twin early use was associated with a nearly 8-fold elevation in risk for use before age 14 and a 3 and a half-fold increase in risk between 14 and 17. Familial contributions to cannabis use were attributable in part to genetics (HR for co-twin early use by zygosity=1.84; CI:1.43–2.37).
