Table 3.
Fixed Effects for Multilevel Models of Time Trends for THC and CBD Daily Dose and THC:CBD Daily Ratio
| Characteristic | THC daily dose beta coefficient (95% CI) | CBD daily dose beta coefficient (95% CI) | THC:CBD daily ratio beta coefficient (95% CI) |
|---|---|---|---|
| Intercept | 14.01 (13.38 to 14.65) | 7.43 (7.08 to 7.77) | 7.42 (7.19 to 7.66) |
| Age group, years | |||
| 18–49 | Ref. | Ref. | Ref. |
| 50–64 | 0.01 (−0.92 to 0.93) | 0.41 (−0.09 to 0.92) | 0.11 (−0.23 to 0.45) |
| ≥65 | −3.56 (−4.56 to −2.55) | 1.79 (1.24 to 2.33) | −1.97 (−2.34 to −1.60) |
| Time (per week) | 0.20 (0.16 to 0.23) | −0.01 (−0.03 to 0.01) | 0.12 (0.11 to 0.13) |
| Age (50–64 years)×time interaction | 0.01 (−0.05 to 0.06) | −0.01 (−0.05 to 0.02) | −0.00 (−0.02 to 0.02) |
| Age (65+ years)×time interaction | −0.02 (−0.08 to 0.04) | 0.02 (−0.01 to 0.06) | 0.01 (−0.01 to 0.03) |
Multilevel models account for clustering of observations within subjects and random effects for slopes of time. Time corresponds to a change in dose/ratio across an average 1 week period from date of first invoice. Interaction corresponds to difference in dose/ratio change across time comparing age groups. Bolded beta coefficients significant at p<0.05.