TABLE 1.
Difference-in-difference estimates for past-month co-use of cigarettes and cannabis
| Adjusted DID estimate | ||||
|---|---|---|---|---|
| MCL aOR (95% CI) | P_int | RCL aOR (95% CI) | P_int | |
| Overall | 1.087 (1.024, 1.155) | 1.061 (0.955, 1.178) | ||
| Age (years) | ||||
| 12–17 | 0.832 (0.764, 0.906) | < 0.001 | 0.645 (0.513, 0.810) | < 0.001 |
| 18–25 | 0.966 (0.906, 1.029) | 0.015 | 0.840 (0.733, 0.963) | 0.014 |
| 25–34 | 1.064 (0.976, 1.159) | Ref. | 1.076 (0.919, 1.261) | Ref. |
| 35–49 | 1.153 (1.056, 1.258) | 0.108 | 1.242 (1.049, 1.471) | 0.190 |
| 50+ | 1.599 (1.391, 1.838) | < 0.001 | 1.374 (1.028, 1.836) | 0.120 |
| F(4) = 25.754 (P < 0.001) | F(4) = 8.421 (P < 0.001) | |||
| Gender | ||||
| Male | 1.082 (1.013, 1.155) | 0.662 | 1.031 (0.910, 1.168) | 0.382 |
| Female | 1.097 (1.022, 1.178) | Ref. | 1.112 (0.961, 1.286) | Ref. |
| F(1) = 0.191 (P = 0.662) | F(1) = 0.763 (P = 0.382) | |||
| Marital status | ||||
| Married | 1.188 (1.074, 1.313) | 0.001 | 1.240 (1.023, 1.504) | 0.012 |
| Widowed/divorced/separated | 1.305 (1.160, 1.469) | < 0.001 | 1.212 (0.959, 1.531) | 0.056 |
| Never married | 1.023 (0.957, 1.093) | Ref. | 0.947 (0.836, 1.074) | Ref. |
| F(2) = 12.347 (P < 0.001) | F(2) = 3.958 (P = 0.019) | |||
| Income | ||||
| < $20 000 | 1.122 (1.040, 1.211) | 0.382 | 1.160 (0.944, 1.425) | 0.109 |
| $20 000–74 000 | 1.064 (0.986, 1.148) | 0.646 | 1.129 (0.968, 1.317) | 0.087 |
| ≥ $75 000 | 1.084 (1.007, 1.167) | Ref. | 0.956 (0.831, 1.099) | Ref. |
| F(2) = 0.853 (P = 0.426) | F(2) = 2.007 (P = 0.135) | |||
| Race/ethnicity | ||||
| Non-Hispanic white | 1.106 (1.037, 1.180) | Ref. | 1.037 (0.915, 1.175) | Ref. |
| Non-Hispanic black | 1.143 (1.024, 1.276) | 0.563 | 1.165 (0.803, 1.690) | 0.544 |
| Hispanic | 0.973 (0.871, 1.088) | 0.019 | 1.038 (0.834, 1.292) | 0.993 |
| Non-Hispanic other | 0.934 (0.814, 1.072) | 0.015 | 1.240 (0.975, 1.578) | 0.164 |
| F(3) = 3.697 (P = 0.011) | F(3) = 0.747 (P = 0.524) | |||
| Educational attainment | ||||
| Less than high school | 1.026 (0.932, 1.130) | 0.049 | 1.118 (0.860, 1.453) | 0.400 |
| High school or equivalent | 1.145 (1.057, 1.241) | 0.816 | 1.043 (0.874, 1.244) | 0.586 |
| Some college | 1.055 (0.974, 1.144) | 0.104 | 1.073 (0.919, 1.252) | 0.453 |
| College graduate or above | 1.160 (1.043, 1.291) | Ref. | 0.973 (0.791, 1.197) | Ref. |
| F(3) = 2.642 (P = 0.048) | F(3) = 0.287 (P = 0.835) | |||
aOR = adjusted odds ratio; CI = confidence interval; DID = difference-in-difference; MCL = medical cannabis laws; P_int: P-value for the interaction term; RCL = recreational cannabis laws.
Adjusted analyses were adjusted for the other socio-demographic variables listed in the table.