Table 4.
Characteristics of the Study Sample by Mean Number of Days of Cannabis Use in the Past 30 Days and Modeled Number of Days of Cannabis Use in the Past 30 Days Among US Pregnant Women (n=2,247). Results of Negative Binomial Regression Models. National Survey of Drug Use and Health, 2015–2017
| Characteristics | Number of Days of Cannabis Use in the Past 30 Days | Frequency of Past 30-Day Cannabis Use in the Total Sample |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Total Sample | Past 30-Day Users | |||||||||
| Sample Size and Meanb (95% CI) | n = 2,247a | n = 152a | IRR | 95% CI | aIRR | 95% CI | ||||
| 0.8 | (0.6, 1.1) | 15.6 | (13.5, 17.7) | |||||||
| Meanb | (95% CI) | Meanb | (95% CI) | |||||||
| Socio-demographic factors | ||||||||||
| Age group (years old) | <0.01 | <0.01 | ||||||||
| 14 to 17 | 1.1 | (−0.2, 2.3) | 9.2 | (1.6, 16.7) | 4.2 | (1.2,14.7) | 0.8 | (0.3, 2.2) | ||
| 18 to 29 | 1.2 | (0.8, 1.7) | 15.5 | (12.7, 18.3) | 3.8 | (2.2, 6.7) | 2.7 | (1.3, 5.4) | ||
| 30 to 44 | 0.6 | (0.4, 0.9) | 16.3 | (13.5, 19.0) | 1 | 1 | ||||
| Self-identified race/ethnicity | <0.01 | <0.01 | ||||||||
| Non-Hispanic White | 0.8 | (0.4, 1.1) | 14.2 | (11.3, 17.2) | 1 | 1 | ||||
| Non-Hispanic Black | 1.8 | (0.8, 2.9) | 18.3 | (14.0, 22.6) | 2.1 | (1.2, 5.5) | 1.3 | (0.8, 3.5) | ||
| Non-Hispanic Other | 0.7 | (−0.0, 1.5) | 16.1 | (5.1, 27.2) | 0.7 | (0.2, 2.2) | 0.8 | (0.3, 2.2) | ||
| Hispanic | 0.4 | (0.2, 0.5) | 15.4 | (10.6, 20.2) | 0.5 | (0.2, 1.0) | 0.5 | (0.2, 1.3) | ||
| Population density | <0.01 | <0.01 | ||||||||
| Large metropolitan | 0.7 | (0.3, 1.0) | 14.6 | (10.8, 18.3) | 1.9 | (1.0, 3.4) | 2.2 | (1.0, 4.9) | ||
| Small metropolitan | 1.1 | (0.7, 1.4) | 17.3 | (14.2, 20.4) | 2.2 | (0.8, 6.0) | 0.6 | (0.2, 1.8) | ||
| Non-metropolitan | 0.9 | (0.2, 1.7) | 12.2 | (4.9, 19.5) | 1 | 1 | ||||
| Poverty level | <0.01 | <0.01 | ||||||||
| Living in poverty | 0.2 | (0.7, 1.4) | 14.2 | (10.9, 17.4) | 2.0 | (1.2, 3.5) | 2.9 | (1.5, 5.7) | ||
| Income up to 2X FPTc | 0.4 | (0.5, 2.1) | 16.6 | (12.5, 20.8) | 2.3 | (1.0, 5.1) | 0.7 | (0.3, 1.6) | ||
| Income more than 2X FPT | 0.1 | (0.4, 0.8) | 16.1 | (13.0, 19.2) | 1 | 1 | ||||
| Residence in medical marijuana legalized state | ||||||||||
| No | 0.7 | (0.4, 1.0) | 15.6 | (12.7, 18.5) | 1 | 1 | ||||
| Yes | 1.0 | (0.7, 1.3) | 15.7 | (13.2, 18.1) | 1.1 | (0.7, 1.7) | 1.6 | (0.8, 3.2) | ||
| Substance use related factors | ||||||||||
| Alcohol and/or tobacco use in the past 30 days | <0.01 | <0.01 | ||||||||
| Neither | 0.3 | (0.1, 0.4) | 15.7 | (11.5, 19.9) | 1 | 1 | ||||
| Alcohol use | 1.7 | (0.4, 3.0) | 10.6 | (5.4, 15.9) | 8.8 | (3.1, 25.2) | 7.4 | (3.1, 18.1) | ||
| Tobacco use | 2.4 | (1.5, 3.3) | 14.8 | (12.0, 17.7) | 13.0 | (5.6, 28.6) | 11.7 | (4.7, 29.5) | ||
| Alcohol and tobacco use | 8.3 | (4.2, 12.5) | 22.0 | (18.0, 26.1) | 36.0 | (14.3, 91.4) | 39.4 | (16.1, 96.7) | ||
| Past 30-day use of drugs other than cannabis | ||||||||||
| No | 0.7 | (0.5. 0.9) | 15.3 | (13.3, 17.3) | 1 | 1 | ||||
| Yes | 6.5 | (1.8, 11.3) | 18.2 | (12.7, 23.7) | 8.2 | (3.8, 17.7) | 4.9 | (1.3, 18.2) | ||
| Health and pregnancy related factors | ||||||||||
| Trimester of pregnancy | <0.01 | <0.01 | ||||||||
| First | 1.4 | (1.0, 1.9) | 16.0 | (13.7, 18.4) | 3.1 | (1.6, 6.1) | 2.8 | (1.1, 6.9) | ||
| Second | 0.6 | (0.3, 0.8) | 16.3 | (12.4, 20.3) | 1.6 | (0.8, 3.3) | 3.2 | (1.3, 7.9) | ||
| Third | 0.5 | (0.2, 0.9) | 14.5 | (9.8, 19.1) | 1 | 1 | ||||
| Self-reported health status | ||||||||||
| Excellent to good | 0.8 | (0.6, 1.0) | 15.4 | (13.4, 17.5) | 1 | 1 | ||||
| Fair to Poor | 2.1 | (0.4, 3.7) | 17.0 | (11.7, 22.3) | 2.4 | (1.1, 5.2) | 1.3 | (0.4, 4.3) | ||
| Past 12-months MDEd | <0.01 | <0.01 | ||||||||
| No | 0.8 | (0.6, 1.0) | 16.0 | (14.1, 17.9) | 1 | 1 | ||||
| Yes | 1.8 | (0.7, 2.8) | 13.9 | (9.7, 18.2) | 2.0 | (1.1, 3.6) | 2.1 | (0.8, 5.9) | ||
| Risk perception of weekly cannabis use | ||||||||||
| Any risk | 0.3 | (0.1, 0.4) | 12.4 | (8.7, 16.1) | 1 | 1 | ||||
| No risk | 2.9 | (2.1, 3.7) | 17.1 | (15.2, 19.0) | 10 | (6.0, 17.7) | 23.4 | (10.8, 50.7) | ||
| Year of the survey | <0.01 | <0.01 | ||||||||
| 2015 | 0.3 | (0.2, 0.4) | 9.7 | (6.0, 13.4) | 1 | 1 | ||||
| 2016 | 0.9 | (0.5, 1.4) | 18.2 | (14.3, 22.0) | 2.9 | (1.6, 5.4) | 9.7 | (3.3, 28.3) | ||
| 2017 | 1.3 | (0.8, 1.8) | 16.4 | (13.3, 19.5) | 4.1 | (2.5, 6.8) | 4.4 | (2.6, 7.5) | ||
Notes: aUnweighted number; bWeigthed mean; cFederal Poverty Threshold; dMajor Depressive Episode as defined by DSM-IV.