Table 3.
IRT analysis of DSM‐IV criteria for marijuana abuse and dependence among past‐year marijuana users aged ≥ 18 years (N = 6917)
| Marijuana abuse and dependence criteria | Prevalence of each criteriona | Factor loadings | Item discrimination parametersb | Item severity parametersb | Mean number of the 10 criteria endorsedc |
|---|---|---|---|---|---|
| % (95% CI) | Estimate (95% CI) | Estimate (95% CI) | Estimate (95% CI) | Mean (95% CI) | |
| A3: Problems with the law | 2.1 (1.65–2.68) | 0.7 (0.66–0.79) | 1.1 (0.86–1.25) | 2.8 (2.51–3.08) | 5.2 (4.61–5.68) |
| A2: Hazardous use | 4.7 (3.99–5.41) | 0.7 (0.60–0.73) | 0.9 (0.74–1.04) | 2.5 (2.29–2.76) | 4.2 (3.73–4.58) |
| A4: Relationship problems | 3.4 (2.90–4.01) | 0.8 (0.74–0.83) | 1.3 (1.07–1.44) | 2.3 (2.16–2.50) | 5.2 (4.88–5.49) |
| D3: Inability to cut down | 5.3 (4.48–6.25) | 0.8 (0.76–0.84) | 1.3 (1.12–1.53) | 2.0 (1.87–2.18) | 4.4 (4.09–4.72) |
| D2: Taking larger amounts/longer | 5.4 (4.54–6.30) | 0.8 (0.76–0.85) | 1.3 (1.13–1.56) | 2.0 (1.85–2.17) | 4.5 (4.16–4.81) |
| A1: Role interference | 4.6 (3.83–5.44) | 0.9 (0.84–0.91) | 1.8 (1.51–2.12) | 1.9 (1.81–2.05) | 5.2 (4.83–5.51) |
| D6: Continued use despite problems | 6.8 (5.98–7.77) | 0.8 (0.75–0.85) | 1.3 (1.11–1.54) | 1.9 (1.72–2.02) | 4.4 (4.15–4.69) |
| D5: Giving up activities | 8.1 (7.15–9.21) | 0.9 (0.84–0.90) | 1.8 (1.51–2.04) | 1.6 (1.51–1.70) | 4.4 (4.12–4.64) |
| D1: Tolerance | 19.7 (17.96–21.52) | 0.8 (0.71–0.79) | 1.1 (0.99–1.28) | 1.1 (1.03–1.24) | 3.0 (2.88–3.16) |
| D4: Time spent using | 30.2 (28.49–31.97) | 0.8 (0.75–0.84) | 1.3 (1.12–1.52) | 0.6 (0.59–0.71) | 2.5 (2.41–2.67) |
Note: Sample sizes are unweighted; all other results are weighted figures. CI, confidence interval.
a
Prevalence of endorsement of each criterion among the 6,917 marijuana users.
b
The IRT model included the 10 abuse and dependence criteria; CFI = 0.97; TLI = 0.97; RMSEA = 0.01.
c
Mean number of the 10 criteria endorsed among those who reported “yes” to the criterion in that row.