Table 1.
| A. Confirmatory factor analysis (CFA) and item response theory (IRT) findings with DSM-5 opioid use disorder among past-year frequent nonmedical prescription opioid users (those that used at least 120 days) in the United States, 2011–2012. | |||||
|---|---|---|---|---|---|
| CFA | IRT | ||||
| n* | % | One factor | Discrimination (SE) | Severity (SE) | |
| Tolerance | 513 | 63.6 | 0.911 | 2.25 (0.29) | −0.38 (0.05) |
| Withdrawal | 314 | 39.0 | 0.743 | 1.11 (0.09) | 0.37 (0.06) |
| Larger/Longer | 231 | 28.7 | 0.827 | 1.48 (0.12) | 0.67 (0.06) |
| Quit/Control | 190 | 23.6 | 0.710 | 1.01 (0.08) | 1.01 (0.08) |
| Time Spent | 485 | 60.2 | 0.918 | 2.35 (0.30) | −0.28 (0.04) |
| Given Up | 250 | 31.0 | 0.948 | 3.05 (0.36) | 0.52 (0.05) |
| Physical/Psychological | 293 | 36.4 | 0.882 | 1.89 (0.16) | 0.39 (0.05) |
| Neglect Roles | 203 | 25.2 | 0.934 | 2.66 (0.31) | 0.71 (0.05) |
| Social/Interpersonal | 253 | 31.4 | 0.887 | 1.94 (0.16) | 0.54 (0.05) |
| Hazardous | 189 | 23.4 | 0.808 | 1.38 (0.11) | 0.89 (0.06) |
| B. LCA model fit statistics of 10 of the 11 DSM-5 opioid use disorder criteria among those that used prescripton opioids at least 120 days in the past year. | ||||||||
|---|---|---|---|---|---|---|---|---|
| Model | LL | AIC | BIC | SSABIC | p-Vuong | Entropy | df | Low class % |
| Two-class | −3420,307 | 6930.614 | 7141.758 | 6998.857 | 0.046 | 0.931 | 1001 | 43.5 |
| Three-class | −3103.551 | 6367.102 | 6742.469 | 6488.423 | 0.715 | 0.921 | 990 | 29.0 |
| Four-class | −2956.643 | 6143.286 | 6682.875 | 6317.684 | 0.799 | 0.943 | 975 | 7.4 |
| Five-class | −2878.842 | 6057.684 | 6761.497 | 6285.161 | 0.760 | 0.953 | 965 | 7.3 |
| Six-class | −2760.087 | 5890.174 | 6758.209 | 6170.728 | 0.761 | 0.966 | 954 | 8.4 |
| Seven-class | −2734.234 | 5908.469 | 6940.727 | 6242.100 | 0.755 | 0.967 | 943 | 3.2 |
| Eight-class | −2693.464 | 5896.928 | 7093.410 | 6283.638 | 0.760 | 0.976 | 935 | 1.8 |
Estimated value of n since after de imputation of weights/clusters/strata it is not possible to calculate the exact value of n
DSM-5 Opioid Use Disorder criteria: Tolerance - as defined by either of the following: (a) a need for markedly increased amounts of opioids to achieve Intoxication or desired effect; (b) markedly diminished effect with continued use of the same amount of opioid; Withdrawal - as manifested by either of the following: (a) the characteristic withdrawal syndrome for opioid (refer to Criteria A and B of the criteria sets for withdrawal from alcohol); (b) opioids (or a closely related substance) is used to relieve or avoid withdrawal criteria; Larger/Longer - opioids is often used in larger amounts or over a longer period than was intended; Quit/Control - there is a persistent desire or unsuccessful efforts to cut down or control opioid use; Time Spent - a great deal of time is spent in activities necessary to obtain opioid, use opioid, or recover from its effects; Given Up - important social, occupational, or recreational activities are given up or reduced because of opioid use; Physical/Psychological - alcohol use is continued despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by opioid; Neglect Roles - recurrent opioid use resulting in a failure to fulfill major role obligations at work, school, or home; Social/Interpersonal - continued opioid use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of the opioid; Hazardous Use - recurrent opioid use in situations in which it is physically hazardous. Craving criterion was not included in the present study.
LL = Log-likelihood; AIC = Akaike Information Criteria; BIC = Bayesian Information Criteria; SSABIC = Sample-size adjusted BIC; p-Vuong = p of Vuong-Lo-Mendel-Rubin; df = degrees of freedom; NC = The model did not reach convergence.