Table 5 Test characteristics for ASSIST-FC thresholds, as compared to ASSIST 3.1 problematic use
Substance (prevalence of ASSIST 3.1) | N | Prevalence % | Sensitivity % | Specificity % | Positive predictive value % | Negative predictive value % | Agreement (kappa) |
|---|---|---|---|---|---|---|---|
Tobacco (36.9%) | |||||||
2+ | 1,046 | 42.3 | 99.5 (98.7, 99.8) | 91.2 (89.7, 92.6) | 86.9 (84.7, 88.9) | 99.6 (99.2, 99.9) | 0.88 (0.86, 0.90) |
3+ | 885 | 35.8 | 88.5 (86.3, 90.5) | 95.1 (93.9, 96.1) | 91.4 (89.4, 93.2) | 93.4 (92.1, 94.6) | 0.84 (0.82, 0.86) |
4+ | 641 | 25.9 | 70.1 (67.0, 73.1) | 100 (99.8, 100) | 100 (99.4, 100) | 85.1 (83.4, 86.7) | 0.75 (0.72, 0.78) |
Alcohol (13.1%) | |||||||
5+ | 323 | 13.1 | 64.9 (59.5, 70.1) | 94.8 (93.8, 95.7) | 65.3 (59.9, 70.5) | 94.7 (93.7, 95.6) | 0.60 (0.55, 0.65) |
6+ | 291 | 11.8 | 60.0 (54.4. 65.4) | 95.5 (94.6, 96.4) | 67.0 (61.3, 72.4) | 94.0 (93.4, 95.0) | 0.58 (0.53, 0.63) |
7+ | 152 | 6.1 | 39.7 (34.3, 45.2) | 98.9 (98.4, 99.3) | 84.9 (78.2, 90.2) | 91.6 (90.4, 92.7) | 0.50 (0.44, 0.55) |
Cannabis (10.9%) | |||||||
2+ | 408 | 16.5 | 100 (98.6, 100) | 93.7 (92.6, 94.7) | 65.9 (61.1, 70.5) | 100 (99.8, 100) | 0.76 (0.73, 0.80) |
3+ | 261 | 10.5 | 75.1 (69.5, 80.1) | 97.3 (96.9, 98.0) | 77.4 (71.8, 82.3) | 97.0 (96.2, 97.6) | 0.73 (0.69, 0.78) |
4+ | 148 | 6.0 | 55.0 (48.9, 61.1) | 100 (99.8, 100) | 100 (97.5, 100) | 94.8 (93.8, 95.7) | 0.69 (0.63, 0.73) |
Cannabis (threshold 8+; 6.8%) | |||||||
2+ | 408 | 16.5 | 100 (97.8, 100) | 89.6 (88.3, 90.8) | 41.2 (36.4, 46.1) | 100 (99.8, 100) | 0.54 (0.49, 0.59) |
3+ | 261 | 10.5 | 87.5 (81.5, 92.1) | 95.1 (94.1, 95.9) | 56.3 (50.1, 62.4) | 99.1 (98.6, 99.4) | 0.66 (0.60, 0.71) |
4+ | 148 | 6.0 | 76.8 (69.7, 82.9) | 99.2 (98.7, 99.5) | 87.2 (80.7, 92.1) | 98.3 (97.7, 98.8) | 0.80 (0.75, 0.85) |
Sedatives (3.9%) | |||||||
2+ | 122 | 4.9 | 99.0 (94.3, 100) | 98.9 (98.4, 99.3) | 77.9 (68.5, 84.9) | 100 (99.8, 100) | 0.87 (0.81, 0.91) |
3+ | 85 | 3.4 | 79.2 (69.7, 86.8) | 99.6 (99.3, 99.8) | 89.4 (80.8, 95.0) | 99.2 (98.7, 99.5) | 0.83 (0.77, 0.89) |
4+ | 52 | 2.1 | 54.2 (43.7, 64.4) | 100 (99.8, 100) | 100 (93.2, 100) | 98.2 (97.6, 98.7) | 0.69 (0.60, 0.77) |
Prescription stimulants (3.8%) | |||||||
2+ | 144 | 5.8 | 100 (96.2, 100) | 97.9 (97.2, 98.4) | 65.3 (56.9, 73.0) | 100 (99.8, 100) | 0.78 (0.72, 0.84) |
3+ | 93 | 3.8 | 77.7 (67.9, 85.6) | 99.2 (98.7, 99.5) | 78.5 (68.8, 86.3) | 99.1 (98.7, 99.5) | 0.77 (0.70, 0.83) |
4+ | 55 | 2.2 | 58.5 (47.9, 68.6) | 100 (99.8, 100) | 100 (93.5, 100) | 98.4 (97.8, 98.9) | 0.73 (0.64, 0.81) |
Prescription painkillers (2.6%) | |||||||
2+ | 93 | 3.8 | 98.5 (91.7, 100) | 98.8 (98.3, 99.2) | 68.8 (58.4, 78.0) | 100 (99.8, 100) | 0.80 (0.74, 0.87) |
3+ | 47 | 1.9 | 64.6 (51.8. 76.1) | 99.8 (99.5, 99.9) | 89.4 (76.9, 96.5) | 99.1 (98.6, 99.4) | 0.74 (0.64, 0.83) |
4+ | 31 | 1.3 | 47.7 (35.1, 60.5) | 100 (99.8, 100) | 100 (88.8, 100) | 98.6 (98.1, 99.0) | 0.64 (0.52, 0.75) |