Self-reported ATS use compared to urine toxicology results by age group | |||
Age 16-18 years | Urine toxicology results (n) | ||
 |  | Positive | Negative |
Self-reported use (n) | Yes | 2 | 1 |
 | No | 0 | 8 |
 |  |  | 95% CI |
Sensitivity (%) | 100 |  | −− |
Specificity (%) | 88.9 |  | 68.4–100 |
Positive predictive value (%) | 66.7 |  | 13.3–100 |
Negative predictive value (%) | 100 |  | −− |
Age 19-24 years | Urine toxicology results (n) | ||
 |  | Positive | Negative |
Self-reported use (n) | Yes | 5 | 3 |
 | No | 2 | 52 |
 |  |  | 95% CI |
Sensitivity (%) | 71.4 |  | 38.3–100 |
Specificity (%) | 94.6 |  | 88.5–100 |
Positive predictive value (%) | 62.5 |  | 29.0–96.0 |
Negative predictive value (%) | 96.3 |  | 91.3–100 |
Age 25-29 years | Urine toxicology results (n) | ||
 |  | Positive | Negative |
Self-reported use (n) | Yes | 18 | 2 |
 | No | 1 | 106 |
 |  |  | 95% CI |
Sensitivity (%) | 94.7 |  | 84.7–100 |
Specificity (%) | 98.2 |  | 95.6–100 |
Positive predictive value (%) | 90.0 |  | 76.9–100 |
Negative predictive value (%) | 99.1 |  | 97.2–100 |
Self-reported ATS use compared to urine toxicology results by HIV status | |||
HIV positive | Urine toxicology results (n) | ||
 |  | Positive | Negative |
Self-reported use (n) | Yes | 9 | 2 |
 | No | 1 | 21 |
 |  |  | 95% CI |
Sensitivity (%) | 90.0 |  | 71.4–100 |
Specificity (%) | 91.3 |  | 79.8–100 |
Positive predictive value (%) | 81.8 |  | 59.0–100 |
Negative predictive value (%) | 95.5 |  | 86.8–100 |
HIV negative | Urine toxicology results (n) | ||
 |  | Positive | Negative |
Self-reported use (n) | Yes | 16 | 4 |
 | No | 2 | 145 |
 |  |  | 95% CI |
Sensitivity (%) | 88.9 |  | 74.4–100 |
Specificity (%) | 97.3 |  | 94.7–99.9 |
Positive predictive value (%) | 80.0 |  | 62.5–97.5 |
Negative predictive value (%) | 98.6 |  | 96.8–100 |
Self-reported ATS use compared to urine toxicology results by type of sex work setting | |||
Entertainment and/or service | Urine toxicology results (n) | ||
 |  | Positive | Negative |
Self-reported use (n) | Yes | 3 | 3 |
 | No | 2 | 131 |
 |  |  | 95% CI |
Sensitivity (%) | 60.0 |  | 17.1–100 |
Specificity (%) | 97.8 |  | 95.3–100 |
Positive predictive value (%) | 50.0 |  | 10.0–90.0 |
Negative predictive value (%) | 98.5 |  | 96.4–100 |
Freelance and/or brothel | Urine toxicology results (n) | ||
 |  | Positive | Negative |
Self-reported use (n) | Yes | 22 | 3 |
 | No | 1 | 35 |
 |  |  | 95% CI |
Sensitivity (%) | 95.7 |  | 87.3–100 |
Specificity (%) | 92.1 |  | 82.5–100 |
Positive predictive value (%) | 88.0 |  | 75.2–100 |
Negative predictive value (%) | 97.2 |  | 91.9–100 |