| Author, date and country | Patient group | Study type (level of evidence) | Outcomes | Key results | Study weaknesses |
|---|---|---|---|---|---|
| Karhunen PJ et al, 1992, Finland | 82 patients suspected of internal drug carriage | Prospective observational series | Detection of internal drug packages using abdominal radiography | Sensitivity 90% Specificity 97% | Small numbers. No blinding |
| Heirholzer J et al, 1995, Germany | 12 patients suspected of internal drug carriage | Prospective observational series | Detection of internal drug packages | 7 of 12 cases detected | Small study. Questionable gold standard applied |