Characteristics of 105 trials registered in http://ClinicalTrials.gov
| Characteristic | Trials, no. (%) |
| Disease examined | |
| Malignant disease | 45 (43%) |
| Inflammatory bowel disease | 16 (15%) |
| Viral hepatitis | 11 (10%) |
| Gastro-oesophageal reflux disease | 6 (6%) |
| Liver (autoimmune and cirrhosis) | 8 (8%) |
| Other diseases | 19 (18%) |
| Experimental intervention | |
| Drugs | 86 (82%) |
| Surgery | 12 (11%) |
| Other interventions | 7 (7%) |
| Control group intervention | |
| Drugs | 50 (47%) |
| Placebo or no intervention | 40 (38%) |
| Surgery | 10 (10%) |
| Other intervention | 5 (5%) |
| Funding source | |
| Profit | 62 (59%) |
| Non-profit | 38 (36%) |
| Profit and non-profit | 3 (3%) |
| Not reported | 2 (2%) |