Characteristics of studies that met the inclusion criteria
| Study design | No of articles n (%) | No of patients N (%) |
| Case reports | 157 (88.7) | 219 (37.1) |
| Retrospective cohort studies | 10 (5.6) | 254 (43.1) |
| Prospective cohort studies | 5 (2.8) | 44 (7.5) |
| Case–control studies | 3 (1.7) | 36 (6.1) |
| Cross-sectional study | 1 (0.6) | 27 (4.6) |
| Prospective uncontrolled study | 1 (0.6) | 10 (1.7) |
| Total | 177 (100) | 590 (100) |