| Quality of information | Satisfactory | Approximate | Insufficient | TOTAL |
| Qualification of informant | ||||
| Surgeon | 36 | 26 | 1 | 63 |
| Anesthetist | 2 | 1 | 3 | 6 |
| Fellowship | 8 | 3 | 0 | 11 |
| Internship | 5 | 3 | 1 | 9 |
| Chief nurse | 2 | 2 | 3 | 7 |
| Unspecified | 1 | 3 | 0 | 4 |
| TOTAL | 54 | 38 | 8 | 100 |