| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | patients who have [verb] | 48 |
|
| 2 | patients who have [vb pp] | 47 |
|
| 3 | patients who have had | 16 |
|
| 4 | patients who have have | 16 |
|
| 5 | patients who have undergone | 6 |
|
| 6 | patients who have undergo | 6 |
|
