. 2018 Feb 20;6:15. doi: 10.1186/s40425-018-0320-3
© The Author(s). 2018
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Table 1.
The OS grading System
| Grade | OS in days |
|---|---|
| A+ | > 240 |
| A | > 180–240 |
| B | > 120–180 |
| C | 60–120 |
| D | < 60 |