Flow of shoulder disorders (cases) during the three sampling rounds: baseline (R1), 1 year follow up (R2), and 2 years follow up (R3)
| R1 | R2 | R3 | n | |
| Remained case | C | C | C | 6 |
| C | C | M | 4 | |
| C | M | C | 6 | |
| 16 | ||||
| Case to non-case | C | C | NC | 2 |
| C | NC | NC | 4 | |
| C | M | NC | 3 | |
| C | NC | M | 3 | |
| 12 | ||||
| Remained non-case | NC | NC | NC | 78 |
| NC | NC | M | 38 | |
| NC | M | NC | 16 | |
| 132 | ||||
| Non-case to case | NC | NC | C | 6 |
| NC | C | C | 4 | |
| NC | M | C | 3 | |
| NC | C | M | 5 | |
| 18 | ||||
| Missing | C | M | M | 12 |
| NC | M | M | 48 | |
| 60 |
C=case; NC=non-case; M=missing.