Number of studies reporting key deployment length and ‘mismatch’ effects
| Post-traumatic stress disorder | General mental health problems | Alcohol | Family-related problems | |
| Deployment-length effect | 222 27 | 322 24 27 | 314 23 27 | 314 24 25 |
| ‘Mismatch’ effect | 114 | 126 | 0 | 126 |
| No effect | 220 21 | 120 | 0 | 0 |