Quality score of prospective studies, individual items and total score
| Item (weight)3-150 | Canivet29 | Høgdal32 | Rubin35 | Michelsson28 | Rautava37 | Rinne41 | Lehtonen33 | Hide34 |
| Drop out | ||||||||
| Selection: % not included <20% (1) | − | + | + | ? | + | ? | − | ? |
| Follow up: loss to follow up <20% (1)3-151 | − | + | + | ? | + | + | − | ? |
| Diagnosis—definition sufficient (1) | + | + | − | + | − | + | + | − |
| Outcome (method) | ||||||||
| Diary during at least 7 days (2) | + | − | − | − | − | − | − | − |
| Diary less than 7 days (1) | − | − | − | + | − | − | − | − |
| Other method (0) | − | + | + | − | + | + | + | + |
| Outcome (timing) | ||||||||
| Multiple measurement periods (2) | + | + | + | − | − | − | − | + |
| Single measurement period (0) | − | − | − | + | + | + | + | − |
| Total quality score (0–6) | 4 | 4 | 3 | 2 | 2 | 2 | 1 | 0 |