Overview of the results
| Employment status | Absenteeism | Presenteeism | |
|---|---|---|---|
| Uncontrolled cohorts | N=3 | N=4 | N=4 |
| Positive results | 4 studies25–28 | 3 studies24 25 27 | |
| Conflicting results | 1 study23 | 1 study28 | |
| Negative results | 2 studies26 28 | ||
| Controlled cohorts | N=6 | N=2 | N=1 |
| Positive results | 2 studies31 34 | 2 studies30 32 | |
| Conflicting results | 1 study29 | 1 study30 | |
| Negative results | 3 studies4 32 33 | ||
| RCTs studies | N=5 | N=4 | N=4 |
| Positive results | 2 studies35 39 | 4 studies35 38–40 | 3 studies35 36 38 |
| Conflicting results | 1 study37 | 1 study39 | |
| Negative results | 2 studies36 40 | ||
| RCTs, randomised controlled trials. | |||