Variations in outcome measures with different sampling frequencies
| Sample | Sample every | Sample every | |
|---|---|---|---|
| Weekly | 2 weeks | 4 weeks | |
| Number of completed questionnaires | 4469 | 2244 | 1124 |
| Number of health problems identified | 617 | 428 | 294 |
| Illnesses | 329 | 216 | 132 |
| Injuries | 288 | 212 | 162 |
| Number of substantial problems | 320 | 220 | 131 |
| Illnesses | 198 | 129 | 71 |
| Injuries | 122 | 91 | 60 |
| Average prevalence (all health problems) | 36 (34–38) | 36 (34–38) | 37 (34–40) |
| Average prevalence (substantial) | 15 (14–16) | 16 (14–17) | 16 (14–17) |
| Average weekly severity score | 40 (38–42) | 40 (38–42) | 38 (35–41) |
| Average cumulative severity score | 114 (96–132) | 83 (71–95) | 60 (51–69) |
| Average duration of problems (weeks) | 3 (3–3) | 2 (2–2) | 2 (1–2) |