Review eligibility criteria checklist
| Study design | Cohort studies (retrospective and prospective) Case–control and nested case–control studies Cross-sectional studies |
| Study characteristics | Full articles Reference lists of any recent review article Eligible manuscript identified by the database search |
| Participants | Adult aged ≥18 years High user of healthcare Accrue high healthcare costs Presence of Medically unexplained symptoms (MUS) |
| Comparator | Non-high cost and non-high users of healthcare |
| Outcome | Prevalence of MUS Patient characteristics and context associated with high service usage/costs among patients with MUS Magnitude of cost or use of healthcare associated with the presence of MUS |