Table 1.

Quality assessment criteria.

Category	Description
C1. Sample	Are details provided about the total population who are eligible to take part during the study period in enough detail that a response rate can be calculated?
C2. Valid measure	Is the measure valid for the included population, i.e., has been validated for the age and there is a valid translation available if used outside of the language it was originally developed?
C3. Purpose	Is it clear what the PROM measures?
C4. Domains	If the PROM is known to have domain scores, have these been accurately reported?
C5. Scoring	Have details of how the total and/or domain score are interpreted?
C6. Administration	Are details of the administration of the PROM included; as a minimum this needs to state the mode (interview, postal, or online)?
C7. Missing data	Have statistical approaches for dealing with missing data been explicitly stated?
C8. Nonparticipants	Has a comparison been made between those who participated and those who refused?