Two reviewers will independently assess the suitability
of the preference - based instruments for measuring outcomes in palliative care
using the ISOQOL, minimum standards for patient - reported outcome measures (conceptual and measurement model, reliability, content validity, construct validity, responsiveness, interpretability
of scores, translation
of measure, patient and investigator burden), 43 and the CREATE
checklist (descriptive system, health states values, sampling, preference data collection, study sample, modelling, scoring algorithm).44 The ISOQOL minimum standards were chosen as these standards were developed from a
systematic review
of published and unpublished guidance on patient - reported outcome measures, including the COnsensus - based Standards for the selection
of health Measurement Instruments (COSMIN).46 To the authors» knowledge, the CREATE
checklist is the only published guidance on what key components should be reported in a valuation study.44 Information on how the contents
of the instruments were developed, psychometric properties and valuation will be
used to assess the suitability
of the instruments for the palliative setting; instruments will be scored on whether the domains or dimensions were developed
using input from informal caregivers
of people receiving palliative care (yes / no) and whether each
of the reporting
checklist items has been evaluated for this population (if yes, then a score
of one will be allocated) and a total score calculated.