TableĀ 1

Phases of development for the ASAS Health Index

IaPreparatoryDevelopment of a pool of items representing the categories of the Comprehensive ICF Core Set for ASLinkage of various assessment tools for functioning and health to ICF categories
IbPatient meetingPatient preference and weighting of the items per ICF categoryRelative weight to each item, patient-distributed 100 points per ICF category.
II1st international cross-sectional surveyItem reduction (within and across ICF categories)Rasch analysis, Spearman's rank correlation coefficient
IIIExpert consultationAgreement on item reductionNominal consensus process
IV2nd international cross-sectional surveyValidation of the draft version and further item reductionTesting psychometric properties
Rasch analysis
VConsensus MeetingAgreement on a final versionNominal consensus process
  • AS, ankylosing spondylitis; ASAS, Assessment of SpondyloArthritis international Society; ICF, International Classification of Functioning, Disability and Health.