Lack of understanding in fibromyalgia and rheumatoid arthritis: the Illness Invalidation Inventory (3*I)
- 1Department of Clinical and Health Psychology, Utrecht University, Utrecht, The Netherlands
- 2Department of Psychology, Wayne State University, Detroit, Michigan, USA
- 3Department of Rheumatology, Diakonessenhuis Utrecht, Utrecht, The Netherlands
- 4Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
- Correspondence to Marianne B Kool, Department of Clinical and Health Psychology, Utrecht University, PO Box 80140, 3508 TC Utrecht, The Netherlands;
- Accepted 4 April 2010
- Published Online First 24 May 2010
Background Patients with rheumatic diseases may face ‘discounting’ (denying and patronising) or ‘lack of understanding’ because of having symptoms without external clinical signs, but instruments to assess such invalidation experiences are lacking.
Objectives To develop and evaluate the Illness Invalidation Inventory (3*I), to compare invalidation experiences of two groups of patients who differ in visual signs and laboratory findings—rheumatoid arthritis (RA) and fibromyalgia—and to examine the association of invalidation with health status.
Methods A questionnaire (eight items with respect to five sources: spouse, family, medical professionals, work environment and social services) was constructed. It was completed by 142 patients with RA and 167 patients with fibromyalgia.
Results Principal axis factoring with oblimin rotation yielded two factors with high internal consistency (α>0.70): ‘discounting’ (five items) and ‘lack of understanding’ (three items). Patients with fibromyalgia experienced significantly more discounting and lack of understanding from their family, medical professionals, colleagues and social services than did patients with RA. Both patient groups experienced more invalidation from social services, colleagues and family than from medical professionals and spouses. More discounting and lack of understanding correlated with poorer mental well-being and social functioning in both patient groups. Discounting correlated with more physical disability and pain in patients with RA.
Conclusions The 3*I is a brief, reliable instrument for assessing patients' perceptions of invalidation from different sources, which differ between patient groups and are associated with health status. Future validation research should clarify the clinical impact of invalidation on treatment adherence and outcome.
Funding Dutch Arthritis Association.
Competing interests None.
Ethics approval This study was conducted with the approval of the medical ethics committee of the University Medical Center Utrecht.
Provenance and peer review Not commissioned; externally peer reviewed.