To investigate the strength of chronic fatigue syndrome (CFS) patients' negative illness perceptions by comparing illness perceptions and self-reported disability in patients with CFS and rheumatoid arthritis (RA).
Seventy-four RA patients and 49 CFS patients completed the Illness Perception Questionnaire-Revised and the 36-item Short-Form Health Survey.
When compared to the RA group, the CFS group attributed a wider range of everyday somatic symptoms to their illness, perceived the consequences of their illness to be more profound and were more likely to attribute their illness to a virus or immune system dysfunction. Both groups reported equivalent levels of physical disability but the CFS group reported significantly higher levels of role and social disability.
Although the symptoms of CFS are largely medically unexplained, CFS patients have more negative views about their symptoms and the impact that these have had on their lives than do patients with a clearly defined and potentially disabling medical condition. The data support the cognitive behavioural models of CFS that emphasise the importance of patients' illness perceptions in perpetuating this disorder.