Correlation of invalidation with symptom severity and health status in fibromyalgia

Invalidation is a new construct in health psychology, especially in diseases with inherently invisible symptoms such as FM. It can potentially affect both the quality of life and disease severity in patients with FM. This study aimed to investigate the correlation of illness invalidation with health status and symptom severity in FM.

A total of 112 consecutive patients with FM referred to the rheumatology clinic were enrolled. Invalidation was measured by the Illness Invalidation Inventory (3*I). To measure patient status and progress of FM, the Revised Fibromyalgia Impact Questionnaire (FIQR) was used and patients' quality of life was assessed by the 12-item Short Form Health Survey (SF-12). Multiple linear regression analyses were performed and Spearman's correlations were calculated.

All the patients were female and aged between 18 and 61 years. No significant differences in discounting and lack of understanding between various sources of invalidation were found. The strongest correlation was observed between FIQR symptom score and discounting by work (r = 0.519, P < 0.05). Multiple linear regression analyses revealed that only discounting from the spouse significantly predicted FIQR total scores of FM patients [P = 0.03 (CI 0.28, 10.64)].

Discounting correlated more strongly with SF-12 subscales and FIQR domains than did lack of understanding. The current study revealed that active negative social responses and the source of invalidation are important in predicting symptom severity and quality of life in FM.