Subgroups identified using the Fibromyalgia Impact Questionnaire

Psychological distress is a feature present only in some patients with Fibromyalgia Syndrome (Fibro), and the Fibromyalgia Impact Questionnaire can be used to differentiate these patients from others, according to a recent article from a group of Canadian researchers. [1]

The main goal of the study, by researchers at the Université de Sherbrooke, Canada, was to identify the presence of Fibro subgroups using a simple and frequently used clinical tool, the Fibromyalgia Impact Questionnaire (FIQ). [1]

A total of 61 women diagnosed with Fibro participated in the study and were asked to fill in a FIQ. The researchers also recorded experimental pain, psychosocial functioning and demographic characteristics. [1]

Fibro subgroups were identified by applying a hierarchical cluster analysis on selected items of the FIQ (pain, fatigue, morning tiredness, stiffness, anxiety and depressive symptoms) and group differences were also tested for on experimental pain, psychosocial functioning and demographic characteristics. [1]

The researchers found that two cluster profiles best fit the data: FM-Type I was characterized by the lowest levels of anxiety, depressive and morning tiredness symptoms, while FM-Type II was characterized by elevated levels of pain, fatigue, morning tiredness, stiffness, anxiety and depressive symptoms. Both of the Fibro subgroups showed hyperalgesic responses to experimental pain.

The researchers concluded that:

"These results suggest that pain and stiffness are universal symptoms of the disorder but that psychological distress is a feature present only in some patients."

References:

1. de Souza JB, Goffaux P, Julien N, Potvin S, Charest J, Marchand S. Fibromyalgia subgroups: profiling distinct subgroups using the Fibromyalgia Impact Questionnaire. A preliminary study. Rheumatol Int. 2008 Sep 27. [Epub ahead of print]