Co-morbidity and physician use in fibromyalgia

To describe comorbidity in women with FM, and to examine the effects of different types of comorbidity on physician use.

Women (n = 180) with primary FM were evaluated at baseline and 6 months later for self-reported health resource use and covariates. Reported comorbidity was classified into 4 categories: medical, psychiatric, "functional", and unknown. The category for "functional" conditions included disorders that have been classified by previous authors as medically unexplained symptoms such as the irritable bowel and chronic fatigue syndromes. Logistic regression models were developed to examine associations between types of comorbidity and physician use.

Comorbid conditions were reported by over 90% of the sample. Total number of comorbid complaints was associated with high number of physician visits. In logistic regression models (controlling for age, ethnicity, education, disability, pain, and psychological vulnerability) medical comorbidity was a much stronger determinant of high number of physician visits than was "functional" comorbidity.

Comorbidity with other disorders, both functional and medical, was high in this sample. Medical and psychiatric comorbidity were stronger determinants of high physician use than "functional" comorbidity.