Depression and fibromyalgia: treatment and cost when diagnosed separately or concurrently

Depression and fibromyalgia (FM) are often coincident. Both syndromes share common symptoms and impose significant economic burdens. This study compared claims for treatment and costs of FM plus depression with those for FM or depression alone.

Administrative claims data from a national Fortune 100 manufacturer were used to identify 3 mutually exclusive patient cohorts based on claims with a diagnosis for: FM only, depression only, and FM plus depression. A fourth cohort comprised a random sample of 10% of the employer's overall beneficiary population. Cohorts were compared for demographics, comorbid conditions, and healthcare resources utilization. Mean direct (treatment) costs were calculated and indirect (work loss) costs imputed, and these were assessed using Student's t test and Bonferroni adjustments.

Mean annual employer payments (direct plus indirect costs) per patient were 5,163 dollars for FM only, 8,073 dollars for depression only, 11,899 dollars for FM plus depression, and 2,486 dollars for the overall sample. Mean incremental employer payments (i.e., above those for the random sample) per patient with FM plus depression were 9,413 dollars, an amount more than the sum of incremental costs for those with FM or depression alone (8,264 dollars). These costs are consistent with costs of other chronic diseases.

Patients with FM plus depression are high users of healthcare services. As in studies that established relationships between depression and other medical conditions, incremental costs for patients with FM plus depression were more than additive of costs for each condition alone.