Objective. To evaluate the use and costs of medical resources before and after a diagnosis of fibromyalgia syndrome (FMS) in a large primary care population in the UK.Methods. We applied an existing data set for medical resource use among patients with a coded diagnosis of FMS. The observed quantities of 157 types of medical resource use before and after the diagnosis of FMS were multiplied by unit costs in order to calculate the cost of care (general practitioner [GP] visits, drugs, referrals, and diagnostics) within the National Health Service, excluding hospital costs. Costs before diagnosis were used in a trend analysis to predict later costs, assuming the diagnosis had never been made, and these predicted costs were compared with the observed costs after diagnosis.Results. Following a diagnosis of FMS, a decrease in costs as compared with the predicted trend was observed. In the 4 years after diagnosis, the average difference between the predicted and observed cost was £66.21 per 6 months per patient. This suggests that making the diagnosis leads to savings and a decrease in resource use. The main effect was observed for tests and imaging (£24.02 per 6 months), followed by pharmaceuticals (£22.27), referrals (£15.56), and GP visits (£4.36).
Conclusion.Failure to diagnose a true case of FMS has its own costs, largely in excess GP visits, investigations, and prescriptions.