A Markov model including three health states, divided by pain intensity (absence or presence of mild, moderate or severe pain) and considering three-month cycles; costs and effectiveness were estimated for amitriptyline (50 mg/day), fluoxetine (80 mg/day), duloxetine (120 mg/day), gabapentin (900 mg/day), pregabalin (450 mg/day), tramadol/acetaminophen (150 mg/1300 mg/dia) and amitriptyline/fluoxetine (50 mg/80 mg/dia) for the treatment of FM. The clinical outcome considered was the annual rate of pain control. Probabilities assigned to the model were collected from published literature. Direct medical costs for FM treatment were retrieved from the 2006 data of the Mexican Institute of Social Security (IMSS) databases and were expressed in 2010 Mexican Pesos. Probabilistic sensitivity analyses were conducted.
The best pain control rate was obtained with pregabalin (44.8%), followed by gabapentin (38.1%) and duloxetine (34.2%). The lowest treatment costs were for amitriptyline ($ 9047.01), followed by fluoxetine ($ 10 183.89) and amitriptyline/fluoxetine ($ 10 866.01). By comparing pregabalin vs amitriptyline, additional annual cost per patient for pain control would be around $ 50 000 and $ 75 000 and would result cost-effective in 70%and 80%of all cases.
Among all treatment options for FM, pregabalin achieved the highest pain control and was cost-effective in 80%of patients of the Mexican Public Health System.