Fluoxetine and dothiepin therapy in primary care and health resource utilization: Evidence from the United Kingdom

We attempted to evaluate differences in healthcare resource utilization following the initiation of antidepressant therapy with dothiepin or fluoxetine in primary care in the United Kingdom, by means of retrospective analysis of data from the Doctors Independent Network (DIN-LINK) records system, with a two-stage, multiple regression adjusted for potential bias stemming from non-random selection of initial drug choice in clinical practice. We counted patients' use of healthcare resources in the year following initiation of antidepressant therapy. After controlling for both observed and unobserved baseline characteristics correlated with initial drug selection, we found that dothiepin patients would have 0.18 additional non-accident and emergency (ACE) admission, 0.007 more ACE admissions, and 1.09 more general referrals than patients who started therapy with fluoxetine. Fluoxetine patients would have 0.35 more prescriptions for the initial antidepressant. Dothiepin patients would make 5.4 fewer visits to GPs' surgery, have 0.2 fewer prescriptions for hypnotic drugs, and 6.5 fewer prescriptions for other drugs than fluoxetine patients. This shows that the total economic impact of initial antidepressant selection is broader than the acquisition costs of antidepressants.