[The costs of treatment with the new antidepressants in clinical practice].

Objective: To assess if, in usual clinical practice, the patterns of use of new antidepressant are associated to different health resource utilisation.
Design: Naturalistic, retrospective, observational study.
Setting: Urban health center.
Patients: DSM-IIIR diagnostic criteria of depressive disorder and treatment with a new antidepressant (n = 328).
Interventions: Information on resource utilisation was collected in those patients treated with fluoxetine (FLX), fluvoxamine (FLV) sertraline (SER), paroxetine (PAR) and venlafaxine (VLF). Direct, indirect and total costs were compared according to the different patterns of use (stable therapy, upward dose titration, switching or augmentation) and according to the initially prescribed antidepressant. The follow-up period was 6 months.
Results: Direct and total daily costs of those patients with unestable therapy (upward dose titration, switching or augmentation) were 55% (p < 0.01) and 87% (p = 0.001) higher than for patients with stable therapy, respectively. Patients who initiated therapy on SER, VLF and PAR had 35% (p < 0.05), 80% (p < 0.05) and 37% (p < 0.05), respectively, higher average total costs per day than patients who initiated therapy with FLX. Regarding direct costs, patients who initiated therapy on SER and VLF had 48% (p < 0.001) and 58% (p < 0.05) higher average costs per day than patients who initiated therapy with FLX.
Conclusions: New antidepressants show different patterns of use in a clinical practice setting, being FLX the agent more associated to a stable pattern of use. The pattern of use is associated to different health resource utilisation. Patients under stable therapy show lower health costs than those who need upward titration, switching or augmentation strategies. It is necessary to conduct randomized naturalistic studies to confirm these results.