Background: Major depressive disorder is a prevalent psychiatric disorder in primary care associated with impaired patient functioning and well-being. We compared patient utilities for hypothetical depression-related and current health states and to examine differences in utilities by patient demographic and clinical characteristics.
Methods: Seventy patients with DSM-III-R major depressive disorder or dysthymia who completed at least 8 weeks of antidepressant treatment were recruited from primary care practices. Patients assessments included the Hamilton Depression Rating Scale (HDRS), SF-36 Health Survey, and standard gamble interviews to obtain utilities for 11 hypothetical depression-related states, varying depression severity and antidepressant treatment, and the patient's current health state.
Results: The mean utility for severe depression was 0.30 and 25% of patients rated this state as worse than or equivalent to death. Utilities varied from 0.55 to 0.63 for moderate depression, 0.64 to 0.73 for mild depression, and 0.72 to 0.83 for antidepressant maintenance therapy. Statistically significant differences were observed in mean utilities by level of disease severity and by tricyclic antidepressants compared with the newer antidepressants (i.e., fluoxetine, nefazodone). There were no significant differences in utilities for hypothetical states by demographic variables. Mean patient-assigned utilities for current health varied by depression severity and presence of medication side effects.
Conclusions: Health state utility scores can be provided by patients with depression and the utility scores provided by patients for hypothetical states demonstrate differences by disease severity and antidepressant treatment.
Limitations: The sample size was small which may limit generalizability and statistical power for detecting important differences. The study findings are limited to patients who have successfully completed 8 weeks of antidepressant treatment.
Clinical relevance: Understanding patient preferences for depression outcomes is important for economic evaluations of new antidepressants and for understanding patient behavior and adherence to antidepressant treatment regimens.