Impact of non-remission of depression on costs and resource utilization: from the COmorbidities and symptoms of DEpression (CODE) study

OBJECTIVE: To determine the economic impact of sustained non-remission of depression on the total annual all-cause healthcare costs of patients with a history of depression. METHODS: Adults with ≥2 claims with depression diagnosis codes from the HealthCore Integrated Research Database were invited to participate in this retrospective/prospective fixed-cohort repeated-measures study. Patients with scores >5 at initial survey and 6 month assessment on the Quick Inventory of Depressive Symptomatology (QIDS-SR) were considered to be in 'sustained non-remission', while those with scores ≤5 at both assessments were considered to be in 'sustained remission'. Patients also completed self-report instruments to assess pain, fatigue, anxiety, sleep difficulty, and other health and wellness domains. Survey data were linked to patient claims (12 month pre- and post-initial-survey periods). After adjusting for demographic and clinical characteristics using propensity scores, post-survey costs and resource utilization were compared between remission and non-remission groups using non-parametric bootstrapping methods. RESULTS: Of the 640 patients who met inclusion criteria, 140 (21.9%) were in sustained remission and 348 (54.5%) never achieved remission. Using propensity-score adjusted costs, sustained non-remission of depression was associated with higher annual healthcare expenditures of >$2300 per patient ($14,627 vs. $12,313, p = 0.0010) compared to remitted patients. Higher costs were associated with greater resource utilization and increased medication use. Non-remitters were prescribed more medications than remitters, including antidepressants and second-generation antipsychotics. Although length of antidepressant exposure over 12 months was similar, remitters were more likely to be adherent to antidepressants. Non-remission was associated with anxiety, pain, fatigue, sleep disruption, diabetes, anemia, obesity, and heavy drinking. CONCLUSION: Failing to achieve remission of depression was associated with increased costs and greater resource utilization. Clinicians should strive to achieve sustained remission in patients with depression. Study limitations included reliance on claims data for initial identification of cohort and high rate of attrition in the analytic sample.