PMH11 Quantifying the Real-World Economic Burden of Major Depressive Disorder and Treatment-Resistant Depression in England: National and Regional Estimates

Abstract

Treatment-Resistant Depression (TRD) refers to a subtype of Major Depressive Disorder (MDD), an episodic psychiatric illness, in which patients have not responded to at least two successive antidepressant treatments in a single episode. This research assessed healthcare resource utilisation (HCRU) and direct healthcare costs associated with MDD and TRD in England, of which limited data currently exist, particularly by geographic region. Adult patients (aged 18yrs+) were indexed on first antidepressant prescription, requiring MDD diagnosis (Read/ICD-10 code) within 90 days, from Jan 2011-May 2015 using linked primary, secondary and specialist mental healthcare data in England from the Clinical Practice Research Datalink (Protocol: 19_019R). Failure of 2+ adequate oral antidepressant regimens within the index episode (i.e. substitution, addition or augmentation of antidepressant treatments) constituted TRD. HCRU/cost outcomes (primary care, medication, outpatient, inpatient) were assessed from indexing by treatment resistance and region. 40,686 patients with MDD were included (mean age 43yrs, 62% female); 1,301 (3%) were classified as TRD during follow-up (median follow-up: TRD 40mths, non-treatment-resistant MDD 28mths). Mean total healthcare costs per-patient [per-patient per-month] of £2,650 [£113] observed for non-treatment-resistant MDD (range: East Midlands £1,101 [£76], South East Coast £3,065 [£119]) and £4,715 [£121] observed for TRD (range: East Midlands £2,170 [£79], North East £5,784 [£166]). Total costs were primarily driven by inpatient stays (non-treatment-resistant MDD: £1,368 [£61] vs. TRD: £2,259 [£59]) and primary care visits (non-treatment-resistant MDD: £786 [£32] vs. TRD: £1,431 [£37]), with similar regional trends. Total direct healthcare costs were numerically higher for TRD compared with non-treatment-resistant MDD, with substantial geographical variations. Inpatient stays and primary care visits accounted for ≈80% of all costs; outpatient costs were negligible in comparison. Further research in a larger sample of patients with TRD is warranted to fully understand regional differences observed, and to explore reasons for these differences.