(P-321) Epidemiology of Treatment Resistant Depression in the US

Location: Poster Gallery-Disease Epidemiology/Clinical Course

Presenting Author(s)

XL

Xinyue Liu

Epidemiologist
Merck & Co., Inc.
West Point, Pennsylvania, United States

Co-Author(s)

YM

Yuki Mukai

Global Clinical Development, Merck & Co., Inc., New Jersey, United States
CF

Christ Furtek

Clinical Sciences and Study Management, Merck & Co., Inc., Pennsylvania, United States
Edward A. Bortnichak, MPH, PhD

Merck & Co., Inc.
West Point, Pennsylvania, United States
KL

Kai-Li Liaw

Pharmacoepidemiology, Center for Observational and Real-World Evidence (CORE), Merck & Co., Inc., Pennsylvania, United States
WZ

Wenjun Zhong

Merck & Co., Inc.
Titusville, New Jersey, United States

Background: The prevalence of treatment resistant depression (TRD) among pharmaceutically treated depression (PTD) patients varies greatly in publications due to different definitions of TRD and different study populations.

Objectives: The aim of this study is to estimate the prevalence of TRD using two large claims databases in the US.

Methods: This is a cross-sectional study in 2018 Humana and Optum databases. Patients aged >= 18 years and having at least one outpatient or inpatient diagnosis of major depressive disorder (MDD) and one prescription of antidepressant filled in 2018 were identified as having PTD. Among patients with PTD, TRD was defined as the treatment failure of at least two antidepressants (can be either monotherapy or adjunctive) with >= 4 weeks of treatment for each antidepressant. We estimated the prevalence of TRD among patients with PTD and calculated age- and gender- standardized TRD prevalence using 2010 US census data. We then used logistic regression to estimate if TRD risk varies by age, sex, race, and geographic region after controlling for other variables. Finally, we described the timeline of TRD development in patients with incident PTD in 2018 (defined as no antidepressant use prior to index date).

Results: We identified 296,055 and 277,941 patients with PTD in Humana and Optum databases, respectively; among whom 17,640 (6.0%) and 13,959 (5.8%) patients had TRD. After age- and sex- standardization, TRD prevalence among PTD patients was 6.8% (95%CI: 6.7%-6.9%) in Humana vs. 5.8% (95%CI: 5.7%-5.9%) in Optum, respectively. Females, middle-aged adults, Whites had higher risk of TRD to a varying degree. The median time from index antidepressant use to TRD was about six months in incident PTD patients.

Conclusions: The prevalence of TRD among patients with PTD was comparable in the two databases. TRD prevalence varies by age, sex, and race with a higher prevalence in females and in the age group of 45-64. However, the absolute differences were small.