The Impact of Depression and Use of Anti-Depressants on Healthcare Resource Utilization (HCRU) in Multiple Myeloma (MM) Patients

Objectives

Depression and the use of anti-depressants are common co-existing morbidities often encountered by MM patients. Depression among MM patients is estimated at 30-50% versus 7% in the general population (Li HH et al; Blood, 2016).While approximately 11% of the general population >=12 years use antidepressants, the frequency of use in MM patients suffering from depression is unknown. We aimed to better understand real-world frequency of antidepressant use in MM patients in the contemporary era and how their use potentially impacts healthcare resource use (HCRU).

Methods

Newly diagnosed MM patients initiating therapy between 01/01/2013-09/30/2016 were selected from the Inovalon Medical Outcomes Research for Effectiveness and Economics (MORE²) Registry payer claims and remittance dataset containing longitudinal information for 125 million unique covered patient lives, including more than 6 million cancer patients. Depression was ascertained using a combination of ICD9/10-CM, CPT, and HCPCS codes appropriate for behavioral health visits. Antidepressants were identified using National Drug Codes (NDC). Only patients with a diagnosis of depression following the onset of MM treatment were included in this analysis. Patients initiating antidepressants following a depression event (cases) were separated from patients never initiating antidepressants (controls). HCRU was measured from the diagnosis date of depression until the date of last claim and was measured per-patient per-month (PPPM). Patients with polyneuropathy between MM treatment and the medication onset were excluded using ICD9/10-CM codes as antidepressants are sometimes used to treat polyneuropathy. Patients having depression one year prior to initiating MM treatment were also excluded. Patients on anti-depressants were compared to patients never initiating anti-depressants across cost and utilization measures for inpatient, outpatient, office, and ER. P-values for categorical variables were generated using chi-square tests. P-values for continuous variables were calculated using Wilcoxon rank sum test since HCRU measures are often non-normally distributed.

Results

A total of 2,538 MM patients met our inclusion criteria. Depression was diagnosed in 565 patients (22.2%) after beginning a MM treatment. Of these, 129 patients (22.8%) received antidepressants (cases) and 443 patients (78.4%) did not (controls). The average length of follow-up in this cohort was 459.1 days (SD: 331.6). The most common medications prescribed were Sertraline (16.7%), Mirtazapine (15.1%), Duloxetine (12.9%), and Trazodone (12.9%). Compared to controls, cases experienced significantly shorter inpatient stays (mean: 5.02 vs 3.81 for case and control respectively, p-value 0.009). This resulted in lower, but not statistically significant, mean inpatient costs PPPM ($970.58 vs $1873.36). Both groups were otherwise comparable across other cost and utilization outcomes.

Conclusions

Despite 22.2% of MM patients having depression diagnosis post-MM onset, only 22.8% of these patients with depression initiated anti-depressant therapy, resulting in an overall use of 5% of MM patients starting treatment. This is substantially lower than the 11% observed in the general population. The use of antidepressants in this context resulted in a favorable impact on HCRU and underscores the unmet need of proper mental health treatment and education for patients with MM.