This study aimed to characterize the effects of insomnia treatment adherence on the healthcare utilization and cost burden among insomnia patients with Alzheimer’s disease dementia (AD) and comorbid depression, using real-world data.

Insomnia is associated with worsened clinical outcomes and increased healthcare utilization/cost among AD patients with comorbid depression. This study evaluated the association of insomnia medication adherence with real-world healthcare utilization and cost among AD patients with insomnia and comorbid depression.

A retrospective observational study was conducted on AD patients (diagnosed 1/1/15-12/31/17) with evidence of medically treated insomnia and a depression diagnosis selected from the IBM® MarketScan Commercial and Medicare Supplemental Databases. The first insomnia claim was the index date. Patients were required to have a depression diagnosis within 12 months preceding the index date. Medication possession ratio (MPR) was calculated and used to stratify patients by adherence (adherent: MPR≥0.8). 

A total of 1,306 AD patients receiving insomnia medication were included, of whom N=359 (27.5%) were adherent and N=947 (72.5%) were non-adherent. Baseline depression was common among treatment adherent and non-adherent patients (43.0% vs. 37.0%, n.s.). Among depressed patients, AD patients who were adherent to insomnia medication were less likely to have a claim for inpatient admissions(35.6% vs 45.3%, p=.054), emergency room (ER) services (55.6% vs 64.5%, p<.001), and skilled-nursing services (30.4% vs 42.0%, p=.019) compared to non-adherent. Among those with depression, total combined inpatient and outpatient medical costs were significantly lower among adherent compared to non-adherent patients; (Mean (SD) costs: $23,941($35,960) vs $36,037($48,407); median: $10,575 vs $18,797 (p=0.009).

Depressed AD patients who were adherent to their insomnia medication were less likely to incur high-cost services such as ER services, and skilled-nursing care, and incurred lower healthcare costs. Adherence to insomnia treatment may lower the healthcare burden conferred on AD patients suffering from comorbid insomnia and depression.