Healthcare Resource Use and Cost Associated with Negative Symptoms of Schizophrenia
Authors: Basumallik Soumak , Semwal Monika , Afolabi Mosadoluwa , Aweh Gideon , Han Sherry , Tocco Michael , Kulkarni Amit , Dembek Carole 
Published: January 2025

Introduction

Schizophrenia is a chronic neurodevelopmental disorder characterized by positive, negative, and cognitive symptoms. While current antipsychotic (AP) medications are generally effective in treating positive symptoms, they don’t effectively manage the negative symptoms of schizophrenia (NSS). This study examined the healthcare resource utilization (HCRU) and cost among patients with NSS in the United States.

Methods

This retrospective longitudinal observational study utilized de-identified administrative claims data from STATinMED RWD Insights (01/01/2016-09/30/2022). Study sample included patients with schizophrenia identified using ICD-10-CM: F20.XX, diagnosed with NSS (cases; ICD-10-CM: F20.5; index=first NSS diagnosis) or not (controls; random date assigned as index); identification period: 01/01/2017-09/30/2021. Patients were 13 years or older at index, had 12-month of continuous capture data pre-(baseline) and post-(follow-up) index date, and had evidence of AP use at baseline. Outcomes were prevalence of NSS, mental health (MH)-related, schizophrenia-related, and all-cause HCRU and costs per patient per year (PPPY). Patients’ demographic, clinical characteristics, and other psychiatry and neurodevelopmental comorbidities were assessed at baseline. Unadjusted and Inverse Proportional Treatment Weighted (IPTW) comparison were conducted for baseline characteristics and outcomes followed by Generalized Linear Models (GLMs) for HCRU and costs.

Results

The final study sample had 5,691 NSS and 236,895 non-NSS patients. Prevalence rate of NSS was estimated at 24.66 per 1000 patients of Schizophrenia. Patients with NSS were significantly older (mean: 50 vs 48 years), less commercially insured (10% vs 15%), and had greater comorbidities including alcohol abuse (12% vs 8%), depression (30% vs 24%), diabetes without chronic complications (22% vs 17%), drug abuse (21% vs 16%), uncomplicated hypertension (41% vs 32%), and psychoses (80% vs 58%); all p-values<0.001. After controlling for baseline characteristics, patients with NSS had significantly higher all-cause inpatient admissions (mean: 5.2 vs 4.2), outpatient emergency room (ER) visits (mean: 2.8 vs 2.0), inpatient stay costs ($23,830 vs $20,669), outpatient ER visit costs ($1,738 vs $1,167.20) and less prescriptions (mean: 49.2 vs 51.4); all p-values<0.05. GLM analysis also showed patients with NSS had significantly higher all-cause inpatient admissions (mean: 4.8 vs 3.7), number of outpatient visits (mean: 14.3 vs 13.8), and inpatient stay costs ($20,853 vs $17,809); all p-values<0.05. MH- and schizophrenia-related HCRU and costs PPPY were consistent with all-cause HCRU and cost results.

Conclusions

Patients with predominant NSS had higher HCRU and healthcare costs compared to patients without predominant NSS. New therapies that improve negative symptoms may reduce the burden of schizophrenia.

Funding

Sumitomo Pharma America (formerly Sunovion Pharmaceuticals Inc).