Health Care Utilization and Direct Costs Among Patients Diagnosed with Cluster Headache in U.S. Health Care Claims Data

BACKGROUND: Cluster headache (CH) is a rare trigeminal cephalalgia that is associated with extremely painful unilateral headache attacks and autonomic symptoms. Attacks may be episodic or chronic and associated with substantial suffering due to excruciating pain and limited treatment options. Frequent cluster headaches cause substantial burden for patients, resulting in reduced productivity caused by disability, as well as direct costs in some European countries. Less is known, however, about direct costs of recurring health care resource utilization (HCRU) in the United States. OBJECTIVE: To characterize HCRU and direct costs associated with CH in the United States from a third-party payer perspective. METHODS: This retrospective observational study analyzed claims data from the Truven Health Analytics MarketScan Research Databases from 2009-2014. Two cohorts were compared: CH (> 2 diagnostic CH claims) and controls (nonheadache patients). All patients were enrolled continuously for ± 12 months from date of first CH claim. HCRU and direct costs were examined during 12 months post-index as all-cause and CH-specific. Cost and HCRU differences were compared using propensity score-adjusted bin bootstrapping. RESULTS: CH and control cohorts comprised 6,562 and 143,761 patients (aged ≥ 18 years), respectively. Post-index, 36.9% of CH patients versus 16.2% of controls were admitted to the emergency department (ED), and 14.8% versus 6.1% were hospitalized for any reason, respectively (each P < 0.001). CH patients had a 2- to 3-fold significantly greater number of all-cause mean claims for outpatient visits (26.5 vs. 12.4 visits), hospital visits (0.2 vs. 0.1 visits), and ED visits (1.0 vs. 0.3 visits) versus controls (all P < 0.001). The mean number of all-cause visits with reported radiology and laboratory claims was 1.5- to 2.0-fold greater in CH patients versus controls (each P < 0.001). Mean total direct costs for all-cause claims were more than 2-fold greater in post-index ($16,530) for CH patients versus controls ($7,197, P < 0.0001). Similarly, mean direct all-cause costs attributable to outpatient, inpatient, and pharmacy claims were significantly (2-fold) greater; radiology and ED claims were 3- to 4-fold greater among CH patients versus controls (all P < 0.001). However, CH was cited infrequently as a reason for HCRU, indicating that comorbid conditions may substantially increase HCRU in CH patients. The most common reasons for ED admission in CH patients were gastric ulcer with hemorrhage, sub-arachnoid hemorrhage, and headache symptoms. The most common hospital discharge diagnoses for CH patients not observed in top 10 reasons in controls included cerebral artery occlusion/unspecified with cerebral infarction, headache symptoms, syncope/collapse, and diverticulitis. CONCLUSIONS: These findings suggest that, from a payer perspective, CH patients incur significantly higher health care costs versus controls. However, these high costs were not exclusively headache-related. Extrapolating our cost findings to estimated U.S. prevalence rates, approximate total direct cost for CH is greater than $2.8 billion/year.