The association of neurologists with headache health care utilization and costs.

OBJECTIVE: To determine the association of a neurologist visit with headache health care utilization and costs.
METHODS: Utilizing a large privately insured health care claims database, we identified patients with an incident headache diagnosis (ICD-9 codes 339.xx, 784.0x, 306.81) with at least 5 years follow-up. Patients with a subsequent neurologist visit were matched to controls without a neurologist visit using propensity score matching, accounting for 54 potential confounders and regional variation in neurologist density. Co-primary outcomes were emergency department (ED) visits and hospitalizations for headache. Secondary outcomes were quality measures (abortive, prophylactic, and opioid prescriptions) and costs (total, headache-related, and non-headache-related). Generalized estimating equations assessed differences in longitudinal outcomes between cases and controls.
RESULTS: We identified 28,585 cases and 57,170 controls. ED visits did not differ between cases and controls (p = 0.05). Hospitalizations were more common in cases in year 0-1 (0.2%, 95% confidence interval [CI] 0.2%-0.3% vs 0.01%, 95% CI 0.01%-0.02%; p < 0.01), with minimal differences in subsequent years. Costs (including non-headache-related costs) and high-quality and low-quality medication utilization were higher in cases in the first year and decreased toward control costs in subsequent years with small differences persisting over 5 years. Opioid prescriptions increased over time in both cases and controls.
CONCLUSION: Compared with those without a neurologist, headache patients who visit neurologists had a transient increase in hospitalizations, but the same ED utilization. Confounding by severity is the most likely explanation given the non-headache-related cost trajectory. Claims-based risk adjustment will likely underestimate disease severity of headache patients seen by neurologists.