Headaches and Neuroimaging: High Utilization and Costs Despite Guidelines

To the Editor

While most headaches are attributable to benign conditions, patients and physicians are often concerned about intracranial pathology. However, the yield of significant abnormalities on neuroimaging in patients with chronic headaches is 1–3%.^1–3 Given the comparable yield in patients without headaches, multiple guidelines have recommended against routine headache neuroimaging,^4–6 and efforts to improve the efficiency of health care utilization, such as the Choosing Wisely campaign, have identified these tests as a target. However, little is known about recent headache neuroimaging utilization, associated expenditures, and temporal trends in the United States.

Methods

We utilized the National Ambulatory Medical Care Survey (NAMCS), a nationally representative survey that uses a three-stage sampling design (geographic regions, physician practices stratified within specialties, and patient visits within practices) to characterize all outpatient, office-based care in the United States. We analyzed all headache visits for patients ≥ 18 years old identified using the Healthcare Cost and Utilization Project (HCUP) Single-level Clinical Classification System (CCS) (ICD-9CM codes 339.xx, 784.0x, 346.xx, and 307.81). For migraine, ICD-9-CM codes 346.xx were used.

To characterize recent headache neuroimaging utilization, the proportion of headache visits with CT or MRI ordered from 2007–2010 was estimated using descriptive statistics for multiple visit categories: all headache visits, all migraine visits, and visits with a primary diagnosis of headache or migraine. Neuroimaging use (CT or MRI) was directly entered onto the NAMCS survey instrument by physicians or their staff. Neuroimaging payments were determined using the Medicare physician fee schedule. To evaluate for trends over time, we identified headache neuroimaging utilization in years where these tests were directly abstracted onto the NAMCS survey instrument: 1995–2000 and 2005–2010 in all headache visits. Survey weights were applied for all analyses.

Results

Eighty-eight percent of the population was under the age of 65 and 78% was female. Most visits were to primary care physicians (54.8%), followed by neurologists (20%), other specialists (12.9%), and non-primary care generalists (12.4%). Over four years, a total of 51.1 million headache visits were identified including 25.4 million migraine visits. Neuroimaging was obtained in 12.4% (95% CI 10.5–14.7) of all headache visits and 9.8% (95% CI 7.4–12.9) of migraine visits (Table 1). Headache neuroimaging utilization was higher if the headache or migraine diagnosis was listed as the primary diagnosis for the visit. Total neuroimaging expenditures were estimated at $3.9 billion over 4 years including $1.5 billion from migraine visits. Between 1995 and 2010, neuroimaging utilization increased from 5.1% (95% CI (2.7%–7.5%) to 14.7% (95% CI 9.4%–20.0%) of all annual headache visits (Figure 1, p<0.001 for trend).

Table 1.

Neuroimaging utilization and associated costs from 2007–2010 utilizing different definitions of a headache visit

	Total Visits # in millions (95% CI)	MRI % of Visits (95% CI)	CT % of Visits (95% CI)	MRI or CT % of Visits (95% CI)	Imaging Payments Millions USD (95% CI)
All Headache Diagnoses	51.1 (43.2 – 58.9)	7.6% (6.1% – 9.4%)	5.1% (3.7% – 6.9%)	12.4% (10.5% – 14.7%)	3,910 (3,020 – 4,800)
All Migraine Diagnoses	25.4 (19.6 – 31.2)	6.0% (4.4% – 8.2%)	3.8% (2.1% – 6.8%)	9.8% (7.4% – 12.9%)	1,530 (976 – 2,080)
Primary Headache Diagnosis	29.2 (23.8 – 34.6)	10.1% (7.9% – 12.9%)	6.2% (4.2% – 9.0%)	15.9% (13.1% – 19.1%)	2,940 (2,180 – 3,710)
Primary Migraine Diagnosis	16.1 (11.6 – 20.6)	7.2% (4.9% – 10.5%)	4.5% (2.2% – 9.1%)	11.7% (8.4% – 16.0%)	1,160 (670 – 1,660)

USD=United States dollars

Figure 1.

Trends in neuroimaging utilization for the entire headache population from 1995–2000 and 2005–2010.

Discussion

In the United States, neuroimaging is frequently ordered during outpatient headache visits (12%), contributes substantial cost (nearly $1 billion in annual costs), and is increasing over time. Since 2000, multiple guidelines have recommended against routine neuroimaging in patients with headaches because serious intracranial pathology is an uncommon cause.^4–6 Consequently, the magnitude of per-visit neuroimaging use found in this study suggests considerable overuse. Perhaps guidelines have not curbed utilization because patients, as opposed to providers, may be the primary drivers of utilization. If so, efforts such as the Choosing Wisely campaign, which seeks to empower patients with knowledge regarding unwarranted testing, may be more effective than guidelines alone. Requiring pre-authorization of these costly tests and/or value-based insurance designs that shift the cost burden for costly, low yield tests to patients are alternative strategies. Given that headache neuroimaging is common, costly, and likely substantially overused, interventions to curb utilization of these tests have the potential to substantially reduce healthcare expenditures while improving guideline concordance. Therefore, optimizing headache neuroimaging practices should be a major national priority.