Screen for medication overuse headache

“Do you take an attack treatment more than 10 days per month?” “Is this intake on a regular basis?”

With these two questions, clinicians at a headache treatment center in France quickly screened and identified patients with medication overuse headache, according to a validation study of the screening questions.

The traditional approach to diagnosis of medication overuse headache involving the revised International Classification of Headache Disorders (ICHD-II) criteria requires a face-to-face interview that takes considerable clinician time and expertise, said at the congress, which is sponsored by the International Headache Society and the American Headache Society.

“In this context, it would be useful to have a tool to screen for medication overuse headache sufferers for clinical studies and for general practitioners.”

Colleagues transformed the second edition ICHD-II criteria into four simplified questions for a patient self-administered screening tool. To determine its sensitivity and specificity, they recruited 79 consecutive patients between September 2009 and February 2010. All participants presented for their first evaluation at the Bordeaux Headache Centre at the University of Bordeaux.

After 2 participants withdrew, 42 patients with medication overuse headache and 35 migraine sufferers without medication overuse were assessed further. Investigators compared their responses to the questions with diagnoses made by headache specialists using the formal ICHD-II criteria.

The initial screen featured four questions. But when the two questions regarding attack treatment frequency and regular use of medications were combined, they had the best sensitivity (95%) and specificity (80%) for identification of medication overuse headache.

“This self-questionnaire is simple, rapid, and easily administered in headache clinics to screen medication overuse headache patients.”

The question, “Do you have headache on 15 days or more per month?” had 81% sensitivity and 85% specificity. A fourth question that asked about headache duration exceeding 3 months had 98% sensitivity but a specificity of only 18%. Therefore, this item was dropped for insufficient discrimination between medication overuse and other types of headache.

Participants included both men and women aged 18 years or older with a normal clinical examination. They had no primary headache type other than migraine. Mean age was significantly higher in the medication overuse headache cohort at 47 years, compared with a mean of 37 year in the migraine cohort. Both groups consisted mostly of women: 81% with medication overuse headache and 63% with migraine.

The self-questionnaire and neurologic diagnosis were performed independently on the same day. A nurse unaware of the neurologic diagnosis supervised patients but offered no help on the questionnaire. The neurologist was blinded to the results of the patient questionnaire.

The results concur with a previous study by other researchers that showed a sensitivity of 75% and specificity of 100% for medication overuse headache diagnosis when patients reported a headache more than 15 days/month and intake of medication 4 or more days/week.

It is important to screen for medication overuse headaches because they impair quality of life for patients and lead to increased disability and decreased productivity. These headaches also are common, affecting an estimated 0.9%-1.8% of the general population and up to 80% of patients referred to a headache center for specialty care.

She believes asking these two questions will prove an effective screening method for patients seen in a primary care setting as well.