Researchers have developed a new tool that can accurately identify patients with chronic migraine (CM).
The screening questionnaire — called the ID-CM — can potentially be used by physicians or by patients themselves.
“The way we imagine it in clinical practice is that someone completes this questionnaire in a physician’s office and it provides a suggestion that the patient may have chronic migraine,” said researcher Dawn Buse, PhD, director of Behavioral Medicine, Montefiore Headache Center, Bronx, New York. “The physician would still go through a careful history and physical and complete the diagnostic criteria.”
“It may be helpful for people living with chronic migraine who don’t realize there’s a term for what they’re living with,” she said. “It might help connect them with specialist health care professionals who can treat them well, and it may help connect them with the right treatment.”
The only treatment approved by the US Food and Drug Administration for chronic migraine, defined as having 15 or more migraine days a month, is onabotulinum toxin A (Botox, Allergan Inc), although patients do use other migraine therapies, including triptans.
Developing the tool took almost 3 years and involved a rigorous multistep process. The research team reviewed existing instruments, sought input and consensus from headache physicians and research scientists from around the world, and had a group of people with CM assess the relevance of the questions being developed.
Another important step in the development process was psychometric validation. “This is where we look at someone with chronic migraine, someone with episodic migraine, and someone with no headache and see how well a particular item (for example, whether the pain is pulsating or how often the pain is severe) identifies or separates the different groups,” explained Dr. Buse.
As well, headache experts used a semi-structured clinical interview to provide their own diagnosis, which was used as the gold standard. Compared to this gold standard, the screening tool had a sensitivity of 82%, a specificity of 87%, a negative predictive value of 77%, and a positive predictive value of 90%.
Among other things, the final 12-item screening tool asks respondents how often their pain is moderate or severe, how often they’re unusually sensitive to light and sound, how often they feel nauseated or sick to their stomach, and how often they worry about missing work, school, or social events because of headaches.
Despite its substantial economic and quality-of-life burden, chronic migraine remains underdiagnosed and undertreated.
Dr. Buse and her colleagues hope to have the screening tool available in the next month or 2 and are working on a manuscript for possible publication.
Asked to comment, pain expert Lynn Webster, MD, vice president, scientific affairs, PRA Health Sciences, Salt Lake City, Utah, said he thought Dr. Buse’s presentation was “very interesting” and relevant to the average physician who sees many patients with headaches in his or her daily practice.
“An accurate diagnosis is challenging for many physicians and a tool to help make that diagnosis would be welcomed,” said Dr. Webster.
The tool appears to be reasonably accurate and sensitive, “which is always a challenge in developing such tools,” added Dr. Webster.