NEW ORLEANS—The median length of time from when patients contacted a health care professional until they were diagnosed with narcolepsy was 22 months, while 44% of patients were diagnosed within one year and 18% were diagnosed more than five years after symptom onset, according to research presented at the 2013 Annual Meeting of the American Neurological Association.
About 67% of patients were evaluated by multiple physicians before being diagnosed with narcolepsy. In addition, 85% of patients were rated as having moderate to severe symptoms at their initial visit, and these symptoms often interfered with daytime functioning, reported Christine Acebo, PhD, Medical Scientist at Jazz Pharmaceuticals in Palo Alto, California, and colleagues.
“Even though many of these patients had pathologic hypersomnia and other characteristic symptoms of narcolepsy as well as health insurance, [the patients] often had remarkably long and variable paths to receiving a diagnosis of narcolepsy,” stated Dr. Acebo, who is also an Adjunct Assistant Professor of Psychiatry and Human Behavior at the Warren Alpert Medical School of Brown University in Providence, Rhode Island.
Journey to a Narcolepsy Diagnosis
The researchers conducted a physician survey and chart review to analyze how patients were ultimately diagnosed with narcolepsy. A total of 77 physicians in neurology, pulmonology, psychiatry, and other areas reviewed 252 patient charts for the survey. About 55% of patients were men (median age, 38), and 67% were white. At least half of the patients were obese, and two-thirds had a comorbid disorder, with psychiatric and metabolic comorbidities the most frequent.
According to the researchers, 67% of patients were referred to the respondent physician by another physician or health care provider, and 76% were referred by their primary care physician. The respondent physician diagnosed narcolepsy in 72% of cases in which a patient was referred; in 28% of referrals, the referring provider had made the diagnosis. The most common reason for referral was excessive daytime sleepiness (occurring in 87% of such cases), followed by trouble staying awake during the day (in 39%).
The most common symptom at initial presentation was excessive daytime sleepiness, occurring in 90% of patients; more than 40% had trouble staying awake or functioning during the day, and 26% had difficulties with activities of daily living. About 85% of patients were rated as having moderate or severe symptoms at their initial visit, with more than one-third having severe symptoms.
A High Rate of Misdiagnosis
The investigators reported that misdiagnoses occurred in 60% of patients. The most common misdiagnoses were depression (31%), insomnia (20%), and obstructive sleep apnea (13%). About 67% of participants had been observed by multiple providers before being diagnosed with narcolepsy.
Dr. Acebo stated that “even among the physicians who made the diagnosis, patients were frequently seen multiple times—only 51% were diagnosed by the respondent physician at the first visit. Many patients experienced a substantial delay from their report of the onset of their symptoms to receiving a diagnosis of narcolepsy.”
“The presence of comorbid conditions, some with symptoms overlapping with narcolepsy, likely increased the complexity of making a diagnosis and resulted in more than 50% of patients being misdiagnosed prior to receiving a narcolepsy diagnosis,” the investigators concluded. “Taken together, these data highlight the need for increased awareness and timely diagnosis of the signs and symptoms of narcolepsy.”
—Colby Stong