The objective of our study was to evaluate diagnostic delay in patients with headaches. A high number of patients referred to us have chronic migraine (CM) and medication overuse headache (MOH). We wanted to see how many of these patients had not been previously diagnosed, who else they had seen for evaluation and what treatment they had received.

All new patients referred to our university headache clinic complete a detailed patient intake questionnaire prior to their first visit. Clinicians diagnose headache disorders using the International Classification of Headache Disorders 3 (ICHD-3) diagnostic criteria. After this patients are seen face-to-face by the headache providers, who perform a full evaluation, enter a formal diagnosis according to ICHD-3 and note whether this diagnosis had previously been established. 

Out of total N=1,765, 73% (N=1296) of patients presenting to headache clinic have diagnostic delay. The most common were CM and MOH, which had never been previously diagnosed despite over half (52%) of these patients having previously seen a neurologist. More than 68% of MOH and CM patients were not taking preventive medications at the time of evaluation, and less than 24% had a prior adequate trial of them. Over a 3-month period, many individuals with CM missed work due to headache.

Delayed diagnosis means delayed treatment. Most patients in our sample had a diagnostic delay of many years. Emphasis needs to be placed on accurate diagnosis using Classification of Headache Disorders 3 (ICHD-3) diagnostic criteria criteria to guide optimal treatment selection. Accurate records of headache days and medication use are needed for the diagnosis of CM and MOH.