The analysis of the first interview characterized the individual center profiles. The survey revealed that in 2017/2018, 94.5% of the patients treated by a headache specialist have been referred by a healthcare professional and only 15.7% of these patients were then referred back to their allocator or another center. For more than a quarter (28.2%) of the migraine patients medical care was provided by joint treatment by the allocating physician and the headache specialist (Fig. 1).
More than two thirds of the patients (68.6%) that were referred to headache specialists were referred by a general practitioner and every tenth patient (9.9%) by another neurologist. Referral by other health care professionals account for only 20.9% of the remaining referrals (Fig. 2).
Altogether, 41.6% of the migraine patients at headache specialists were receiving a prophylactic migraine treatment during that time (Fig. S1, supplementary information). 17.9% of their patients had discontinued and stopped treatment with a migraine prophylaxis.
About half (53.1%) of the patients receiving a prophylactic treatment were on their first medication, one third (31.8%) on their second medication, and one sixth (16.6%) on their third prophylactic migraine treatment (Fig. 3).
More than half of the physicians (58.0%) considered frequency and intensity of migraine attacks as the most important factors influencing their decision to initiate prophylactic migraine treatment. Impairment of quality of life (33.6%) and prior or concomitant diseases (28.6) were also considered as important by some of the physicians. Other factors like the patient wish or an insufficient response to acute treatment seem to play subordinate roles (Fig. 4A).
For the choice among the established prophylactic migraine treatments in 2017/2018, more than half (52.1%) of the physicians considered prior or concomitant diseases and the physical constitution of the patient as key factors. However, about one quarter to one third of the physicians stated also patient preferences and patient circumstances (33.6%), adverse events and interactions (27.7%), demographics (26.1%) and prior or concomitant medications (24.4%) as important factors for their choice of a particular prophylactic treatment (Fig. 4B).
Overall, most of the patients received beta-blockers (45.5%), while 28.1% received anticonvulsants and 17.0% antidepressants as first prophylactic treatment. If the first prophylactic treatment was insufficient and considered a so-called treatment failure, these particular medications were used in different sequences as second or third prophylactic treatment. With increasing number of prophylactic treatment failures, the proportion of patients receiving calcium antagonists increased approximately 2-fold from first (6.0%) to third prophylactic treatment (12.8%). In line with this, the proportion of patients receiving other prophylactic treatments, like botulinum toxin increased substantially with increasing number of prophylactic treatment failures and was almost ten-fold higher after failure of the third prophylactic treatment compared to end of the first prophylactic option (2.0% vs. 19.8%) (Fig. 5).
Upon discontinuation of the first migraine prophylaxis, 42.9% of the patients switched substance class, 34.4% switched to acute therapy alone and only 23.2% switched to another drug within substance class. The more prophylactic treatments fail, the lower the proportion of patients receiving drugs of the same substance class. Compared to first prophylactic treatment, there was a more than 50% decrease in the proportion of patients receiving a different drug from a certain substance class after discontinuation of third prophylactic treatment (23.2% vs. 10.3%). Conversely, the proportion of patients switching acute therapy alone steadily increased with increasing number of prophylactic migraine treatment failures, i.e. from 34.4% after end of first, up to 42.5% after end of third prophylactic migraine treatment. Summarizing, whereas after discontinuation of first prophylactic migraine treatment, switch of substance class seems to be the method of choice, it is rather switching to acute therapy after discontinuing the third prophylactic treatment (Fig. 6).
The majority of the surveyed physicians considered prophylactic treatment options available before monoclonal antibodies targeting the CGRP pathway came onto the market, as not sufficient. In this regard in 2017/2018, over 90.7% of the participating physicians stated a high to very high need for novel prophylactic migraine treatments including monoclonal antibodies (Fig. S2, supplementary information).