Botulinum toxin type A for chronic migraine: 24 month predicted versus actual analysis
Page last updated: 27 October 2017
Drug utilisation sub-committee (DUSC)
June 2017
Abstract
Purpose
To compare the predicted and actual utilisation of botulinum toxin type A (Botox®) for chronic migraine in adults since it was PBS listed for this indication in March 2014.
Current PBS restriction for chronic migraine
Authority required (Streamlined)
Patients must have experienced an average of 15 or more headache days per month, with at least 8 days of migraine, over a period of at least 6 months, prior to commencement of treatment with botulinum toxin type A neurotoxin, AND;
Patients must have experienced an inadequate response, intolerance or a contraindication to at least three prophylactic migraine medications prior to commencement of treatment with botulinum toxin type A neurotoxin (prophylactic migraine medications are propranolol, amitriptyline, methysergide, pizotifen, cyproheptadine or topiramate) AND;
Patients must be appropriately managed by his or her practitioner for medication overuse headache, prior to initiation of treatment with botulinum toxin AND;
Patients must be aged 18 years or older and must be treated by a neurologist.
Patients must have achieved and maintained a 50% or greater reduction from baseline in the number of headache days per month after two treatment cycles (each of 12 weeks duration) in order to be eligible for continuing PBS-subsidised treatment.
Botoxâis the only botulinum toxin type A preparation PBS subsidised for chronic migraine. For brevity the term ‘botulinum toxin’ is used throughout this report.
Data Sources
Data to assess utilisation of botulinum toxin for chronic migraine was obtained from three sources:
- Department of Human Services (DHS) - Complex Drugs (Tasmania) Section 100 Botulinum Toxin Program reports
- DHS Pharmaceutical Benefits Scheme (PBS) prescription claims data
- DHS Medicare Benefits Schedule (MBS) claims data relating to injection services for botulinum toxin A (Item 18377 for chronic migraine).
Key Findings
- There were 3,517 and 5,444 patients treated with botulinum toxin for chronic migraine in the first and second year of PBS listing, respectively. The number of patients treated was substantially higher than predicted.
- There were 7,826 and 13,873 services for the administration of botulinum toxin in the first and second year of listing, respectively, substantially more than expected.
- Continuation rate on treatment at 24 weeks (i.e. after 2 treatments), 71.4%, was more than double that predicted from trial data, 32.9%.
- PBS prescription data are insufficient to assess compliance with the PBS restriction regarding patients having experienced an inadequate response, intolerance or a contraindication to at least three prophylactic migraine medications and management of medication overuse headache prior to commencing botulinum toxin. Many prophylactic and acute treatments for migraine are available over the counter, can be provided on private prescription, and/or are priced under the general patient co‑payment and are not included in the PBS dataset.
- Treatment rates in most states were similar with approximately 23-32 patients per 100,000. Treatment rates were substantially higher in the ACT (105 per 100,000) and substantially lower in the NT (5 per 100,000).
