Developing standardised treatment for adults with myositis and different phenotypes: an international survey of current prescribing preferences.

Objectives: The evidence base for treatment of the idiopathic inflammatory myopathies is extremely limited. The rarity and heterogeneity of these diseases has hampered the development of good quality clinical trials and while a range of immunomodulatory treatments are commonly used in clinical practice, as yet there are no clear guidelines directing their use. We aimed to establish current prescribing regimens used to treat adults with myositis internationally.

Methods: An electronic survey based on different clinical scenarios was distributed internationally to clinicians involved in the treatment of patients with myositis. Participants were asked to select their first-line treatment preferences in each situation. A multinomial regression analysis was used to assess the influence of clinical scenario, respondent expertise and country of origin on first-line treatment choice.

Results: 107 survey responses were received. 57% of respondents considered themselves an expert in myositis and the majority of respondents were rheumatologists although responses from other specialities were also received. Pharmacological treatment with steroids and additional immunotherapy was the preference in most scenarios. First-line immunosuppressant choice was significantly influenced by the clinical scenario, the expertise of the treating physician and country of practice. Azathioprine, methotrexate and mycophenolate mofetil were the most commonly chosen agents.

Conclusions: In the absence of available evidence, clinical experience and expert consensus often forms the basis of treatment guidelines. These results suggest that an international consensus approach would be possible in myositis and would overcome an urgent, yet unmet need for patients suffering with this difficult disease.