Non-adherence to interferon-beta therapy in Swedish patients with multiple sclerosis Introduction Immune-modulating therapy (IMT) in multiple sclerosis (MS) with interferon-beta (IFNb) has been available in Sweden since 1995, when Beta- feron Ò (IFNb-1b) was registered, followed by Avonex Ò (IFNb-1a) in 1997 and Rebif Ò (IFNb- 1a) in 1998. The World Health Organization (WHO) defines adherence as Ôthe extent to which a personÕs behaviour – taking medication, follow- ing a diet, and ⁄ or executing lifestyle changes, corresponds with agreed recommendations from a healthcare providerÕ (1). Clinical experience indicates that many patients stop their IFNb- therapy or switch to a different drug, but few studies have investigated factors associated with adherence or reasons for stopping or switching therapy in clinical practice. Reports indicate that some 2–20% of patients on IFNb-therapy have discontinued therapy during the initial six months (2–7), and longer studies show that 8– 46% of the patients stop or switch their therapy (2, 6–14). Factors such as new ⁄ increased depression, flu- like side effects, soreness at injection site and inappropriate expectations of changes in functional status are related to discontinuing therapy (4) and adherence is predicted by injection administrator, place of injection, and post-injection anxiety (3). Although the side-effects of the IFNb-therapies are not, in general, medically serious (15) and are reported by patients as having little impact on daily life (16), together with the inconvenience of administering injections, they may diminish patient adherence. In Sweden, healthcare services and costs for prescribed drugs are primarily financed through the tax system, where individual costs are free of charge after a maximum annual amount of approximately 300 Euros for healthcare and med- icines has been exceeded (17). IFNb are prescribed to patients with MS by neurologists and are not subject to a reporting procedure or central regis- tration with healthcare authorities. Furthermore, in accordance with the WHO and Swedish law, patients should have influence on decisions regard- ing their healthcare and therapy (1, 17). At the MS Acta Neurol Scand 2010: 121: 154–160 DOI: 10.1111/j.1600-0404.2009.01285.x Copyright Ó 2009 The Authors Journal compilation Ó 2009 Blackwell Munksgaard ACTA NEUROLOGICA SCANDINAVICA Cunningham A, Gottberg K, von Koch L, Hillert J. Non-adherence to interferon-beta therapy in Swedish patients with multiple sclerosis. Acta Neurol Scand: 2010: 121: 154–160. Ó 2009 The Authors Journal compilation Ó 2009 Blackwell Munksgaard. Objectives – To explore the occurrence and reasons for stopping, switching or continuing first prescribed interferon-beta therapy in patients with multiple sclerosis in Sweden, with respect to demographic, clinical and ⁄ or therapy-related factors. Materials and methods – A retrospective study reviewing the medical charts of 259 patients with multiple sclerosis, comparing patients continuing therapy for at least 3 years with those switching or stopping therapy. Results –Sixty 9% stopped (15%), or switched (54%), interferon-beta therapy within 3 years. Stoppers had longer disease duration before starting therapy (P = 0.002), less frequently relapsing-remitting multiple sclerosis (P = 0.046), and more often Expanded Disability Status Scale scores 6–9.5 (P = 0.045) compared to Switchers. The most common reasons for switching ⁄ stopping therapy were perceived lack of effect and side-effects. Conclusions – Adherence to initial immune- modulating therapy is low; identification of patients at higher risk of stopping therapy and provision of adequate support are essential. A. Cunningham 1 , K. Gottberg 1,2 , L. von Koch 1,2 , J. Hillert 1 1 Department of Clinical Neuroscience, Division of Neurology, Karolinska Institutet, Huddinge, Sweden; 2 Department of Neurobiology, Care Sciences and Society, Division of Nursing, Karolinska Institutet, Huddinge, Sweden Key words: adverse effects; multiple sclerosis; treatment Anna Cunningham, Division of Neurology R54, Karo- linska University Hospital, Huddinge, SE-141 86 Stock- holm, Sweden Tel.: +46 8 585 822 75 Fax: +46 8 774 48 22 e-mail: cunningham.anna@gmail.com Accepted for publication September 14, 2009 154