Background Poor compliance with drugs for rheumatoid arthritis (RA) can lead to treatment failure, delayed recovery, disease progression and a need for more aggressive therapy. Understanding factors associated with poor compliance has potential to improve treatment outcomes.
Objectives A comprehensive review was performed to investigate: the effect of route of administration on drug compliance in RA; compliance with oral drugs in RA compared with that in a non-pain-related disease (dyslipidaemia); the effect of poor compliance on clinical outcomes; the relationship between compliance and economic outcomes, such as healthcare resource utilisation and costs; and the impact of patient education/support programmes on compliance.
Methods Comprehensive database searches and searches of the reference lists of relevant publications were performed to identify studies investigating drug compliance in adults with RA being treated with conventional synthetic or biologic agents. Similar searches were performed for studies of patients with dyslipidaemia being treated with statins. Studies had to be published after 1998 and in English, and had to involve ≥6 months of follow up. Compliance data were extracted and compared between the different routes of drug administration in RA, and between the two diseases for oral agents.
Results A total of 33 and 22 papers underwent data extraction for RA and dyslipidaemia, respectively. The definitions and range of compliance values across studies was wide, making comparisons between drug formulations and diseases difficult. Within the constraints of the analysis, compliance and persistence rates were broadly similar for the different routes of drug administration in RA (compliance for intravenous [i.v.], subcutaneous [s.c.] and oral drugs, respectively: 68%, 59–73% and 33–107% [some patients took extra doses] at 6 months; 38–64% [i.v.] and 16–97% [s.c.] at 1 year; and 58–71% [oral] at 2 years). Compliance with oral drugs was also broadly similar across the two diseases (for RA: 33–107% at 6 months, 58–71% at 2 years; for dyslipidaemia: 40–100% at 6 months, 72–75% at 2–3 years). Poor compliance had clinical consequences in both diseases: greater disease activity, pain and functional disability in RA, and increased serum cholesterol levels and risk of ischaemic heart disease in dyslipidaemia (Figure). The only factors associated with compliance/persistence across both diseases were age, race and the extent of copayment/out-of-pocket expenses. Over 1–3 years, poor compliance with biologic RA drugs led to increased resource use and medical costs but lower total direct costs due to reduced biologic (s.c. and i.v.) drug costs. By contrast, poor compliance with dyslipidaemia drugs resulted in increased total direct costs. For RA, compliance improved with patient education/support.
Conclusions The route of drug administration and the symptomatic (pain) nature of the disease do not appear to be dominant factors for drug compliance in RA.
Disclosure of Interest B. Fautrel: None declared, A. Balsa: None declared, P. Van Riel: None declared, M. Casillas Employee of: Employee of Eli Lilly and Company, J.-P. Capron Employee of: Employee of Eli Lilly and Company, C. Cueille Employee of: Employee of Eli Lilly and Company, I. De La Torre Employee of: Employee of Eli Lilly and Company