Background Poor adherence to therapy increases the burden and complexity of chronic diseases such as rheumatoid arthritis (RA). In the past 15 years, biologics have revolutionized the treatment of RA. However, little data is available on impact of adherence to biologics on health-care resources.
Methods As part of a pilot project at the Institute for Clinical Evaluative Sciences (ICES), analyses were performed by ICES scientists on ICES administrative data to study the research question provided by Janssen Inc. Note, the approach and methodological details were determined by Janssen researchers. Patients were identified from the Ontario RA Database which contains all Ontario RA patients identified since 1991. Study population included RA patients, age 65+, with a prescription for a biologic drug between January 1, 2003 and December 31, 2013. Exclusion criteria are diagnosis of inflammatory bowel disease, psoriatic arthritis or psoriasis in the 5 years prior to the index event and discontinuation of biologic drug during the 12 months after the index event. Adherence was defined as a Medication Possession Ratio (MPR) of ≥0.8 measured as the proportion of days for which a patient had biologic treatment(s) over a defined follow-up period. Adherent were matched to non-adherent patients on a propensity score calculated using seventeen variables capturing patient demographics and heathcare resource use in the year prior to index event.
Results A total of 4,667 RA patients were identified. Patients had a mean age (SD) of 69.9 (5.46) years and 75% were female. Of the total study cohort 1,877 matched pairs were identified (adherent to non-adherent patients). Relative rates for resource use (GP and cardiologist visits, ED visits, hospitalization, home care and rehabilitation) for the matched cohort were significantly lower (p<0.0001) in adherent patients. Additionaly the median (IQR) length of stay of hospitilizations was shorter for adherent patients - 10 days (4–23) vs. 14 days (5–38). 67% of non-adherent patients used oral prednisone which is significantly higher (p<0.001) than 54% in the adherent cohort.
Conclusions The results of this large population based study have shown that RA patients who are adherent to biologic therapy have lower heathcare resource use and lower steroid use compared to non-adherent patients. Despite the inherent limitations of administrative database studies, the findings of the study have implications for physicians, patients and healthcare payers demonstarting the importance of adherence in the management of RA.
Disclosure of Interest None declared