Background/Purpose: Lack of adherence to medications is a well-known problem with chronic conditions, RA included. Nonadherence is associated with decreased quality of life and poorer outcomes. This study explores the effect of adherence to DMARDs on the time to biologic initiation, cycle time on each DMARD, and on healthcare utilization and cost in patients with new-onset RA utilizing a large claims-based database.

Methods: A cohort of adult patients with new-onset RA within Allegheny Health Network Rheumatology was created utilizing our administrative database. Incident RA was defined using a previously validated algorithm: ICD9 code 714 or ICD10 codes M05.XX and M06.XX with no DMARD use for at least 6 months prior, no RA diagnosis visits or biologic use for at least 1 year prior, and with continuous enrollment during the study period (01/01/2015-07/31/2018 with a 9 month follow up period to account for adherence until 04/01/2019). Demographics (age/sex), socio-economic status, insurance, medications (non-biologic DMARDs, tofacitinib, biologics, glucocorticoids, other daily oral medications) were recorded. Proportion of days covered (PDC) ≥80% was counted as adherence. Time to biologic initiation (primary outcome) was defined as number of days from first DMARD prescription until the first biologic prescription. Cycle time on DMARD was defined as number of days on a DMARD before switching to or adding another DMARD. We compared non-adherent vs adherent group characteristics to examine if certain factors correlate with adherence using SAS Enterprise Guide 7.11 HF3.

Results: A total of 132 patients with new-onset RA met our criteria. Ninety patients (68%) were found to be adherent to their non-biologic DMARDs prior to biologic initiation. Our cohort had a mean age of 52 years and 62% female. Patients in the non-adherent group were younger (49 vs 55 years, p-value 0.011) and had lower estimated income (p-value 0.0015). Median time to biologic was longer in the non-adherent group (287 vs 191 days, p-value 0.076). Cycle times on the first and second DMARDs were found to be longer in the adherent vs non-adherent group (501 vs 115 days, p-value < 0.0001, and 314 vs 99 days, p-value 0.02 respectively). Total cost of DMARD medications prior to biologics was higher in the adherent group. The most common first DMARD prescription in both groups was methotrexate, but higher in adherent vs non-adherent (74% vs 48%, respectively, p-value 0.011). In both groups, approximately half of patients were prescribed a biologic as their second medication. Comparison of the groups can be found in Table 1.

Conclusion: Our study found that overall DMARD medication adherence is low and the time to biologic initiation may be longer in the non-adherent patients. Non-adherent patients tended to be younger, have lower household income, and spend less time on each DMARD prior to initiating a biologic. We plan to implement a team-based care approach focusing on medication education and integrating pharmacists and social workers at point of care, especially for those patients with unfavorable social determinants of health.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/associations-of-disease-modifying-anti-rheumatic-drug-dmard-adherence-with-time-to-first-biologic-and-cycle-time-on-dmards-and-healthcare-utilization-cost-in-a-new-ra-patient-cohort/