Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


High Adherence with Bisphosphonate Therapy in US Veterans with Rheumatoid Arthritis.

Richards10,  J. Steuart, Cannon9,  Grant W., Hayden8,  Candace L., Amdur11,  Richard L., Mikuls6,  Ted R., Reimold2,  Andreas, Caplan3,  Liron

Brooklyn NY VA Medical Center, New York, NY
Washington DC VA Medical Cener, Washington, DC
Washington DC VA Medical Center, Washington, DC
Dallas TX VA Medical Center, Dallas, TX
Denver CO VA Medical Center, Denver, CO
Iowa City IA VA Medical Center, Iowa City
Jackson MS VA Medical Center, Jackson, MS
Omaha NE VA Medical Center, Omaha, NE
Portland OR VA Medical Center, Portland, OR
Salt Lake City UT VA Medical Center, Salt Lake City, UT
Salt Lake City VA Medical Center, Salt Lake City, UT

Background:

Patients adherent with prescribed bisphosphonates have a reduction in fractures compared with noncompliant patients. Most reports on compliance with bisphosphonate therapy are for post menopausal osteoporosis with unclear relevance for other groups. We examined predictors of being prescribed a bisphosphonate, as well as predictors of patients who are adherent to therapy and remain on therapy.

Methods:

Patient data from the Veterans Affairs Rheumatoid Arthritis (VARA) registry were available for analysis, and included demographics, features of disease severity and activity of rheumatoid arthritis (RA), osteoporosis, prior dual energy X-ray absorptiometry (DXA) testing, use of prednisone and site of enrollment (Dallas, TX; Denver, CO; Jackson, MS; Omaha, NE; Salt Lake City, UT and Washington, DC). Using data from the Veterans Affairs' national Pharmacy Benefits Management (PBM) database for each bisphosphonate prescription, we determined predictors of bisphosphonate adherence and persistence. The time gap between anticipated refill and actual refill of the next prescription was calculated. Treatment course duration was defined as the time from the initial prescription until the expected refill date for the bisphosphonate prescription before a 90 day gap or discontinuation. The medication possession ratio (MPR), a measure of adherence, was calculated as the proportion of treatment time that the patient had drug available. Adherence was defined as an MPR >= 0.80.The persistence ratio on bisphosphonate therapy (PRBT), defined as duration of prescribed therapy from the time of the initial prescription until the last expected refill date of the final prescription. Factors associated with receipt of a bisphosphonate, adherence by MPR, and persistence by PRBT were determined by multiple regression analyses.

Results:

Bisphosphonates were prescribed to 573 (41.5%) of 1382 VARA subjects. These subjects were mostly males (89.9%), with a mean age of 68.7 years, (± 10.3); 82.4% were Caucasian, 12.7% African American (AA), and 3.5% Hispanic. 258 subjects (45.3%) had a DXA; 66 (11.5%) had osteoporosis and 392 (70.4%) had been prescribed prednisone. Older subjects, females, non-Caucasians, prednisone use, DXA, a higher MDHAQ score and enrollment at Washington, DC site were predictive of receiving a bisphosphonate.

The mean MPR was 0.69 ± 0.28 and only 271 (47.3%) subjects had MPR >= 0.80. Subjects from Omaha, NE had the highest rate of adherence (55.3%) while those from Washington, DC had the lowest (30%). MPR >= 0.80 was 50%, 35% and 25% for Caucasians, AA and Hispanics, respectively (p < 0.01). Gender, age, DXA, and use of prednisone were not predictive of MPR. In multivariate analysis AA ethnicity was associated with low MPR.

The PRBT for bisphosphonates was 39.2 ± 31.4 months, and longer PRBT was associated with older age and enrollment at Omaha, NE; there was no association with clinical diagnosis of osteoporosis or performance of a prior DXA.

Conclusions:

Adherence with bisphosphonates was greater in VARA cohort than most previous reports. Factors associated with higher adherence were Caucasian ethnicity and treatment site.

To cite this abstract, please use the following information:
Richards, J. Steuart, Cannon, Grant W., Hayden, Candace L., Amdur, Richard L., Mikuls, Ted R., Reimold, Andreas, et al; High Adherence with Bisphosphonate Therapy in US Veterans with Rheumatoid Arthritis. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :970
DOI: 10.1002/art.28737

Abstract Supplement

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