Publications

OBJECTIVE

In 2013, the American College of Rheumatology published its Choosing Wisely list, which identified 2 radiographic procedures (peripheral joint magnetic resonance imaging [MRI] and dual x-ray absorptiometry [DXA] scans) that were at risk for overuse.

METHODS

We performed a retrospective cross-sectional cohort study to measure the use of peripheral joint MRI, peripheral joint radiographs, and DXA scans in a national cohort of Medicare patients with rheumatoid arthritis (RA) during 2008-2009, before the start of the Choosing Wisely campaign. Diagnoses were identified via International Classification of Diseases, Ninth Revision, codes; utilization was calculated using Current Procedural Terminology codes. Utilization was analyzed at the individual level and at the regional level (by hospital referral region [HRR]).

RESULTS

There were 8,051 patients with RA who were included: 81% were women, and the mean age was 76 years. Over a 2-year period, the mean number of peripheral joint MRIs per beneficiary was 0.3 (median 0 [range 0-50]), peripheral joint radiographs per beneficiary was 2.6 (median 1 [range 0-33]), and DXA scans per beneficiary was 0.7 (median 0 [range 0-11]). Only 6.8% of patients received >1 peripheral joint MRI, and 6% of HRRs had a mean number of peripheral joint MRIs >1.

CONCLUSION

There is variation in the use of peripheral joint MRI, peripheral joint radiographs, and DXA scans among Medicare patients with RA, although only a small number of HRRs have consistently high utilization. Although we cannot judge the appropriateness of each procedure, variation in use across regions signals the need for investigations to examine potential overutilization.

The Food and Drug Administration recommends rosuvastatin dosage reductions in Asian patients because pharmacokinetic studies have demonstrated an approximate 2-fold increase in median exposure to rosuvastatin in Asian subjects compared with Caucasian controls. Yet, no explanation for this ethnic difference has been confirmed. Here we show that rosuvastatin exposure in Asians and Whites does not differ significantly when all subjects are wild-type carriers for both solute carrier organic anion transporter 1B1 *1a and ATP-binding cassette subfamily G member 2 c.421 transporters in a 2-arm, randomized, cross-over rosuvastatin pharmacokinetics study in healthy white and Asian volunteers. For single rosuvastatin doses, AUC were 92.5 (±36.2) and 83.5 (±32.2) ng/mL × h and C were 10.0 (±4.1) and 7.6 (±3.0) ng/mL for Asians and Whites, respectively. When transporters were inhibited by intravenous rifampin, rosuvastatin AUC and C also showed no ethnic differences. Our study suggests that both SLCO1B1 and ABCG2 polymorphisms are better predictors of rosuvastatin exposure than ethnicity alone and could be considered in precision medicine dosing of rosuvastatin.