Measuring Concurrent Adherence to Multiple Related MedicationsByNiteesh K. Choudhry, MD, PhD,William H. Shrank, MD, MSHS,Raisa L. Levin, MS,Joy L. Lee, BA,Saira A. Jan, MS, PharmD,M. Alan Brookhart, PhD,Daniel H. Solomon, MD, MPHJuly 7th 2009This study compares the performance of several definitions of concurrent adherence to related medications.