An observational analysis of pharmacy claims collected from 2001 to 2003 by researchers at Brigham & Women's Hospital finds that where a person lives and the socioeconomic implications of that location have a lot do with his use of generic drugs.
Of the 5,399 new prescriptions filled during the study period, 1,262 (23.4 percent) were for generics.
Of those patients who were initially prescribed branded medications, 606 (14.9 percent) switched to a generic drug in the same class in the subsequent year.
The researchers note that patients residing in high-income ZIP codes are more likely to be prescribed a generic medication initially than are patients in low-income regions. Pharmacy benefit design and pharmacy type are not associated with initiation of generic medications.
Patients enrolled in three-tier pharmacy plans were 2.5 times as likely to switch from branded to generic medications than beneficiaries in plans with two tiers or less, and patients who use mail-order pharmacies were 60 percent more likely to switch to a generic after beginning treatment with a branded drug.
Results were published in the Journal of General Medicine. Researchers found that patients who live in the poorest ZIP codes receive generic drugs least often.
While tiered pharmacy benefit designs and mail-order pharmacies help steer patients toward generic medications once the first prescription has been filled, they have little effect on initial prescriptions, the report says.