What do medical records tell us about potentially harmful co-prescribing?
GROUND: Previous efforts document drug-drug interactions in ambulatory care. Yet little is known about medical record documentation or clinical management when interacting medications are received. METHODS: The study population was identified from the HMO Research Network’s Centers for Education and Research on Therapeutics (n = 2,020,037). A random subsample of patients > or = 18 years of age with drug coverage in 2000 initiating a co-dispensing for (1) warfarin with a nonsteroidal anti-inflammatory drug (n = 97), (2) digoxin with verapamil or diltiazem (n = 100), or (3) lovastatin/simvastatin with diltiazem or verapamil (n = 89) was identified. RESULTS: The majority (63%-74%) of patients had documentation indicating receipt of both drugs during a single office visit. Documentation of risks and patient education was less common (< or = 14%, with all corresponding upper bounds of the 95% CIs < 23%). Clinical management changes were more frequently documented, ranging from 64% (95% CI: