Journal of General Internal Medicine

, 23:1589

Patient Reported Receipt of Medication Instructions for Warfarin is Associated with Reduced Risk of Serious Bleeding Events

  • Joshua P. Metlay
  • Sean Hennessy
  • A. Russell Localio
  • Xiaoyan Han
  • Wei Yang
  • Abigail Cohen
  • Charles E. Leonard
  • Kevin Haynes
  • Stephen E. Kimmel
  • Harold I. Feldman
  • Brian L. Strom
Original Article

DOI: 10.1007/s11606-008-0708-8

Cite this article as:
Metlay, J.P., Hennessy, S., Localio, A.R. et al. J GEN INTERN MED (2008) 23: 1589. doi:10.1007/s11606-008-0708-8

Abstract

Background

Adverse drug events are an important cause of preventable hospitalizations.

Objective

To identify whether patient report of receipt of medication instructions and markers of complex care (multiple physicians, recent hospitalization) predict the risk of serious bleeding for older adults on warfarin.

Design

Prospective cohort study of older adults.

Participants

Subjects filled new or refill prescriptions for warfarin at the time of enrollment.

Measurements

Hospitalizations were identified through a state-wide registry. Discharge summaries of hospitalizations for possible warfarin related bleeding events were reviewed by trained abstractors and clinical experts. Incidence rate ratios (IRR) were estimated based on person-months of exposure using Poisson regression models.

Results

From March 2002 through May 2003, we enrolled a total of 2346 adults on warfarin. Over a two-year follow-up period, there were 126 hospitalizations due to warfarin-related bleeding (4.6 hospitalizations per 100 person-years of exposure). Patients who reported receiving medication instructions from either a physician or nurse plus a pharmacist had a 60% reduced rate of subsequently experiencing a serious bleeding event over the next 2 years (adjusted IRR 0.40, 95% CI 0.24–0.68). Having ≥4 physicians providing medication prescriptions over the last 3 months and filling prescriptions at >1 pharmacy over the last 3 months were independently associated with increased bleeding rates (adjusted IRRs 2.37, 95% CI 1.22–4.57 and 1.61, 95% CI 0.97–2.67, respectively).

Conclusions

The rate of warfarin-related hospitalization for bleeding is substantially lower for patients who report receiving medication instructions from a physician or nurse and a pharmacist.

KEY WORDS

anticoagulationpatient communicationmedication safety

Copyright information

© Society of General Internal Medicine 2008

Authors and Affiliations

  • Joshua P. Metlay
    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
  • Sean Hennessy
    • 1
    • 2
    • 3
  • A. Russell Localio
    • 1
    • 3
  • Xiaoyan Han
    • 1
    • 2
  • Wei Yang
    • 1
    • 2
  • Abigail Cohen
    • 1
    • 2
    • 3
  • Charles E. Leonard
    • 1
    • 2
    • 3
  • Kevin Haynes
    • 1
    • 3
  • Stephen E. Kimmel
    • 1
    • 2
    • 3
    • 4
  • Harold I. Feldman
    • 1
    • 2
    • 3
    • 4
  • Brian L. Strom
    • 1
    • 2
    • 3
    • 4
  1. 1.Center for Clinical Epidemiology & Biostatistics, Department of Biostatistics & EpidemiologyUniversity of Pennsylvania School of MedicinePhiladelphiaUSA
  2. 2.University of Pennsylvania Program for the Reduction in Medication Errors (PRIME)PhiladelphiaUSA
  3. 3.Center for Education and Research on Therapeutics (CERTs)University of PennsylvaniaPhiladelphiaUSA
  4. 4.Department of MedicineUniversity of Pennsylvania School of MedicinePhiladelphiaUSA
  5. 5.Center for Health Equity Research and Promotion, Veterans Affairs Medical CenterPhiladelphiaUSA
  6. 6.712 Blockley HallPhiladelphiaUSA