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Improving Prescription Drug Warning Labels

This study has been completed.
Louisiana State University Health Sciences Center Shreveport
Emory University
Information provided by:
Northwestern University Identifier:
First received: February 13, 2009
Last updated: February 17, 2009
Last verified: February 2009

Prior studies have documented a high prevalence of patients misunderstanding prescription drug warning labels, placing them at risk for medication error.

We sought to evaluate the effectiveness of 'enhanced print' drug warnings to improve patient comprehension beyond a current standard.A three-arm, controlled clinical trial was conducted. Patients were assigned to receive 1) current standard drug warning labels on prescription containers (standard), 2) 'enhanced' drug warnings with text rewritten in plain language (enhanced text), or 3) enhanced language and icons developed with patient feedback (enhanced text + icon).

Setting: Two academic and two community health primary care clinics in Chicago, IL and Shreveport, LA.

Patients: 500 adult patients consecutively recruited at each clinic. Main Outcome Measure: Rates of correct interpretation of nine drug warning labels as determined by a blinded panel review of patients' verbatim responses.

Condition Intervention Phase
Enhanced Text Enhanced Text + Icon Other: Enhanced drug labeling Phase 4

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Health Services Research

Further study details as provided by Northwestern University:

Enrollment: 500
Study Start Date: June 2007
Study Completion Date: February 2009
Primary Completion Date: August 2008 (Final data collection date for primary outcome measure)
Intervention Details:
    Other: Enhanced drug labeling
    use of clear concise text and icons on drug warning labels
  Show Detailed Description


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • > 18 years old

Exclusion Criteria:

  • cognitive impairment
  • vision or hearing impairment
  • non-English speaking
  • severely ill
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00846209

United States, Illinois
Northwestern Memorial Faculty Foundation
Chicago, Illinois, United States, 60611
Sponsors and Collaborators
Northwestern University
Louisiana State University Health Sciences Center Shreveport
Emory University
  More Information

Responsible Party: Michael Wolf, PhD MPH, Northwestern University Identifier: NCT00846209     History of Changes
Other Study ID Numbers: 0923-010
Study First Received: February 13, 2009
Last Updated: February 17, 2009

Keywords provided by Northwestern University:
prescription drug
health literacy
enhanced language processed this record on July 19, 2017