Labeling Morphine Milligram Equivalents on Opioid Packaging: a Potential Patient Safety Intervention

To evaluate the evidence regarding the optimal content and format of prescription labels that might improve readability, understanding, and medication use. We performed a systematic review of randomized controlled trials, observational studies, and systematic reviews from MEDLINE and the Cochrane Database (1990-June 2005), supplemented by reference mining and reference lists from a technical expert panel. We selected studies that focused on the content of physician-patient communication about medications and the content and format of prescription drug labels. Two reviewers extracted and synthesized information about study design, populations, and outcomes. Of 2009 articles screened, 36 that addressed the content of physician-patient communication about medications and 69 that were related to the content or format of medication labels met review criteria. Findings showed that patients request information about a drug's indication, expected benefits, duration of therapy, and a thorough list of potential adverse effects. The evidence about label format supports the use of larger fonts, lists, headers, and white space, using simple language and logical organization to improve readability and comprehension. Evidence was not sufficient to support the use of pictographic icons. Little evidence linked label design or content to measurable health outcomes, adherence, or safety. Evidence suggests that specific content and format of prescription drug labels facilitate communication with and comprehension by patients. Efforts to improve the labels should be guided by such evidence, although additional study assessing the influence of label design on medication-taking behavior and health outcomes is needed. Several policy options exist to require minimal standards to optimize medical therapy, particularly in light of the new Medicare prescription drug benefit.

Patient misunderstanding of prescription drug label instructions is a common cause of unintentional misuse of medication and adverse health outcomes. Those with limited literacy and English proficiency are at greater risk.