Use of a modified informed consent process among vulnerable patients: a descriptive study

J Gen Intern Med. 2006 Aug;21(8):867-73. doi: 10.1111/j.1525-1497.2006.00535.x.


Background: Little is known about patient characteristics associated with comprehension of consent information, and whether modifications to the consent process can promote understanding.

Objective: To describe a modified research consent process, and determine whether literacy and demographic characteristics are associated with understanding consent information.

Design: Descriptive study of a modified consent process: consent form (written at a sixth-grade level) read to participants, combined with 7 comprehension questions and targeted education, repeated until comprehension achieved (teach-to-goal).

Participants: Two hundred and four ethnically diverse subjects, aged > or = 50, consenting for a trial to improve the forms used for advance directives.

Measurements: Number of passes through the consent process required to achieve complete comprehension. Literacy assessed in English and Spanish with the Short Form Test of Functional Health Literacy in Adults (scores 0 to 36).

Results: Participants had a mean age of 61 years and 40% had limited literacy (s-TOHFLA<23). Only 28% of subjects answered all comprehension questions correctly on the first pass. After adjustment, lower literacy (P=.04) and being black (P=.03) were associated with requiring more passes through the consent process. Not speaking English as a primary language was associated with requiring more passes through the consent process in bivariate analyses (P<.01), but not in multivariable analyses (P>.05). After the second pass, most subjects (80%) answered all questions correctly. With a teach-to-goal strategy, 98% of participants who engaged in the consent process achieved complete comprehension.

Conclusions: Lower literacy and minority status are important determinants of understanding consent information. Using a modified consent process, little additional education was required to achieve complete comprehension, regardless of literacy or language barriers.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Comprehension
  • Consent Forms*
  • Educational Measurement*
  • Female
  • Humans
  • Informed Consent*
  • Male
  • Mental Competency*
  • Middle Aged
  • Patient Education as Topic
  • Socioeconomic Factors