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

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

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

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).

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

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).

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.

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.