Repeated Assessments of Informed Consent Comprehension among HIV-Infected Participants of a Three-Year Clinical Trial in Botswana

Informed consent (IC) has been an international standard for decades for the ethical conduct of clinical trials. Yet frequently study participants have incomplete understanding of key issues, a problem exacerbated by language barriers or lack of familiarity with research concepts. Few investigators measure participant comprehension of IC, while even fewer conduct interim assessments once a trial is underway.We assessed comprehension of IC using a 20-question true/false quiz administered in 6-month intervals in the context of a placebo-controlled, randomized trial for the prevention of tuberculosis among HIV-infected adults in Botswana (2004-2009). Quizzes were offered in both Setswana and English. To enroll in the TB trial, participants were required to have ≥ 16/20 correct responses. We examined concepts understood and the degree to which understanding changed over three-years. We analyzed 5,555 quizzes from 1,835 participants. The participants' highest education levels were: 28% primary, 59% secondary, 9% tertiary and 7% no formal education. Eighty percent of participants passed the enrollment quiz (Quiz1) on their first attempt and the remainder passed on their second attempt. Those having higher than primary education and those who took the quiz in English were more likely to receive a passing score on their first attempt (adjusted odds ratios and 95% confidence intervals, 3.1 (2.4-4.0) and 1.5 (1.2, 1.9), respectively). The trial's purpose or procedures were understood by 90-100% of participants, while 44-77% understood randomization, placebos, or risks. Participants who failed Quiz1 on their initial attempt were more likely to fail quizzes later in the trial. Pass rates improved with quiz re-administration in subsequent years.Administration of a comprehension quiz at enrollment and during follow-up was feasible in a large, international collaboration and efficiently determined IC comprehension by trial participants. Strategies to improve understanding of concepts like placebos and randomization are needed. Comprehension assessments throughout a study may reinforce key concepts

Odds of passing comprehension quizzes 1–5 compared to quiz 1 & previous quiz; odds of passing comprehension quizzes 1–5 by time since last quiz (months).

<p>Odds of passing comprehension quizzes 1–5 compared to quiz 1 & previous quiz; odds of passing comprehension quizzes 1–5 by time since last quiz (months).</p

Odds of answering comprehension quiz questions 1–20 correctly at Quizzes 2–5 compared to enrollment quiz.

<p>Odds of answering comprehension quiz questions 1–20 correctly at Quizzes 2–5 compared to enrollment quiz.</p

Proportion of participants answering comprehension quiz questions 1–20 correctly (English & Setswana); Odds of answering correctly if quiz taken in English.

<p>Proportion of participants answering comprehension quiz questions 1–20 correctly (English & Setswana); Odds of answering correctly if quiz taken in English.</p

Number of comprehension quizzes completed by HIV-infected adults enrolled in a tuberculosis prevention trial, Botswana 2004–2008.

<p>Comprehension quizzes were administered at screening for enrolment (Quiz 1) and then every 6 months for a period of 36 months. However because not all participants were administered all quizzes, “Quiz 2” – for instance – refers to the second quiz taken regardless of the time elapsed since Quiz 1.</p

Unadjusted and adjusted odds of passing quizzes 1–5 by language and education.

<p>Odds ratios (OR) shown compare quiz results of those quizzes taken in English to those quizzes taken in Setswana and compare participants who had greater than primary education to those who had either only primary education or no formal education.</p>1<p>Only participants with a score, language, and level of education included; participants with a level of education coded as “other” not included.</p