Use visual aids, testing to improve informed consent 

Indian study looks at comprehension

Using visual aids in the informed consent process can significantly improve comprehension of issues such as risks and confidentiality, according to a study of pregnant women in Pune, India.

The study looked at an informed consent process the women underwent before receiving HIV testing, but has great relevance to the use of informed consent in clinical trials, says Anita V. Shankar, PhD, assistant scientist in the department of international health at the Bloomburg School of Public Health, Johns Hopkins University in Baltimore.

"We feel very strongly that in most settings, women don’t understand as much as they need to when participating in clinical trials," she says.

Shankar says that time constraints and long and complicated consent forms can be major obstacles to comprehension, particularly when dealing with populations where literacy or awareness of legal and medical rights is low.

"Simplifying this process and emphasizing the main points with the use of visuals is an important way to enhance understanding by individuals participating in any clinical trial," she says.

Shankar’s group, which included researchers from Johns Hopkins and from BJ Medical College in Pune, interviewed the women at a prenatal clinic at a hospital in Pune, which is located near the west coast of India in the state of Maharashtra.

The team tested the women’s knowledge of information they had received during the informed consent process for an HIV testing program. During that process, the women participated in a group session of eight to 10 people, and then received individual counseling. Observers also watched the sessions to see how well the necessary topics were covered.

The women were retested after the group made enhancements to the informed consent sessions — most significantly, introducing posters and flip charts with photo illustrations that depicted key concepts for both the group and individual sessions.

The women’s comprehension of the information jumped from 38% to 72% with the addition of posters in the group sessions. After similar visual aids on flip charts were used in one-on-one counseling, the women’s level of understanding rose to 96%.

Shankar notes that previous studies at this clinic had shown that about a third of the women were illiterate or had only a primary education. However, she says it’s still possible to convey the necessary information with some effort.

"This study demonstrates that complex constructs such as informed consent can be conveyed in populations with little education and within busy government hospital settings," she says.

Another enhancement to the sessions was to provide areas with greater privacy for both the group counseling and the one-on-one sessions. Giving the women a chance to talk privately with a counselor allowed them to ask questions that they may have been unwilling to discuss with the group, Shankar notes.

She says a small team of behavioral scientists developed the visual materials, using digital cameras and computer software.

"We tried to keep the visuals simple and covering only one main issue," she says. "The amount of text was limited and did not cause any problem in comprehension among the patients."

The visual aids, which can be reviewed at the group’s web site,, use photographs to convey different messages, including modes of HIV transmission and statistics about infection.

One page shows two photographs, one of a finger stick and another of blood being drawn from an arm, to illustrate the testing process. Another shows a woman in a screened area, with text describing confidentiality concerns. Yet another shows a person signing a consent form in one photo, and using a thumbprint to sign the form in a second photo.

Shankar says the group originally planned to use cartoons to illustrate the key concepts, but discussions with the women at the clinic showed they preferred to see photographs.

"We tested and retested various versions of the visuals on a representative sample of women to see what they understood from the pictures, and if anything, from the text," she says. After making several changes and reviewing the materials again with counselors, doctors and nurses on the team, the visuals were approved.

Shankar says it’s important to take local cultural concerns into consideration when preparing materials. In this case, for example, the study noted that many women in the population have relatively little sense of autonomy — decisions often are made by a woman’s father or husband. So the visual aids and counseling sessions reinforced concepts of a woman’s right to refuse to participate, and the meaning of her signature on a consent form.

"The type of cultural issues that might arise will, of course, vary by location," Shankar says. "The main difficulty is to convey the complex constructs embedded in most informed consent forms, which are often devised in a country different from where the research is taking place.

"Issues such as confidentiality, autonomy, individual responsibility, individual rights, may or may not be understood by the local population," she says. "Also, the sheer length of many informed consent forms is often a barrier to comprehension."

Shankar says that in an effort to include all the necessary technical and legal information required, the form itself can be so cumbersome that it distracts from true informed consent, rather than enhancing it.

In some studies, the original consent document is composed in English and then translated almost word for word into the local language, which further complicates understanding.

"The informed consent process is exactly that, a process," Shankar says. "The signing of an informed consent paper does not ensure that an individual has truly understood the material discussed." 

When setting out to create a more understandable consent process, Shankar recommends that at least a sample of participants be tested on their understanding of informed consent concepts.

"Once the level of understanding has been assessed, the informed consent process should be modified to enhance this understanding," she says. "If visuals or other aids are required, they should be developed and included."

"We need to make the informed consent process effective in communicating the key information to the participant, and properly designed visual aids are one simple way enhance this," she says.

(Editor’s note: A complete electronic version of the article can be found on-line at The visuals used in the study are available to be viewed in both English and the local language at 


1. Sastry J, Pisal H, Sutar S, et al. Optimizing the HIV/ AIDS informed consent process with visuals in India. BMC Med 2004; 2(1)8.