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This article is part of the supplement: AIDS Vaccine 2012

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A mixed-methods assessment of understanding (AoU) tool for AIDS vaccine trials in sub-Saharan Africa: results from a pilot study

G Lindegger1, M Quayle1, S Singh2, S Welsh7, D Mark3, M Wallace3, S Roux3, L Bekker3, L Mwananyanda4, W Kilembe4, E Chomba5, S Allen6, F Priddy7* and P Fast7

  • * Corresponding author: F Priddy

Author Affiliations

1 School of Psychology, University of Kwa-Zulu Natal, Pietermaritzburg, South Africa

2 GHAR Consulting Inc, New York, NY, USA

3 Desmond Tutu HIV Foundation, University of Cape Town, Cape Town, South Africa

4 Zambia-Emory HIV Research Project, Lusaka, Zambia

5 Zambia-Emory HIV Reseach Project, Lusaka, Zambia

6 Emory University, Atlanta, GA, USA

7 International AIDS Vaccine Initiative, New York, NY, USA

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Retrovirology 2012, 9(Suppl 2):P135  doi:10.1186/1742-4690-9-S2-P135

The electronic version of this article is the complete one and can be found online at:

Published:13 September 2012

© 2012 Lindegger et al; licensee BioMed Central Ltd.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Assessments of understanding (AoUs) in clinical trials are often composed of true/false multiple choice questions, however, these tools can be difficult for volunteers with limited education or without prior testing experience.


35 adults were recruited at two research centers in Southern Africa. A within-subjects, repeated measures design was used, whereby each volunteer served as his /her own control. An AoU tool with closed- and open-ended questions was administered within a hypothetical AIDS vaccine trial setting. Performance on closed- and open-ended questions was compared using correlations and repeated-measure t-tests, limited to 4 complex concepts: false sense of security, risk of false positive test, need for contraception, and potentially enhanced susceptibility.


Mean scores of understanding for each concept assessed by closed-ended questions ranged from 0.73 (need for contraception) to 0.84 (risk of false positive test); and by open-ended questions from 0.4 (risk of false positive test) – 0.6 (need for contraception). Scores for the open-ended measure were all lower than the equivalent closed-ended measure. Correlations between the closed- and open-ended measures were generally low, achieving significance for false sense of security (r=0.377), potentially enhanced susceptibility (r=0.393), and total score across concepts (r=0.617). Volunteers’ understanding as assessed by the closed- and open-ended methods differed significantly: false sense of security= -3.862; risk of false positive test= -7.210; need for contraception= -2.303; and potentially enhanced susceptibility= -8.007. The correlation with years of education was consistently and significantly higher for the open-ended measure than the true/false questionnaire with the exception of need for contraception.


The results suggest the qualitative measure better assesses understanding than the quantitative measure. The scores from the two assessment methods have limited interchangeability. The standard closed-ended questions appear to provide an inflated measure of volunteers’ understanding. An assessment tool with closed- and open-ended questions is better suited to determine genuine understanding.