The validity of self-reported likelihood of HIV infection among the general population in rural Malawi
- 1Université de Montréal, Montréal, Canada
- 2University of Pennsylvania, Philadelphia, Pennsylvania, USA
- 3University of North Carolina Project, Lilongwe, Malawi
- Correspondence to: Assistant Professor Simona Bignami-Van Assche Département de Démographie, Université de Montréal, CP 6128, Succursale Centre-ville, Montréal, Canada H3C 3J7;
- Accepted 11 June 2006
- Published Online First 21 June 2006
Background: Understanding HIV risk perception is important for designing appropriate strategies for HIV/AIDS prevention, because these interventions often rely on behaviour modification. A key component of HIV risk perception is the individual’s own assessment of HIV status, and the extent to which this assessment is correct. However, this issue has received limited attention.
Objectives: To examine the validity of self-reported likelihood of current HIV infection among the general population in rural Malawi.
Methods: As part of a panel household survey, data on behaviour and biomarkers were collected for a population-based sample of approximately 3000 respondents in rural Malawi aged ⩾15 years. Information on self-assessed likelihood of currently having HIV was collected by survey interview. Saliva was obtained from all consenting respondents to assess actual HIV status.
Results: Of 2299 survey respondents who assessed their likelihood of being infected with HIV at the time of the survey, 71% were accurate. Most incorrect assessments (88%) were due to respondents overestimating (rather than underestimating) their likelihood of being infected with HIV. Women were less likely than men to correctly assess their HIV status. The two most important predictors of false-positive responses were marital status and self-reported health.
Conclusions: Self-reports of HIV infection were generally valid. Most invalid self-reports were due to overestimating the risk of having HIV. The implications of this finding are highlighted, as they pertain to the design of HIV prevention interventions and the expansion of HIV counselling, testing and treatment programmes in developing countries.
↵i The United Nations Group on HIV/AIDS (UNAIDS) and the World Health Organization countries (WHO) estimate that in low and middle income countries only 10% of people who need voluntary counselling and testing have access to HIV testing services.2
↵iii The accuracy of using saliva for detecting HIV antibodies was shown to be comparable to serum-based tests.12–17 An important motivation for using saliva in population-based surveys is the assumption that a non-invasive method might contribute to reducing selection bias due to non-consent. Studies that used saliva for detecting HIV antibodies have generally achieved higher consent rates, but data are still lacking to make a sound evaluation of the ways in which saliva and serum compete with regard to acceptability.18
↵iv Although OraSure has a sensitivity and specificity >99% as reported by the manufacturer, the actual figures for Malawi are unknown. As the test does not detect the very early phase of HIV infection, the actual sensitivity in our setting is probably <99%. Our results should be interpreted taking this issue into account.
↵v We measured perceived HIV prevalence in the community by using the respondent’s answer to the question “If we took a group of 10 people from this area—just normal people who you found working in the fields or in homes—how many of them do you think would now have HIV?” Answers to this question were on a continuous scale from 1 to 10, but in the multivariate regression analysis we dichotomised them into 0–50% and 50–100% to maximise the sample size for the analysis.
Published Online First 21 June 2006
Funding: The Malawi Diffusion and Ideational Change Project has been funded by the National Institute of Child Health and Human Development (NICHD), grants R01-HD37276, R01-HD044228-01, R01-HD050142 and R01-HD/MH-41713-0. The MDICP has also been funded by the Rockefeller Foundation, grant RF-99009#199. L-WC was supported by the NIH Fogarty International Center, grant K01-TW006658.
Competing interests: None declared.
Contributors: SBVA designed the 2004 MDICP biomarker testing protocol and was the lead author for the paper; SBVA, PA and L-WC participated in the coordination and supervision of fieldwork operations of the study; PA was the data manager and undertook the record linkage between HIV test results and survey data; DC was the general manager of the University of North Carolina Project in Malawi; AB was the 2004 MDICP nurses’ coordinator; SB led the data analysis and writing of the manuscript; PA and L-WC contributed to the data analysis and write up, as well as revising the manuscript; and DC and AB provided comments and feedback.