Rapid HIV Self-Test Proves Ineffective in At-Risk Individuals

NEW YORK (Reuters Health) Aug 28 - In a study conducted at two major HIV centers in Singapore, rapid HIV self-tests were used improperly, or the results were interpreted incorrectly, in individuals at risk for HIV or with confirmed HIV seropositivity.

The major problem was in collecting an adequate blood sample, Dr. Vernon J. Lee of Tan Took Seng Hospital in Singapore and others report in the August 1st issue of the Journal of Acquired Immune Deficiency Syndromes. In addition, a significant number of study subjects were unable to interpret results or interpreted them incorrectly.

Dr. Lee's team tested the Abbott Determine HIV 1/2 test on 350 subjects, 88 of whom were known to be HIV-positive and 262 of whom were at-risk.

Before testing, 90% said the test steps were easy to understand and the instructions were easy to read and follow.

However, Dr. Lee and colleagues found that 85% of participants failed to perform all of the steps correctly, or were unable to perform the test. As a result, invalid results occurred in 56% of cases.

Twelve percent were unable to correctly interpret the test results, including 2% who incorrectly interpreted positive results and 7% who incorrectly interpreted negative results.

Dr. Lee and associates found the sensitivity and specificity to be similar to the test manufacturer's claims.

The investigators found that "blood sampling via fingerprick and collection via a capillary tube was difficult for participants."

At-risk subjects tended to be younger and had more trouble performing the test properly. Those known to be HIV-positive correctly performed the test and interpreted the results more often, which "may reflect the latter's exposure to and experience with blood tests."

Inconvenience and long waiting times were cited by 18% of participants as deterrents to being tested for HIV at health care centers.

Subjects reported that "pre- and post-test confidential counseling was necessary, which poses challenges for self-testing."

"Implementation of self-testing should be reconsidered until kit design and downstream issues have been adequately addressed," the Singapore team concludes.

J Acquir Immune Defic Syndr 2007;45:449-453.