NEW YORK - In a study conducted at two major HIV centers in Singapore, rapid HIV self-tests were used improperly, or the results were interpreted incorrectly, by individuals at risk for HIV infection or those who were already infected.

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

Lee's team tested the Abbott Determine HIV 1/2 test in 350 subjects, 88 of whom were known to be HIV-positive. Before testing, 90 percent said the test steps were easy to understand and the instructions were easy to read and follow.

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

Twelve percent were unable to correctly interpret the test results, including 2 percent who incorrectly interpreted positive results and 7 percent who incorrectly interpreted negative results. However, Lee and associates found the test itself, when properly used, was similar in accuracy to the manufacturer's claims.

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

The subjects who were known to be HIV-positive correctly performed the test and interpreted the results more often, which might reflect their "exposure to and experience with blood tests."

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

The researchers conclude that the "implementation of self-testing should be reconsidered until kit design and downstream issues have been adequately addressed."

SOURCE: Journal of Acquired Immune Deficiency Syndromes, August 1, 2007.