A second HIV test may avoid significant costs.
Nearly every medical test carries the risk of inaccuracy due to variables, including patient genetics and related factors. Misdiagnosis has been linked to unnecessary stress for the patient and caregivers, in addition to increasing avoidable health care spending.
A new PLOS Medicine study suggests that confirmatory HIV testing can lower the rate of pediatric patients misdiagnosed with HIV in South Africa.
Since nucleic acid amplification tests (NAATs) for early infant HIV diagnosis (EID) are less than 100% accurate, it can result in incorrect HIV diagnoses in infants. Patients incorrectly diagnosed with HIV may start therapy and receive unnecessary services.
Currently, a second HIV test is recommended by the World Health Organization and the country’s guidelines; however, the authors report that the uptake has lagged.
In the study, the authors used a computer simulation model to project the impact of a second NAAT in infants if the first result was positive. Each test was estimated to cost $25, with a specificity of 99.6% and a sensitivity of 100%, according to the authors.
Without the second NAAT, 128 out of every 1000 infants who started antiretroviral therapy (ART) were HIV-positive. In comparison, the addition of confirmatory testing dropped unnecessary ART initiation to 1 out of 1000 infants, according to the study.
The authors also found that confirmatory testing reduced unnecessary spending on ART and health care. The second NAAT resulted in savings over a lifetime, costing $1790 per infant tested compared with $1830 without the second test, according to the study.
"We find that use of a second NAAT for confirmatory testing in EID programmes [sic] will substantially reduce the proportion of infants incorrectly diagnosed as HIV-infected and initiated on ART in settings with low infant HIV transmission rates like South Africa" said researcher Lorna Dunning, MPH.
The authors noted that when confirmatory testing is used, ART should be started after the first positive test. The authors caution that waiting even 1 month to start ART can reduce short-term and long-term survival for HIV-infected infants, according to the study.
These results highlight the importance of early ART initiation and the need for more accurate HIV testing methods for vulnerable populations, such as infants.
"While projected cost differences are small, confirmatory testing is likely to be cost-saving under a wide range of scenarios in South Africa," said senior study author Andrea Ciaranello MD. "Concerns about the cost of the second test itself should not be the reason to avoid this important intervention."