New 20-Minute Screening Test Identifies HIV Neurocognitive Disorder

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By Mark Mascolini

From TheBodyPRO.com

 

November 2, 2016

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A 20-minute computer screening test had 100% sensitivity and 98% specificity for identifying symptomatic HIV-associated neurocognitive disorder (HAND) when compared with a standard eight-domain neurocognitive battery, according to results of a 326-person study. The 20-minute test could help HIV clinicians more readily identify patients with mild or advanced neuropsychological problems, the study found.

Despite widespread virologic response to current antiretroviral regimens, HAND persists in a proportion of virologic responders. Even mild HAND may affect medication adherence, quality of life, employment and mortality risk. Researchers in Sydney, Australia, who conducted the new study note that comprehensive neuropsychological testing remains the gold standard for detecting HAND, but it is expensive and not widely available. They designed a relatively simple and faster computer screening tool that reflects classic cognitive constructs and compared it with gold-standard neurocognitive testing in adults with and without HIV.

Researchers recruited HIV-positive and negative people from a community practice in Sydney. All participants completed the 20-minute CogState computer screen, while one-quarter also underwent eight-domain gold-standard neuropsychological testing. CogState assesses five cognitive domains across six individual tasks. The researchers interpreted test results as indicating asymptomatic neurocognitive impairment (ANI), symptomatic mild neurocognitive disorder (MND) or HIV-associated dementia (HAD). They used standard statistical tests to determine the sensitivity and specificity of CogState in determining these three outcomes. Sensitivity is the ability of a test to identify people who meet certain criteria; specificity is the ability of a test to classify people who do not meet certain criteria as negative.

The analysis involved 254 people with HIV and 72 demographically matched HIV-negative controls. Among people invited to participate, 83% agreed. Median age stood at 49 years in both groups, and almost all were white men. More than half of each group had some college education, and less than 10% in each group had alcohol use disorder. Almost everyone with HIV, 92%, was taking antiretroviral therapy, and 83% had plasma HIV RNA below 200 copies/mL.

HAND prevalence among people with HIV measured 30.7% (ANI 15.0%, MND 12.6%, HAD 3.2%), while 13.8% of HIV-negative controls had HAND (P = .004). Fifty-three people with HIV and 22 HIV-negative controls completed both CogState and complete neuropsychological assessment. Among combined HIV-positive and negative participants, CogState had a sensitivity of 73% and a specificity of 82% in identifying HAND (ANI, MND or HAD). When considering only MND and HAD, CogState had a sensitivity of 100% and a specificity of 98%. Positive predictive value for MND and HAD was 92% and negative predictive value was 100%. CogState misclassified only one person for MND or HAD.

The researchers believe their study "demonstrated the feasibility of HAND screening in HIV clinics by nonspecialists who are trained by neuropsychologists." They stress that they do not aim to replace standard neuropsychological testing, but they suggest their approach "streamlines testing for patients who need it the most, creating sustainable and targeted care pathways."
Mark Mascolini writes about HIV infection.

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