Details

Autor(en) / Beteiligte

• Meyer, Ana-Claire L.
• Boscardin, W. John
• Kwasa, Judith K.
• Price, Richard W.

Titel

Is It Time to Rethink How Neuropsychological Tests Are Used to Diagnose Mild Forms of HIV-Associated Neurocognitive Disorders? Impact of False-Positive Rates on Prevalence and Power

Ist Teil von

• Neuroepidemiology, 2013-01, Vol.41 (3-4), p.208-216

Ort / Verlag

Basel, Switzerland: S. Karger AG

Erscheinungsjahr

2013

Quelle

MEDLINE

Beschreibungen/Notizen

• Background: Between 0 and 48% of normal HIV-uninfected individuals score below threshold neuropsychological test scores for HIV-associated neurocognitive disorders (HAND) or are false positives. There has been little effort to understand the effect of varied interpretations of research criteria for HAND on false-positive frequencies, prevalence and analytic estimates. Methods: The proportion of normal individuals scoring below Z score thresholds drawn from research criteria for HAND, or false-positive frequencies, was estimated in a normal Kenyan population and a simulated normal population using varied interpretations of research criteria for HAND. We calculated the impact of false-positive frequencies on prevalence estimates and statistical power. Results: False-positive frequencies of 2-74% were observed for asymptomatic neurocognitive impairment/mild neurocognitive disorder and 0-8% for HIV-associated dementia. False-positive frequencies depended on the definition of an abnormal cognitive domain, Z score thresholds and neuropsychological battery size. Misclassification led to clinically important overestimation of prevalence and dramatic decreases in power. Conclusions: Minimizing false-positive frequencies is critical to decrease bias in prevalence estimates and minimize reductions in power in studies of association, particularly for mild forms of HAND. We recommend changing the Z score threshold to ≤-1.5 for mild impairment, limiting analysis to 3-5 cognitive domains and using the average Z score to define an abnormal domain.