Is the HIV Dementia Scale a Reliable Tool for Assessing HIV-related Neurocognitive Decline?
- *Corresponding Author:
- Lucette A Cysique
Department of Neurology
level 4 Xavier building
St. Vincent’s Hospital
Darlinghurst, NSW, 2010, Australia
Tel: 02 8382 4930
Fax: 02 8382 4101
E-mail: [email protected]
Received Date: October 31, 2013; Accepted Date: December 15, 2013; Published Date: December 19, 2013
Citation: Lu GM, Brew BJ, Siefried KJ, Draper B, Cysique LA (2013) Is the HIV Dementia Scale a Reliable Tool for Assessing HIV-related Neurocognitive Decline? J AIDS Clin Res 5:269. doi:10.4172/2155-6113.1000269
Copyright: © 2013 Lu GM, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Background: The HIV Dementia scale (HDS) has been recommended as a cross-sectional screen for HIVassociated neurocognitive disorder (HAND) but its longitudinal usefulness has not been optimally established.
Method: 55 HIV+ participants underwent baseline and follow-up HDS screening after an average of 3.9 (SD=1.1) months. They had completed standard neuropsychological (NP) evaluations within the last 6-18 months to calculate a baseline HAND rate (49.1%) and gold standard cognitive change performance: 12.7% showed mild to moderate decline compared to normative standards for NP change; 80% confidence interval; 1-tailed, the rest of the sample was cognitively stable. After normalizing HDS raw-scores, standard regression-based change scores were developed to quantify HDS-based decline, which corrected for practice effect, regression towards the mean, and yielded individual predictions of neurocognitive change. Clinically significant decline was defined as a z-score outside the 80% confidence interval; 1-tailed. Baseline HIV disease and laboratory data were collected.
Results: The magnitude of HDS reliability was very large r=0.76 (p<0.0001). HDS-testing found that 21.8% significantly declined. Compared to gold standard NP decline, the HDS showed 57% sensitivity and 82% specificity. Only participants (n=4) that declined moderately (median HDS-change z-score=-2 SD below mean of zero; at least 3-4 points decline in raw HDS-score) were congruently identified. Standard regression-based change scores did not operate optimally at smaller magnitudes of decline. HAND diagnosis (gold standard) at baseline (p<0.03) and more severe HAND were associated with greater chance of decline (p<0.03). No baseline HIV biomarkers were associated with decline.
Conclusions: The HDS is a reliable screen to detect at least moderate neurocognitive decline in individuals with MND and HAD. Other screening instruments are needed to detect milder levels of neurocognitive decline. Alternatively, non-parametric statistical modelling is needed to improve predictions of individual cognitive change on such scales that typically have a restricted range of values.