Intraindividual variability in neurocognitive performance: No influence due to HIV status or self-reported effort

ABSTRACT

Introduction: HIV-associated neurocognitive disorders (HAND) are estimated to affect approximately 50% of infected individuals at any one time. Dispersion, a type of intraindividual variability in neurocognitive test performance, has been identified as a potential behavioral marker of HAND; however, the specificity of dispersion to HAND and how it is influenced by participant effort when taking neurocognitive tests remain unclear.

Method: Data were analyzed from 996 (474 HIV–, 522 HIV+) men enrolled in the Multicenter AIDS Cohort Study (MACS). Dispersion was calculated based on the standard deviation of an individual’s test scores within a single assessment. Effort was determined using the Visual Analogue Effort Scale. Predictors of dispersion were determined using stepwise linear regression. Dispersion was compared between the HIV serostatus groups using analysis of covariance (ANCOVA), considering demographic and psychosocial variables that differed between the groups.

Results: Contrary to our hypothesis, dispersion was not influenced by effort. Instead, poorer neurocognitive ability and race were the sole predictors of dispersion. Dispersion did not differ between the serostatus groups.

Conclusions: Our results indicate that dispersion is a valid indicator of neurocognitive dysfunction that is not due to suboptimal effort; however, it is not specific to HIV and is therefore of limited utility as a behavioral marker of HIV-related neurocognitive impairment.

KEYWORDS:

• Dispersion
• HIV-associated neurocognitive disorders
• neuroHIV
• suboptimal effort
• visual analogue scale

Acknowledgments

Data in this manuscript were collected by the Multicenter AIDS Cohort Study (MACS). MACS (Principal Investigators): Johns Hopkins University Bloomberg School of Public Health (Joseph Margolick); Northwestern University (Steven Wolinsky); University of California, Los Angeles (Roger Detels, Oto Martinez-Maza); University of Pittsburgh (Charles Rinaldo); the Center for Analysis and Management of MACS, Johns Hopkins University Bloomberg School of Public Health (Lisa Jacobson, Gypsyamber D’Souza). The contents of this publication are solely the responsibility of the authors and do not represent the official views of the National Institutes of Health (NIH), Johns Hopkins ICTR, or the National Center for Advancing Translational Sciences (NCATS). The MACS website is: http://aidscohortstudy.org

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Data in this manuscript were collected by the Multicenter AIDS Cohort Study (MACS). MACS (Principal Investigators): Johns Hopkins University Bloomberg School of Public Health (Joseph Margolick, Todd Brown), U01-AI35042; Northwestern University (Steven Wolinsky), U01-AI35039; University of California, Los Angeles (Roger Detels, Otoniel Martinez-Maza, Otto Yang), U01-AI35040; University of Pittsburgh (Charles Rinaldo, Lawrence Kingsley, Jeremy Martinson), U01-AI35041; the Center for Analysis and Management of MACS, Johns Hopkins University Bloomberg School of Public Health (Lisa Jacobson, Gypsyamber D'Souza), UM1-AI35043. The MACS is funded primarily by the National Institute of Allergy and Infectious Diseases (NIAID), with additional co-funding from the National Cancer Institute (NCI), the National Institute on Drug Abuse (NIDA), and the National Institute of Mental Health (NIMH). Targeted supplemental funding for specific projects was also provided by the National Heart, Lung, and Blood Institute (NHLBI), and the National Institute on Deafness and Communication Disorders (NIDCD). MACS data collection is also supported by UL1-TR001079 (JHU ICTR) from the National Center for Advancing Translational Sciences (NCATS) a component of the National Institutes of Health (NIH), and NIH Roadmap for Medical Research. The contents of this publication are solely the responsibility of the authors and do not represent the official views of the National Institutes of Health (NIH), Johns Hopkins ICTR, or NCATS. The MACS website is located at http://aidscohortstudy.org/.