The effects of age and physical health on processing speed in HIV

Abstract

The impact of age and physical health on processing speed was investigated in 42 non-demented HIV+ individuals ranging in age from 30 to 75. We used the Medical Outcomes Study-HIV Healthy Survey (MOS-HIV) to measure self-reported physical health, neuropsychological tests to measure psychomotor and cognitive processing speed (Delis–Kaplan Executive Function System Trail Making Test, Grooved Pegboard Test, letter and category fluency), and a test of the foreperiod effect to measure reaction time under increasing attentional load. Results indicated that aging and worse physical health each independently contributed to slowing on different processing speed measures, while the interaction between aging and physical health did not contribute to processing speed. These findings highlight the importance of considering physical health separately from age when measuring cognitive function in HIV+ adults.

Keywords:

• HIV
• physical health
• aging
• attention
• processing speed

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplementary 1 (content) is available via the “Supplementary” tab on the article's online page (http://dx.doi.org/10.1080/09540121.2015.1054340).

Notes

1. All analyses were performed with and without these two participants. Analyses of the SRT were unchanged. Regression results that did change include increased p values on contribution of age to ISI-Short2, ISI-Long, and Grooved Pegboard (from p ≤ 0.01 to p ≤ 0.05). Both participants’ data were included in the analyses reported here.

2. The total of all error trials, including anticipatory trials, erroneous click responses, missed responses, and outliers, was examined: 11 participants had <1% error trials, 23 participants had 1–5% error trials, and 8 participants had >5% error trials. There was no age group difference on the number of error trials (age group (χ² = .00, p = 1.0) Also, all subsequent analyses were performed with and without the eight participants and results were unchanged.

Additional information

Funding

This work was supported by the Alzheimer's Association [grant number IIRG-05-13534]; a Professional Staff Congress-City University of New York [grant number 61056-00-39] awarded to N. S. F.; and a City University of New York Graduate Center Doctoral Student Council Grant 2010 awarded to K. V. D.