Improved neurocognitive test performance in both arms of the SMART study: Impact of practice effect

Birgit Grund; Edwina J. Wright; Bruce J. Brew; Richard W. Price; Mollie P. Roediger; Margaret P. Bain; Jennifer F. Hoy; Judith C. Shlay; Michael J. Vjecha; Kevin R. Robertson

doi:10.1007/s13365-013-0190-x

Improved neurocognitive test performance in both arms of the SMART study: Impact of practice effect

Birgit Grund, Edwina J. Wright, Bruce J. Brew, Richard W. Price, Mollie P. Roediger, Margaret P. Bain, Jennifer F. Hoy, Judith C. Shlay, Michael J. Vjecha, Kevin R. Robertson

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Abstract

We evaluated factors associated with improvement in neurocognitive performance in 258 HIV-infected adults with baseline CD4 lymphocyte counts above 350 cells/mm³ randomized to intermittent, CD4-guided antiretroviral therapy (ART) (128 participants) versus continuous therapy (130) in the Neurology substudy of the Strategies for Management of Antiretroviral Therapy trial. Participants were enrolled in Australia, North America, Brazil, and Thailand, and neurocognitive performance was assessed by a five-test battery at baseline and month 6. The primary outcome was change in the quantitative neurocognitive performance z score (QNPZ-5), the average of the z scores of the five tests. Associations of the 6-month change in test scores with ART use, CD4 cell counts, HIV RNA levels, and other factors were determined using multiple regression models. At baseline, median age was 40 years, median CD4 cell count was 513 cells/mm³, 88 % had plasma HIV RNA ≤400 copies/mL, and mean QNPZ-5 was -0.68. Neurocognitive performance improved in both treatment groups by 6 months; QNPZ-5 scores increased by 0.20 and 0.13 in the intermittent and continuous ART groups, respectively (both P < 0.001 for increase and P = 0.26 for difference). ART was used on average for 3.6 and 5.9 out of the 6 months in the intermittent and continuous ART groups, respectively, but the increase in neurocognitive test scores could not be explained by ART use, changes in CD4, or plasma HIV RNA, which suggests a practice effect. The impact of a practice effect after 6 months emphasizes the need for a control group in HIV studies that measure intervention effects using neurocognitive tests similar to ours.

Original language	English (US)
Pages (from-to)	383-392
Number of pages	10
Journal	Journal of neurovirology
Volume	19
Issue number	4
DOIs	https://doi.org/10.1007/s13365-013-0190-x
State	Published - Aug 2013

Bibliographical note

Funding Information:
The study was funded by NIH grants U01-AI4636 (National Institute of Mental Health [NIMH] and the National Institute of Neurological Disorders and Stroke [NINDS]), U01AI042170, and U01AI46362 (National Institute of Allergy and Infectious Diseases [NIAID]). We gratefully acknowledge the contributions of participants, investigators, and staff who were crucial to the success of the study. Clinical sites and investigators participating in the SMART Neurology substudy were published (Wright et al. ).

Funding Information:
The following authors received research support from the NIH: BG and MPR from NIH/NIAID (U01-AI068641, U01-AI042170, and U01-AI46362); EJW (NIMH/NINDS 1U01-AI068641); BJB (R01 NS43103); RWP (NIDA P01DA026134, NIMH R01-MH62701, NIMH R21-MH083520, NIMH U01-MH083545, NIMH R01MH081772, NIMH/NIAIDU01-AI068641, and NIMH/NIAID U01-AI38858); and KRR (NIAID, supplement to 1U01AI068636-01, NIMH MH067751, NIAID U01-AI068641, and NINDS R21NS0692). MPB, JH, JCS, and MJV declare that they have no conflicts of interest.

Keywords

HIV
Learning effect
Neurocognitive performance
Neuropsychological tests
Practice effect
Test-retest

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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title = "Improved neurocognitive test performance in both arms of the SMART study: Impact of practice effect",

abstract = "We evaluated factors associated with improvement in neurocognitive performance in 258 HIV-infected adults with baseline CD4 lymphocyte counts above 350 cells/mm3 randomized to intermittent, CD4-guided antiretroviral therapy (ART) (128 participants) versus continuous therapy (130) in the Neurology substudy of the Strategies for Management of Antiretroviral Therapy trial. Participants were enrolled in Australia, North America, Brazil, and Thailand, and neurocognitive performance was assessed by a five-test battery at baseline and month 6. The primary outcome was change in the quantitative neurocognitive performance z score (QNPZ-5), the average of the z scores of the five tests. Associations of the 6-month change in test scores with ART use, CD4 cell counts, HIV RNA levels, and other factors were determined using multiple regression models. At baseline, median age was 40 years, median CD4 cell count was 513 cells/mm3, 88 % had plasma HIV RNA ≤400 copies/mL, and mean QNPZ-5 was -0.68. Neurocognitive performance improved in both treatment groups by 6 months; QNPZ-5 scores increased by 0.20 and 0.13 in the intermittent and continuous ART groups, respectively (both P < 0.001 for increase and P = 0.26 for difference). ART was used on average for 3.6 and 5.9 out of the 6 months in the intermittent and continuous ART groups, respectively, but the increase in neurocognitive test scores could not be explained by ART use, changes in CD4, or plasma HIV RNA, which suggests a practice effect. The impact of a practice effect after 6 months emphasizes the need for a control group in HIV studies that measure intervention effects using neurocognitive tests similar to ours.",

keywords = "HIV, Learning effect, Neurocognitive performance, Neuropsychological tests, Practice effect, Test-retest",

author = "Birgit Grund and Wright, {Edwina J.} and Brew, {Bruce J.} and Price, {Richard W.} and Roediger, {Mollie P.} and Bain, {Margaret P.} and Hoy, {Jennifer F.} and Shlay, {Judith C.} and Vjecha, {Michael J.} and Robertson, {Kevin R.}",

note = "Funding Information: The study was funded by NIH grants U01-AI4636 (National Institute of Mental Health [NIMH] and the National Institute of Neurological Disorders and Stroke [NINDS]), U01AI042170, and U01AI46362 (National Institute of Allergy and Infectious Diseases [NIAID]). We gratefully acknowledge the contributions of participants, investigators, and staff who were crucial to the success of the study. Clinical sites and investigators participating in the SMART Neurology substudy were published (Wright et al. ). Funding Information: The following authors received research support from the NIH: BG and MPR from NIH/NIAID (U01-AI068641, U01-AI042170, and U01-AI46362); EJW (NIMH/NINDS 1U01-AI068641); BJB (R01 NS43103); RWP (NIDA P01DA026134, NIMH R01-MH62701, NIMH R21-MH083520, NIMH U01-MH083545, NIMH R01MH081772, NIMH/NIAIDU01-AI068641, and NIMH/NIAID U01-AI38858); and KRR (NIAID, supplement to 1U01AI068636-01, NIMH MH067751, NIAID U01-AI068641, and NINDS R21NS0692). MPB, JH, JCS, and MJV declare that they have no conflicts of interest.",

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AU - Grund, Birgit

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AU - Brew, Bruce J.

AU - Price, Richard W.

AU - Roediger, Mollie P.

AU - Bain, Margaret P.

AU - Hoy, Jennifer F.

AU - Shlay, Judith C.

AU - Vjecha, Michael J.

AU - Robertson, Kevin R.

N1 - Funding Information: The study was funded by NIH grants U01-AI4636 (National Institute of Mental Health [NIMH] and the National Institute of Neurological Disorders and Stroke [NINDS]), U01AI042170, and U01AI46362 (National Institute of Allergy and Infectious Diseases [NIAID]). We gratefully acknowledge the contributions of participants, investigators, and staff who were crucial to the success of the study. Clinical sites and investigators participating in the SMART Neurology substudy were published (Wright et al. ). Funding Information: The following authors received research support from the NIH: BG and MPR from NIH/NIAID (U01-AI068641, U01-AI042170, and U01-AI46362); EJW (NIMH/NINDS 1U01-AI068641); BJB (R01 NS43103); RWP (NIDA P01DA026134, NIMH R01-MH62701, NIMH R21-MH083520, NIMH U01-MH083545, NIMH R01MH081772, NIMH/NIAIDU01-AI068641, and NIMH/NIAID U01-AI38858); and KRR (NIAID, supplement to 1U01AI068636-01, NIMH MH067751, NIAID U01-AI068641, and NINDS R21NS0692). MPB, JH, JCS, and MJV declare that they have no conflicts of interest.

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N2 - We evaluated factors associated with improvement in neurocognitive performance in 258 HIV-infected adults with baseline CD4 lymphocyte counts above 350 cells/mm3 randomized to intermittent, CD4-guided antiretroviral therapy (ART) (128 participants) versus continuous therapy (130) in the Neurology substudy of the Strategies for Management of Antiretroviral Therapy trial. Participants were enrolled in Australia, North America, Brazil, and Thailand, and neurocognitive performance was assessed by a five-test battery at baseline and month 6. The primary outcome was change in the quantitative neurocognitive performance z score (QNPZ-5), the average of the z scores of the five tests. Associations of the 6-month change in test scores with ART use, CD4 cell counts, HIV RNA levels, and other factors were determined using multiple regression models. At baseline, median age was 40 years, median CD4 cell count was 513 cells/mm3, 88 % had plasma HIV RNA ≤400 copies/mL, and mean QNPZ-5 was -0.68. Neurocognitive performance improved in both treatment groups by 6 months; QNPZ-5 scores increased by 0.20 and 0.13 in the intermittent and continuous ART groups, respectively (both P < 0.001 for increase and P = 0.26 for difference). ART was used on average for 3.6 and 5.9 out of the 6 months in the intermittent and continuous ART groups, respectively, but the increase in neurocognitive test scores could not be explained by ART use, changes in CD4, or plasma HIV RNA, which suggests a practice effect. The impact of a practice effect after 6 months emphasizes the need for a control group in HIV studies that measure intervention effects using neurocognitive tests similar to ours.

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KW - Learning effect

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KW - Neuropsychological tests

KW - Practice effect

KW - Test-retest

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Improved neurocognitive test performance in both arms of the SMART study: Impact of practice effect

Abstract

Bibliographical note

Keywords

UN SDGs

Access

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