Practice Effect and Normative Data of an HIV-specific Neuropsychological Testing Battery among Healthy Thais
Pasiri Sithinamsuwan MD*, Nicholas Hutchings BA**, Jintanat Ananworanich MD, PhD***,****,*****, Lauren Wendelken MS******, Putthachard Saengtawan BNS***, Robert Paul PhD*******, Nitiya Chomchey MSc***, James LK Fletcher BMBCh***, Thep Chalermchai MD, PhD***, Victor Valcour MD, PhD******
Affiliation : * Division of Neurology, Department of Medicine, Phramongkutklao Hospital, Bangkok, Thailand ** College of Physicians and Surgeons, Columbia University, New York, USA *** SEARCH, The Thai Red Cross AIDS Research Centre, Bangkok, Thailand **** HIV-NAT, The Thai Red Cross AIDS Research Centre, Bangkok, Thailand ***** Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand ****** Memory and Aging Center, University of California, San Francisco, CA, USA ******* Department of Psychology, University of Missouri in Saint Louis, Saint Louis, MO, USA
Objective : A longitudinal cohort study was conducted in Bangkok, Thailand between 2008 and 2013 in order to determine the
practice effect of serial neuropsychological testing and establish normative data among normal (HIV-uninfected) Thai
volunteers.
Material and Method: The authors enrolled 511 cognitively healthy individuals (HIV-uninfected, no drug abuse or other
previous/current neurological or psychological conditions) to assess baseline performance on a HIV-specific neuropsycho-
logical testing battery. Ninety-nine subjects were re-assessed at 6 and 12 months to evaluate practice effects.
Results : The mean age of the 99 subjects completing longitudinal visits was 49.2 years and 53 were male. The authors
identified improved mean raw scores on most neuropsychological tests with repeated measurements; however, only change
in WHO Auditory Verbal Learning Test (AVLT) scores (learning, attention, immediate and delayed recall tasks) met statistical
significance, with larger differences seen between baseline and 6-month compared to 6 and 12 months follow-up. Older age
correlated with poorer baseline raw score, and was a predictor of worse performance at 6 months and 12 months on several
tasks. Level of education was associated with practice effects on several tests. No similar effects were observed with gender.
Conclusion : The authors identified improved performance after repeated measurements revealing a significant practice
effect on an HIV-specific neuropsychological testing battery employed in Bangkok, Thailand. Main predictors were age and
educational attainment.
Keywords : Thailand, Neuropsychological test, Cognition
