OBJECTIVE: To quantify and characterize the nature of cognitive change over 1 year in a cohort of HIV-positive former plasma donors in rural China.
DESIGN: The present study is an observational cohort study.
METHODS: One hundred and ninety-two HIV-positive and 101 demographically comparable HIV-negative individuals, all former plasma donors, who lived in a rural part of China, received comprehensive medical and neuropsychological examinations. At study entry, 56% of HIV-positive group was on combination antiretroviral treatment and 60.9% at follow-up. Multiple regression change score approach was used with the HIV-negative sample to develop norms for change that would be then applied to the HIV-positive participants. Follow-up test scores adjusted for the control group practice effect.
RESULTS: Fifty-three HIV-positive individuals (27%) developed significant cognitive decline as compared with five (5%) HIV-negative individuals. Cognitive decline was predicted at baseline by AIDS status, lower nadir CD4, and worse processing speed; at follow-up, it was associated with lower current CD4 cell count and failure of viral suppression on combination antiretroviral treatment. Neuropsychological decline also was associated with decreased independence in activities of daily living. Using neuropsychological impairment scores that were corrected for 'practice' on repeated testing, we found that among the decliners, 41.5% (N = 22) had incident impairment, whereas 38% (N = 20) declined within the impaired range and another 20.7% (N = 11) declined within the normal range.
CONCLUSION: The present study demonstrates that despite ongoing combination antiretroviral treatment, cognitive decline in HIV-positive people is common over a 1-year follow-up. Regression-based norms for change on western neuropsychological tests can be used to detect disease-related cognitive decline in a developing country.