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.
Subject(s)
AIDS Dementia Complex/prevention & control , Anti-Retroviral Agents/administration & dosage , HIV Infections/drug therapy , Learning , Neuropsychological Tests , Adult , Female , Humans , Male , Middle AgedABSTRACT
BACKGROUND: The growing number of older individuals with HIV in Australia implies that the prevalence of dementia and additional HIV-associated neurocognitive disorders will increase. There are currently no estimates of the future burden of neurocognitive disease in this population. METHODS: We estimated the number and age profile of people living with HIV to the end of 2009 using HIV/AIDS Registry data, and extrapolated these estimates to 2030. Prevalence of HIV-associated dementia (HAD) from 2005 to 2010 from a large Sydney hospital and cost estimates from the AIDS Dementia and HIV Psychiatry Service were used to estimate future HAD burden and costs. RESULTS: Based on our calculations, the number of HIV-positive individuals in Australia will increase from 16228 men and 1797 women in 2009 to 26963 men and 5224 women in 2030, while the number of individuals aged 60+ years will increase from 1140 men and 78 women to 5442 men and 721 women, i.e. a 377% increase of older men and an 825% increase in older women. Based on a 7.8% (157/2004) HAD prevalence obtained from hospital data, individuals with HAD will increase in number from 1314 men and 143 women in 2009 to 2204 men and 421 women in 2030. An estimated 22 men and 2 women with non-HIV dementia in 2009 will increase to 104 men and 12 women by 2030. The annual cost of care will increase from ~$29 million in 2009 to $53 million in 2030, mostly for full-time residential care. CONCLUSIONS: Neurocognitive disorders will place an increasing burden on resources, especially as those living with HIV age. Because it is unclear if HAD is an increased risk factor for non-HIV dementia, our calculations may be conservative.
Subject(s)
AIDS Dementia Complex/economics , AIDS Dementia Complex/epidemiology , Cost of Illness , Delivery of Health Care/economics , Life Expectancy , Population Dynamics , AIDS Dementia Complex/therapy , Age Distribution , Aged , Aged, 80 and over , Aging , Antiretroviral Therapy, Highly Active/statistics & numerical data , Australia/epidemiology , Cognition Disorders/economics , Cognition Disorders/epidemiology , Delivery of Health Care/trends , Female , Forecasting , Health Care Costs , Humans , Male , Patient Acceptance of Health Care/statistics & numerical data , Population Surveillance , Risk Factors , Sex DistributionABSTRACT
The authors investigated the combined age and HIV effects on cognitive functions in 146 individuals, 116 of whom had HIV infection. Forty-two percent had HIV-associated neurocognitive disorder, and all were receiving highly active antiretroviral therapy. Using linear and nonlinear regression modeling, the authors found only a trending effect of the quadratic term HIV status × age, both including dementia cases (p=0.12) and excluding dementia cases (p<0.06). Our results suggest that either this early-2000 cohort is not old enough to detect a clear interactive age and HIV effect or that there may be a survivor bias for individuals with long-term infection. Further longitudinal studies are warranted.
