Abstract
HIV-Associated Neurocognitive Disorder (HAND) is a prevalent condition among persons with HIV resulting in cognitive impairments that may impact daily functioning. The relationship between neuropsychological (NP) test performance and functional status was investigated based on social services received (SSR) among 285 HIV-infected and 242 HIV-negative participants enrolled in the Hawai‘i Aging with HIV Cohort. HIV-infected participants scored significantly lower than the HIV-negative group on all measures of NP testing and also reported receiving SSR at a higher rate. Among HIV-infected participants, more SSR correlated with poorer overall global NP performance (ρ = −0.25, P < .001), as well as poorer performance in NP domains assessing psychomotor speed (ρ = −0.25, P < .001), and learning and memory (ρ = −0.19, P = .02). NP test performance did not correlate with the number of SSR among HIV-negative participants. Supplemental Security Income (SSI) was the most commonly utilized social service among HIV-infected. Receiving SSI was associated on multivariate analysis with poorer NP performance independent of lack of full time work, or nadir CD4 count. Poorer NP performance among HIV-infected individuals is associated with increased risk for social services. Interventions to address causes of cognitive dysfunction in this population may decrease demand for social services.
Keywords: HIV, Neuropsychological testing, social services
Introduction
HIV-associated Neurocognitive Disorder (HAND) occurs as a spectrum ranging from mild disease to its severest form, HIV-associated dementia (HAD). HAND is highly prevalent and seen in approximately 50% of HIV-infected individuals despite potent antiretroviral therapy (ART).1 Specific impairments in activities of daily living (eg, managing finances, medication management, shopping, employment, and driving) have been identified in individuals with HAND.2
Neurocognitive dysfunction remains highly prevalent among HIV-infected individuals despite the common availability of potent ART.1 Utilizing the Frascati criteria for HAND, a recent large study of 1,555 HIV-infected adults recruited from six university clinics across the United States diagnosed 32.7% to have asymptomatic neurocognitive impairment, 11.7% to have mild neuropsychological impairment, and 2.4% with HIV-associated dementia.1,3
HIV-associated neuropsychological (NP) impairment, even in its mildest form, has been previously associated with the inability to return to work, adhere to medication regimen, or operate a motor vehicle.2 Kalechstein and colleagues identified general intellectual functioning, memory, and executive functioning as the NP domains most associated with unemployment.4 van Gorp and colleagues found that in a group of 130 symptomatic HIV-positive individuals, the unemployed showed twice the occurrence of impairment (22%) compared to the employed group (11%).5 As learning, memory, and executive functioning are often impaired in HIV, and employment status is affected by impairments in these areas, NP measures sensitive to these domains have been used as predictors for return to work and functional ability.5,6,7 Gorman and colleagues found that HIV-positive individuals who were unemployed were likely to have a higher prevalence of cognitive impairment that related in this review to physical impairment, CD4 count, and age.2
The purpose of the current study was to supplement current literature by investigating the relationship between NP test performance and the number of social services received (SSR) among HIV-infected individuals and to compare findings to individuals without HIV infection. It was hypothesized that lower NP testing scores would result in increased use of social services, suggesting a lower ability to live independently. This study further aimed to determine if specific NP measures were associated with the amount of social services received.
Methods
Parent Cohort
This was a cross-sectional analysis of baseline data from the Hawai‘i Aging with HIV Cohort (HAHC) Study, a 5-year longitudinal study conducted between 2001 and 2006 to examine the impact of HIV and aging on various physiological, neurological, and neuropsychological dimensions.8 Briefly, the HAHC study recruited 157 older (age > 50 years) and 128 younger (age ≤ 40 years) HIV-infected participants with similar numbers of HIV-negative older and younger controls. All participants were living in Hawai‘i at the time of enrollment, reported English as their primary language, and denied neurological or major psychiatric disorders, head injury, or learning disability.8 The parent study was approved through the University of Hawai‘i Committee on Human Subjects and all participants provided informed consent which included permission to utilize data and specimens from the HAHC for future studies involving HIV and cognitive impairment.
Procedures
Data from HIV-infected and HIV-negative participants who completed data collection at entry (baseline) were utilized for this study. Data on younger and older participants were combined within the HIV-infected and HIV-negative group for the purpose of this analysis. Participants completed a comprehensive NP test battery assessing global and domain-specific cognitive functioning (ie, psychomotor speed, learning and memory, and executive functioning). Information on social service assistance, and relevant socio-demographic and economic variables regarding work status and living situation were also collected.
Social Services Received (SSR)
This label was used as a collective measure of the number of social services each participant endorsed receiving. Participants were asked about their current use of the following social services: Employer or union disability coverage, Supplemental Security Income (SSI), Social Security Disability (SSD), special transportation services, rent supplement, food stamps, subsidy for medicine, meal services, and home health care services. A summative score totaling the number of different social services received by each participant was then calculated (eg, endorsement of two different social services equated to a score of 2).
Neuropsychological Tests and Assessment of Mood
Participants underwent an 80-minute neuropsychological test battery assessing multiple cognitive domains typically affected by HIV. The cognitive domains were measured using a battery of tests including: Attention/Concentration (Choice and Sequential Reaction time from the California Computerized Assessment Package [CalCAP], Digit Span); Learning/Memory (Rey Auditory Verbal Learning Test [RAVLT], Rey Complex Figure Test [copy and recall]); Psychomotor speed (Trail Making Test - Part A, Wechsler Adult Intelligence Scale-Revised [WAIS-R] Digit Symbol, Grooved Pegboard); Executive Functioning (Verbal Fluency Test [FAS], Trailmaking Test - Part B); Language (Animal Naming, Boston Naming Test); Gross motor (Timed Gait). The National Adult Reading Test (NART) was used as a measure of premorbid functioning. This test is designed to measure an individual's level of general intellectual functioning prior to the onset of disease (eg, HIV). Results from the NART were used to exclude individuals with borderline or lower intellectual functioning that may otherwise confound that data. This neuropsychological battery was adapted from that used in the NorthEast AIDS Dementia (NEAD) cohort.9 Depression symptomatology was assessed using the Beck Depression Inventory.10 Published age and education-adjusted normative data were used to calculate z-scores used in clinical characterization of performance. NPZ composite scores were calculated by taking the arithmetic mean of z-scores within the cognitive domain as follows: NPZglobal: Trail Making Test - Parts A & B, Grooved Pegboard, dominant hand and nondominant hand, WAIS-R Digit Symbol, RAVLT Total, RAVLT Delayed Recall, Rey- Complex Figure Test - Delayed Recall Trial, Timed Gait, CalCap Choice and Sequential times, FAS, Animals; Psychomotor speed (NPZpm): Trail Making Test -Part A, Grooved Pegboard, dominant hand, Grooved Pegboard, nondominant hand, WAIS-R Digit Symbol; Learning and memory (NPZlrnmem): RAVLT Total, RAVLT Delayed Recall, Rey Complex Figure Test -Delayed Recall Trial; Executive functions (NPZef): Trail Making Test - Part B, FAS. It is expected that higher NPZ composite scores are associated with higher functioning.
Data Management and Statistical Analysis
Spearman correlation coefficients were used to investigate the relationships between the number of SSR and NP test performance. Mann Whitney U was utilized to compare NP composite scores between groups. As SSI was the most commonly utilized social service in the HIV-infected population, univariate logistic regression was conducted to identify variables associated with availing of SSI. The effects of NPZ composite scores in availing of SSI were adjusted for significant socio-demographic variables (P < .05) using multivariate logistic regression. Analyses were completed using SPSS statistical software package, version 20.0, and Stata statistical software.
Results
As shown in Table 1, the cohort consisted of 285 participants infected with HIV (128 younger and 157 older) and 242 HIV-negative participants (120 younger and 122 older). HIV-infected and HIV negative groups were similar in ethnicity (57% Caucasian), gender (84% men), and in age and education distribution within their young and older respective groups. Within the younger HIV-infected group, the mean age and education was 35.1 (SD = 4.8) and 13.2 (1.9) years, respectively. The older HIV-infected group had a mean age of 54.6 (SD = 5.4) and education of 14.6 (SD = 2.5) years. In the younger HIV-negative group mean age was 35.5 (SD = 4.8) and education was 13.4 (SD = 2.2) years. The older HIV-negative group had a mean age of 55.2 (SD = 5.5) and 14.9 (SD = 2.7) years of education (data not shown in table). Among the HIV-1 group, mean duration of HIV infection was 9.7 (SD = 5.9) years, with a mean CD4 count of 459.3 (normal range: 500–1000 cells/mm3). Older participants differed from younger participants in duration of HIV infection (median 12.6 years vs 6.6 years), age (median 53.6 vs 36.5 years), and education (14 years vs 12 years). Table 1 shows baseline characteristics for the entire sample by group. HIV-infected participants received social services at a significantly higher rate (P< .001), with 70% receiving at least one service, compared to 28% in the HIV-negative group (data not shown in table). Although the HIV-infected group reported an average of two services (median 2.0, IQR = 0.0, 3.0) compared to an average of 0 (median 0, IQR = 0.0, 1.0) services in the HIV-negative group, 20% of the HIV-infected group received four or more services compared to less than 1% of the HIV-negative group. The HIV-infected participants also scored significantly lower on all measures of NP testing (see Table 1). The number of SSR correlated with NPZglobal (ϱ = −0.3, P < .001), NPZpm (ϱ = −0.3, P < .001), and NPZlrnmem (ϱ = −0.2, P = .02) (see Table 2). In contrast, the number of SSR was not correlated with NP test performance among the HIV-negative group.
Table 1.
Baseline Characteristics of Subjects by Group
| HIV+ | HIV− | P-value | |
| Sample Size (n) | 285 | 242 | − |
| Gender (% male) | 239 (84%) | 203(84%) | .98 |
| Age (Mean, SD) | 45.83 (10.1) | 45.43(11.2) | |
| Education (Mean, SD) | 14 (2.3) | 14.18(2.6) | .41 |
| Ethnicity by group ( %) | .69 | ||
| Caucasian | 163 (57.2%) | 140(57.9%) | − |
| Asian/Pacific Islander | 80 (28.2%) | 66(27.2%) | − |
| Hispanic | 19 (6.7%) | 12(5.0%) | − |
| African American | 13 (5.6%) | 12(5.0%) | − |
| Native American/Alaskan | 6 (2.1%) | 6(2.5%) | |
| Other | 4 (7.1%) | 6(2.1%) | − |
| Duration of HIV infection (Mean, SD) | 9.64 (5.87) | − | − |
| CD4 Count | 459.33 (245.17) | − | − |
| CD4 Nadir Count | 224.31 (192.1) | − | − |
| NPZ Global + | −.10 (−0.52, 0.19) | .003 (−0.34,0.34) | .002* |
| NPZ Psychomotor Speed + | −0.05 (−0.43, 0.30) | 0.06 (−0.30, 0.36) | .045* |
| NPZ Learning and memory + | −.24 (−0.82, 0.28) | −0.13 (−.66, 0.50) | .01* |
| NPZ Executive Functioning + | −.16 (−0.81, 0.36) | −.004 (−.56, .47) | .02* |
| Median number of social services received per person | 2.0 (0.0, 3.0) | 0.0 (0.0, 1.0) | < .001* |
| Total number of patients availing social security income (SSI)% | 112 (40%) | 13 (5%) | < .001* |
Note: +Mann Whitney U and IQR reported; * significant difference between HIV+ and HIV-negative groups (P < .05, two-tailed)
Table 2.
Correlations Between Number of Social Services Received and Neuropsychological Composite Scores by Group
| Social Services Received | ||
| HIV-infected (n= 285) | Spearman's ρ | P-value |
| NPZ Global | −0.25 | < .001* |
| NPZpm | −0.25 | < .001* |
| NPZlrnmem | −0.19 | .02* |
| NPZef | −0.12 | .051 |
| HIV-negative (n=242) | Spearman's ρ | P-value |
| NPZ Global | −0.08 | .21 |
| NPZpm | −0.10 | .14 |
| NPZlrnmem | −0.07 | .30 |
| NPZef | −0.08 | .24 |
Note: *P < .05, two-tailed.
Among the HIV-infected group, SSI was the most commonly utilized social service (40%). SSI is a Federal income supplement program funded by general tax revenues (not Social Security taxes). It is designed to help aged, blind and disabled people who have little or no income, and provides cash to meet basic needs for food, clothing, and shelter. Because of its importance as a national program and its prominence in SSR among our HIV-infected participants, the role of NP performance as a risk factor for SSI was specifically examined. Analyzing the entire cohort, participants who were HIV positive were more likely to receive SSI than HIV-negative participants (adjusted odds ratio [aOR] 11.7, 95% confidence interval: [6.3, 21.0]), P < .001, even when adjusting for living situation, work status, years of education, and age on multivariate logistic regression. HIV-infected participants availing SSI scored significantly lower than HIV-infected participants not availing SSI on all measures of cognitive functioning (NPZglobal: median −0.3 vs −0.01, P = .003; NPZpm: median −0.2 vs 0.07; P < .001; NPZlrnmem: median −0.4 vs −0.1; P = .04; NPZef: median −0.4 vs −0.07; P = .04).
Subgroup analysis of participants by HIV status was conducted to investigate how NPZ scores impact the availing of SSI (Table 3). Among HIV-infected participants, lack of full time work, current CD4 count, CD4 Nadir, NPZglobal, NPZpm ,NPZef, and NPZlrnmem were associated with availing SSI. In the multivariate analysis, NPZglobal (aOR = 0.6, P = .04), NPZpm (aOR = 0.5, P = .02), and NPZlrnmem (aOR = 0.6, P = .02) as well as CD4 Nadir (aOR = 1.0, P < .001) remained significantly associated with SSI. Lack of full time work was also consistently significant on multivariate logistic regression (aOR ranging from 14.2 to 19.2 depending on NPZ score used, P < .001).
Table 3a.
Factors Associated with Availing of Social Security Income Among HIV- infected Participants on Univariate and Multivariate Analyses
| HIV-infected | Univariate | Multivariate | ||||
| Odds Ratio | Confidence Interval (95%) | P-value | Adjusted Odds Ratio | Confidence Interval (95%) | P-value | |
| Age | 1.01 | 1.0, 1.03 | .24 | |||
| Education | 0.92 | 0.82, 1.01 | .09 | |||
| Gender | 1.31 | 0.69, 2.51 | .41 | |||
| Living alone | 1.25 | 0.77, 2.04 | .37 | |||
| No full time work | 15.89 | 6.16, 40.96 | < .001* | 19.15 | 6.44, 56.97 | < .001* |
| Current CD4 count | 0.99 | 0.99, 0.99 | .04* | 0.99 | 0.99, 1.0 | .17 |
| Nadir CD4 count | 0.99 | 0.99, 0.99 | < .001* | 0.99 | 0.99, 0.99 | < .001* |
| NPZglobal | 0.38 | 0.23, 0.61 | < .001* | 0.55 | 0.31, 0.99 | .04* |
| NPZpm | 0.42 | 0.28, 0.64 | < .001* | 0.54 | 0.33, 0.90 | .02* |
| NPZef | 0.73 | 0.56, 0.95 | .02* | 0.79 | 0.59, 1.07 | .13 |
| NPZlrnmem | 0.56 | 0.40, 0.77 | < .001* | 0.64 | 0.44, 0.94 | .02* |
Among the HIV-negative group, variables associated with availing SSI on univariate analyses were NPZglobal, and NPZpm. All HIV-negative participants without full time work (n = 13) received SSI. Hence, work status was collinear on univariate logistic regression analysis.
Discussion
The current study investigated the relationship between NP test performance and utilization of social services. HIV-infected participants endorsed receiving more social services of different types than their HIV-negative counterparts, and poorer NP test performance was associated with the need for social services. Furthermore, the current study found that poorer NP performance is a risk factor for being on SSI, a national social service commonly utilized by HIV-infected individuals, and that this association is independent of lack of work or of certain immunologic parameters.
The current study extends the information in this field by adding data that impairment in NP performance is linked to the use of social services. More specifically, the use of social services was extremely common among HIV-infected participants with 70% of participants receiving at least one service and 20% receiving four or more services. The need for such services among HIV-infected participants, as assessed by the number of SSR, correlated directly with global NP performance as well as sub-domain performance in psychomotor speed and learning and memory. Interestingly this association was not seen among HIV-negative participants, perhaps because the degree of impairment in this group may have been insufficient for such associations to be seen.
SSI, one costly aspect of SSR, was the most commonly utilized social service among HIV-infected participants, with 40% of participants utilizing this service compared to 5% in HIV-negative participants. SSI is also of particular significance because it is a national program with standardized criteria for eligibility. The current study demonstrated that impaired NP performance is a risk for need of SSI independent of lack of full-time work, or of current CD4 count, one important HIV-specific immunologic parameter denoting current immunologic status. No specific pattern of NP impairment was found in association with the need for social services. The need for social services was associated with global NP performance as well as with all NP subdomains assessed, with executive functioning perhaps demonstrating the weakest association. This is somewhat puzzling as many of the defined “social services received” in this study were associated with financial responsibility and external assistance, which is typically associated with impairments in executive functions (eg, organization and planning skills).2
The study has several very important limitations. First, the study was a retrospective analysis of data collected between 2001 to 2006, and may not reflect the utilization of social services in more recent years. In addition, because the HAHC was recruited by young and old age groups with no individuals aged 40 to 49, the data may not accurately reflect the overall social service or NP performance status of the entire population of HIV-infected individuals.
Conclusion
In summary, the current study revealed that the use of social services was high in the HIV-infected population and NP impairment was associated with the need for such services. NP impairment was also found to be a predictor of being on SSI, independent of work status or HIV-specific immunologic parameters. The need for social services was not linked to any specific pattern of NP impairment. Interventions to address cognitive dysfunction among the HIV-infected population on potent ART may decrease the demand for social services.
Table 3b.
Factors Associated with Availing of Social Security Income Among HIV- negative Participants on Univariate and Multivariate Analysis.*
| HIV-negative | Univariate | Multivariate | ||||
| Odds Ratio | Confidence Interval | P-value | Adjusted Odds Ratio | Confidence Interval | P-value | |
| Age | 1.05 | .08 | ||||
| Education | .82 | 0.62, 1.09 | .17 | |||
| Gender | .41 | 0.05, 3.28 | .40 | |||
| Living alone | 1.06 | 0.28, 4.0 | .93 | |||
| NPZglobal | .30 | 0.1, 0.88 | .03* | .43 | 0.13, 1.36 | .15 |
| NPZpm | .33 | 0.14, 0.76 | .01* | |||
| NPZef | .66 | 0.33, 1.31 | .24 | |||
| NPZlrnmem | .50 | 0.23, 1.07 | .08 | |||
Note: “No full time work” was collinear on univariate analysis.
Acknowledgements
The authors thank the participants of the Hawai‘i Aging with HIV cohort for their commitment. This work was supported in part by NIH grant U54 NS43049.
Conflict of Interest
None of the authors identify a conflict of interest.
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