Assessing cognitive capacity for participation in a research study

Neuropsychological assessment without upper limb involvement: a systematic review of oral versions of the Trail Making Test and Symbol-Digit Modalities Test

The Trail Making Test (TMT) and written version of the Symbol Digit Modalities Test (SDMT) assess attention, processing speed, and executive functions but their utility is limited in populations with upper limb dysfunction. Oral versions of the TMT and SDMT exist, but a systematic review of their psychometric properties and clinical utility has not been conducted, which was the goal of this study. Searches were conducted in PubMed and PsycINFO, test manuals, and the reference lists of included articles. Four measures were identified: the SDMT-oral, oral TMT-A, oral TMT-B, and the Mental Alternation Test (MAT). Two investigators independently reviewed abstracts to identify peer-reviewed articles that reported on these measures in adult populations. From each article, one investigator extracted information on reliability, validity, responsiveness, minimum detectable change, normative data, and demographic influences. A second investigator verified the accuracy of the data in a random selection of 10% of papers. The quality of the evidence for each psychometric property was rated on a 4-point scale (unknown, poor, adequate, excellent). Results showed excellent evidence for the SDMT-oral, adequate evidence for the oral TMT-B and MAT, and adequate to poor evidence for the oral TMT-A. These findings inform the clinical assessment of attention, processing speed, and executive functions in individuals with upper limb disability.

Evaluation of brief screening tools for neurocognitive impairment in HIV/AIDS: a systematic review of the literature

OBJECTIVE(S)

To systematically review literature on brief screening tools used to detect and differentiate between normal cognition and neurocognitive impairment and HIV-associated neurocognitive disorders (HANDs) in adult populations of persons with HIV.

DESIGN

A formal systematic review.

METHODS

We searched six electronic databases in 2011 and contacted experts to identify relevant studies published through May 2012. We selected empirical studies that focused on evaluating brief screening tools (<20 min) for neurocognitive impairment in persons with HIV. Two reviewers independently reviewed retrieved literature for potential relevance and methodological quality. Meta-analyses were completed on screening tools that had sufficient data.

RESULTS

Fifty-one studies met inclusion criteria; we focused on 31 studies that compared brief screening tools with reference tests. Within these 31 studies, 39 tools were evaluated and 67% used a comprehensive neuropsychological battery as a reference. The majority of these studies evaluated HIV-associated dementia (HAD). Meta-analyses demonstrated that the HIV Dementia Scale (HDS) has poor pooled sensitivity (0.48) and the International HIV Dementia Scale (IHDS) has moderate pooled sensitivity (0.62) in detecting a range of cognitive impairment. Five newer screening tools had relatively good sensitivities (>0.70); however, none of the tools differentiated HAND conditions well enough to suggest broader use. There were significant methodological shortcomings noted in most studies.

CONCLUSION

HDS and IHDS perform well to screen for HAD but poorly for milder HAND conditions. Further investigation, with improved methodology, is required to understand the utility of newer screening tools for HAND; further tools may need to be developed for milder HAND conditions.

Assessing cognitive capacity for participation in a research study

To give informed consent in research, persons must be mentally capable of understanding the study, risks, and benefits. An objective screening tool may assess cognitive capacity better than brief conversations or clinician input. The purpose is to explore the validity of the Mental Alternations Test (MAT) to assess the cognitive capacity of older (ages 50 years +) HIV+ persons (N = 81). Descriptive correlational quantitative method was used. About 12% of the sample was cognitively impaired. Contrary to expectations, primary language was the only variable with a significant relationship with the MAT (r = -.22, p = .02); there were no significant relationships between the MAT and age, education, alcohol, smoking, injection drug use, street or mind-altering drug use, physical functional status, depressive symptoms, comorbidities, or being diagnosed with AIDS. Our findings suggest caution in using the MAT as an instrument for assessing cognitive impairment in a linguistically diverse population.