The role of cognitive reserve in protecting cognitive ability in people with HIV
Bibliographic record
Abstract
The landscape of HIV-1 disease has radically improved with the contemporary anti-retroviral therapy. However, HIV-associated neurocognitive disorders (HAND) continue to be a challenge even among those with an optimal drug regime. Although neurocognitive deficits are typically of mild nature, the burden associated with HAND is an emerging public health concern due to unrelenting repercussions on everyday functioning including medication adherence, employment, and overall survival. Could people with HIV somehow protect themselves from cognitive impairment? Cognitive reserve is a theoretical entity which has been put forward to offset the deleterious impact of brain pathology on cognitive performance. This thesis investigated the impact of cognitive reserve on cognitive performance in individuals with HIV.The thesis commenced with a systematic review and a meta-analysis of the published literature (N=10) to estimate the strength of association between cognitive reserve and cognitive performance in HIV (Manuscript I). The association between the two constructs was found to be moderately strong. This work showed that discrepant indicators have been employed to operationalize cognitive reserve in HIV. It was found that participation in leisure and social activities was infrequently employed as an indicator of cognitive reserve in these HIV studies. This review produced a framework which hypothesized the mediating role of cognitive reserve on brain pathology and its consequences from the context of rehabilitation.The second manuscript quantified cognitive reserve into a single numeric value utilizing various indicators which have been proposed to build cognitive reserve. Pertinent data (including education, occupation, social network, number of spoken languages, and participation in other cognitively stimulating activities) were acquired from a Canadian longitudinal study (N=856) with HIV+ individuals to devise an index of cognitive reserve based on the differential impact of each indicator. This work involved a standard methodology where the regression coefficients for each contributing indicator were used in the scoring algorithm. A correlation coefficient of 0.3 between the developed index and a measure of cognitive performance at follow-up was expected given its hypothesized role as a mediator of cognitive performance rather than having a direct effect. Manuscript III documented the feasibility and efficacy potential of a 12-week combined aerobic and resistance training program in improving cognitive performance in HIV (N=27). This study was a subset of a cohort multiple randomized controlled trial which provided access to the participants who were eligible for the exercise program. As expected, physical performance measures showed improvements post-training. No positive influence was observed on the primary efficacy potential outcome of cognitive performance.Lastly, a systematic review was carried out to address some questions which surfaced at the outset of the aforementioned feasibility study. For instance, are pilot and feasibility studies the same? What should be the key objectives of a pilot study? What happens to a pilot study once it is completed? Does an effect size observed in a pilot study predict its follow-up? These questions were addressed based on 191 feasibility studies published in a specific rehabilitation journal since its inception. This work demonstrated that feasibility outcomes were often disregarded in the measurement strategy of these studies. Only a minor proportion of the studies got followed-up in a full-strength clinical trial and effect size did not drive this follow-up. This manuscript generated key areas of focus relevant to feasibility studies designed in rehabilitation research.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.004 | 0.015 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".