“Do It-Yourself”: Home Blood Pressure as a Predictor of Traditional and Everyday Cognition in Older Adults

Background Hypertension guidelines recommend home blood pressure (HBP) monitoring in adjunct to office blood pressure (OBP) for its greater reproducibility and prognostic utility in the prevention of cardiovascular outcomes, especially stroke. To date, the relationship between HBP and cognitive function remains unexplored. Methods We examined HBP as a cognitive predictor in a multi-ethnic group of community-dwelling adults aged 60 and over (N = 133) using neuropsychological measures and analyzed the data using multiple regression analyses. We also employed “everyday cognition” measures that have been found to have higher prognostic utility for real-world functioning than traditional cognitive tasks. Results Good to perfect HBP monitoring compliance over seven days was achieved by 88.7% of the participants with superior reliability (ICC≥.96) to office readings. Higher home systolic BP and pulse pressure predicted worse processing speed, executive function, and everyday cognitive function, whereas lower home diastolic BP predicted worse everyday cognition. Office readings were similarly associated with everyday cognitive function but with no other cognitive measures. Conclusion Our findings are the first to validate HBP as a predictor of neuropsychological function in older adults beyond cognitive screening. Differential relationships among blood pressure variables and specific cognitive domains were observed. With proper standardization and training, we demonstrated that HBP can be obtained in a multi-ethnic community-dwelling older adult cohort. Our findings emphasize the importance of employing blood pressure and cognitive measures that are adequately sensitive to detect vascular-related cognitive impairment in a relatively healthy population. Implications regarding proper HBP measurement for hypertension management, cognitive health, and everyday function are discussed

Medication Adherence in Renal Transplant Recipients: A Latent Variable Model of Psychosocial and Neurocognitive Predictors

Objective Estimates indicate that 20–70% of renal transplant recipients are medication non-adherent, significantly increasing the risk of organ rejection. Medication adherence is negatively impacted by lower everyday problem solving ability, and associations between depressive symptoms, self-efficacy, and adherence are reported in renal transplant recipients. Nonetheless, to date, these associations have not been examined concurrently. Given the relationship between non-adherence and organ rejection, it is critical to gain a better understanding of the predictors of adherence in renal transplant recipients. To this end, we modeled relationships among cognitive abilities, depressive symptoms, self-efficacy, and adherence in this group. Methods Participants (N = 211) underwent renal transplant at least one year prior to participation. Adherence was measured via self-report, medication possession ratio, and immunosuppressant blood-level. Traditionally-measured neurocognitive and everyday problem-solving abilities were assessed. Depressive symptoms were measured via self-report, as were general and medication adherence related self-efficacy. Structural equation modeling was used to assess the fit of the model to available data. ResultsEveryday problem solving and self-efficacy had direct positive associations with adherence. Depressive symptoms were negatively associated with self-efficacy, but not adherence. Traditionally-measured neurocognitive abilities were positively associated with self-efficacy, and negatively associated with depressive symptoms. Conclusions We present a comprehensive investigation of relationships between cognitive and psychosocial factors and adherence in medically stable renal transplant recipients. Findings confirm the importance of everyday problem solving and self-efficacy in predicting adherence and suggest that influences of depressive symptoms and neurocognitive abilities are indirect. Findings have important implications for future development of interventions to improve medication adherence in renal transplant recipients

Impact of Once- Versus Twice-Daily Tacrolimus Dosing on Medication Adherence in Stable Renal Transplant Recipients: A Canadian Single-Center Randomized Controlled Trial

Background: Prevalence of immunosuppressant nonadherence in renal transplant recipients is high despite negative clinical outcomes associated with nonadherence. Simplification of dosing has been demonstrated to improve adherence in renal transplant recipients as measured through electronic monitoring and self-report. Objective: The purpose of this study was to replicate and extend previous findings by measuring adherence with multiple methods in a Canadian sample. Design: The study design was a randomized controlled medication dosing trial in adult renal transplant patients. The trial length was 4 months. Setting: This study was conducted within the Solid Organ Transplant (SOT) Clinic at Vancouver General Hospital (VGH; Vancouver, Canada). Patients: A total of 46 adult renal recipients (at least 1 year post-transplant) were recruited through the SOT clinic. With 8 withdrawals, 38 individuals completed all phases of the study. Measurements: Medication adherence was measured for a period of 4 months using multiple methods, including electronic monitoring (MEMS [Medication Event Monitoring System]), pharmacy refill data (medication possession ratio [MPR]), and by self-report using the Adherence subscale of the Transplant Effects Questionnaire (TEQ). Methods: Participants were randomized to twice-daily (n = 19) or once-daily tacrolimus dosing (n = 19) and followed over a 4-month period via monthly clinic study visits. Comparisons between the treatment groups were performed using the Mann-Whitney U and chi-square tests, for continuous and categorical variables, respectively. Results: As outlined in Table 3, the once-daily dosing group showed significantly better MEMS Dose Adherence (P = .001), whereas MEMS Timing Adherence showed a tendency toward better adherence for this group, but was not significant (P = .052). MEMS Days Adherent (P = .418), MPR% (P = .123), and self-reported adherence (P = .284) did not differ between the once- and twice-daily dosing groups when measured as continuous variables. The MPR% was significantly better for the once-daily dosing group when measured dichotomously but not continuously (P = .044). Notably, most of those exposed to once-daily dosing (63.2%) preferred this to the twice-daily regimen. Limitations: Limitations included small sample size and short follow-up period, precluding the examination of clinical outcome differences. Conclusions: Results for dose adherence replicate the finding that dose simplification increases adherence to immunosuppressants as measured through electronic monitoring. Such an advantage for the once-daily dosing group was not seen across the 2 other electronic monitoring measurement variables (days and timing adherence). This study extends previous research by examining adherence in once versus twice-daily dosing via prescription refill data in a Canadian sample. Given the gravity of potential health outcomes associated with nonadherence, although results indicate inconsistencies in significance testing across measurement methods, the medium to large effect sizes seen in the data favoring better adherence with once-daily dosing provide an indication of the potential clinical significance of these findings. Trial registration: This study was registered with ClinicalTrials.gov (NCT01334333) on April 11, 2011

False-Belief Reasoning From 3 to 92 Years of Age

False-belief reasoning, defined as the ability to reason about another person’s beliefs and appreciate that beliefs can differ from reality, is an important aspect of perspective taking. We tested 266 individuals, at various ages ranging from 3 to 92 years, on a continuous measure of false-belief reasoning (the Sandbox task). All age groups had difficulty suppressing their own knowledge when estimating what a naïve person knew. After controlling for task-specific memory, our results showed similar false-belief reasoning abilities across the preschool years and from older childhood to younger adulthood, followed by a small reduction in this ability from younger to older adulthood. These results highlight the relative similarity in false-belief reasoning abilities at different developmental periods across the lifespan

Diffusion Tensor Imaging of Neurocognitive Profiles in a Community Cohort Living in Marginal Housing

Objective:  We investigated white matter differences associated with distinct neurocognitive profiles derived from a large cohort of marginally housed persons with comorbid physical and mental illnesses. Our prior work identified three profile cluster groups: a high functioning group (Cluster 1), a low functioning group with relative strength in decision‐making (Cluster 3), and an intermediary group with a relative decision‐making weakness (Cluster 2). This study extends previous findings of cortical gray matter differences between these groups with evidence for putative neurodevelopmental abnormalities in the low cognitive functioning group (i.e., Cluster 3). We hypothesized that altered white matter diffusion would be associated with the lowest functioning neurocognitive profile and would be associated with previously observed gray matter differences. Method:  Participants from a socially impoverished neighborhood in Vancouver, Canada underwent neurocognitive evaluation and neuroimaging. We performed Tract‐Based Spatial Statistics using diffusion tensor imaging data from 184 participants to examine whole‐brain differences in white matter microstructure between cluster analytically derived neurocognitive profiles, as well as unitary neurocognitive measures. Correlations between frontal gray and white matter were also examined. Results:  Cluster 3 showed increased diffusion in predominately bilateral frontal and interhemisphere tracts (vs. Clusters 1 and 2), with relatively greater diffusion in the left hemisphere (vs. Cluster 1). Differences in radial diffusivity were more prominent compared with axial diffusivity. A weak association between regional frontal fractional anisotropy and previously defined abnormalities in gyrification was observed. Conclusions:  In a socially marginalized sample, we established several patterns in the covariation of white matter diffusion and neurocognitive functioning. These patterns elucidate the neurobiological substrates and vulnerabilities that are apt to underlie functional impairments inherent to this complex and heterogeneous population

Traumatic Brain Injury in Precariously Housed Persons: Incidence and Risks

Background Homeless and precarious housed persons are particularly prone to traumatic brain injuries (TBIs), but existent incidence rates are hampered by poor case acquisition. We rigorously documented TBIs in precariously housed persons transitioning in and out of homelessness. Methods Between December 2016 and May 2018, 326 precariously housed participants enrolled in a longitudinal study in Vancouver, Canada were assessed monthly for TBI occurrences after education on sequelae. Over one participant-year, 2433 TBI screenings were acquired for 326 person-years and variables associated with odds of incident TBI were evaluated. Findings One hundred participants acquired 175 TBIs, yielding an observed incidence proportion of 30¢7% and event proportion of 53¢7%. Of the injured, 61% reported one TBI and 39% reported multiple injuries. Acute intoxication was present for more than half of the TBI events assessed. Additionally, 9¢7% of TBI events occurred in the context of a drug overdose. Common injury mechanisms were falls (45¢1%), assaults (25¢1%), and hitting one’s head on an object (13¢1%). In this community-based but non-randomly recruited sample, exploratory analyses identified factors associated with odds of an incident TBI over one year of follow-up, including: schizophrenia disorders (odds ratio (OR) = 0¢43, 95% confidence interval (CI) 0¢19, 0¢94), role functioning (OR = 0¢69, 95% CI 0¢52, 0¢91), opioid dependence (OR = 2¢17, 95% CI 1¢27, 3¢72) and those reporting past TBIs (OR = 1¢99, 95% CI 1¢13, 3¢52). Interpretation Given the ubiquity of TBIs revealed in this precariously housed sample, we identify an underappreciated and urgent healthcare priority. Several factors modified the odds of incident TBI, which can facilitate investigations into targeted prevention efforts

Component Processes of Decision Making in a Community Sample of Precariously Housed Persons: Associations With Learning and Memory, and Health-Risk Behaviors

The Iowa Gambling Task (IGT) is a widely used measure of decision making, but its value in signifying behaviors associated with adverse, “real-world” consequences has not been consistently demonstrated in persons who are precariously housed or homeless. Studies evaluating the ecological validity of the IGT have primarily relied on traditional IGT scores. However, computational modeling derives underlying component processes of the IGT, which capture specific facets of decision making that may be more closely related to engagement in behaviors associated with negative consequences. This study employed the Prospect Valence Learning (PVL) model to decompose IGT performance into component processes in 294 precariously housed community residents with substance use disorders. Results revealed a predominant focus on gains and a lack of sensitivity to losses in these vulnerable community residents. Hypothesized associations were not detected between component processes and self-reported health-risk behaviors. These findings provide insight into the processes underlying decision making in a vulnerable substance-using population and highlight the challenge of linking specific decision making processes to “real-world” behaviors

Mean participant performance across cognitive measures.

<p>Mean participant performance across cognitive measures.</p

Multiple regressions examining effects of demographic variables, office blood pressure (OBP), and cognitive factors.

<p>Multiple regressions examining effects of demographic variables, office blood pressure (OBP), and cognitive factors.</p