Specialist Availability and Drug Adherence in Older Adults with Dementia Across Regions of the United States.

BACKGROUND: Access to specialists facilitates appropriate Alzheimer's disease and related dementia (ADRD) medication use and adherence. However, there is little information on the impact of specialists' availability on ADRD medication adherence, especially in regions of the United States (US) where specialists are scarce, e.g., the Deep South (DS). OBJECTIVE: To ascertain whether the availability of specialty physicians in the DS and other US regions predicts ADRD medication adherence among community-dwelling older adultsMethods:We conducted secondary analyses of claims data for 54,194 Medicare beneficiaries with ADRD in 2013-2015. Medication adherence was measured using the proportion of days covered (PDC). Multivariable-adjusted Modified Poisson regression was used to examine associations of adherence with physicians' availability by region. RESULTS: The race/ethnicity distribution was 81.44% white, 9.17% black, 6.24% Hispanic, 2.25% Asian, and 1% other; 71.81% were female, and 42.36% were older than 85 years. Beneficiaries across regions differed in all individual and contextual characteristics except sex and comorbidities. Neurologists and psychiatrists' availability was not significantly associated with adherence (DS = 1.00, 0.97-1.03 & non-DS = 1.01, 1.00-1.01). Race and having ≥1 specialist visits were associated with a lower risk of adherence in both regions (p < 0.0001). Advanced age, dual Medicare/Medicaid eligibility, and living in non-large metropolitan areas, were associated with adherence in the non-DS region. CONCLUSION: Among older Americans with ADRD, a context defined by specialist availability does not affect adherence, but other context characteristics related to socioeconomic status may. Research should further examine the influence of individual and contextual factors on ADRD treatment among older adults.

Dementia Care in Diverse Older Adults in the U.S. Deep South and the Rest of the United States.

BACKGROUND: Use of specialists and recommended drugs has beneficial effects for older adults living with Alzheimer's disease and related dementia (ADRD). Gaps in care may exist for minorities, e.g., Blacks, and especially in the United States (U.S.) Deep South (DS), a poor U.S. region with rising ADRD cases and minority overrepresentation. Currently, we have little understanding of ADRD care utilization in diverse populations in this region and elsewhere in the U.S. (non-DS), and the factors that adversely impact it. OBJECTIVE: To examine utilization of specialists and ADRD drugs (outcomes) in racial/ethnic groups of older adults with ADRD and the personal or context-level factors affecting these outcomes in DS and non-DS. METHODS: We obtained outcomes and personal-level covariates from claims for 127,512 Medicare beneficiaries with ADRD in 2013-2015, and combined county-level data in exploratory factor analysis to define context-level covariates. Adjusted analyses tested significant association of outcomes with Black/White race and other factors in DS and non-DS. RESULTS: Across racial/ethnic groups, 33%-43% in DS and 43%-50% in non-DS used specialists; 47%-55% in DS and 41%-48% in non-DS used ADRD drugs. In adjusted analyses, differences between Blacks and Whites were not significant. Vascular dementia, comorbidities, poverty, and context-level factor "Availability of Medical Resources" were associated with specialist use; Alzheimer's disease and senile dementia, comorbidities, and specialist use were associated with drug use. In non-DS only, other individual, context-level covariates were associated with the outcomes. CONCLUSION: We did not observe significant gaps in ADRD care in DS and non-DS; however, research should further examine determinants of low specialist and drug use in these regions.

Assessment of drought tolerance of 49 switchgrass (Panicum virgatum) genotypes using physiological and morphological parameters.

BACKGROUND: Switchgrass (Panicum virgatum L.) is a warm-season C4 grass that is a target lignocellulosic biofuel species. In many regions, drought stress is one of the major limiting factors for switchgrass growth. The objective of this study was to evaluate the drought tolerance of 49 switchgrass genotypes. The relative drought stress tolerance was determined based on a set of parameters including plant height, leaf length, leaf width, leaf sheath length, leaf relative water content (RWC), electrolyte leakage (EL), photosynthetic rate (Pn), stomatal conductance (g s), transpiration rate (Tr), intercellular CO2 concentration (Ci), and water use efficiency (WUE). RESULTS: SRAP marker analysis determined that the selected 49 switchgrass genotypes represent a diverse genetic pool of switchgrass germplasm. Principal component analysis (PCA) and drought stress indexes (DSI) of each physiological parameter showed significant differences in the drought stress tolerance among the 49 genotypes. Heatmap and PCA data revealed that physiological parameters are more sensitive than morphological parameters in distinguishing the control and drought treatments. Metabolite profiling data found that under drought stress, the five best drought-tolerant genotypes tended to have higher levels of abscisic acid (ABA), spermine, trehalose, and fructose in comparison to the five most drought-sensitive genotypes. CONCLUSION: Based on PCA ranking value, the genotypes TEM-SEC, TEM-LoDorm, BN-13645-64, Alamo, BN-10860-61, BN-12323-69, TEM-SLC, T-2086, T-2100, T-2101, Caddo, and Blackwell-1 had relatively higher ranking values, indicating that they are more tolerant to drought. In contrast, the genotypes Grif Nebraska 28, Grenville-2, Central Iowa Germplasm, Cave-in-Rock, Dacotah, and Nebraska 28 were found to be relatively sensitive to drought stress. By analyzing physiological response parameters and different metabolic profiles, the methods utilized in this study identified drought-tolerant and drought-sensitive switchgrass genotypes. These results provide a foundation for future research directed at understanding the molecular mechanisms underlying switchgrass tolerance to drought.

Doppler myocardial performance index in assessment of ventricular function in children with single ventricles.

BACKGROUND: Quantitative assessment of ventricular function in children with single ventricles is both difficult and subjective because of asymmetric ventricular geometry. The Doppler myocardial performance index (MPI) allows the assessment regardless of ventricular shape. This study was designed to evaluate the feasibility of MPI in assessing ventricular function in children with single ventricles before and after total cavopulmonary connection (TCPC). METHODS: Subjects consisted of 161 pediatric patients with single ventricles and 80 normal children without heart disease. The maximum positive rate of ventricular pressure change (Max dp/dt) was obtained in 58 patients by cardiac catheterization. Sixty-eight children with single ventricles received TCPC. MPI was calculated from Doppler tracings of ventricular inflow and outflow, then MPI of single ventricles before and after surgery and normal heart were compared. RESULTS: Normal MPI value was 0.30+/-0.08 in the left ventricle and 0.26+/-0.08 in the right ventricle. Compared to normal children, MPI was significantly higher in 161 children with single ventricles (0.54+/-0.11, P<0.001). MPI correlated inversely with Max (dp/dt) (r=-0.77, P<0.01), and was positively related to age (r=0.54, P<0.01) in patients with single ventricles. MPI did not differ significantly before and after surgery in 68 patients with single ventricles (0.55+/-0.21 vs 0.51+/-0.20, P>0.05). However, MPI in 48 patients of <6 years old decreased significantly (0.55+/-0.21 vs 0.48+/-0.18, P<0.05), suggesting improved ventricular function. CONCLUSIONS: Compared to normal children, ventricular function is impaired in patients with single ventricles and may worsen with age. MPI provides an accurate method for assessing ventricular function in children with single ventricles before and after TCPC.