Recent Research Publications and Funding

Background: Atrial fibrillation (AF) activation rates have been calculated using both frequency domain and time complex analyses. Direct comparisons of these methods are limited. We report: (1) their correlation when measuring AF activation rates, (2) comparisons of recording durations required to minimize variability, and (3) differences in the temporal reproducibility.

Methods: AF activation rates were calculated using domain frequency (DF) (via fast Fourier transform) and time complex (TC) (via beat-to-beat activation measurements) analyses. We compared: (1) AF frequencies derived from each method; (2) successively longer subinterval durations to their 16-second reference intervals, and (3) the correlation between consecutively collected 8-second segments and segments collected 10 minutes apart.

Results: There was low intraclass correlation coefficient (ICC = 0.234) when comparing AF activation rates derived using DF versus TC analysis. There was no difference in the frequencies between any of the subintervals compared to their 16-second reference intervals, but variability of measurements was higher for intervals <8 seconds (P < 0.01). Correlations between successive segments and segments taken 10 minutes apart were 0.92 and 0.75 using DF analysis (P < 0.001), and 0.72 and 0.49 using TC analysis (P < 0.001).

Conclusions: There is low correlation between the DF and TC methods of analyzing AF activation rates. While AF rates do not differ between subintervals and 16-second reference electrograms, the variability of measurements is dependent upon the subinterval duration, and increases for durations less than 8 seconds. AF rates were prone to change over a 10-minute time period. These results point out existing clinical limitations of measuring atrial activation rates in AF patients.

 This study estimated whether 1990-1997 changes in expenditures per capita of local health departments (LHDs) and percentage share of local public revenue allocated to LHDs were associated inversely with 1990-1997 changes in mortality rates for Black and White racial/ethnic groups in the US. Population was 883 local jurisdictions with 1990 and 1997 mortality rates for Black and White racial populations from the Centers for Disease Control and Prevention Wonder Compressed Mortality File and LHD expenditures from the National Association of County and City Health Officials. Using a time-trend ecologic design, changes in LHD expenditures per capita and percentage share of public revenue were not related to reductions in Black/White disparities in total, all-cause mortality rates. Increased LHD expenditures or percentage share were associated with reduced Black/White disparities for adults aged 15-44 and males. LHD expenditures or percentage share were related to absolute reductions in mortality for infants, Blacks, and White females but did not close Black-White mortality differences for these groups. Therefore, disparities in Black and White mortality rates for subgroups with the greatest mortality gaps may be more likely to be reduced by public investment in local health departments than disparities in Black and White total, all-cause mortality rates.

 Although hypotheses about the link between literacy and health outcomes were published in the 1980s,1 the potential consequences of limited literacy in U.S. health care settings was brought to the attention of the larger clinical and health policy communities by a study published in 1995. In this landmark study, researchers revealed dramatic statistics: up to two-thirds of patients seen in public hospitals in the United States were unable to comprehend key health information such as how to take a medication or schedule a follow-up appointment.2 Hundreds of studies have since explored how patients' ability to read and comprehend the written information encountered in health care settings is independently associated with a variety of poorer health outcomes.

Because low literacy is more common among vulnerable populations (racial and ethnic minorities, elderly people, patients with chronic conditions, and those seeking care in public systems), it likely contributes to the disproportionate burden of disease-related problems among disadvantaged and vulnerable populations.3 In fact, when literacy is considered, the role of race in health disparities decreases dramatically.4,5

With an estimated 40% of adults in the United States having less-than-functional literacy,6 addressing health literacy has moved to the forefront of several policy agendas aimed at improving health care quality and outcomes.

Exposure to adverse life events typically predicts subsequent negative effects on mental health and well-being, such that more adversity predicts worse outcomes. However, adverse experiences may also foster subsequent resilience, with resulting advantages for mental health and well-being. In a multiyear longitudinal study of a national sample, people with a history of some lifetime adversity reported better mental health and well-being outcomes than not only people with a high history of adversity but also than people with no history of adversity. Specifically, U-shaped quadratic relationships indicated that a history of some but nonzero lifetime adversity predicted relatively lower global distress, lower self-rated functional impairment, fewer posttraumatic stress symptoms, and higher life satisfaction over time. Furthermore, people with some prior lifetime adversity were the least affected by recent adverse events. These results suggest that, in moderation, whatever does not kill us may indeed make us stronger.