Hope HealthCare Services

Evidence-Based Answer We do not know how well family physicians differentiate murmurs on auscultation. Cardiac auscultation by emergency room physicians can distinguish benign from pathologic systolic murmurs with a sensitivity of 82% and specificity of 69%. In evaluating patients for heart failure, the detection of an S3 has sensitivity of 50% by cardiology attendings, but poor interobserver agreement by less experienced physicians (SOR: B, diagnostic cohort studies with heterogeneous results).

Human mortality in US cities is highest on extremely hot, humid summer days, but in general, winter-mortality rates are significantly higher than summer rates. The observed winter- dominant warming pattern, which has been linked to increasing greenhouse-gas concentrations, has led some researchers to propose future mortality decreases, while others contend that increasing heat-related mortality in summer will more than offset any winter-mortality reductions. Because winter mortality is only weakly linked to daily weather, we examine the seasonality of mortality using monthly data for 28 major US cities from 1964 to 1998. Daily all-causes mortality counts are age- standardized, aggregated monthly, and related to mean monthly 07:00 h local standard time (LST) air temperature in each city. The climate-mortality seasonality patterns are examined for spatial and temporal (decadal-scale) variability, and the impact of climate change on mortality rates is inves- tigated after an approximation of the inherent technology/adaptation trend is removed from the monthly time series. Mortality seasonality varies little between most US cities with comparable climates. By the 1990s, monthly mortality anomalies were similar between all cities regardless of climate, suggesting there is no net mortality benefit to be derived from a location's climate. After removing the impact of long-term declining mortality rates, some statistically significant monthly climate-mortality relationships remain in most cities, with generally positive temperature-mortality relationships in summer and negative relationships in winter. Future mortality could be reduced with a winter-dominant warming but increase with pronounced summer warming. In each case, however, net future climate-related mortality rates are very low relative to the baseline death rate, indicating that climate change will have little impact in defining future mortality patterns in US cities.

Recent studies suggest that anthropogenic climate warming will result in higher heat-related mortality rates in U.S. cities than have been observed in the past. However, most of these analyses assume that weather-mortality relationships have not changed over time. We examine decadal-scale changes in relationships between human mortality and hot, humid weather for 28 U.S. cities with populations greater than one million. Twenty-nine years of daily total mortality rates, age-standardized to account for underlying demographic changes, are related to afternoon apparent temperatures ( T(a)) and organized by decade for each city. Threshold T(a) values, or the T(a) at and above which mortality is significantly elevated, are calculated for each city, and the mortality rates on days when the threshold T(a) was exceeded are compared across decades. On days with high T(a), mortality rates were lower in the 1980s and 1990s than in the 1960s and 1970s in a majority of the cities. Regionally, northeastern and northern interior cities continue to exhibit elevated, albeit reduced, death rates on warm, humid days in the 1980s and 1990s, while most southern cities do not. The overall decadal decline in mortality in most cities is probably because of adaptations: increased use of air conditioning, improved health care, and heightened public awareness of the biophysical impacts of heat exposure. This finding of a more muted mortality response of the U.S. populace to high T(a) values over time raises doubts about the validity of projections of future U.S. mortality increases linked to potential greenhouse warming.