The shape of the exposure curve and the change in exposure levels over time is the main interest in the inclusion of D T. D T was defined by growth and decline rates for years in multiples of 10 before and after the maximum exposure year, called Peakyear (at which the gradient of the exposure curve is zero).
However, there are several key methodological challenges in the estimation of the health effects of low-level exposure to air pollution, such as the shape of the exposure response curve, threshold of air pollution, interactive effects of air pollution and weather conditions, and model uncertainty and potential bias.
Decisions regarding the shape of the exposure profile in this region must draw on other sources of evidence about the extent of population exposure more recently.
The shape of the exposure time distribution was investigated from the velocity fluctuations measured with a hot-film anemometer in the immediate vicinity of the interface.
The shape of the exposure and response curve is very important.
However, the shape of the exposure curve after 1978 is required to use the model to make longer-term predictions.
However, the prediction intervals of our projections incorporate only the uncertainty in the fitted model parameters, and not the unquantifiable but potentially considerable degree of additional uncertainty arising from the particular chosen shape of the exposure curve beyond 1978.
While the observed pattern persists even after excluding peripheral areas or inaccurately geo-coded addresses, the nature of the study does not permit inferences about the shape of the exposure response function.
Using a categorical exposure puts no restrictions on the shape of the exposure-risk relationship, but reduces statistical power.
Breaking the exposure into quartiles reduces power, but puts no restrictions on the shape of the exposure-risk relationship.
The shape of the exposure-response relation was examined with a case-control analysis.
