Time series analysis of heat stroke related hospitalizations in the elderly residents in the Boston Metropolitan Statistical Area, from 1991 to 2006.
Abstract: The adverse
impact of extreme weather on human health is attracting substantial attentions of public
health professionals, environmental scientists, and policy makers. This study uses time
series analysis to investigate the direct effects of high ambient temperatures on the
health of older residents in the Boston Metropolitan Statistical Area (MSA). This study
has three goals: to in... read morevestigate the seasonality of hospitalizations due to heat stroke
(HSH), to describe the association between ambient temperature and HSHs; and to
determine the independent effect of heat waves on HSHs in the presence of
well-pronounced seasonality. Medical records were abstracted form the Centers of
Medicare and Medicaid Services from 1991 through 2006 and regressed against daily
meteorological records using Poisson generalized linear regression model. The ambient
temperature is positively correlated with HSHs, the relationship exhibits strong
exponential growth when temperature exceeds a certain threshold point. The proposed
transformation of daily temperature facilitates the capture of rapid increase in HSHs
beyond the threshold. Six types of indicator variables were tested to determine the
effects of heat waves and their lag structures. The seasonal peaks in HSHs follow the
first heat wave each year. The final regression model includes terms for ambient
temperatures transformed with respect to threshold points; the best indicator variable
for heat waves adjusted for annual, seasonal and weekly fluctuations explains 56%
variability in HSHs. The developed methodology for building and validating a regression
model sensitive to local temperature features can be further extended to other locations
and health outcomes.
Thesis (M.S.)--Tufts University, 2013.
Submitted to the Dept. of Civil Engineering.
Advisor: Elena Naumova.
Committee: Kenneth Kwan Ho Chui, and Shinsuke Tanaka.
Keyword: Environmental health.read less