High temperature and hospitalizations for cardiovascular and respiratory causes in 12 European cities.
BACKGROUND
Episode analyses of heat waves have documented a comparatively higher impact on mortality than on morbidity (hospital admissions) in European cities. The evidence from daily time series studies is scarce and inconsistent.


OBJECTIVE
To evaluate the impact of high environmental temperatures on hospital admissions during April to September in 12 European cities participating in the Assessment and Prevention of Acute Health Effects of Weather Conditions in Europe (PHEWE) project.


METHODS
For each city, time series analysis was used to model the relationship between maximum apparent temperature (lag 0-3 days) and daily hospital admissions for cardiovascular, cerebrovascular, and respiratory causes by age (all ages, 65-74 age group, and 75+ age group), and the city-specific estimates were pooled for two geographical groupings of cities.


RESULTS
For respiratory admissions, there was a positive association that was heterogeneous between cities. For a 1 degrees C increase in maximum apparent temperature above a threshold, respiratory admissions increased by +4.5% (95% confidence interval, 1.9-7.3) and +3.1% (95% confidence interval, 0.8-5.5) in the 75+ age group in Mediterranean and North-Continental cities, respectively. In contrast, the association between temperature and cardiovascular and cerebrovascular admissions tended to be negative and did not reach statistical significance.


CONCLUSIONS
High temperatures have a specific impact on respiratory admissions, particularly in the elderly population, but the underlying mechanisms are poorly understood. Why high temperature increases cardiovascular mortality but not cardiovascular admissions is also unclear. The impact of extreme heat events on respiratory admissions is expected to increase in European cities as a result of global warming and progressive population aging.
Michelozzi
Paola
P
Department of Epidemiology Local Health Authority Rome E, Rome, Italy. michelozzi@asplazio.it
Accetta
Gabriele
G
De Sario
Manuela
M
D'Ippoliti
Daniela
D
Marino
Claudia
C
Baccini
Michela
M
Biggeri
Annibale
A
Anderson
H Ross
HR
Katsouyanni
Klea
K
Ballester
Ferran
F
Bisanti
Luigi
L
Cadum
Ennio
E
Forsberg
Bertil
B
Forastiere
Francesco
F
Goodman
Patrick G
PG
Hojs
Ana
A
Kirchmayer
Ursula
U
Medina
Sylvia
S
Paldy
Anna
A
Schindler
Christian
C
Sunyer
Jordi
J
Perucci
Carlo A
CA
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000032:analysis / Q000506:poisoning; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D002561:Cerebrovascular Disorders / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D005060:Europe / Q000453:epidemiology; D005260:Female; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D010343:Patient Admission / Q000706:statistics & numerical data; D016012:Poisson Distribution; D012140:Respiratory Tract Diseases / Q000453:epidemiology*; D014504:Urban Health / Q000706:statistics & numerical data; D055815:Young Adult
D000393:Air Pollutants