title: Searching for the best modeling specification for assessing the effects of temperature and humidity on health: a time series analysis in three European cities.
abstract: Epidemiological time series studies suggest daily temperature and humidity are associated with adverse health effects including increased mortality and hospital admissions. However, there is no consensus over which metric or lag best describes the relationships. We investigated which temperature and humidity model specification most adequately predicted mortality in three large European cities. Daily counts of all-cause mortality, minimum, maximum and mean temperature and relative humidity and apparent temperature (a composite measure of ambient and dew point temperature) were assembled for Athens, London, and Rome for 6 years between 1999 and 2005. City-specific Poisson regression models were fitted separately for warm (April-September) and cold (October-March) periods adjusting for seasonality, air pollution, and public holidays. We investigated goodness of model fit for each metric for delayed effects up to 13 days using three model fit criteria: sum of the partial autocorrelation function, AIC, and GCV. No uniformly best index for all cities and seasonal periods was observed. The effects of temperature were uniformly shown to be more prolonged during cold periods and the majority of models suggested separate temperature and humidity variables performed better than apparent temperature in predicting mortality. Our study suggests that the nature of the effects of temperature and humidity on mortality vary between cities for unknown reasons which require further investigation but may relate to city-specific population, socioeconomic, and environmental characteristics. This may have consequences on epidemiological studies and local temperature-related warning systems.
authors: Department of Hygiene, Epidemiology and Medical Statistics, Medical School, University of Athens, 75 Mikras Asias Str, 115 27, Athens, Greece.
authors: Sophia
authors: S
authors: Rodopoulou
authors: Department of Hygiene, Epidemiology and Medical Statistics, Medical School, University of Athens, 75 Mikras Asias Str, 115 27, Athens, Greece.
authors: Evangelia
authors: E
authors: Samoli
authors: Department of Hygiene, Epidemiology and Medical Statistics, Medical School, University of Athens, 75 Mikras Asias Str, 115 27, Athens, Greece.
authors: Antonis
authors: A
authors: Analitis
authors: Population Health Research Institute and MRC-PHE Centre for Environment and Health, St George's, University of London, London, UK.
authors: Richard W
authors: RW
authors: Atkinson
authors: Department of Epidemiology, Lazio Regional Health Authority, Rome, Italy.
authors: Francesca K
authors: FK
authors: de'Donato
authors: Department of Hygiene, Epidemiology and Medical Statistics, Medical School, University of Athens, 75 Mikras Asias Str, 115 27, Athens, Greece. kkatsouy@med.uoa.gr.|Environmental Research Group and Department of Primary Care & Public Health Sciences, King's College London, London, UK. kkatsouy@med.uoa.gr.
authors: Klea
authors: K
authors: Katsouyanni
mesh_terms: D002947:Cities / Q000453:epidemiology; D002980:Climate; D004739:England / Q000453:epidemiology; D006115:Greece / Q000453:epidemiology; D006801:Humans; D006813:Humidity; D007558:Italy / Q000453:epidemiology; D008962:Models, Theoretical; D009026:Mortality; D013696:Temperature
keywords: Ambient temperature; Apparent temperature; Distributed lags; Mortality; Relative humidity; Time-series
references: Int J Biometeorol. 2005 Nov;50(2):121-9
references: 15912362
references: Sci Total Environ. 2014 Aug 1;488-489:297-315
references: 24836139
references: Environ Health Toxicol. 2011;26:e2011009
references: 22125770
references: Gynecol Obstet Invest. 2008;66(1):22-6
references: 18230912
references: Environ Health. 2009 Sep 16;8:40
references: 19758453
references: Environ Res. 2010 Aug;110(6):604-11
references: 20519131
references: Epidemiology. 2008 Sep;19(5):711-9
references: 18520615
references: Am J Epidemiol. 2008 Dec 15;168(12):1397-408
references: 18952849
references: Stat Med. 2003 Oct 15;22(19):3055-71
references: 12973787
references: Epidemiology. 2005 Jan;16(1):58-66
references: 15613946
references: Environ Health Perspect. 2010 Jan;118(1):80-6
references: 20056571
references: Epidemiology. 2006 Nov;17(6):624-31
references: 17028505
references: J Stat Softw. 2011 Jul;43(8):1-20
references: 22003319
references: Sci Total Environ. 2006 May 1;360(1-3):5-25
references: 16289266
references: Sci Total Environ. 2012 Jun 15;427-428:41-9
references: 22575378
references: Am J Epidemiol. 2008 Jun 15;167(12):1476-85
references: 18408228
references: Stat Med. 2006 Dec 30;25(24):4164-78
references: 16991105
references: Environ Health Perspect. 2004 Feb;112(2):179-85
references: 14754572
references: Environ Health Perspect. 2013 Oct;121(10):1111-9
references: 23934704
references: J Epidemiol Community Health. 1993 Apr;47(2):121-6
references: 8326269
references: Environ Health Perspect. 2013 Aug;121(8):932-8
references: 23687008
references: Epidemiology. 2001 Nov;12(6):662-7
references: 11679794
references: J Epidemiol Community Health. 1996 Apr;50 Suppl 1:S12-8
references: 8758218
references: Am J Public Health. 1997 Jul;87(7):1205-7
references: 9240114
references: Am J Epidemiol. 2002 Jan 1;155(1):80-7
references: 11772788
references: Stat Med. 2014 Dec 10;33(28):4904-18
references: 25052462
references: Am J Public Health. 2010 Jun;100(6):1137-44
references: 20395585
references: Stat Med. 2010 Sep 20;29(21):2224-34
references: 20812303
references: Am J Respir Crit Care Med. 2004 Nov 15;170(10):1080-7
references: 15282198
references: Occup Environ Med. 2008 Apr;65(4):255-60
references: 17890300
references: Sci Total Environ. 2013 Sep 1;461-462:627-35
references: 23764675
references: Environ Health Perspect. 2011 Sep;119(9):1233-8
references: 21586369
references: Environ Health. 2007 Apr 24;6:12
references: 17456236
references: J Expo Anal Environ Epidemiol. 2001 Jul-Aug;11(4):286-94
references: 11571608
references: Environ Res. 2010 Aug;110(6):633-8
references: 20576259
references: Epidemiology. 2001 Sep;12(5):521-31
references: 11505171
references: J Epidemiol. 2012;22(1):28-36
references: 22041530
references: Epidemiology. 2005 Jul;16(4):436-45
references: 15951661
references: J Sci Med Sport. 2008 Jan;11(1):20-32
references: 17765661