The impact on mortality of heat waves in

The impact on mortality of heat waves in Budapest, Hungary R Sari Kovats, Shakoor Hajat, London School of Hygiene and Tropical Medicine, London, United Kingdom Anna Páldy, Fodor Jozsef National Center for Public Health, National Institute of Environmental Health, Budapest, Hungary János Bobvos Capital Institute of State Public Health Service, Budapest, Hungary

Background • Heat wave August 2003 estimated excess deaths • No standard definition • Events not comparable – magnitude – duration – time of occurrence • Methods to create baseline – regression model – episode analysis • Short term mortality displacement • France 10, 000 excess deaths • Portugal 1, 316 excess deaths • Italy reports 20 % more than average in July/Aug • Spain has reported 100 deaths

Objectives • Describe and quantify the relationship between daily temperature extremes and mortality in Budapest • Describe any differences between subgroups (by age and cause)

Data – Budapest residents – Years 1993 -2000

Defining heat episodes • Create daily series with mean temperature (lags 0 -2) • Identified days with Temp above the 99 th centile (26. 6ºC). • Heat waves = three continuous days

Methods: Episode analysis – Baseline = expected mortaltiy – Regression model • day of week • time of year • air pollution • temperature • relative humidity – Excess % • [observed - expected]/expected * 100 • Confidence intervals

Observed and expected mortality 2000 all cause Heat wave 6 Heat wave 5 Mean temperature

Excess mortality [all cause, all ages] for each event

Results by age group Cardiovascular All cause Number of “excess deaths”

Short term mortality displacement Heat wave 1

Short-term mortality displacement • Is excess compensated completely by “dip” following heat wave? • We estimated the excess over a one week and a two week period, beginning on the day of the heat wave • Excess over two weeks =6 -7%

Conclusions · Heat waves have significant impact on mortality · Heatwaves early in summer have a bigger impact than heatwaves in late summer ~ harvesting ~ acclimatization · Attributable deaths ~ short term harvesting does not “account” for all excess mortality ~ unknown contribution · Limitations ~ difficulty in identifying episodes ~ estimating “expected mortality” ~ ozone has significant independent effect on mortality in summer.