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6.2.5.3 Proposed Pilot Action: Preliminary Assessment of a Possible
Development of the Heat Risk Alert System Based on the Use
of Emergency Ambulance Data
The suggested pilot action aims at verifying a possible improvement of the Heat
Risk Alert System currently operational in the Emilia-Romagna region. The development would be based on the use of emergency ambulance data.
Today the discomfort index threshold levels have been identified via epidemiological analysis based on historical mortality data. A study developed by Arpa on all
most important cities of the Emilia-Romagna region, except Rimini, evaluated the
exposure–response curve of ambulance dispatches in relation to biometeorological
conditions using time series techniques showing a strong correlation between ambulance dispatches increase and apparent temperature. The effects of high temperatures on health were evaluated for respiratory and cardiovascular diseases as well as
for all non-traumatic conditions.
For apparent temperatures lower than 25 °C, ambulance dispatches were not
affected by changes in biometeorological conditions. Above that threshold, an
increase of ambulance dispatches associated with respiratory diseases has been
found, while cardiovascular diseases remained unaffected by variations in apparent
temperature. For apparent temperatures higher than 30 °C, the percent increases
associated with each unit increment of apparent temperature became very high, with
the main effect seen with cardiovascular diseases.
The findings of the study demonstrated the usefulness of ambulance dispatch
data due to their strong link with heat and their real-time availability. As a matter of
fact, these data are collected and stored with the same software and the same protocols across the region Emilia–Romagna, and are the only health data available in
real-time.
Based on these reasons ARPA tried to test the possibility of the use of these data
for a development of the heat risk alert system. The main goal of the analysis was to
verify how strong was the relationship between bioclimatic discomfort conditions
and increased ambulance dispatches across the Region on a daily basis.
ARPA defined as “alert day” a day when apparent temperature averaged among
the main towns of the region is above 25 °C. The expected number of ambulance
dispatches for each summer day was calculated averaging the daily ambulance dispatches in a 15-day period centered in the selected day over the years 2003-2006
(excluding all the alert days from the computation); a standard deviation was also
computed as a variability indicator. Days with a number of ambulance dispatches
exceeding the expected number for that day plus twice the standard deviation were
considered as days with an elevated number of dispatches (“case day”).
The strength of the correlation between case and alert days was tested using
sensitivity, specificity and positive predictive value defined as follows.
S. Zauli Sajani et al.
6.2.5.3 Proposed Pilot Action: Preliminary Assessment of a Possible
Development of the Heat Risk Alert System Based on the Use
of Emergency Ambulance Data
The suggested pilot action aims at verifying a possible improvement of the Heat
Risk Alert System currently operational in the Emilia-Romagna region. The development would be based on the use of emergency ambulance data.
Today the discomfort index threshold levels have been identified via epidemiological analysis based on historical mortality data. A study developed by Arpa on all
most important cities of the Emilia-Romagna region, except Rimini, evaluated the
exposure–response curve of ambulance dispatches in relation to biometeorological
conditions using time series techniques showing a strong correlation between ambulance dispatches increase and apparent temperature. The effects of high temperatures on health were evaluated for respiratory and cardiovascular diseases as well as
for all non-traumatic conditions.
For apparent temperatures lower than 25 °C, ambulance dispatches were not
affected by changes in biometeorological conditions. Above that threshold, an
increase of ambulance dispatches associated with respiratory diseases has been
found, while cardiovascular diseases remained unaffected by variations in apparent
temperature. For apparent temperatures higher than 30 °C, the percent increases
associated with each unit increment of apparent temperature became very high, with
the main effect seen with cardiovascular diseases.
The findings of the study demonstrated the usefulness of ambulance dispatch
data due to their strong link with heat and their real-time availability. As a matter of
fact, these data are collected and stored with the same software and the same protocols across the region Emilia–Romagna, and are the only health data available in
real-time.
Based on these reasons ARPA tried to test the possibility of the use of these data
for a development of the heat risk alert system. The main goal of the analysis was to
verify how strong was the relationship between bioclimatic discomfort conditions
and increased ambulance dispatches across the Region on a daily basis.
ARPA defined as “alert day” a day when apparent temperature averaged among
the main towns of the region is above 25 °C. The expected number of ambulance
dispatches for each summer day was calculated averaging the daily ambulance dispatches in a 15-day period centered in the selected day over the years 2003-2006
(excluding all the alert days from the computation); a standard deviation was also
computed as a variability indicator. Days with a number of ambulance dispatches
exceeding the expected number for that day plus twice the standard deviation were
considered as days with an elevated number of dispatches (“case day”).
The strength of the correlation between case and alert days was tested using
sensitivity, specificity and positive predictive value defined as follows.
S. Zauli Sajani et al.