Association between use of air-conditioning or fan and survival of elderly febrile patients:

a prospective study

George Theocharis, MD, Giannoula S. Tansarli, MD, Michael N. Mavros, MD, Theodore Spiropoulos, MD, Spyridon G. Barbas, MD,Matthew E. Falagas, MD, MSc, DSc

Impact of heat and infections on elderly

• Elderly comprise a large social group which has been steadily increasing over time.

• Greece is the 4th country around the world among major nations with regard to people aged 65 years and over; 19.1% of the total population was ≥ 65 years old in 2008.

• As regards infections, studies have shown that elderly patients with infections experience higher mortality than younger age groups with the same infections.

• Therefore, the impact of heat on elderly febrile patients, whom fever in the majority is attributed to infections, is expected to be greater than that of general population.

Data about heat affected mortality

• Every summer many deaths are attributed to high temperatures. Summer of 2003 was one of the warmest ever and landmark for Europe regarding the impact of excessive heat on mortality.

• France, Italy and Portugal were among the countries most affected by the high temperatures that had been recorded.

• Heat-related mortality appears more excessive in Mediterranean than in North European cities and is mostly attributed to respiratory diseases.

Higher morbidity and mortality of elderly during warm months

• In one of our previous studies, published in 2012, we concluded that elderly individuals of an urban, Mediterranean population carried higher morbidity and mortality in August compared to November.

• We established that mortality is significant higher in August compared to November. We introduced the informal term of “Augustitis” to describe this phenomenon in Greece.

Higher morbidity and mortality of elderly during warm months

• One of the reasons of higher mortality of the elderly in the summer is probably exposure to excess heat during febrile illness.

• SOS Doctors’ experience, during their visits in patients’ houses, is that many of the patients although febrile, they prefer not to use cooling systems, especially the elderly.

Purpose of the study

• To evaluate the impact of use or not use of a cooling system on febrile elderlies' morbidity and mortality.

• We prospectively studied febrile patients who requested medical services of SOS Doctors from July 10 to August 20, 2011.

SOS Doctors of Athens, Greece

SOS Doctors is an organized provider of home visits in Athens, that operates since 1993 and performs currently about 40.000 home visits per year. About 75% of cases can be characterized as emergency medical cases.

Model of SOS Doctors

Call center with medical coordinator on line 24 hours a day.

Specialized doctors perform emergency home visits with properly equipped vehicles.

Performing blood tests, x-rays, total body ultra sound and other tests immediately in patient’ s home.

Rapid Point Of Care diagnostic tests.

Provision of hospital type care at home.

Secondary hospital of reference

Data collection

• SOS Doctors visited 2.626 patients during the study period.

• 339 (13%) patients were both elderly (>75) and febrile.

• 265 (78%) of them used a cooling system (users), while 74 (22%) did not use an air-condition/a fan or although they owned a cooling system, they did not use it during febrile illness (non users)

Elderly users v.s. non users of cooling systems during febrile illness

Patients’ characteristics

Variable

Users Non-users

p-value

N= 265 (%) N= 74 (%)

Age (median, IQs)# 84 (79.50, 89) 82.50 (78.75, 87) 0.26

Gender (female) 133 (50.2) 31 (41.9) 0.24

Living alone* 30 (11.5) 8 (10.8) >0.99

Diagnosis*

Infections 231 (88.2) 62 (83.8)

0.53Unclear 31 (11.8) 12 (16.2)

Diagnoses of examined patients

Emergency hospitalization

Outcome of primary illness

Outcome of primary illness

VariableUsers Non-users

p-valueN= 265 (%) N= 74 (%)

Emergency hospitalization 56 (21.1) 22 (29.7) 0.16

Outcome of primary illness±

Improvement 212 (85.1) 55 (76.4)0.11

Deterioration 37 (14.9) 17 (23.6)

Mortality 27 (10.2) 14 (18.9) 0.046

Conclusions

The use of a cooling system (air-conditioning or fan) by elderly febrile patients during hot summer months was associated with lower mortality.

There was no difference in mortality between users of air-conditioning or fan.

It is a key element of a history taking to ask about the use of cooling system of the elderly with febrile illness.

From the sun democracy of Greece

Thank you!