Population-Based Case-Control Study of Risk Factors for Unintentional Mortality from Carbon Monoxide Poisoning in Taiwan

Abstract

We carried out a population-based case-control study to identify people in Taiwan who are at increased risk of unintentional mortality from carbon monoxide (CO) poisoning (ICD-9 CM: 986 or E868). The study included all 439 deaths from unintentional CO poisoning registered in Taiwan's National Mortality Registry during 1997-2003, whereas 878 control subjects were randomly selected, with a control/case ratio of 2, from all deceased individuals from other causes during the same period. The annual mortality rate of CO poisoning significantly increased in Taiwan over the 7-yr period from 1.6 to 3.5 per 10(6) person-years. Thirty-six percent (n = 160) of the deaths occurred at home, and 21% (n = 93) were registered as in-hospital mortalities. A multivariate logistic regression analysis indicated that married people had a significantly reduced mortality odds ratio (MOR) of 0.50 (95% CI = 0.30-0.82) compared to single individuals. Additionally, residents of northern Taiwan (which is relatively urban) had a notably higher MOR of CO poisoning (MOR = 3.44, 95% CI = 1.40-8.44) than people residing in eastern Taiwan (which is relatively rural). Moreover, the MOR peaked in cold periods. A daily maximum temperature of < 18.4 degrees C was associated with a 2.15-fold increase in the MOR compared to a daily maximum temperature of > or = 27.1 degrees C. This study demonstrates an alarming increase in the unintentional death rate from CO poisoning in Taiwan between 1997 and 2003. Certain demographic and geographic characteristics were significant predictors for CO poisoning, suggesting a need for preventive strategies targeting these high-risk populations. Precautions should also be taken during periods of low temperatures.

Carbon Monoxide–Related Deaths in Greece

“…Recent studies estimated that this equipment could have helped save lives and unmask the ''silent killer.'' 2,22 Public alert about possible sources of CO in the indoor environment and the relative problems from CO exposure should always be a major concern of health authorities.…”

“…2,16 Because this gas is almost undetectable by the human senses and is potentially present in most households as well as in many workplaces, identification of people at higher risks of poisoning can be valuable in its prevention.…”

“…All these cases show that, although CO is a very old poison, it can cause even today severe poisonings and can be the cause of death. 2,8 During the period between 1987 and 2009, 176 cases of CO poisoning death were sent to our department for forensic investigation. This number may not seem significant, because some regions of Greece belong to other departments of forensic medicine, for which we have no data, but they reflect the situation in Greece as our laboratory covers at least half to two thirds of the Greek population.…”

“…It is responsible for a great number of accidental domestic poisonings and deaths throughout the world, particularly in homes that have faulty or poorly vented combustion appliances, and it may be the cause of more than one half of the fatal poisonings reported in many countries. 1,2 Death from CO poisoning is an obscure death, and fatal cases also are grossly underreported or misdiagnosed by medical professionals. 1,3 The main source of CO exposure is the indoor use of gasoline generators and propane or kerosene heaters and charcoal grills, especially when winter storms disrupt electrical service.…”

“…All these cases, as well as relative data from the literature, 4Y7,15 show that, although CO is a very old poison, it can cause even today severe poisoning and can be the cause of several deaths each year worldwide. 2,8 The aim of this survey was to present the cases of CO poisoning that were investigated by the Department of Forensic Medicine and Toxicology of the University of Athens, during the period between January 1987 and December 2009.…”