CMAJ OPEN

Unintentional nonfire-related carbon monoxide poi-soning is a leading cause of accidental poisoning in the United States.1,2 Exposure to carbon monoxide occurs mostly in indoor home environments through malfunctioning home-heating systems, the operation of gasoline-powered equipment in enclosed or semienclosed areas, and improperly vented gas appliances.3,4 Inhalation of carbon monoxide can result in reduced oxygen transport by the blood, a condition that starves the cells and organs in the body. The adverse effects associated with carbon monoxide poisoning vary depending on the level and duration of expo-sure, and range from minor flulike symptoms and shortness of breath, to confusion, unconsciousness, coma and death.5 Since 1968, studies have reported a decrease in mortality and hospital admission rates for this type of carbon monox-ide poisoning in the US6–8 and in the United Kingdom,9 whereas increasing or stable mortality for carbon monoxide poisoning has been reported in other European countries.10 There are no reports available on changes in these rates in Canada. Few studies have provided magnitude estimates of the changes over time in mortality and hospital admissions for carbon monoxide poisoning, and few investigations have evaluated long-term trends in rates as a function of the site of the carbon monoxide exposure.8,9,11 There is lack of demographic data in Canada regarding carbon monoxide poisoning. The aim of this study was to evaluate trends in mortality and hospital admission rates for unintentional nonfire-related carbon monoxide poisoning across Canada, including analyses by province, age, sex, and month and site of occurrence. Mortality and hospital admission rates for unintentional nonfire-related carbon monoxide poisoning across Canada: a trend analysi