Highlights

doi:10.1503/cmaj.151256

Hypothermia as a cause of death

Although Canada has extremes in weather, little is known about mortality caused by hypothermia in this country. Using data obtained from the death registry of the British Columbia Vital Statistics Agency, the authors of this descriptive study found that hypothermia or exposure to excessive natural cold was the underlying or contributing cause in 384 deaths among residents of British Columbia between 1998 and 2012. The annual death rate for hypothermia increased with age, ranging from 0.3 per 100 000 population among people aged 1–34 years to 1.6 per 100 000 population among those older than 75 years. The highest annual death rate occurred among older men (2.1 per 100 000 population), followed by older women. Although hypothermia-related deaths occurred year-round, nearly half (45.9%) occurred during winter months and, in particular, on days with lower temperatures (mean 0.56°C) (Figure 1). Use of alcohol (40.1%) and other psychoactive substances (22.7%) were the most common additional causes of death. The authors conclude, however, that further assessment of both the occurrence and determinants of mortality due to hypothermia are needed to inform measures to reduce its impact. CMAJ Open 2015;3:E352–8.

Figure 1:

Frequency of hypothermia mortality in British Columbia (1998–2012) by mean apparent temperature on day of death.

Maternal placental syndromes among women living with HIV

Increasing numbers of women with HIV are giving birth. Are these women at increased risk of maternal placental syndromes, such as preeclampsia, eclampsia, placental infarction and placental abruption? Using administrative health databases, the authors of this population-based study identified all pregnancies resulting in a live birth between 2002 and 2011 in Ontario (n = 1 132 871). After multivariable adjustment, they found no difference in the risk of maternal placental syndrome between women living with HIV (n = 634) and those without HIV infection (5.8% v. 5.6%). In contrast, an increased risk of maternal placental syndromes was associated with pre-existing diabetes (adjusted odds ratio [AOR] 1.47, 95% confidence interval [CI] 1.39–1.54), pre-existing hypertension (AOR 4.28, 95% CI 4.15–4.42) and chronic kidney disease (AOR 1.83, 95% CI 1.61–2.08) (Table 1). These findings underscore the importance of optimizing the management of comorbid illness associated with maternal placental syndromes during the prenatal period for all women, irrespective of HIV status, say the authors. CMAJ Open 2015;3:E360–5.

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Table 1:

Predictors of maternal placental syndrome