Increased Risk of Opioid Overdose Death Following Cold Weather: A Case-Crossover Study.

Background: The United States is in the midst of an opioid overdose crisis. Little is known about the role of environmental factors in increasing risk of fatal opioid overdose.
Methods: We conducted a case-crossover analysis of 3,275 opioid overdose deaths recorded in Connecticut and Rhode Island in 2014-2017. We compared the mean ambient temperature on the day of death, as well as average temperature up to 14 days before death, to referent periods matched on year, month, and day of week.
Results: Low average temperatures over the 3-7 days before death were associated with higher odds of fatal opioid overdose. Relative to 11°C, an average temperature of 0°C over the 7 days before death was associated with a 30% higher odds of death (odds ratio: 1.3; 95% confidence interval, 1.1, 1.5).
Conclusions: Low average temperature may be associated with higher risk of death due to opioid overdose.