Table 1:

Description and technical definition of each of the algorithms tested

Algorithm	Description	ICD-10 codes
1	Underlying cause of death: poisoning	X40–X49, X60–X69, X85–X90, Y10–Y19
	and	and
	Multiple cause of death: prescription opioid poisoning	T402, T403, T404
2	Underlying cause of death: poisoning	X40–X49, X60–X69, X85–X90, Y10–Y19
	and	and
	Multiple cause of death: prescription opioid poisoning and/or other unspecified narcotics	T402, T403, T404, T406
3	Multiple cause of death: prescription opioid poisoning	T402, T403, T404
4	Multiple cause of death: prescription opioid poisoning or other unspecified narcotics	T402, T403, T404, T406
5	Underlying cause of death or multiple cause of death: narcotic poisoning	X42, X62, Y12, T509
	and not	and not
	Multiple cause of death: illicit opioids	(T401, T405, T407–T409)
	or	or
	Multiple cause of death: prescription opioid poisoning or other unspecified narcotics	T402,T403,T404,T406