Drug overdose in the ED: a record linkage study examining emergency department ICD-10 coding practices in a cohort of people who inject drugs

Table 4 Number of ED presentations with diagnoses in selected ICD-10 categories, and hierarchical position of the diagnosis within each presentation

		Presentations with relevant code mention (N = 3459)		Occurrences as Primary Diagnosis	Occurrences as Secondary Diagnosis	Occurrences as Tertiary Diagnosis	Other T code (T36.- to T50.-) within same encounter	Other F code (F10.- to F19.-) within same encounter
ICD-10 Codes	Description	n	%	n	n	n	n	n
T40.0-T40.4 & T40.6	Opioid poisonings	74	2	72	2	0	2	0
F11.0-F11.9^a	Mental and behavioural disorders due to opioids	30	1	30	0	0	0	1
T50.9	Poisoning: Other and unspecified drugs, medicaments and biological substances	79	2	73	6	0	2	3
F19.0-F19.9^b	Mental and behavioural disorders due to multiple drugs and psychoactive substances	52	2	47	4	1	1	1
T36.0-T50.9	ALL: Poisoning by drugs, medicaments and biological substances	228	7	220	12^d	0	–	6
F10.0-F19.9^c	ALL: Mental and behavioural disorders due to psychoactive substances	190	6	174	19^e	1	6	–

^aExcludes withdrawal states F11.3, F11.4 (n = 0)
^bExcludes withdrawal states F19.3, F19.4 (n = 33)
^cExcludes all withdrawal states (F subdivisions .3 and .4) (n = 37)
^dOverlapping primary diagnosis in same category (n = 4), hence sum of mentions > total number of encounters
^eOverlapping primary diagnosis in same category (n = 4), hence sum of mentions > total number of encounters

ISSN: 1472-6963