Table 1.

Summary Statistics for Street Drug Lethality Index.

Steps 1− 3 of the Analysis by Drug
Drug	Step 1: Pure Deaths 2017	Step 2: Pure Seizures 2017	Step 3: Lethality Ratio (LR)
Fentanyl	1497	3812	0.393
Cocaine	254	5781	0.044
Prescription Opioids	217	3650	0.059
Heroin	110	2486	0.044
Amphetamines	85	9012	0.009
Benzodiazepines	28	5437	0.005

Step 4: Street Drug Lethality Index (SDLI) by Drug and Year
Year	Fentanyl	Cocaine	Prescription Opioids	Heroin	Amphetamines	Benzodiazepines
2009	15	252	277	134	16	16
2010	12	205	317	134	13	16
2011	11	218	323	169	17	18
2012	11	176	315	242	27	20
2013	27	202	289	291	29	19
2014	220	215	285	340	29	18
2015	565	245	314	403	40	20
2016	1435	312	298	343	61	30
2017	2123	300	270	225	98	31
2018	1989	268	258	208	131	26

Steps 5: Summed Annual Lethality Index (SALI) and Observed and Predicted Unintentional Overdose Deaths by Year
Year	Step 5:SALI	Observed	Predicted
2009	710	1389	1730
2010	697	1511	1719
2011	756	1720	1774
2012	791	1864	1808
2013	857	2065	1872
2014	1107	2476	2123
2015	1587	2986	2652
2016	2479	3939	3788
2017	3047	4979	4617
2018	2880	3614	4362

Note: Step 1 is a count of all unintentional overdose deaths attributable to only one drug of abuse (single-drug deaths) for calendar year 2017.

Step 2 is a count of all seizure events from the Ohio Bureau of Criminal Investigation database where only one drug was present (single-drug seizures).

Step 3 is the lethality ratio calculated by dividing single-drug deaths by single-drug seizures.

Step 4 calculates the Street Drug Lethality Index (SDLI) by multiplying the total number of seizures (single-drug and mixed) by the lethality ratios calculated in step 3.

Step 5, is the summation of all annual SDLI scores, SALI. SALI is used as the predictor variable in the regression analysis.