. Author manuscript; available in PMC: 2024 Jan 17.

Published in final edited form as: Clin Toxicol (Phila). 2023 Apr;61(4):248–259. doi: 10.1080/15563650.2023.2177552

Table 1b.

Percentage changes in Δ9-tetrahydrocannabinol immunoassay positivity for sequential years in states with no laws.

	2015–2016	2016–2017	2017–2018	2018–2019	Cumulative
KY	2.9	2.4	0.7	−3.3	2.7
SC	1.3	0.5	0.7	−0.1	2.5
TN	2.1	−0.3	0.4	0.3	2.5
TX	−0.8	−0.2	2.6	−3.6	−1.9
Average per year	1.4	0.6	1.1	−1.7	1.0;0.4^†

Gray shading = significant change between years shown; P = 0.024 (2018–2019 in Kentucky), P = 0.018 (2015–2016 in Tennessee), P = 0.024 (2017–2018 in Texas) and P = 0.002 (2018–2019 in Texas).

^†

1.0 = cumulative average; 0.4 = average of transitions per year.

KY: Kentucky; SC: South Carolina; TN: Tennessee; TX: Texas.