Table 2.

Difference-in-differences analysis of opioid and other medication prescriptions in Oregon relative to Colorado.

Prescription	State	Pre	Post	Difference	Difference-in-differences (95% confidence interval)	Relative change (95% confidence interval)
Opioids
Total	Oregon	0.2481***	0.2427***	−0.0054*	0.0021	0.8%
		(0.0026)	(0.0025)	(0.0031)	(−0.0047 to 0.0089)	(−1.9% to 3.6%)
	Colorado	0.1883***	0.1809***	−0.0074***
		(0.0014)	(0.0014)	(0.0016)
>120 MED	Oregon	0.0321 ***	0.0143***	−0.0179***	−0.0174***	−53.0%
		(0.0014)	(0.0009)	(0.0014)	(−0.0204 to −0.0143)	(−63.6 to −44.5)
	Colorado	0.0247***	0.0242***	−0.0005
		(0.0007)	(0.0006)	(0.0008)
61–120 MED	Oregon	0.0537***	0.0548***	0.0012	0.0011	2.0%
		(0.0016)	(0.0015)	(0.0019)	(−0.0031 to 0.0052)	(−5.8% to 9.7%)
	Colorado	0.0420***	0.0421 ***	0.0001
		(0.0007)	(0.0007)	(0.0009)
<61 MED	Oregon	0.2042***	0.2072***	0.0030	0.0101***	4.9%
		(0.0025)	(0.0024)	(0.0030)	(0.0035 to 0.0168)	(1.7% to 8.2%)
	Colorado	0.1604***	0.1533***	−0.0071***
		(0.0012)	(0.0012)	(0.0015)
Other drug classes
Arthritis	Oregon	0.0806***	0.0826***	0.0020	0.0027	3.3%
		(0.0017)	(0.0017)	(0.0020)	(−0.0016 to 0.007)	(−2.0% to 8.7%)
	Colorado	0.0563***	0.0557***	−0.0007
		(0.0008)	(0.0007)	(0.0010)
Neuropathic pain	Oregon	0.1374***	0.1461***	0.0087***	0.0123***	9.0%
		(0.0025)	(0.0026)	(0.0025)	(0.0066 to 0.0181)	(4.8% to 13.2%)
	Colorado	0.1103***	0.1066***	−0.0037**
		(0.0014)	(0.0014)	(0.0015)
Benzodiazepines	Oregon	0.0703***	0.0700***	−0.0003	−0.007***	−10.0%
		(0.0018)	(0.0018)	(0.0019)	(−0.0116 to −0.0024)	(−16.5% to −3.4%)
	Colorado	0.0737***	0.0804***	0.0067***
		(0.0012)	(0.0012)	(0.0015)

Note. MED = morphine equivalent daily dose (mg). Estimates indicate monthly predicted probabilities with standard errors in parentheses unless indicated otherwise. Relative change is relative percentage change in Oregon following the high dosage policy.

^*P < .0001;

^**P < .001;

^***P < .05.