Table 4.

Modeling differences in street price and number of sales.

Parameters				Model estimate		P value		Exponentiated parameter (95% CI)
Differences in street pricea
	Simplified linear model
		Intercept	2.36		<.001		10.6 (6.93-16.3)
		Drug (reference: tapentadol)	0.089		.67		1.09 (0.729-1.64)
		Year	−0.032		.35		0.968 (0.904-1.04)
	Linear model with potency added
		Intercept	2.10		<.001		8.19 (5.36-12.5)
		Drug (reference: tapentadol)	0.191		.34		1.21 (0.816-1.79)
		Year	−0.0326		.33		0.968 (0.906-1.03)
		10-MMEb increase	0.0754		<.001		1.08 (1.05-1.10)
Quarterly number of sales
	Simplified Poisson model
		Intercept	−1.23		.004		0.294 (0.127-0.677)
		Drug (reference: tapentadol)	3.99		<.001		54.2 (27.0-109)
		Total website reports	0.00465		<.001		1.005 (1.003-1.007)
	Poisson model with availability added
		Intercept	−2.03		<.001		0.131 (0.0457-0.378)
		Drug (reference: tapentadol)	0.0482		.98		1.05 (0.0289-38.1)
		Total website reports	0.00557		<.001		1.006 (1.003-1.008)
		100,000-unit increase in standard units sold	0.00882		.03		1.01 (1.00-1.02)

^aStreet price, the dependent variable, was log-transformed for modeling.

^bMME: morphine milligram equivalents.