Table 1:

Regression Results for Prescribing Patterns, NAMCS 2002–2004 and 2006–2009

	Number of Drugs Prescribed or Continued During Physician Visits						Number with Generic Equivalents
	DD-RD	Before 2006	After 2006	DD-RD	DD-RD		DD-RD	Before 2006	After 2006	DD-RD	DD-RD
Panel A: sample without 2005	(1)	(2)	(3)	(4)	(5)		(6)	(7)	(8)	(9)	(10)
Age 65 * Year 2006	0.606*	−0.286	0.292*	0.563**	0.621**		0.260*	0.025	0.265***	0.256**	0.318**
	(0.310)	(0.226)	(0.155)	(0.267)	(0.310)		(0.137)	(0.099)	(0.086)	(0.127)	(0.155)
Covariates	No	Yes	Yes	Yes	Yes		No	Yes	Yes	Yes	Yes
Order of Polynomial	3	3	3	3	4		3	3	3	3	4
R-squared	0.041	0.187	0.189	0.204	0.204		0.054	0.123	0.136	0.161	0.161
Observations	26,474	9,737	16,737	26,474	26,474		26,474	9,737	16,737	26,474	26,474
Panel B: sample with 2005
Age 65 * Year 2006	0.770***	−0.397**	0.292*	0.715***	0.628**		0.465***	−0.134	0.265***	0.425***	0.423***
	(0.285)	(0.188)	(0.155)	(0.253)	(0.274)		(0.139)	(0.097)	(0.086)	(0.130)	(0.162)
Covariates	No	Yes	Yes	Yes	Yes		No	Yes	Yes	Yes	Yes
Order of Polynomial	3	3	3	3	4		3	3	3	3	4
R-squared	0.035	0.190	0.189	0.203	0.204		0.050	0.124	0.136	0.158	0.158
Observations	29,775	13,038	16,737	29,775	29,775		29,775	13,038	16,737	29,775	29,775

^1.Control variables for all regressions include a dummy for year 2006 or later, age 65 or over, a polynomial control of age in days and full interaction with the age 65 dummy and year2006 dummy.

^2.Additionally, specifications with covariates include patient sex, race, Charlson index dummies, disease category by primary diagnosis codes, visit quarter, physician specialty type, whether it is a solo practice or not, electronic medical records utilization (yes or no), metropolitan statistical area (MSA) status and dummy for revenue from Medicare patients above median of the sample.

^3.***Significant at the 1% level (two-tail test); ** Significant at the 5% level (two-tail test); * Significant at the 10% level (two-tail test).