We were interested in estimating the impact of the PCIP on the supply of PCPs and patients’ access to their services. We measured improvements in access to care by studying changes in the volume of primary care services provided and the number of PCP providers. Both the supply of PCPs and volume of services are measures of access to care previously used in the literature.36 In addition, we investigated the impact of the PCIP on the allowed charges associated with eligible E&M claims.
Primary Care Providers with PCIP Eligible Specialties
First, we examined the trend in the number of eligible providers submitting Medicare claims. An increase in the number of primary care providers relative to the population is expected to improve access to primary care. As shown in Exhibit 4, the number of PCPs accepting Medicare patients increased steadily over the study period with an approximate 40 percent increase in the number of providers treating Medicare patients from 2005 to 2011. This trend is common to all four physician specialties under study.37 In addition, the number of non-physician practitioners more than doubled over this period. This significant increase in the number of non-physician providers, especially nurse practitioners, has been documented elsewhere.38
Exhibit 4: Number of Primary Care Providers under Medicare by Specialty, 2005-2011
Volume of E&M PCIP Eligible Claims
Our second measure of supply of primary care services is the volume of claims submitted by primary care providers for E&M services. As presented in Exhibit 5, the volume of E&M claims submitted by physicians increased by roughly 9 percent between 2005 and 2008. E&M claims took a slight dip in 2009, increased in 2010, and then stabilized in 2011 at roughly the levels in 2008. The same general increasing trend applied to each of the four eligible physician specialties, with the exception of geriatrics, which experienced a constant and substantial increase in E&M claims of 52 percent over the study period. Internal medicine physicians provided the majority of services, generating more than 50 percent of E&M claims each year over the study period. Family physicians are the second largest group of providers to supply E&M services, representing about 40 percent of the total, followed by geriatricians and pediatricians.
Consistent with the increase in the number of non-physicians documented above, we observe an even more dramatic increase in the total number of E&M claims submitted by non-physicians (clinical nurses, nurse practitioners and physician assistants). The volume of E&M claims more than doubled over the study period, from roughly 9 million in 2005 to more than 20 million in 2011.
Exhibit 5: Total Number of PCIP Eligible E&M Claims submitted by All PCPs under Medicare by PCP Specialty, 2005-2011
With both the aggregate number of E&M claims and the number of providers rising over time, we further explore the change in the volume of claims per provider over time. In other words, we examined whether the increase in the aggregate number of claims could be due to the increase in claims per provider or whether it is just due to the increase in the number of providers.
Inspection of Exhibit 6 reveals that in the case of all physicians the average number of eligible E&M claims per provider in 2011, was lower than in 2005. For instance, the average number of eligible E&M claims for internal medicine was 653 in 2011 compared to the higher value of 869 in 2005. The decreasing trend in average claims per physicians may be due to the increase in the number of PCPs in the absence of a substantial increase in the patient population.
Exhibit 6: Average Number of PCIP Eligible E&M Claims per PCP
under Medicare by Specialty, 2005-2011
Finally, in the case of non-physicians, there was an overall increase in the average number of E&M claims submitted by physician assistants (PA), nurse practitioners (NP) and clinical nurse specialists (CNS) after 2009 (see Exhibit B2, Appendix B). For example, the number of claims per PA increased from 125 in 2005 to almost 140 in 2011. On the other hand, the number of claims per NP was 253 in 2005, then declined to 219 in 2009 and then increased to about 228 in 2011. The increase in the average number of claims submitted suggests that the dramatic increase in services provided is due to both an increase in the number of providers and in the number of services provided by each non-physician. The average number of claims per PCIP recipients by specialty and the average allowed charges per PCIP recipients by specialty are presented in Appendix B Exhibit 12 and 13 respectively.
Allowed Charges for PCIP Eligible E&M Claims
So far, we have focused on the level of E&M services provided, measured in terms of number of claims and the number of providers. Next, we turn to the dollar value associated with E&M claims measured using allowed charges. As shown in Exhibit 7, the total allowed charges (in million dollars) for eligible E&M claims increased for all providers over the period of analysis. Overall, total allowed charges increased by 58 percent, with internal medicine and family medicine physicians accounting for most of this increase. It is also noteworthy that the value of claims submitted by non-physicians increased substantially over the same period, by a factor between 2 and 3.
Exhibit 7: Total Allowed Charges (in million $) for the PCIP Eligible E&M Claims submitted by All PCPs under Medicare, 2005-2011
As shown in Exhibit 8, the average allowed charge per PCP for E&M claims increased slightly for internal medicine physicians and pediatricians after 2009 (also see Appendix B Exhibit B2). The average value of E&M claims increased for the other PCPs, but not as fast as the total value of these claims. Given the moderate increase in the average allowed charges for E&M claims, the substantial increase in the aggregate allowed charges is likely due to the increase in the number of claims, which in turn, as discussed above may be driven by the increase in the number of providers. Another important observation is that although the average number of claims submitted by physicians declined over the 2005-2011 period, the average allowed charges remained the same or even increased. This observed increase in allowed charges per provider, despite the documented decline in the number of claims, may reflect changes in the composition of services that physicians are providing. We hypothesize that this change in the composition is due to an increase in the supply of services that take more time and which are typically associated with higher charges. We explore this hypothesis in the following section.
Exhibit 8: Average Allowed Charges ($) for the PCIP Eligible E&M Claims per PCP under Medicare by Specialty, 2005-2011
Finally, we constructed the proportion of practitioner’s allowed charges under the Medicare fee schedule (excluding hospital inpatient admission and emergency room visits) that are for PCIP eligible primary care services. As observed in Exhibit 9, for both physicians and non-physicians, the proportion of services that are PCIP eligible varies across specialties and is in general steadily increasing over the observation period. However, compared to primary care physicians, the non-physicians experienced a much larger percentage change in the share of allowed charges that are associated with PCIP eligible services.
Exhibit 9: Share of Allowed Charges for PCIP Eligible E&M Claims by Specialty,2005-2011
*Note: the proportions are of allowed charges for all Medicare claims (excluding hospital inpatient, ER, drug and lab)
While the proportion of services that are PCIP eligible is increasing over the observation period, the opposite is true for the proportion of E&M claims (Exhibit 10). Consistent with the decrease in the aggregate number of E&M claims documented above, we observe that the share of E&M claims out of the total Medicare claims is also slightly decreasing over the period. For example, in the case of providers specializing in internal medicine, the share decreased from 41.1 percent in 2005 to 37.5 percent in 2011.
Exhibit 10: Share of PCIP Eligible E&M Claims by Specialty, 2005-2011
Note: the proportions are calculated out of all Medicare claims (excluding hospital inpatient, ER, drug and lab)
The trends in primary care services and providers discussed above, apply in general to the more restricted sample of PCIP recipients (Exhibits B4-7 in Appendix B). When we limit the number of providers to 2011 PCIP recipients we observe a slight decrease in the average number of eligible claims submitted by physicians
36 For instance, see Stensland et al. 2013.
37 In 2005 almost half of the primary care providers (PCPs) were male, but the share of male PCPs declined to almost 40 percent in 2011 (Exhibit B.1, Appendix B). On the other hand, the share of PCPs aged 55 and above among all male PCPs increased from 24 percent in 2005 to 37.5 percent in 2011 (Exhibit B.1, Appendix B). As observed in Appendix Exhibit B.1, the physician population appears to be aging. The share of male physicians aged 65 and above underwent the largest increase recently, from 18.6 percent in 2010 to 21 percent in 2011 (Exhibit B.9a, Appendix B). A similar increasing trend is also observed among female physicians aged 55 and above (Exhibit B.9b, Appendix B). Finally, in the case of non-physicians, we observe the same steady increase in the share of providers aged 55 and above for both male and female providers (Exhibit B10-11, Appendix B).
38 Source: GAO (2008) – “Primary care Professionals. Recent Supply Trends, Projections, and Valuation of Services “ GAO 08-472T.