1. March 31, 2016 Comparing the Cost and Resource Use of Nurse Practitioner and Physician assigned Beneficiaries By Jennifer Perloff, Ph.D., Peter Buerhaus, PhD, RN, FAAN, Catherine DesRoches, Ph.D. Working Document

2. 1 Brandeis Team Working Document Project Overview Initial empirical work focused on: Methodological issues in studying NPs (attribution, risk adjustment) Cost Quality Value * See for example Donelan K, DesRoches CM, Dittus RS, Buerhause P (2013). Perspectives of physicians and nurse practitioners on primary care practice. The new England Journal of Medicine, 368(20): 1898-1906.

3. 2 Brandeis Team Working Document Organizations & key personnel  Montana State University –Project oversight and administration, coordination, reporting, policy –Peter Buerhaus  Massachusetts General Hospital –Survey research w Karen Donelan  Mathematica –Analysis of Medicare claims data –Catherine DesRoches  Brandeis University –Analysis of Medicare claims data –Jennifer Perloff, Moaven Razavi, Galina Zolotusky, Monica O'Reilly- Jacob

4. 3 Brandeis Team Working Document Why NPs?*  Shortages of primary care physicians  Worries about access to care  Health reform and ACA provisions –Insurance reform – 32 million –National health service corp. – 1900 NPs –Community health center program – more than 800 NPs –Nurse managed clinics – serving over 94 K, more than 900 NPs –Home visiting programs –CMS graduate nursing education demonstration  Recommendations from IOM and MedPAC - reduce barriers to practice to full extent of licensure and training *Source: Peter Buerhaus, presentation, Academy Health, 2012

5. 4 Brandeis Team Working Document Comparing NPs and PCPs cost and quality  RCTs indicate similar clinical outcomes and patient satisfaction for NPs and PCPs  Limited research on costs –Disease specific or setting specific studies show comparable or lower costs for NPs as compared to MDs; –Many studies are single site –Often consider only a single encounter  Therefore, this study will use Medicare claims to compare the annual costs of care for beneficiaries assigned either to an NP (with an independent billing number) or a PCP

6. 5 Brandeis Team Working Document National Estimate of NPs with Independent Billing Number (NPIs) and Medicare Beneficiaries Served Year Number NPs with NPI Beneficaires Percent All Benes 200946,3864,806,12414.10% 201052,0625,218,03515.10% 201159,1965,780,00016.50%

7. 6 Brandeis Team Working Document Sample Construction # Based on all Medicare Part B claims maintained by Buccaneer for 2009-2010. * Beneficiaries are attributed to a provider if that provider accounts for the plurality of E&M services and at least 30 percent of total E&M for that beneficiary. Number of Clinicians in Medicare# Number of Clinicians in Random Sample Number of Clinicians in Observed Sample Beneficiaries Assigned to Clinician* NP57,5974,3639,422128,006 MD266,72454168,069474,243

8. 7 Brandeis Team Working Document Why so Many NPs: Distribution of Providers within TINs Providers within the same TINNP Primary Care MD 160.5471.48 216.3510.56 37.494.88 43.982.8 5+11.6410.28 Mean2.823.14

9. 8 Brandeis Team Working Document Single Attribution, Threshold Comparison Percent E&M Total Providers10%20%30%40%50%60%70%90% NPs38,17920,13715,11211,8859,7008,0236,7515,8294,806 Median E&M 0.2380.3780.5060.6280.7510.8630.9591 Percent of all NPs 0.5270.3960.3110.2540.2100.1770.1530.126 MDs145,60498,85185,25273,07161,72951,37341,68333,33621,437 Median E&M 0.3280.4250.5170.610.7010.7970.8871 Percent of all MDs 0.6790.5860.5020.4240.3530.2860.2290.147

10. 9 Brandeis Team Working Document Cost and Utilization Outcomes of Interest  Medicare allowed amounts on paid claims –Total Part A –Total Part B –Part B E&M  RVUs –Dollar adjusted total work RVUS (Part B); –Dollar adjusted E&M work RVUS (Part B).

11. 10 Brandeis Team Working Document Addressing Selection bias  Propensity score weighted regression  Logistic regression to determine the odds of seeing and NP  For the regression models, NP beneficiaries have a weight of 1 and PCP beneficiaries have a weight of 1/(1-p) where p is the probability of seeing an NP

12. 11 Distribution of Propensity Scores for Nurse Practitioner and Physician Assigned Beneficiaries

13. 12 Brandeis Team Working Document Beneficiary Co-morbidities before and after Weighting UnweightedWeighted Characteristic of beneficiariesPCP (%)NP (%)p-valuePCP (%)NP (%)p-value Congestive heart failure (CHF)21.519.4<.000119.519.40.31 Valve disorders17.911.1<.000111.1 0.74 Pulmonary circulation disease6.64.4<.00014.4 0.36 Peripheral vascular disease24.622.5<.000122.522.60.78 Hypertension78.768.3<.000168.168.20.12 Complex hypertension4.93.7<.00013.7 0.9 Paralysis4.55.2<.00015.45.20.02* Neurological disorders2427.7<.000128.127.80.0008 Chronic pulmonary disease31.325.7<.000125.925.70.12 Diabetes w/o complications36.531.8<.000131.8 0.78 Diabetes w/complications15.312.8<.000112.912.80.66 Psychoses17.220.6<.000120.920.60.005* Depression19.921.3<.000121.821.30.0001 Sidak's adjustment =.0012205 Bonferroni adjustment =.0011905

14. 13 Brandeis Team Working Document Adjusted Costs for NP and PCP attributed beneficiaries Inpatient Allowed Amount ^ Part B Allowed Amount ^ Evaluation and Management Allowed Amount ^ Intercept$23,376$2,682$86 Female-2458.74-63.6120.66 White-1779.6693.550.96 Age (years)-329.78-34.030.33 Duals-2565.39-481.910.13 NP-1848.78-531.51-52.73 Adjusted R- squared0.250.360.35

15. 14 Brandeis Team Working Document Adjusted RVUs for NP and PCP attributed beneficiaries Total Relative Value Unit*$40/unit ^ Evaluation and management relative value unit*$40/unit # Intercept$1,834$725 Female-31.17-18.44 White76.395.47 Age (years)-24.09-11.83 Duals-345.58-119.12 NP-282.32-70.67 Adjusted R- squared0.450.48

16. 15 Brandeis Team Working Document Comparison of NP and Primary Care Attributed Beneficiaries on Dollar Adjusted RVUs*

17. 16 Brandeis Team Working Document What Drives Difference in Expenditures?  Oaxaca decomposition  Decompose the MD-NP gap into 3 factors : –price (pay rate), –intensity and –technology mix.  Stratify beneficiaries by severity: –Low –Moderate –high

18. 17 Brandeis Team Working Document Risk-based stratification using predicted values of the pooled sample risk adjustment regression model (n= 467,944) Risk Stratum MD Mean Expected Charges NP Mean Expected Charges MD Mean Observed Charges NP Mean Observed Charges MD Bene Count NP Bene Count Total Bene Count %NP of Total Low Risk (30%) $ 718 $ 676 $ 1,450 $ 1,082 111,473 28,912 140,38521% Mod Risk (40%) $ 2,895 $ 2,859 $ 2,691 $ 2,141 152,382 34,798 187,18019% High Risk (30%) $ 7,636 $ 7,283 $ 7,520 $ 6,222 118,269 22,110 140,37916%

19. 18 Brandeis Team Working Document Differences in Service Mix by Provider Type Revenue/BETOS Name Service Count, NP Service Count, MD D: DME 0.03 0.06 I1I3I4:Standard Img/Echo/UltrSnd 7.37 10.71 I2:Advance Imaging 1.46 2.38 M1:Office visits 6.35 12.35 M4A-HomeVisit 0.59 0.24 M5:Specialist 2.82 2.61 M:Hospital/ER/NrsHom Visit 17.30 19.32 O: Other Services 3.48 4.74 P0: Anesthesia 0.45 0.79 P1-4:Major procedures 0.56 1.00 P5-6:Minor/Ambltry procedures 3.63 5.51 P7-9:Endscpy-Onclgy-Dialys 1.08 1.76 T1:Ordinary Lab Tests 16.22 17.91 T2: Other Tests 2.36 4.27 Y-Z 2.86 1.83

20. 19 Brandeis Team Working Document MD patients’ mean costs ($) by service category, by risk stratum Primary Care MD

21. 20 Brandeis Team Working Document Drivers of MD-NP Cost Gap

22. 21 Brandeis Team Working Document Limitations  Despite propensity score weighted regression, there may still be clinical differences between NP and PCP attributed beneficiaries;  Not all NP activity is captured by NPI – scope of practice laws and ‘incident to’ billing means that there are NP services billed under and MD’s NPI;

23. 22 Brandeis Team Working Document Conclusions  NP attributed beneficiaries appear to systematically cost less than MD attributed beneficiaries;  The closer you get to the primary care provider’s locus of control, the bigger the cost difference;  Time horizon matters – when you look at total costs for 12 months to can see differences in practice style play out;  NP managed patients appear to have fewer and less expensive services as compared to MD managed patients;  The practice pattern differences are more pronounced for the sickest patients.

24. 23 Brandeis Team Working Document Questions/Discussion ?