AMI, Heart failure, Pneumonia Hospital-wide all-cause
Program phase Pre Post Pre Post1 Post2 Post3
MSSP Control MSSP Control MSSP Control MSSP Control MSSP Control MSSP Control
Number of beds* 286 242 289 241 287 228 285 226 287 228 284 224
(226.28) (181.54) (228.47) (187.63) (229.95) (184.90) (230.07) (185.01) (232.11) (186.38) (231.65) (186.07) Ownership (%)
Government 6.9 15.0 6.8 14.7 6.7 13.9 6.8 14.0 6.7 14.1 6.7 14.2
Not-for-profit 85.8 61.7 86.0 61.4 85.6 58.7 85.2 58.5 85.4 58.3 85.4 57.5
For-profit 7.3 23.3 7.2 23.9 7.6 27.4 8.0 27.6 8.0 27.6 8.0 28.3
Medical school
affiliation (%) 45.3 37.7 50.4 39.4 46.2 36.4 45.6 36.7 46.4 37.3 48.8 36.5
Disproportionate patient percent*
0.27 (0.20)
0.29 (0.18)
0.30 (0.20)
0.31 (0.18)
0.28 (0.20)
0.28 (0.19)
0.29 (0.20)
0.28 (0.19)
0.28 (0.20)
0.28 (0.19)
0.28 (0.19)
0.28 (0.19) Registered nurse
per average daily census ratio*
3.68
(19.66) 2.34
(1.74) 4.23
(21.14) 3.06
(6.26) 3.88
(20.99) 3.05
(8.86) 4.06
(21.03) 3.25
(10.46) 4.17
(20.99) 3.33
(10.57) 4.12
(21.06) 3.40 (7.14) Market competition
(1-HHI)* 0.84
(0.14) 0.85
(0.13) 0.84
(0.14) 0.85
(0.13) 0.84
(0.14) 0.85
(0.13) 0.84
(0.14) 0.85
(0.13) 0.84
(0.14) 0.85
(0.13) 0.84
(0.14) 0.85 (0.13) Total physicians per
100,000 residents* 218
(32.87) 204
(32.28) 218
(32.78) 203
(31.96) 218
(32.73) 203
(32.18) 218
(32.76) 203
(32.34) 218
(32.64) 203
(32.29) 217
(32.19) 202 (31.39)
SOURCE: Authors’ analysis of data from the archived Hospital Compare annual files, linked to the Shared Savings Program participants files, the CMS impact files, the Provider of Services Current files, and the Dartmouth Atlas of Health Care files.
NOTES: AMI is acute myocardial infarction. MSSP is Medicare shared savings program. HHI is Herfindahl-Hirschman Index.
Control consists of non-MSSP participating hospitals. For AMI, heart failure, and pneumonia, Pre indicates the period between July 1, 2008 and June 30, 2011; Post indicates the period between July 1, 2013 and June 30, 2016. For hospital-wide all-cause, Pre indicates the period between July 1, 2011 and June 30, 2012; Post1 indicates the period between July 1, 2012 and June 30, 2013; Post2 indicates the period between July 1, 2013 and June 30, 2014; Post3 indicates the period between July 1, 2014 and June 30, 2015. *Numbers indicate mean with SD in parentheses.
Appendix Table A2. Full model results of the random-effects difference-in-differences
regression estimates of MSSP-participating hospitals on readmission rate for Medicare patients initially admitted for AMI (n=1,631)
Variable Name Estimated
coefficients Standard errors
95%
lower confidence
interval
95%
higher confidence
interval
p-value
MSSP 0.0911 0.1177 -0.1396 0.3217 0.4390
Post -3.3797 0.0440 -3.4660 -3.2933 0.0000
MSSP × Post -0.1380 0.1141 -0.3616 0.0856 0.2260
Beds 0.0002 0.0002 -0.0001 0.0005 0.2780
Disproportionate patient percent 0.8583 0.1466 0.5709 1.1457 0.0000
Medical school affiliation 0.0764 0.0537 -0.0289 0.1817 0.1550
Ownership
Government -0.0622 0.0750 -0.2091 0.0847 0.4060 For-profit 0.1493 0.0611 0.0295 0.2691 0.0150 Registered nurse per average daily census ratio -0.0044 0.0020 -0.0083 -0.0005 0.0260
Market competition (1-HHI) 0.8665 0.1964 0.4816 1.2514 0.0000
Total physicians per 100,000 residents 0.0037 0.0008 0.0022 0.0052 0.0000
SOURCE: Authors’ analysis of data from the archived Hospital Compare annual files, linked to the Shared Savings Program participants files, the CMS impact files, the Provider of Services Current files, and the Dartmouth Atlas of Health Care files.
NOTES: AMI is acute myocardial infarction. MSSP is Medicare shared savings program. HHI is Herfindahl-Hirschman Index. Control consists of non-MSSP participating hospitals. Post
indicates the period between July 1, 2013 and June 30, 2016. R-squared: 0.6629. df: 11.
regression estimates of MSSP-participating hospitals on readmission rate for Medicare patients initially admitted for heart failure (n=1,889)
Variable Name Estimated
coefficients Standard errors
95%
lower confidence
interval
95%
higher confidence
interval
p-value
MSSP 0.2244 0.1373 -0.0447 0.4934 0.1020
Post -2.9656 0.0505 -3.0645 -2.8667 0.0000
MSSP × Post -0.4663 0.1507 -0.7617 -0.1709 0.0020
Beds 0.0000 0.0002 -0.0004 0.0004 0.9880
Disproportionate patient percent 1.9052 0.1916 1.5297 2.2807 0.0000
Medical school affiliation 0.0136 0.0732 -0.1299 0.1571 0.8530
Ownership
Government 0.0622 0.0994 -0.1326 0.2570 0.5320 For-profit 0.3931 0.0873 0.2219 0.5643 0.0000 Registered nurse per average daily census ratio -0.0079 0.0025 -0.0127 -0.0031 0.0010
Market competition (1-HHI) 1.1820 0.2622 0.6681 1.6960 0.0000
Total physicians per 100,000 residents 0.0073 0.0011 0.0051 0.0095 0.0000
SOURCE: Authors’ analysis of data from the archived Hospital Compare annual files, linked to the Shared Savings Program participants files, the CMS impact files, the Provider of Services Current files, and the Dartmouth Atlas of Health Care files.
NOTES: MSSP is Medicare shared savings program. HHI is Herfindahl-Hirschman Index.
Control consists of non-MSSP participating hospitals. Post indicates the period between July 1, 2013 and June 30, 2016. R-squared: 0.4559. df: 11.
Appendix Table A4. Full model results of the random-effects difference-in-differences
regression estimates of MSSP-participating hospitals on readmission rate for Medicare patients initially admitted for pneumonia (n=1,896)
Variable Name Estimated
coefficients Standard errors
95%
lower confidence
interval
95%
higher confidence
interval
p-value
MSSP 0.1775 0.1156 -0.0490 0.4040 0.1250
Post -1.4814 0.0423 -1.5643 -1.3985 0.0000
MSSP × Post -0.2577 0.1162 -0.4854 -0.0300 0.0270
Beds 0.0006 0.0002 0.0003 0.0010 0.0010
Disproportionate patient percent 0.9316 0.1542 0.6295 1.2338 0.0000
Medical school affiliation 0.0769 0.0604 -0.0415 0.1953 0.2030
Ownership
Government 0.0838 0.0805 -0.0739 0.2415 0.2980 For-profit 0.2830 0.0742 0.1376 0.4284 0.0000 Registered nurse per average daily census ratio -0.0014 0.0022 -0.0058 0.0030 0.5430
Market competition (1-HHI) 0.8754 0.2294 0.4258 1.3251 0.0000
Total physicians per 100,000 residents 0.0069 0.0010 0.0050 0.0088 0.0000
SOURCE: Authors’ analysis of data from the archived Hospital Compare annual files, linked to the Shared Savings Program participants files, the CMS impact files, the Provider of Services Current files, and the Dartmouth Atlas of Health Care files.
NOTES: MSSP is Medicare shared savings program. HHI is Herfindahl-Hirschman Index.
Control consists of non-MSSP participating hospitals. Post indicates the period between July 1, 2013 and June 30, 2016. R-squared: 0.2454. df: 11.
regression estimates of MSSP-participating hospitals on readmission rate for Medicare patients initially admitted for any cause (n=2,067)
Variable Name Estimated
coefficients Standard errors
95%
lower confidence
interval
95%
higher confidence
interval
p-value
MSSP 0.0135 0.0751 -0.1336 0.1606 0.8570
Post1 -0.3572 0.0180 -0.3924 -0.3219 0.0000
Post2 -0.7069 0.0199 -0.7459 -0.6678 0.0000
Post3 -0.3489 0.0215 -0.3912 -0.3067 0.0000
MSSP × Post1 -0.0957 0.0536 -0.2008 0.0095 0.0750
MSSP × Post2 -0.0661 0.0591 -0.1819 0.0498 0.2640
MSSP × Post3 -0.0418 0.0625 -0.1643 0.0807 0.5040
Beds 0.0006 0.0001 0.0003 0.0008 0.0000
Disproportionate patient percent 1.2588 0.1053 1.0525 1.4651 0.0000
Medical school affiliation 0.0601 0.0364 -0.0113 0.1314 0.0990
Ownership
Government 0.1086 0.0537 0.0034 0.2139 0.0430 For-profit 0.1646 0.0464 0.0736 0.2556 0.0000 Registered nurse per average daily census ratio -0.0026 0.0007 -0.0040 -0.0012 0.0000
Market competition (1-HHI) 0.6907 0.1438 0.4090 0.9725 0.0000
Total physicians per 100,000 residents 0.0059 0.0007 0.0045 0.0072 0.0000
SOURCE: Authors’ analysis of data from the archived Hospital Compare annual files, linked to the Shared Savings Program participants files, the CMS impact files, the Provider of Services Current files, and the Dartmouth Atlas of Health Care files.
NOTES: MSSP is Medicare shared savings program. HHI is Herfindahl-Hirschman Index.
Control consists of non-MSSP participating hospitals. Post1 indicates the period between July 1, 2012 and June 30, 2013. Post2 indicates the period between July 1, 2013 and June 30, 2014.
Post3 indicates the period between July 1, 2014 and June 30, 2015. R-squared: 0.1894. df: 15.
Appendix Table A6. Full model results of the random-effects difference-in-differences regression estimates of MSSP-participating hospitals on the three condition-specific risk standardized readmission rates, after excluding BPCI participating hospitals
Percentage point change in readmission rate (Standard error in parentheses)
Variable Name AMI Heart Failure Pneumonia
MSSP 0.0566 0.198 0.170
(0.120) (0.140) (0.119)
Post -3.363*** -2.957*** -1.467***
(0.0445) (0.0510) (0.0427)
MSSP × Post -0.0993 -0.452*** -0.262**
(0.116) (0.154) (0.117)
Beds 0.0000932 -0.0000501 0.000584***
(0.000160) (0.000217) (0.000182)
Disproportionate patient percent 0.841*** 1.911*** 0.916***
(0.147) (0.194) (0.157)
Medical school affiliation 0.0793 0.00666 0.0645
(0.0546) (0.0738) (0.0615)
Ownership
Government -0.0503 0.0647 0.0817
(0.0752) (0.0995) (0.0807)
For-profit 0.151** 0.383*** 0.271***
(0.0619) (0.0869) (0.0751)
Registered nurse per average daily census ratio -0.00423** -0.00768*** -0.00123
(0.00193) (0.00241) (0.00220)
Market competition (1-HHI) 0.925*** 1.288*** 0.949***
(0.194) (0.257) (0.226)
Total physicians per 100,000 residents 0.00355*** 0.00698*** 0.00679***
(0.000776) (0.00115) (0.000979)
Number of Hospitals 1,586 1,843 1,850
SOURCE: Authors’ analysis of data from the archived Hospital Compare annual files, linked to the Shared Savings Program participants files, the archived Bundled Payments for Care
Improvement files, the CMS impact files, the Provider of Services Current files, and the Dartmouth Atlas of Health Care files.
NOTES: AMI is acute myocardial infarction. BPCI is bundled payments for care improvement.
MSSP is Medicare shared savings program. HHI is Herfindahl-Hirschman Index. Control
consists of non-MSSP participating hospitals. Post indicates the period between July 1, 2013 and June 30, 2016. Appendix Exhibits A2-A4 present full results.
*** p < 0.01, ** p < 0.05, * p < 0.10
regression estimates of MSSP-participating hospitals on readmission rate for Medicare patients initially admitted for any cause, after excluding BPCI participating hospitals
Percentage point change in readmission rate (Standard error in parentheses)
Variable Name Hospital-wide all-cause
MSSP 0.0235
(0.0767)
Post1 -0.358***
(0.0182)
Post2 -0.709***
(0.0202)
Post3 -0.347***
(0.0218)
MSSP × Post1 -0.0932*
(0.0551)
MSSP × Post2 -0.0662
(0.0613)
MSSP × Post3 -0.0536
(0.0647)
Beds 0.000555***
(0.000126) Disproportionate patient percent 1.262***
(0.107)
Medical school affiliation 0.0564
(0.0366) Ownership
Government 0.107**
(0.0538)
For-profit 0.161***
(0.0465) Registered nurse per average daily
census ratio -0.00255***
(0.000695)
Market competition (1-HHI) 0.746***
(0.141) Total physicians per 100,000
residents 0.00564***
(0.000691)
Number of Hospitals 2,021
SOURCE: Authors’ analysis of data from the archived Hospital Compare annual files, linked to the Shared Savings Program participants files, the archived Bundled Payments for Care
Improvement files, the CMS impact files, the Provider of Services Current files, and the Dartmouth Atlas of Health Care files.
NOTES: BPCI is bundled payments for care improvement. MSSP is Medicare shared savings program. HHI is Herfindahl-Hirschman Index. Control consists of non-MSSP participating hospitals. Post1 indicates the period between July 1, 2012 and June 30, 2013. Post2 indicates the period between July 1, 2013 and June 30, 2014. Post3 indicates the period between July 1, 2014 and June 30, 2015. *** p < 0.01, ** p < 0.05, * p < 0.10
Appendix Table A8. The fixed-effects difference-in-differences regression estimates of MSSP- participating hospitals on the three condition-specific risk standardized readmission rates
Percentage Point Change in Readmission Rate
MSSP × Post -0.127 -0.488*** -0.247**
(0.117) (0.154) (0.117)
MSSP 0 (omitted) 0 (omitted) 0 (omitted)
Post -3.349*** -2.932*** -1.470***
(0.0493) (0.0551) (0.0446)
Number of Hospitals 1,631 1,889 1,896
SOURCE: Authors’ analysis of data from the archived Hospital Compare annual files, linked to the Shared Savings Program participants files, the CMS impact files, the Provider of Services Current files, and the Dartmouth Atlas of Health Care files.
NOTES: AMI is acute myocardial infarction. MSSP is Medicare shared savings program.
Control consists of non-MSSP participating hospitals. Post indicates the period between July 1, 2013 and June 30, 2016. *** p < 0.01, ** p < 0.05, * p < 0.10
Appendix Table A9. The fixed-effects difference-in-differences regression estimates of MSSP- participating hospitals on readmission rate for Medicare patients initially admitted for any cause
Percentage Point Change in Readmission Rate
(Standard Error in Parentheses) Hospital wide all-cause
MSSP × Post1 -0.0930*
(0.0536)
MSSP × Post2 -0.0692
(0.0590)
MSSP × Post3 -0.0465
(0.0625)
MSSP 0 (omitted)
Post1 -0.353***
(0.0181)
Post2 -0.701***
(0.0200)
Post3 -0.343***
(0.0218)
Number of Hospitals 2,067
SOURCE: Authors’ analysis of data from the archived Hospital Compare annual files, linked to the Shared Savings Program participants files, the CMS impact files, the Provider of Services Current files, and the Dartmouth Atlas of Health Care files.
NOTES: MSSP is Medicare shared savings program. Control consists of non-MSSP participating hospitals. Post1 indicates the period between July 1, 2012 and June 30, 2013. Post2 indicates the period between July 1, 2013 and June 30, 2014. Post3 indicates the period between July 1, 2014 and June 30, 2015. *** p < 0.01, ** p < 0.05, * p < 0.10
Appendix Table A10. The propensity score difference-in-differences regression estimates of MSSP-participating hospitals on the three condition-specific risk standardized readmission rates
Percentage Point Change in Readmission Rate (Standard Error in Parentheses)
(0.124) (0.165) (0.126)
MSSP 0.0184 0.126 0.148
(0.124) (0.147) (0.123)
Post -3.422*** -3.132*** -1.531***
(0.0650) (0.0819) (0.0643)
Number of Hospitals 854 917 939
SOURCE: Authors’ analysis of data from the archived Hospital Compare annual files, linked to the Shared Savings Program participants files, the CMS impact files, the Provider of Services Current files, and the Dartmouth Atlas of Health Care files.
NOTES: AMI is acute myocardial infarction. MSSP is Medicare shared savings program.
Control consists of non-MSSP participating hospitals. Post indicates the period between July 1, 2013 and June 30, 2016. *** p < 0.01, ** p < 0.05, * p < 0.10
Appendix Table A11. The propensity score difference-in-differences regression estimates of MSSP-participating hospitals on readmission rate for Medicare patients initially admitted for any cause
Percentage Point Change
in Readmission Rate (Standard Error in Parentheses)
Hospital wide all-cause
MSSP × Post1 -0.0648
(0.0579)
MSSP × Post2 -0.0335
(0.0638)
MSSP × Post3 0.0222
(0.0678)
MSSP -0.00996
(0.0806)
Post1 -0.389***
(0.0281)
Post2 -0.741***
(0.0310)
Post3 -0.420***
(0.0338)
Number of Hospitals 950
SOURCE: Authors’ analysis of data from the archived Hospital Compare annual files, linked to the Shared Savings Program participants files, the CMS impact files, the Provider of Services Current files, and the Dartmouth Atlas of Health Care files.
NOTES: MSSP is Medicare shared savings program. Control consists of non-MSSP participating hospitals. Post1 indicates the period between July 1, 2012 and June 30, 2013. Post2 indicates the period between July 1, 2013 and June 30, 2014. Post3 indicates the period between July 1, 2014 and June 30, 2015. *** p < 0.01, ** p < 0.05, * p < 0.10