In each hospital-year, we calculated a 30-day unplanned. readmission rate among patients who survived at least 30 days

Romley JA, Goldman DP, Sood N. US hospitals experienced substantial productivity growth during 2002 11. Health Aff (Millwood). 2015;34(3). Published online February 11, 2015. Appendix

Adjusting hospital output for readmissions In each hospital-year, we calculated a 30-day unplanned readmission rate among patients who survived at least 30 days beyond their admission, and multiplied the number of survivors by the value of one minus the calculated rate. In calculating readmission rates, we followed the methodology used by CMS for quality reporting, which was developed by the Yale New Haven Health Services Corporation / Center for Outcomes Research & Evaluation.(1) Rates were calculated independently for heart attack, heart failure, and pneumonia. For each condition, index admissions with the corresponding primary diagnosis were identified. Admissions within 30 days of an index admission did not qualify as additional index admissions. Unplanned readmissions within 30 days of discharge from an index admission were then identified. Readmissions for certain treatments (such as chemotherapy) were defined to be planned; other readmissions were defined as potentially planned, and then adjudicated to have been planned if the primary diagnosis of the readmission was neither acute nor a complication of care. Diagnoses were characterized by Clinical Classification Software developed by the Agency for Healthcare Research and Quality and, in some cases, by specific ICD-9-CM codes. Where multiple hospitalizations occurred within 30 days of an index admission, the index admission was defined as not having a readmission if and only if the first subsequent admission was planned, regardless of the nature of the other 2

subsequent admissions. An index admission was excluded from the readmission rate (that is, from both the numerator and denominator of the measure) if there was a transfer to another acute-care hospital, as defined by an admission to another hospital within one day of discharge from the index admission; admissions for the same index diagnosis to the same index hospital on the same day as discharge were treated similarly. The study cohorts described in Appendix Exhibit 1 were used consistently across the productivity analyses. Comparing productivity estimates across analyses To compare productivity estimates (for example, unadjusted versus severity-adjusted), we estimated the standard error of the difference in estimates based on the bootstrapped distribution of the differences from 250 sets of regressions. In the bootstrapping, sampling was done at the hospital level to allow for correlation within hospitals over time. 3

Appendix Exhibit 1: Cohort Selection Criteria for Heart Attack 4

Appendix Exhibit 2: Cohort Selection Criteria for Heart Failure 5

Appendix Exhibit 3: Cohort Selection Criteria for Pneumonia 6

Appendix Exhibit 3, Continued 7

Appendix Exhibit 4: Costs per Stay 20 18.8 18 18.2 Costs per Stay (Thousands of $2012) 16 14 12 10 8 9.7 9.1 9.0 8.9 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 Heart attack Heart failure Pneumonia Note: Costs per stay are adjusted for geographic differences in wages and general inflation in the cost of hospital care over time. 8

Appendix Exhibit 5: Trends in Selected Measures of Patient Demographics and Severity of Illness at Admission >1 indicates increasing trend Age, Sex and Race / Ethnicity >1 indicates increasing trend Comorbidities and Inpatient Mortality Risk 9

Appendix Exhibit 6: Rate of Survival with No Unplanned Readmissions 82 81.5 Rate of Survival with No Unplanned Readmissions (%) 80 78 76 74 77.5 76.0 80.1 76.1 72 71.0 70 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 Heart attack Heart failure Pneumonia 10

Appendix Exhibit 7: Medicare Payment per Stay 16 15 14 15.1 14.6 13 Medicare Payment per Stay (Thousands of $2012) 12 11 10 9 8 7 6 8.3 7.2 7.3 7.0 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 Heart attack Heart failure Pneumonia Note: Medicare payment per stay is adjusted for inflation in the economy over time. 11

Appendix Exhibit 8: Sensitivity Analysis Using Elixhauser Comorbidities and Adjusting for Proportions of Patients Admitted through Emergency Department or Transferred from Another Hospital 12

Appendix Exhibit 9: Summary Statistics for Study Cohorts Heart attack Heart failure Pneumonia Patient stays, n 403,253 906,918 764,623 Hospitals, n 3,315 3,621 3,675 Year of admission 2006.0 2006.4 2005.9 Adjusted cost per stay (2012 dollars) $18,762 $10,017 $8,942 30-day survival with no unplanned readmissions 78.7% 71.8% 77.4% Teaching hospital 4.4% 3.4% 2.5% AHRQ predicted inpatient mortality 10.7% 4.5% 6.1% Location of heart attack: Anterolateral (410.0x) 2.2% Location of heart attack: Other Anterior Wall (410.1x) 8.6% Location of heart attack: Inferolateral Wall (410.2x) 1.8% Location of heart attack: Inferoposterior Wall (410.3x) 1.2% Location of heart attack: Other Inferior Wall (410.4x) 10.5% Location of heart attack: Other Lateral Wall (410.5x) 1.3% Location of heart attack: True Posterior Wall (410.6x) 0.3% Location of heart attack: Sub-Endocardial (410.7x) 65.7% Location of heart attack: Other Specified Sites (410.8x) 1.6% Location of heart attack: Unspecified site (410.9x) 6.7% No Charlson-Deyo comorbidities 0.0% 1.3% 17.9% 1 Charlson-Deyo comorbidity 28.1% 26.1% 38.4% 2 Charlson-Deyo comorbidities 36.8% 41.0% 29.3% 3 Charlson-Deyo comorbidities 25.0% 24.6% 11.8% 4 Charlson-Deyo comorbidities 8.6% 6.3% 2.3% 5+ Charlson-Deyo comorbidities 1.5% 0.8% 0.2% Age 78.4 79.9 79.9 Female 49.4% 56.7% 55.0% African American 7.8% 13.0% 7.9% Hispanic 1.5% 2.0% 1.9% Other race 3.0% 2.6% 3.1% Patient zip code characteristics Median household income ($000) 41.9 41.3 41.7 Social Security income ($000) 11.3 11.2 11.3 Poor 12.3% 13.1% 12.7% Employed 58.3% 57.9% 58.3% Less than high school education 20.3% 21.2% 20.8% Urban 71.3% 74.5% 71.7% Hispanic 8.6% 9.5% 9.2% Single 42.0% 43.1% 42.2% Elderly in an institution 4.6% 4.6% 4.8% Non-institutionalized elderly with physical disability 29.5% 30.0% 30.0% Sensory disability among elderly 12.3% 13.1% 12.7% Mental disability 11.0% 11.4% 11.4% Self-care disability 9.8% 10.1% 10.0% Difficulty going-outside-the-home disability 20.6% 21.3% 20.9% Notes: Statistics are means unless otherwise indicated; all statistics calculated at the patient stay level. For heart-attack locations, ICD-9-CM diagnosis codes appear in parentheses. AHRQ = Agency for Healthcare Research and Quality. 13

Appendix Exhibit 10: Trends in Patient Characteristics Condition Heart attack Heart failure Pneumonia Variable Mean, 2002 Mean, 2011 Ratio Mean, 2002 Mean, 2011 Ratio Mean, 2002 Mean, 2011 Ratio Teaching hospital 4.4% 4.0% 0.914 3.2% 3.4% 1.064 2.4% 2.5% 1.073 AHRQ predicted inpatient mortality 9.9% 11.9% 1.203 3.7% 6.6% 1.779 5.5% 8.6% 1.564 Location of heart attack: Anterolateral (410.0x) 2.6% 1.7% 0.656 Location of heart attack: Other Anterior Wall (410.1x) 10.7% 6.6% 0.616 Location of heart attack: Inferolateral Wall (410.2x) 2.1% 1.6% 0.784 Location of heart attack: Inferoposterior Wall (410.3x) 1.6% 1.0% 0.663 Location of heart attack: Other Inferior Wall (410.4x) 12.2% 9.1% 0.742 Location of heart attack: Other Lateral Wall (410.5x) 1.4% 1.0% 0.665 Location of heart attack: True Posterior Wall (410.6x) 0.4% 0.3% 0.830 Location of heart attack: Sub-Endocardial (410.7x) 58.8% 73.6% 1.252 Location of heart attack: Other Specified Sites (410.8x) 1.9% 0.5% 0.280 Location of heart attack: Unspecified site (410.9x) 8.3% 4.5% 0.548 No Charlson-Deyo comorbidities 0.0% 0.0% 3.2% 0.1% 0.031 18.7% 18.3% 0.981 1 Charlson-Deyo comorbidity 29.7% 27.5% 0.927 29.7% 21.8% 0.735 39.8% 36.6% 0.920 2 Charlson-Deyo comorbidities 37.3% 36.0% 0.963 40.7% 39.8% 0.978 28.6% 28.9% 1.012 3 Charlson-Deyo comorbidities 24.2% 24.7% 1.021 21.2% 28.5% 1.348 10.7% 12.9% 1.206 4 Charlson-Deyo comorbidities 7.5% 9.9% 1.318 4.7% 8.6% 1.829 2.0% 2.9% 1.413 5+ Charlson-Deyo comorbidities 1.3% 1.9% 1.498 0.6% 1.2% 1.912 0.2% 0.4% 1.842 Age 78.4 78.0 0.995 79.6 80.5 1.011 80.1 79.9 0.998 Female 50.3% 47.6% 0.947 58.6% 55.3% 0.943 54.8% 55.0% 1.003 African American 7.4% 8.4% 1.124 13.2% 12.7% 0.960 8.5% 7.8% 0.919 Hispanic 1.5% 1.5% 0.981 1.9% 1.9% 1.012 1.7% 2.0% 1.205 Other race 2.6% 3.4% 1.288 2.4% 3.0% 1.260 2.9% 3.3% 1.148 Patient zip code characteristics Median household income ($000) 41.6 42.3 1.018 40.5 42.5 1.050 40.7 42.5 1.043 Social Security income ($000) 11.3 11.3 0.999 11.1 11.3 1.011 11.2 11.3 1.008 Poor 12.4% 12.1% 0.978 13.5% 12.5% 0.924 13.1% 12.3% 0.940 Employed 58.2% 58.4% 1.004 57.5% 58.4% 1.015 57.9% 58.7% 1.013 Less than high school education 20.4% 20.2% 0.990 21.7% 20.5% 0.946 21.3% 20.4% 0.961 Urban 72.0% 70.1% 0.974 74.6% 74.1% 0.994 71.3% 71.4% 1.001 Hispanic 8.6% 8.7% 1.013 9.6% 9.3% 0.973 9.2% 9.2% 0.997 Single 42.4% 41.5% 0.980 43.6% 42.5% 0.974 42.7% 41.8% 0.980 Elderly in an institution 4.6% 4.5% 0.977 4.7% 4.5% 0.971 4.9% 4.8% 0.980 Non-institutionalized elderly with physical disability 29.5% 29.6% 1.002 30.2% 29.7% 0.982 30.3% 29.8% 0.985 Sensory disability among elderly 12.4% 12.1% 0.978 14.7% 14.5% 0.986 15.0% 14.8% 0.987 Mental disability 11.0% 11.1% 1.004 11.5% 11.3% 0.980 11.5% 11.3% 0.984 Self-care disability 9.8% 9.8% 1.002 10.3% 10.0% 0.971 10.1% 9.9% 0.979 Difficulty going-outside-the-home disability 20.6% 20.6% 0.997 21.5% 20.9% 0.975 21.2% 20.8% 0.980 Notes: Means calculated at the patient stay level. For heart-attack locations, ICD-9-CM diagnosis codes appear in parentheses. AHRQ = Agency for Healthcare Research and Quality. 14

Appendix Exhibit 11: Regression Results for Log of the Number of Survivors without Unplanned Readmissions Divided by Total Costs, Heart Attack Patient Cohort Output Hospital stays Hospital stays Survivors without unplanned readmissions Parameter Estimate (Standard Error) Constant -2.861*** (0.008) -18.68*** (1.09) -21.22*** (1.10) Year of admission -0.006*** (0.001) -0.006*** (0.001) 0.008*** (0.001) Teaching hospital -0.10*** (0.03) -0.10*** (0.03) AHRQ predicted inpatient mortality risk, logged 0.11* (0.06) -1.19*** (0.06) Location of heart attack: Anterolateral (410.0x) -0.72*** (0.07) -0.67*** (0.07) Location of heart attack: Other Anterior Wall (410.1x) -0.71*** (0.04) -0.54*** (0.05) Location of heart attack: Inferolateral Wall (410.2x) -0.57*** (0.07) -0.39*** (0.08) Location of heart attack: Inferoposterior Wall (410.3x) -0.96*** (0.09) -0.69*** (0.10) Location of heart attack: Other Inferior Wall (410.4x) -0.82*** (0.04) -0.59*** (0.04) Location of heart attack: Other Lateral Wall (410.5x) -0.47*** (0.08) -0.34*** (0.09) Location of heart attack: True Posterior Wall (410.6x) -0.89*** (0.15) -0.55*** (0.16) Location of heart attack: Sub-Endocardial (410.7x) -0.41*** (0.03) -0.19*** (0.03) Location of heart attack: Other Specified Sites (410.8x) -0.28*** (0.06) -0.19*** (0.06) 1 Charlson-Deyo comorbidity 2 Charlson-Deyo comorbidities 0.00046*** (0.0002) -0.00058*** (0.0002) 3 Charlson-Deyo comorbidities 0.0020*** (0.0002) 0.0002 (0.0003) 4 Charlson-Deyo comorbidities 0.0040*** (0.0003) 0.0017*** (0.0004) 5+ Charlson-Deyo comorbidities 0.005*** (0.001) 0.002*** (0.001) Age, logged 4.20*** (0.09) 3.33*** (0.09) Female patients 0.0019*** (0.0002) 0.0017*** (0.0002) African American patients 0.0014*** (0.0005) 0.0011*** (0.0005) Hispanic patients -0.0007 (0.0008) -0.0001 (0.0008) Other non-white patients 0.0004 (0.0005) 0.0005 (0.0005) Zip code characteristics Median household income ($000) -0.02 (0.06) -0.07 (0.06) Social Security income ($000) -0.10 (0.11) -0.05 (0.11) Poor residents -0.039 (0.04) -0.033 (0.03) Employed residents -0.01 (0.06) 0.03 (0.05) Less than high school education 0.11*** (0.03) 0.08*** (0.03) Urban -0.09*** (0.02) -0.09*** (0.02) Hispanic -0.01 (0.01) 0.00 (0.01) Single -0.19*** (0.07) -0.18*** (0.07) Elderly in an institution -0.000002 (0.00002) -0.000004 (0.00002) Non-institutionalized elderly with physical disability 0.02 (0.07) 0.01 (0.07) Sensory disability 0.23*** (0.05) 0.23*** (0.05) Mental disability -0.02 (0.04) -0.04 (0.04) Self-care disability -0.10*** (0.04) -0.10*** (0.04) Difficulty going-outside-the-home disability -0.10* (0.06) -0.11* (0.06) Other Statistics Hospital-years, n R squared 0.002 23,585 0.365 0.191 Equality of year parameter, relative to prior column 0.812 < 0.001 Notes: Unit of analysis is the hospital-year. Standard errors clustered at the hospital-level. * indicates statistical significance at the 10% level, ** at the 5% level, and *** at the 1% level. For linear time trend, 2002 is year 0. All covariates are percentages from 0-100, unless otherwise noted. Zip code characteristics are logged, except for the percentage of elderly living in an institution. For heart-attack locations, ICD-9-CM diagnosis codes appear in parentheses. Equality of year parameter based on bootstrapped standard error for difference (250 draws). AHRQ = Agency for Healthcare Research and Quality. 15

Appendix Exhibit 12: Regression Results for Log of the Number of Survivors without Unplanned Readmissions Divided by Total Costs, Heart Failure Patient Cohort Output Hospital stays Hospital stays Survivors without unplanned readmissions Parameter Estimate (Standard Error) Constant -2.213*** (0.007) -26.08*** (1.44) -27.64*** (1.47) Year of admission -0.009*** (0.001) -0.005*** (0.001) 0.006*** (0.001) Teaching hospital -0.15*** (0.04) -0.16*** (0.03) AHRQ predicted inpatient mortality risk, logged -2.97*** (0.17) -3.92*** (0.17) Location of heart attack: Anterolateral (410.0x) Location of heart attack: Other Anterior Wall (410.1x) Location of heart attack: Inferolateral Wall (410.2x) Location of heart attack: Inferoposterior Wall (410.3x) Location of heart attack: Other Inferior Wall (410.4x) Location of heart attack: Other Lateral Wall (410.5x) Location of heart attack: True Posterior Wall (410.6x) Location of heart attack: Sub-Endocardial (410.7x) Location of heart attack: Other Specified Sites (410.8x) 1 Charlson-Deyo comorbidity 0.00076 (0.0011) -0.00006 (0.0011) 2 Charlson-Deyo comorbidities 0.00234*** (0.0010) 0.00068 (0.0011) 3 Charlson-Deyo comorbidities 0.0033*** (0.0010) 0.0013 (0.0011) 4 Charlson-Deyo comorbidities 0.0046*** (0.0011) 0.0024*** (0.0011) 5+ Charlson-Deyo comorbidities 0.007*** (0.001) 0.004*** (0.002) Age, logged 3.08*** (0.13) 2.52*** (0.13) Female patients 0.0035*** (0.0003) 0.0032*** (0.0003) African American patients 0.0022*** (0.0004) 0.0023*** (0.0004) Hispanic patients -0.0003 (0.0010) -0.0009 (0.0009) Other non-white patients 0.0015*** (0.0006) 0.0015*** (0.0006) Zip code characteristics Median household income ($000) -0.08 (0.06) -0.13*** (0.06) Social Security income ($000) -0.18* (0.10) -0.21*** (0.10) Poor residents -0.108*** (0.04) -0.119*** (0.04) Employed residents -0.16*** (0.06) -0.07 (0.06) Less than high school education 0.19*** (0.03) 0.18*** (0.03) Urban -0.11*** (0.02) -0.10*** (0.02) Hispanic -0.02*** (0.01) -0.01*** (0.01) Single -0.30*** (0.07) -0.30*** (0.07) Elderly in an institution 0.000004 (0.00002) -0.000011 (0.00002) Non-institutionalized elderly with physical disability 0.12 (0.08) 0.05 (0.08) Sensory disability 0.26*** (0.05) 0.31*** (0.05) Mental disability -0.06 (0.04) -0.06 (0.04) Self-care disability -0.10*** (0.04) -0.10*** (0.04) Difficulty going-outside-the-home disability -0.16*** (0.06) -0.19*** (0.06) Other Statistics Hospital-years, n R squared 0.006 29,872 0.247 0.196 Equality of year parameter, relative to prior column < 0.001 < 0.001 Notes: Unit of analysis is the hospital-year. Standard errors clustered at the hospital-level. * indicates statistical significance at the 10% level, ** at the 5% level, and *** at the 1% level. For linear time trend, 2002 is year 0. All covariates are percentages from 0-100, unless otherwise noted. Zip code characteristics are logged, except for the percentage of elderly living in an institution. For heart-attack locations, ICD-9-CM diagnosis codes appear in parentheses. Equality of year parameter based on bootstrapped standard error for difference (250 draws). AHRQ = Agency for Healthcare Research and Quality. 16

Appendix Exhibit 13: Regression Results for Log of the Number of Survivors without Unplanned Readmissions Divided by Total Costs, Pneumonia Patient Cohort Output Hospital stays Hospital stays Survivors without unplanned readmissions Parameter Estimate (Standard Error) Constant -2.137*** (0.005) -14.96*** (0.89) -16.86*** (0.95) Year of admission -0.004*** (0.001) 0.008*** (0.001) 0.019*** (0.001) Teaching hospital -0.04 (0.03) -0.04 (0.03) AHRQ predicted inpatient mortality risk, logged -2.83*** (0.07) -3.81*** (0.08) Location of heart attack: Anterolateral (410.0x) Location of heart attack: Other Anterior Wall (410.1x) Location of heart attack: Inferolateral Wall (410.2x) Location of heart attack: Inferoposterior Wall (410.3x) Location of heart attack: Other Inferior Wall (410.4x) Location of heart attack: Other Lateral Wall (410.5x) Location of heart attack: True Posterior Wall (410.6x) Location of heart attack: Sub-Endocardial (410.7x) Location of heart attack: Other Specified Sites (410.8x) 1 Charlson-Deyo comorbidity -0.00133*** (0.0002) -0.00158*** (0.0002) 2 Charlson-Deyo comorbidities -0.00187*** (0.0002) -0.00245*** (0.0003) 3 Charlson-Deyo comorbidities -0.0022*** (0.0003) -0.0031*** (0.0003) 4 Charlson-Deyo comorbidities -0.0023*** (0.0005) -0.0034*** (0.0006) 5+ Charlson-Deyo comorbidities -0.001 (0.002) -0.003* (0.002) Age, logged 0.88*** (0.08) 0.35*** (0.09) Female patients -0.0003* (0.0002) -0.0001 (0.0002) African American patients -0.0002 (0.0003) -0.0006* (0.0003) Hispanic patients -0.0015*** (0.0007) -0.0011 (0.0007) Other non-white patients 0.0014*** (0.0006) 0.0018*** (0.0007) Zip code characteristics Median household income ($000) -0.30*** (0.04) -0.37*** (0.05) Social Security income ($000) -0.15* (0.08) -0.16*** (0.08) Poor residents -0.190*** (0.03) -0.200*** (0.03) Employed residents -0.01 (0.04) 0.07* (0.04) Less than high school education 0.07*** (0.02) 0.03* (0.02) Urban -0.04*** (0.02) -0.03*** (0.02) Hispanic -0.02*** (0.00) -0.01*** (0.00) Single 0.04 (0.05) 0.03 (0.05) Elderly in an institution 0.000010 (0.00001) -0.000013 (0.00002) Non-institutionalized elderly with physical disability -0.04 (0.05) -0.09 (0.06) Sensory disability 0.22*** (0.04) 0.26*** (0.04) Mental disability -0.04 (0.03) -0.03 (0.03) Self-care disability -0.06* (0.03) -0.07*** (0.03) Difficulty going-outside-the-home disability -0.03 (0.05) -0.07 (0.05) Other Statistics Hospital-years, n R squared 0.002 30,557 0.213 0.229 Equality of year parameter, relative to prior column < 0.001 < 0.001 Notes: Unit of analysis is the hospital-year. Standard errors clustered at the hospital-level. * indicates statistical significance at the 10% level, ** at the 5% level, and *** at the 1% level. For linear time trend, 2002 is year 0. All covariates are percentages from 0-100, unless otherwise noted. Zip code characteristics are logged, except for the percentage of elderly living in an institution. For heart-attack locations, ICD-9-CM diagnosis codes appear in parentheses. Equality of year parameter based on bootstrapped standard error for difference (250 draws). AHRQ = Agency for Healthcare Research and Quality. 17

References 1. Yale New Haven Health Services Corporation/Center for Outcomes Research & Evaluation. 2013 Measures Updates and Specifications Report: Hospital-Level 30-Day Risk-Standardized Readmission Measures for Acute Myocardial Infarction, Heart Failure, and Pneumonia (Version 6.0). 2013. 18