Supplementary Appendix

Supplementary Appendix This appendix has been provided by the authors to give readers additional information about their work. Supplement to: Bucholz EM, Butala NM, Ma S, Normand S-LT, Krumholz HM. Life expectancy after myocardial infarction, according to hospital performance. N Engl J Med 2016;375:1332-42. DOI: 10.1056/NEJMoa1513223

Life Expectancy after Myocardial Infarction by Hospital Performance SUPPLEMENTARY APPENDIX Emily M. Bucholz, M.D., Ph.D., M.P.H. Neel M. Butala, M.D., M.B.A. Sharon-Lise T. Normand, Ph.D. Shuangge Ma, Ph.D. Harlan M. Krumholz, M.D., S.M. 1

TABLE OF CONTENTS Supplementary Methods Pages Study Population 4 Outcome Variable 4 Calculation of Risk-Standardized Mortality Rates 4-5 Sample Stratification 5-6 Life Expectancy Calculations 6-7 Supplementary Tables Supplementary Appendix Table S1 8-10 Supplementary Appendix Table S2 11-12 Supplementary Appendix Table S3 13-14 Supplementary Appendix Table S4 15 Supplementary Figures Supplementary Appendix Figure S1 16 Supplementary Appendix Figure S2 17 Supplementary Appendix Figure S3 18 Supplementary Appendix Figure S4 19 Supplementary Appendix Figure S5 20 Supplementary Appendix Figure S6 21 Supplementary Appendix Figure S7 22 Supplementary Appendix Figure S8 23-24 Supplementary Appendix Figure S9 25 Supplementary Appendix Figure S10 26 Supplementary Appendix Figure S11 27 Supplementary Appendix Figure S12 28 Supplementary Appendix Figure S13 29 2

Supplementary Appendix Figure S14 30 Supplementary Appendix Figure S15 31-32 3

Supplementary Appendix Methods Study Population We analyzed data from the Cooperative Cardiovascular Project (CCP), a Health Care Financing Administration quality-improvement initiative for patients with acute myocardial infarction. The CCP included fee-for-service Medicare beneficiaries hospitalized with a principle discharge diagnosis of acute myocardial infarction (International Classification of Diseases, Ninth Revision, Clinical Modification, code 410), except acute myocardial infarction readmissions (code 410.x2). We did not have information on Medicare Advantage patients in CCP. The sample was identified from hospital bills in the Medicare National Claims History File (form UB-92). Each hospital was sampled for an 8-month period during the interval between February 1994 and July 1995. Trained personnel at centralized data abstraction centers abstracted patient records for information on patient demographics, medical history, presentation, laboratory and electrocardiographic data, in-hospital events, and treatment. In our analyses, we used similar inclusion criteria to those used in the established riskstandardized mortality rate measures to define our study cohort. Specifically, we limited our sample to patients 65 years of age or older with clinically confirmed acute myocardial infarction. Confirmed acute myocardial infarction was defined as an elevation of creatine kinase-mb (>5% of total creatine kinase), an elevation of lactate dehydrogenase level >1.5 times the upper limit of normal with isoenzyme reversal, or the present of 2 of the following: chest pain prior to admission, a 2-fold elevation in total creatine kinase, and electrocardiographic evidence of acute myocardial infarction (ST-segment elevation or new pathological Q-waves). When patients were hospitalized more than once during the study period, we used only the first admission. Consistent with current risk-standardized mortality rate models, we excluded patients admitted directly from ambulatory surgery or other acute hospital stays, patients transferred from other acute care hospitals, and patients who left the hospital against medical advice. Finally, we limited the analysis to only hospitals with at least 30 patients with a discharge diagnosis of acute myocardial infarction during the 8-month sample period in order to reliably estimate riskstandardized mortality rates. Outcome Variable We used data from the 1994 to 2012 Medicare Denominator files to ascertain survival over 17 years of follow-up. The Denominator files contain demographic and enrollment information on all Medicare fee-for-service beneficiaries in a given year, including dates of death. Time to death was defined as days from admission to the date of death and was censored at 17 years of follow-up. Calculation of Risk-Standardized Mortality Rates Calculations of risk-standardized mortality rates were performed using a medical record model described by Krumholz et al. 1 This model has been compared to the Medicare claims model now used for public reporting. Comparisons of hospital risk-standardized mortality rates from the Medicare claims model and the CCP medical record model showed strong agreement (correlation coefficient 0.90, SE 0.003) suggesting that they may be used as proxies for one another. Briefly, we used a hierarchical logistic model that linked the log-odds of mortality within 30 days of admission as a function of patient demographic and clinical variables, and a random hospital-specific effect. This approach accounts for the within-hospital correlation of observed outcomes and allows for the separation of within-hospital variation from between-hospital variation. We used the 31 variables previously identified in the medical record model to estimate hospital-specific mortality: 2 demographic, 7 medical history, and 22 presentation variables. Missing covariates were imputed using a single imputation approach, which allowed 4

incorporation of all patients into the model. A single imputation approach was preferred over a multiple imputation approach because we were unable to generate survival curves required for life expectancy calculations below with multiple imputations. Risk-standardized mortality rates are calculated as the ratio of predicted to expected mortality at a given hospital, multiplied by the national observed mortality rate. For each hospital, the denominator ( expected mortality) is the number of deaths expected within 30 days based on national mortality data for that hospital s case mix. It is calculated using a common intercept for all hospitals in the sample and thus, can be viewed as a measure of hospital case mix. The numerator ( predicted mortality) is the number of deaths predicted based on that specific hospital s performance. It is calculated using a hospital-specific intercept and is analogous to observed mortality. Conceptually, the ratio of predicted to expected mortality compares a particular hospital s performance to that of an average hospital with the same case mix. A lower rate reflects lower-than-expected mortality rates or better quality, whereas a higher rate reflects higher-than-expected mortality rates or worse quality. The c-statistic for the 30-day risk-standardized mortality rate model was 0.772 (95% confidence interval 0.768-7.775). To determine whether the 30-day risk-standardized mortality rate model had adequate model performance when predicting long-term outcomes, we repeated these calculations for 1-year, 5-year, and 10-year mortality in all patients and in 30-day survivors. As shown below, the 30-day risk-standardized mortality rate model provided good model discrimination (c-statistics ranging from 0.77-0.82) over the long-term. C-statistics for risk-standard mortality rate models by duration of follow-up Duration of Follow-up All Patients 30-Day Survivors C-statistic (95% CI) C-statistic (95% CI) 30-day 0.772 (0.768, 0.775) -- 1-year 0.782 (0.779, 0.785) 0.773 (0.769, 0.800) 5-year 0.804 (0.802, 0.807) 0.796 (0.793, 0.800) 10-year 0.819 (0.816, 0.822) 0.813 (0.810, 0.815) *Risk models were calculated using the methods described by Krumholz et al to calculate 30- day risk-standardized mortality rates. Specifically, hierarchical logistic regression was used to estimate the log-odds of mortality with a certain follow-up period. The models included the 31 variables previously identified in the medical record risk-standardized mortality rate model in addition to a random hospital-specific effect. The c-statistics provided represent the area under the survival curve and thus provide a measure of model discrimination. Sample Stratification To ensure that we were comparing life expectancy estimates between patients admitted to hospitals with similar case mix, we first stratified hospitals into quintiles based on their expected mortality (i.e. the denominator of the 30-day risk-standardized mortality rate model), which is a marker of case mix or patient risk (Figure 1). Life expectancy analyses were conducted separately for each case-mix stratum to permit comparisons of patients admitted to hospitals with similar case mix and to account for some of the heterogeneity in case mix across hospitals. Within each case-mix stratum, we ranked hospitals by risk-standardized mortality rate and grouped them into quintiles (Figure 1). These quintiles reflect hospital performance on 30- day mortality among hospitals with similar case mix and were the primary unit of analysis for all 5

life expectancy calculations. We used the terms high-performing and low-performing to refer to those hospitals with the lowest and highest 30-day mortality, respectively, within each casemix stratum. Baseline characteristics for patients admitted to hospitals in each case-mix stratum were calculated. Life Expectancy Calculations Life expectancy is defined as mean or expected survival and can be calculated as the area under the survival curve. We used a 3-step process to calculate life expectancy (Supplementary Appendix Figure S1). First, we fit a separate marginal Cox proportional hazards model within each case-mix stratum. The model included dummy variables for hospital performance quintile and patient age. Marginal models were applied to account for clustering of patients within hospitals. Proportional hazards assumptions were assessed using Schoenfeld residuals, examined graphically, and tested formally. Second, we plotted the expected survival curves separately for patients within each hospital performance quintile and extrapolated the curves to age 100 using exponential models. The constant hazard for the exponential model was specified as the average hazard over the last 2 years of follow-up, and the median age of each case-mix stratum was used to determine the number of years for extrapolation to age 100. For example, the mean age of the lowest case-mix stratum was 75 years, so for each riskstandardized mortality rate quintile in this case-mix stratum, we plotted the survival curve from the Cox model over 17 years of follow-up and then extrapolated the curve using an exponential model over an additional 8 years. We selected exponential models because we lacked information on the shape of the survival curves and thus chose a model with a constant hazard that does not make assumptions about changes to the hazard function over time. Similarly, we chose to extrapolate the curves to age 100 because the Centers for Disease Control and Prevention uses age 100 as the upper threshold for life expectancy estimates in the general population. Finally, mean life expectancy estimates were calculated by summing the areas under the individual Cox and exponential survival functions. Ninety-five percent confidence intervals were calculated using the same approach with the upper and lower confidence limits of the expected survival curves. We then calculated the years of life saved as the difference in life expectancy between patients treated at hospitals in the lowest and highest risk-standardized mortality rate quintiles within each case-mix stratum. To determine whether differences in life expectancy across risk-standardized mortality rate quintiles could be explained by differences in patient characteristics and treatment between hospitals, we repeated the life expectancy calculations above adjusting first for clinical characteristics and then for treatment characteristics. Two separate models were used for adjustment to determine whether differences in patient clinical characteristics or treatment across hospitals explained the differences in life expectancy between low and high performing hospitals. The clinical model included 35 sociodemographic, medical history, frailty, and clinical presentation characteristics, listed below. Sociodemographic Characteristics Medical History Variable Age Gender Race (white versus nonwhite) Income (defined using the 1990 Census median ZIP-code level household income) History of diabetes History of hypertension History of myocardial infarction History of coronary artery bypass grafting History of percutaneous coronary intervention 6

Frailty Measures Clinical Presentation History of cerebrovascular accident or transient ischemic attack History of chronic obstructive pulmonary disease History of congestive heart failure History of chronic kidney disease History of cancer Dementia or Alzheimer s disease Anemia (defined as hematocrit <30%) Current smoking Obesity (defined as body mass index on admission >30kg/m 2 ) Admission from a skilled nursing facility Immobility on admission (defined as requiring assistance with walking or immobile) Incontinent on admission (defined as occasionally incontinent, totally incontinent, or anuric) Heart rate on presentation Initial systolic blood pressure <100mmHg Shock within the first 48 hours of admission Heart failure within the first 48 hours of admission Duration of chest pain before presentation Blood urea nitrogen level Creatinine on admission White blood cell count on admission ST-elevation myocardial infarction Left bundle branch block on initial electrocardiogram Right bundle branch block on initial electrocardiogram Heart block on initial electrocardiogram Anterior or lateral myocardial infarction The treatment model adjusted for the same variables in the clinical model in addition to revascularization (percutaneous coronary intervention or coronary artery bypass grafting) within 30 days, fibrinolytic therapy during hospitalization, aspirin within 48 hours of admission, and beta-blockers within 48 hours of admission. To plot the expected survival curves from the Cox proportional hazards models, we needed to provide values for each of the covariates included in the model so we used covariate frequencies or mean values calculated among all patients in a given case-mix stratum. This approach estimates the effect of risk-standardized mortality rate quintile on life expectancy for an average patient in a given case-mix stratum. By using the same covariate values to plot the survival curves for each risk-standardized mortality rate quintile and thus forcing patients in all risk-standardized mortality rate quintiles to the have the same risk factor profile, we were able to compare life expectancy across quintiles for the average patient admitted to hospitals in a given case-mix stratum. Finally, to determine whether the survival benefit of being admitted to a higherperforming hospital occurred exclusively in the first 30 days or continued to increase after 30 days, we repeated unadjusted and adjusted life expectancy calculations among 30-day survivors only. The same methods and covariates were applied to calculate life expectancy and years of life saved in all patients and in 30-day survivors. Life expectancy was calculated from the time of admission for the overall cohort and from 30 days for 30-day survivors. All statistical analyses were performed using SAS version 9.3 (SAS Institute, Cary, NC). 7

Supplementary Appendix Table S1. Patient clinical characteristics and treatment rates by hospital case mix (i.e. expected mortality) strata (n=119,735) Case-Mix Strata Clinical Presentation Overall N=119,735 Stratum 1 (i.e. hospitals that admitted the healthiest patients) N=21,054 Stratum 2 N=24,891 Stratum 3 N=26,228 Stratum 4 N=24,618 Stratum 5 (i.e. hospitals that admitted the sickest patients) N=22,944 p-value for trend* Initial SBP <0.001 <100mmHg 10,373 (8.7) 1318 (6.3) 1965 (7.9) 2148 (8.2) 2285 (9.3) 2657 (11.6) >100mmHg 108,778 (90.9) 19,686 (93.5) 22,834 (91.7) 23,949 (91.3) 22,196 (90.2) 20,113 (87.7) Missing 584 (0.5) 50 (0.2) 92 (0.4) 131 (0.5) 137 (0.6) 174 (0.8) Shock in first 48 hours 2934 (2.5) 258 (1.2) 468 (1.9) 627 (2.4) 684 (2.8) 897 (3.9) <0.001 Heart failure in first 48 hours 57,921 (48.4) 8922 (42.4) 11,498 (46.2) 12,643 (48.2) 12,546 (51.0) 12,312 (53.7) <0.001 Duration of chest pain before <0.001 presentation <6 hours 18,647 (15.6) 2386 (11.3) 3416 (13.7) 4042 (15.4) 4235 (17.2) 4568 (19.9) 6-12 hours 64,085 (53.5) 12,047 (57.2) 13,596 (54.6) 14,301 (54.5) 12,803 (52.0) 11,338 (49.4) >12 hours 10,682 (8.9) 2025 (9.6) 2273 (9.1) 2267 (8.6) 2207 (9.0) 1910 (8.3) No chest pain 16,047 (13.4) 2899 (13.8) 3406 (13.7) 3421 (13.0) 3285 (13.3) 3036 (13.2) Missing 10,274 (8.6) 1697 (8.1) 2200 (8.8) 2197 (8.4) 2088 (8.5) 2092 (9.1) 8

Blood urea nitrogen (mml), 7.81 (3.16) 7.34 (2.95) 7.59 (3.05) 7.78 (3.14) 7.99 (3.21) 8.33 (3.33) <0.001 mean (SD) 2322 (1.9) 535 (2.5) 513 (2.1) 463 (1.8) 424 (1.7) 387 (1.7) Missing Creatinine, mean (SD) 1.38 (0.97) 1.31 (0.85) 1.35 (0.88) 1.39 (1.04) 1.40 (0.95) 1.46 (1.10) <0.001 Missing 2651 (2.2) 509 (2.4) 514 (2.1) 588 (2.2) 581 (2.4) 459 (2.0) White blood cell count <0.001 <6 7790 (6.5) 1589 (7.6) 1682 (6.8) 1711 (6.5) 1518 (6.2) 1290 (5.6) 6-12 74,078 (61.9) 13,813 (65.6) 15,816 (63.5) 16,073 (61.3) 14,913 (60.6) 13,463 (58.7) >12 35,322 (29.5) 5169 (24.6) 6835 (27.5) 7832 (29.9) 7718 (31.4) 7768 (33.9) Missing 2545 (2.1) 483 (2.3) 558 (2.2) 612 (2.3) 469 (1.9) 423 (1.8) ST-elevation AMI 35,075 (29.3) 6058 (28.8) 7255 (29.2) 7662 (29.2) 7280 (29.6) 6820 (29.7) 0.19 Left bundle branch block <0.001 Yes 7894 (6.6) 1190 (5.7) 1617 (6.5) 1755 (6.7) 1707 (6.9) 1625 (7.1) No 105,521 (88.1) 18,704 (88.8) 21,946 (88.2) 23,096 (88.1) 21,656 (88.0) 20,119 (87.7) Missing 6320 (5.3) 1160 (5.5) 1328 (5.3) 1377 (5.3) 1255 (5.1) 1200 (5.2) Right bundle branch block <0.001 Yes 9273 (7.7) 1470 (7.0) 1876 (7.5) 1992 (7.6) 1984 (8.1) 1951 (8.5) No 104,142 (87.0) 18,424 (87.5) 21,687 (87.1) 22,859 (87.2) 21,379 (86.8) 19,793 (86.3) Missing 6320 (5.3) 1160 (5.5) 1328 (5.3) 1377 (5.3) 1255 (5.1) 1200 (5.2) 9

Heart Block 0.26 Yes 1688 (1.4) 269 (1.3) 359 (1.4) 352 (1.3) 373 (1.5) 335 (1.5) No 111,727 (93.3) 19,625 (93.2) 23,204 (93.2) 24,499 (93.4) 22,990 (93.4) 21,409 (93.3) Missing 6320 (5.3) 1160 (5.5) 1328 (5.3) 1377 (5.3) 1255 (5.1) 1200 (5.2) Anterior or lateral AMI 66,594 (55.6) 11085 (52.7) 13,651 (54.8) 14,509 (55.3) 14058 (57.1) 13,291 (57.9) <0.001 AMI location not noted 7638 (6.4) 1107 (5.3) 1431 (5.8) 1646 (6.3) 1724 (7.0) 1730 (7.5) <0.001 Killip Class >2 45265 (37.8) 6680 (31.7) 8781 (35.3) 9805 (37.4) 10,000 (40.6) 9999 (43.6) <0.001 Pulse, mean (SD) 88.0 (24.9) 86.3 (23.9) 87.7 (25.0) 88.1 (24.9) 88.8 (25.2) 89.1 (25.4) <0.001 Treatment PCI/CABG within 30 days <0.001 Yes 35,958 (30.0) 7032 (33.4) 8137 (32.7) 7917 (30.2) 6881 (28.0) 5991 (26.1) No 81,878 (68.4) 13,704 (65.1) 16,634 (66.8) 17,677 (67.4) 17,382 (70.6) 16,481 (71.8) Missing 1899 (1.6) 318 (1.5) 120 (0.5) 634 (2.4) 355 (1.4) 472 (2.1) Fibrinolytic therapy in-hospital 21,510 (18.0) 4238 (20.1) 4764 (19.1) 4629 (17.7) 4171 (16.9) 3698 (16.1) <0.001 Aspirin on admission 68,924/91,297 12,843/16459 14,656/19,078 15,048/19,82 13,905/18,780 12,472/17,153 <0.001 (of eligible) (75.5) (78.0) (76.8) 7 (75.9) (74.0) (72.7) Beta-blockers on admission 34,075/55,523 6630/10,945 7356/12,099 7518/12,176 6760/10,832 5811/9471 0.04 (of eligible) (61.4) (60.6) (60.8) (61.7) (62.4) (61.4) *P-values are for trend across all 5 case-mix strata. 10

Supplementary Appendix Table S2. Mean (95% confidence interval) unadjusted and adjusted life expectancy estimates (years) for all patients by case-mix strata and risk-standardized mortality rate quintile Case-Mix Strata Stratum 1 (i.e. hospitals that admitted Stratum 2 Stratum 3 Stratum 4 Stratum 5 (i.e. hospitals that admitted RSMR Quintile the healthiest patients) the sickest patients) Unadjusted Life Expectancy (years) 1(high-performing hospitals) 7.15 (6.95, 7.36) 6.56 (6.38, 6.74) 6.25 (6.09, 6.42) 5.90 (5.73, 6.07) 5.23 (5.06, 5.39) 2 6.94 (6.72, 7.16) 6.18 (6.00, 6.37) 6.00 (5.82, 6.19) 5.61 (5.43, 5.79) 5.02 (4.85, 5.20) 3 6.94 (6.72, 7.16) 5.97 (5.78, 6.17) 5.87 (5.68, 6.06) 5.32 (5.14, 5.51) 4.90 (4.73, 5.09) 4 6.52 (6.32, 6.73) 5.95 (5.76, 6.15) 5.64 (5.46, 5.83) 5.12 (4.95, 5.30) 4.65 (4.49, 4.83) 5 (low-performing hospitals) 6.08 (5.88, 6.29) 5.62 (5.45, 5.79) 5.34 (5.18, 5.51) 4.95 (4.79, 5.12) 4.40 (4.24, 4.57) Clinically Adjusted Life Expectancy (years)* 1(high-performing hospitals) 7.40 (4.18-7.62) 6.58 (6.39-6.78) 6.13 (5.96-6.30) 5.97 (5.80-6.16) 5.45 (5.27-5.64) 2 7.05 (6.83-7.29) 6.29 (6.10-6.49) 5.87 (5.69-6.06) 5.70 (5.52-5.89) 5.13 (4.95-5.32) 3 6.98 (6.76-7.21) 6.01 (5.81-6.21) 5.82 (5.64-6.01) 5.45 (5.27-5.65) 5.07 (4.89-5.26) 4 6.65 (6.44-6.88) 5.96 (5.77-6.17) 5.47 (5.29-5.65) 5.29 (5.11-5.48) 4.78 (4.61-4.97) 5 (low-performing hospitals) 6.20 (5.99-6.42) 5.69 (5.51-5.88) 5.18 (5.02-5.35) 5.12 (4.95-5.30) 4.52 (4.35-4.70) Treatment Adjusted Life Expectancy (years) 1(high-performing hospitals) 7.22 (7.01-7.44) 6.41 (6.22-6.61) 5.92 (5.76-6.09) 5.80 (5.62-5.98) 5.27 (5.10-5.46) 11

2 6.88 (6.66-7.11) 6.21 (6.02-6.41) 5.73 (5.56-5.92) 5.55 (5.37-5.73) 5.00 (4.82-5.18) 3 6.91 (6.69-7.14) 5.96 (5.77-6.16) 5.69 (5.51-5.88) 5.33 (5.15-5.52) 4.92 (4.74-5.11) 4 6.66 (6.45-6.88) 5.89 (5.71-6.09) 5.43 (5.26-5.62) 5.23 (5.06-5.42) 4.73 (4.56-4.91) 5 (low-performing hospitals) 6.08 (5.88-6.29) 5.66 (5.49-5.85) 5.12 (4.96-5.29) 5.03 (4.86-5.20) 4.43 (4.27-4.61) *Clinical model is adjusted for patient sociodemographic (age, gender, race, socioeconomic status), medical history (diabetes, hypertension, history of myocardial infarction, history of coronary artery bypass grafting, history of percutaneous coronary intervention, history of cerebrovascular accident or transient ischemic attack, chronic obstructive pulmonary disease, congestive heart failure, chronic kidney disease, cancer, dementia or Alzheimer s disease, anemia, current smoking, obesity), frailty (admission from a skilled nursing facility, immobility or incontinence on admission), and clinical presentation (heart rate on presentation, initial systolic blood pressure, shock within the first 48 hours of admission, duration of chest pain before presentation, blood urea nitrogen, creatinine, white blood cell count, ST-elevation myocardial infarction, left or right bundle branch block, heart block, anterior or lateral acute myocardial infarction). Treatment model is adjusted for those variables in the clinical model in addition to revascularization (percutaneous coronary intervention or coronary artery bypass grafting) within 30 days of admission, fibrinolytic therapy during hospitalization, aspirin, and beta-blockers on admission. 12

Supplementary Appendix Table S3. Mean (95% confidence interval) unadjusted and adjusted life expectancy estimates (years) for 30-day survivors by case-mix strata and risk-standardized mortality rate quintile (n=119,735) Case-Mix Strata Stratum 1 (i.e. hospitals that admitted Stratum 2 Stratum 3 Stratum 4 Stratum 5 (i.e. hospitals that admitted RSMR Quintile the healthiest patients) the sickest patients) Unadjusted Life Expectancy (years) 1(high-performing hospitals) 7.64 (7.43, 7.85) 7.52 (7.33, 7.72) 6.82 (6.65, 6.99) 6.87 (6.69, 7.06) 6.18 (6.00, 6.36) 2 7.63 (7.41, 7.81) 7.32 (7.12, 7.53) 6.78 (6.59, 6.98) 6.84 (6.65, 7.04) 6.18 (5.99, 6.39) 3 7.8 (7.57, 8.04) 7.24 (7.03, 7.46) 6.79 (6.59, 6.99) 6.66 (6.45, 6.88) 6.23 (6.03, 6.45) 4 6.53 (7.31, 7.76) 7.43 (7.21, 7.66) 6.69 (6.49, 6.91) 6.59 (6.39, 6.81) 6.10 (5.90, 6.31) 5 (low-performing hospitals) 7.42 (7.19, 7.66) 7.37 (7.17, 7.59) 6.73 (6.54, 6.94) 6.55 (6.37, 6.73) 6.26 (6.05, 6.48) Clinically Adjusted Life Expectancy (years)* 1(high-performing hospitals) 7.78 (7.55-8.00) 6.99 (6.80-7.21) 6.63 (6.45-6.82) 6.41 (6.23-6.61) 6.06 (5.86-6.25) 2 7.64 (7.41-7.89) 6.93 (6.73-7.15) 6.53 (6.34-6.74) 6.40 (6.21-6.60) 5.90 (5.70-6.11) 3 7.70 (7.47-7.95) 6.78 (6.57-7.01) 6.67 (6.46-6.88) 6.25 (6.05-6.46) 6.01 (5.80-6.23) 4 7.51 (7.28-7.75) 6.89 (6.67-7.12) 6.40 (6.20-6.62) 6.21 (6.01-6.42) 5.86 (5.66-6.08) 5 (low-performing hospitals) 7.37 (7.13-7.62) 6.88 (6.67-7.10) 6.39 (6.20-6.59) 6.38 (6.18-6.59) 5.98 (5.77-6.20) Treatment Adjusted Life Expectancy (years) 1(high-performing hospitals) 7.62 (7.41-7.85) 6.85 (6.66-7.06) 6.46 (6.28-6.64) 6.26 (6.09-6.45) 5.90 (5.72-6.10) 13

2 7.48 (7.25-7.72) 6.84 (6.64-7.06) 6.41 (6.22-6.61) 6.25 (6.07-6.45) 5.76 (5.57-5.97) 3 7.63 (7.40-7.88) 6.71 (6.50-6.93) 6.52 (6.32-6.73) 6.13 (5.93-6.34) 5.85 (5.65-6.06) 4 7.48 (7.26-7.72) 6.79 (6.57-7.01) 6.33 (6.13-6.54) 6.12 (5.93-6.33) 5.77 (5.57-5.98) 5 (low-performing hospitals) 7.22 (6.99-7.47) 6.79 (6.59-7.01) 6.26 (6.07-6.46) 6.25 (6.05-6.46) 5.84 (5.64-6.06) *Clinical model is adjusted for patient sociodemographic (age, gender, race, socioeconomic status), medical history (diabetes, hypertension, history of myocardial infarction, history of coronary artery bypass grafting, history of percutaneous coronary intervention, history of cerebrovascular accident or transient ischemic attack, chronic obstructive pulmonary disease, congestive heart failure, chronic kidney disease, cancer, dementia or Alzheimer s disease, anemia, current smoking, obesity), frailty (admission from a skilled nursing facility, immobility or incontinence on admission), and clinical presentation (heart rate on presentation, initial systolic blood pressure, shock within the first 48 hours of admission, duration of chest pain before presentation, blood urea nitrogen, creatinine, white blood cell count, ST-elevation myocardial infarction, left or right bundle branch block, heart block, anterior or lateral acute myocardial infarction). Treatment model is adjusted for those variables in the clinical model in addition to revascularization (percutaneous coronary intervention or coronary artery bypass grafting) within 30 days of admission, fibrinolytic therapy during hospitalization, aspirin, and beta-blockers on admission. 14

Supplementary Appendix Table S4. Distribution of acute myocardial infarction treatment rates across risk-standardized mortality rate quintiles within case-mix strata RSMR Quintile 1 RSMR Quintile 2 RSMR Quintile 3 RSMR Quintile 4 RSMR Quintile 5 Chi-Square p-value for trend PCI/CABG within 30-days Case-Mix Stratum 1 35.6 34.9 33.0 32.2 33.8 0.013 Case-Mix Stratum 2 36.4 31.6 30.3 33.1 31.9 <0.001 Case-Mix Stratum 3 34.2 30.8 30.8 38.6 28.8 <0.001 Case-Mix Stratum 4 29.8 30.1 28.6 24.6 28.0 0.001 Case-Mix Stratum 5 24.7 29.5 29.5 23.6 26.4 0.980 Fibrinolytic therapy in-hospital Case-Mix Stratum 1 19.8 19.9 20.3 19.1 21.7 0.064 Case-Mix Stratum 2 17.1 20.3 18.5 20.8 19.5 <0.001 Case-Mix Stratum 3 15.4 18.2 18.5 18.4 18.8 <0.001 Case-Mix Stratum 4 14.3 15.6 18.5 18.9 18.6 <0.001 Case-Mix Stratum 5 13.2 16.3 17.4 17.0 17.5 <0.001 Aspirin on admission (of ideal candidates) Case-Mix Stratum 1 80.7 79.5 77.8 76.4 75.5 <0.001 Case-Mix Stratum 2 80.4 78.3 76.2 76.5 72.1 <0.001 Case-Mix Stratum 3 77.9 78.4 74.8 75.6 72.4 <0.001 Case-Mix Stratum 4 75.7 74.9 74.6 73.0 71.6 <0.001 Case-Mix Stratum 5 74.6 73.8 74.0 69.8 71.1 <0.001 Beta-blockers on admission (of ideal candidates) Case-Mix Stratum 1 64.1 61.2 63.8 55.0 58.5 <0.001 Case-Mix Stratum 2 66.6 62.3 61.8 55.3 56.5 <0.001 Case-Mix Stratum 3 67.2 63.8 61.6 56.5 57.4 <0.001 Case-Mix Stratum 4 65.6 63.8 62.9 60.2 58.5 <0.001 Case-Mix Stratum 5 67.7 60.5 59.4 59.7 57.8 <0.001 15

1. Fit a Cox proportional hazards model with age and risk-standardized mortality rate quintile 2. Plotted risk-standardized mortality rate quintile-specific expected survival curves 3A. Calculated average hazard (λ) over last 2 years of available follow-up 3B. Extrapolated the curve to age 100 using exponential model Supplementary Appendix Figure S1. A 3-step process was used to calculate life expectancy after acute myocardial infarction. Caption: Mean life expectancy was calculated as the area under the risk-standardized mortality rate quintile-specific survival curves. First, a Cox proportional hazards model was fit for each case-mix stratum modeling age and risk-standardized mortality rate quintile. risk-standardized mortality rate quintile-specific expected survival curves were plotted over the 17 years of available follow-up. An exponential model was used to extrapolate the survival curves beyond 17 years. The constant hazard for the exponential models was specified as the average hazard over the last two years of follow-up. The area under the survival curves were summed for mean life expectancy. 16

Survival (%) Time (days) RSMR Quintile 1 (High-Performing) RSMR Quintile 2 RSMR Quintile 3 RSMR Quintile 4 RSMR Quintile 5 (Low-Performing) Supplementary Appendix Figure S2. Unadjusted expected survival curves by risk-standardized mortality rate (RSMR) quintile for all patients admitted to hospitals in case-mix stratum 1 (i.e. hospitals that admitted the healthiest patients). 17

Survival (%) Time (days) RSMR Quintile 1 (High-Performing) RSMR Quintile 2 RSMR Quintile 3 RSMR Quintile 4 RSMR Quintile 5 (Low-Performing) Supplementary Appendix Figure S3. Unadjusted expected survival curves by risk-standardized mortality rate (RSMR) quintile for all patients admitted to hospitals in case-mix stratum 2. 18

Survival (%) Time (days) RSMR Quintile 1 (High-Performing) RSMR Quintile 2 RSMR Quintile 3 RSMR Quintile 4 RSMR Quintile 5 (Low-Performing) Supplementary Appendix Figure S4. Unadjusted expected survival curves by risk-standardized mortality rate (RSMR) quintile for all patients admitted to hospitals in case-mix stratum 3. 19

Survival (%) Time (days) RSMR Quintile 1 (High-Performing) RSMR Quintile 2 RSMR Quintile 3 RSMR Quintile 4 RSMR Quintile 5 (Low-Performing) Supplementary Appendix Figure S5. Unadjusted expected survival curves by risk-standardized mortality rate (RSMR) quintile for all patients admitted to hospitals in case-mix stratum 4. 20

Survival (%) Time (days) RSMR Quintile 1 (High-Performing) RSMR Quintile 2 RSMR Quintile 3 RSMR Quintile 4 RSMR Quintile 5 (Low-Performing) Supplementary Appendix Figure S6. Unadjusted expected survival curves by risk-standardized mortality rate (RSMR) quintile for all patients admitted to hospitals in case-mix stratum 5 (i.e. hospitals that admitted the sickest patients). 21

Life Expectancy after Acute Myocardial Infarction (years) 8 7 6 5 4 3 2 1 RSMR Quintile 1 (High-Performing) RSMR Quintile 2 RSMR Quintile 3 RSMR Quintile 4 RSMR Quintile 5 (Low-Performing) 0 Case-Mix Stratum 1 (Hospitals that admitted the healthiest patients) Case-Mix Stratum 2 Case-Mix Stratum 3 Case-Mix Stratum 4 Case-Mix Stratum 5 (Hospitals that admitted the sickest patients) Supplementary Appendix Figure S7. Mean unadjusted life expectancy after acute myocardial infraction (years) by riskstandardized mortality rate (RSMR) quintile calculated from admission. Caption: Models for the calculation of life expectancy were run separately for each case-mix stratum. Higher case-mix stratum signifies hospitals that admitted sicker patients with higher expected mortality. Within each case-mix stratum, higher risk-standardized mortality rate quintile indicates lower-performing hospitals with a higher than expected mortality rate. 22

Life Expectancy after Acute Myocardial Infarction (years) 9 8 7 6 5 4 3 2 1 0 Case-Mix Stratum 1 (Hospitals that admitted the healthiest patients) RSMR Quintile 1 (High-Performing) RSMR Quintile 2 RSMR Quintile 3 RSMR Quintile 4 RSMR Quintile 5 (Low-Performing) Case-Mix Stratum 2 Case-Mix Stratum 3 Case-Mix Stratum 4 Case-Mix Stratum 5 (Hospitals that admitted the sickest patients) Supplementary Appendix Figure S8. Mean clinically adjusted life expectancy after acute myocardial infarction (years) by riskstandardized mortality rate (RSMR) quintile calculated from admission. Caption: Models for the calculation of life expectancy were run separately for each case-mix stratum. Higher case-mix stratum signifies hospitals that admitted sicker patients with higher expected mortality. Within each case-mix stratum, higher risk-standardized mortality rate quintile indicates lower-performing hospitals with a higher than expected mortality rate. The clinical is adjusted for patient sociodemographic (age, gender, race, socioeconomic 23

status), medical history (diabetes, hypertension, history of myocardial infarction, history of coronary artery bypass grafting, history of percutaneous coronary intervention, history of cerebrovascular accident or transient ischemic attack, chronic obstructive pulmonary disease, congestive heart failure, chronic kidney disease, cancer, dementia or Alzheimer s disease, anemia, current smoking, obesity), frailty (admission from a skilled nursing facility, immobility or incontinence on admission), and clinical presentation (heart rate on presentation, initial systolic blood pressure, shock within the first 48 hours of admission, duration of chest pain before presentation, blood urea nitrogen, creatinine, white blood cell count, ST-elevation myocardial infarction, left or right bundle branch block, heart block, anterior or lateral acute myocardial infarction). 24

Survival (%) Time (days) RSMR Quintile 1 (High-Performing) RSMR Quintile 2 RSMR Quintile 3 RSMR Quintile 4 RSMR Quintile 5 (Low-Performing) Supplementary Appendix Figure S9. Unadjusted expected survival curves by risk-standardized mortality rate (RSMR) quintile for 30-day survivors admitted to hospitals in case-mix stratum 1 (i.e. hospitals that admitted the healthiest patients). 25

Survival (%) Time (days) RSMR Quintile 1 (High-Performing) RSMR Quintile 2 RSMR Quintile 3 RSMR Quintile 4 RSMR Quintile 5 (Low-Performing) Supplementary Appendix Figure S10. Unadjusted expected survival curves by risk-standardized mortality rate (RSMR) quintile for 30-day survivors admitted to hospitals in case-mix stratum 2. 26

Survival (%) Time (days) RSMR Quintile 1 (High-Performing) RSMR Quintile 2 RSMR Quintile 3 RSMR Quintile 4 RSMR Quintile 5 (Low-Performing) Supplementary Appendix Figure S11. Unadjusted expected survival curves by risk-standardized mortality rate (RSMR) quintile for 30-day survivors admitted to hospitals in case-mix stratum 3. 27

Survival (%) Time (days) RSMR Quintile 1 (High-Performing) RSMR Quintile 2 RSMR Quintile 3 RSMR Quintile 4 RSMR Quintile 5 (Low-Performing) Supplementary Appendix Figure S12. Unadjusted expected survival curves by risk-standardized mortality rate (RSMR) quintile for 30-day survivors admitted to hospitals in case-mix stratum 4. 28

Survival (%) Time (days) RSMR Quintile 1 (High-Performing) RSMR Quintile 2 RSMR Quintile 3 RSMR Quintile 4 RSMR Quintile 5 (Low-Performing) Supplementary Appendix Figure S13. Unadjusted expected survival curves by risk-standardized mortality rate (RSMR) quintile for 30-day survivors admitted to hospitals in case-mix stratum 4 (i.e. hospitals that admitted the sickest patients). 29

Life Expectancy after Acute Myocardial Infarction (years) 9 8 7 6 5 4 3 2 1 0 Case-Mix Stratum 1 (Hospitals that admitted the healthiest patients) RSMR Quintile 1 (High-Performing) RSMR Quintile 2 RSMR Quintile 3 RSMR Quintile 4 RSMR Quintile 5 (Low-Performing) Case-Mix Stratum 2 Case-Mix Stratum 3 Case-Mix Stratum 4 Case-Mix Stratum 5 (Hospitals that admitted the sickest patients) Supplementary Appendix Figure S14. Mean unadjusted life expectancy after acute myocardial infarction (years) by riskstandardized mortality rate (RSMR) quintile for 30-day survivors. Caption: Models for the calculation of life expectancy were run separately for each case-mix stratum. Higher case-mix stratum signifies hospitals that admitted sicker patients with higher expected mortality. Within each case-mix stratum, higher risk-standardized mortality rate quintile indicates lower-performing hospitals with a higher than expected mortality rate. 30

Life Expectancy after Acute Myocardial Infarction (years) 9 8 7 6 5 4 3 2 1 0 Case-Mix Stratum 1 (Hospitals that admitted the healthiest patients) RSMR Quintile 1 (High-Performing) RSMR Quintile 2 RSMR Quintile 3 RSMR Quintile 4 RSMR Quintile 5 (Low-Performing) Case-Mix Stratum 2 Case-Mix Stratum 3 Case-Mix Stratum 4 Case-Mix Stratum 5 (Hospitals that admitted the sickest patients) Supplementary Appendix Figure S15. Mean clinically adjusted life expectancy after acute myocardial infarction (years) by riskstandardized mortality rate (RSMR) quintile for 30-day survivors. Caption: Models for the calculation of life expectancy were run separately for each case-mix stratum. Higher case-mix stratum signifies hospitals that admitted sicker patients with higher expected mortality. Within each case-mix stratum, higher risk-standardized mortality rate quintile indicates lower-performing hospitals with a higher than expected mortality rate. The clinical model is adjusted for patient sociodemographic (age, gender, race, socioeconomic 31

status), medical history (diabetes, hypertension, history of myocardial infarction, history of coronary artery bypass grafting, history of percutaneous coronary intervention, history of cerebrovascular accident or transient ischemic attack, chronic obstructive pulmonary disease, congestive heart failure, chronic kidney disease, cancer, dementia or Alzheimer s disease, anemia, current smoking, obesity), frailty (admission from a skilled nursing facility, immobility or incontinence on admission), and clinical presentation (heart rate on presentation, initial systolic blood pressure, shock within the first 48 hours of admission, duration of chest pain before presentation, blood urea nitrogen, creatinine, white blood cell count, ST-elevation myocardial infarction, left or right bundle branch block, heart block, anterior or lateral acute myocardial infarction). 32