Supplementary Appendix This appendix has been provided by the authors to give readers additional information about their work. Supplement to: Cohen DJ, Van Hout B, Serruys PW, et al. Quality of life after PCI with drug-eluting stents or coronary-artery bypass surgery. N Engl J Med 2011;364:1016-26.
SYNTAX QOL Supplementary Appendix- 1 Supplementary Appendix Table of Contents Quality of Life Scales.... Page 2 Calculation of Quality-of-life Scores.. Page 3 Table 1: Availability of QOL Instruments by Country.. Page 6 Table 2: Completeness of Follow-up by Individual Subscale... Page 7 Table 3: Mean Values for SAQ Scale Scores at 1 Month, 6 Months, and 12 Months...... Page 8 Table 4: Use of Anti-Anginal Medications over Time... Page 9 Table 5: Mean Values for SF-36 Scale Scores and EQ-5D at 1 Month, 6 Months, and 12 Months.. Pages 10-11 Table 6: Adjusted Effect of CABG vs. PCI on Disease-Specific Health Status Measures with Imputation of Worst Case Values to Patients with Missing Data.. Page 12 Table 7: Adjusted Effect of CABG vs. PCI on Generic Health Status Measures with Imputation of Worst Case Values to Patients with Missing Data.. Pages 13-14 References...... Page 15 Figure 1: Estimated Effect of CABG vs. PCI on the SAQ Angina Frequency Subscale at 6 months, by Prespecified Subgroups... Page 16 Figure 2: Estimated Effect of CABG vs. PCI on the SAQ Angina Frequency Subscale at 12 months, by Prespecified Subgroups. Page 17
SYNTAX QOL Supplementary Appendix- 2 Quality of Life Scales The quality of life data for this analysis were collected using the SAQ, the EQ-5D, and the SF-36. The scales comprised in the HRQOL measures, and for which scores were calculated, are detailed in the table below. QOL Scale Item Number Focus of Scale Seattle Angina Questionnaire (SAQ) Physical Limitations 1a-1i Physical limitations due to heart disease Angina Frequency 3,4 Frequency of angina, need for nitroglyerine Angina Stability 2 Recent change in pattern of angina Treatment Satisfaction 5-8 Satisfaction with treatment Disease Perception/ Quality of Life 9-11 Discrepancy between actual and desired level of function Medical Outcomes Study 36-item Short Form General Health Survey (SF-36) Physical Function 3a-3j Limitations of physical function Role Physical 4a-4d Difficulty performing usual activities due to physical problems Bodily Pain 7,8 Amount of discomfort, interference with activities General Health Perception 1, 11a-d Perception of overall health Vitality 9a, 9e, 9g, 9i Pep and energy Social Function 6, 10a Social contacts and activities Role Emotional Difficulty performing usual activities due to emotional problems Mental Health 9b,9c, 9d, 9f, 9h Depression and anxiety European Quality of Life-5 Dimensions (EQ-5D) Mobility 1 Difficulties with mobility Self-care 2 Ability to maintain self-are Usual Activities 3 Ability to perform usual activities Pain/Discomfort 4 Level of pain and discomfort Anxiety/Depression 5 Level of anxiety or depression Visual Analog Scale VAS Overall rating of health status
SYNTAX QOL Supplementary Appendix- 3 Calculation of Scores Methods for scoring each of the quality of life scales are described below. Seattle Angina Questionnaire Cardiovascular-specific health status was measured using the Seattle Angina Questionnaire (SAQ). Scale scores were calculated according to the developer s guidelines 1, 2 as follows: Physical Limitations: Responses of six ( Limited for other reasons ) were treated as missing values. Activities were grouped into three activity levels based on exertional requirements. The lowest level included dressing, walking, and showering (1a, 1b, 1c); the middle level included climbing, gardening, and walking more than a block (1d, 1e, 1f); and the highest level included running, lifting, and sports (1g, 1h, 1i). Missing items (including recoded scores of six) were assigned the average of the other items within their activity level. If all items within the lowest or highest level were missing, the mean value from the middle group was assigned to each item. If all of the middle group items were missing, the average of the lowest and highest items was assigned to each item. The Physical Limitations score was calculated as the average of all nine items and transformed to a scale ranging from zero to 100 using the following formula: [100*(Mean response - 1) / 4]. If more than four items were missing, the scale was set to missing. Angina Stability: Responses of six ( I ve had no chest pain ) were be recoded to a score of three. The Angina Stability score was transformed to a zero to 100 scale using the following formula: [100*(Response - 1) / 4]. If more than four items were missing, the scale was set to missing. Angina Frequency: Responses were coded sequentially from one to six in order of increasing health status, with one being assigned to the lowest health status. The Angina Frequency score was calculated as the average of the two items and transformed to a zero to 100 scale using the following formula: [100*(Mean response - 1) / 5].
SYNTAX QOL Supplementary Appendix- 4 Treatment Satisfaction: Responses were coded sequentially with one being assigned to the lowest health status. If responses were not contained in one through five, the item was set to missing. A response of six ( My doctor has not prescribed pills ) to Question Five was set to missing. The Treatment Satisfaction score was calculated as the average of the non-missing items and transformed to a zero to 100 scale using the following formula: [100*(Mean response - 1) / 4]. If more than two items were missing, the scale was not calculated. Disease Perception/QOL: Responses were coded sequentially from one to five in order of increasing health status, with one being assigned to the lowest health status. The Disease Perception/QOL score was calculated as the average of the non-missing items and transformed to a zero to 100 scale using the following formula: [100*(Mean response - 1) / 4]. If more than two items were missing, the scale was not calculated. EQ-5D The European Quality of Life-5 Dimensions (EQ-5D) instrument is a generic health status measure that contains five single-item dimensions and is capable of being expressed as a single global index of health-related quality of life (HRQOL). The five dimensions are mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. These dimensions give a choice of three difficulty levels in accomplishing tasks in each dimension. EQ-5D utility weights were assigned to each individual according to published algorithms for the US population. 3 If any of the 5 dimensions of the EQ-5D was missing, a utility value was not calculated. SF-36 Health Survey The eight domains of the Medical Outcomes Study 36-item Short Form General Health Survey (SF-36) were scored according to the standard scoring rules identified in chapter six of the How to Score Version 2 of the SF-36 Health Survey manual. 4 For each of the domains, items were re-coded so that higher values indicate better health, and then
SYNTAX QOL Supplementary Appendix- 5 summed. The summed scores were then transformed to a zero to 100 scale using the following formula: [((actual raw score - lowest possible raw score) / possible raw score range)*100]. Scores for these domains then range from zero to 100, with higher scores reflecting a better quality of life. If a respondent answered at least 50 percent of the items in a domain, the completed items were averaged to obtain values for the incomplete items. If more than 50% of the items in a domain were missing, the overall scale was not scored. In addition to the eight SF-36 domains, two summary scores were calculated: the physical and mental component summary scores (PCS and MCS, respectively). The two summary scores were calculated based on a previously-described weighted linear combination of eight SF-36 scales, designed such that the general population has a mean of 50 and a standard deviation of 10. This algorithm is described in detail in Chapter 7 of the How to Score Version 2 of the SF-36 Health Survey manual. 4
SYNTAX QOL Supplementary Appendix- 6 Supplementary Table 1: Availability of QOL Instruments by Country Country # Patients Languages SAQ SF-36 EQ-5D Austria 52 German Yes Yes Yes Belgium 91 French, Dutch Yes Yes Yes Czech Republic 40 Czech Yes Yes Yes Denmark 32 Danish Yes Yes Yes Finland 24 Finnish NO Yes Yes France 208 French Yes Yes Yes Germany 179 German Yes Yes Yes Hungary 83 Hungarian Yes Yes Yes Italy 197 Italian Yes Yes Yes Latvia 40 Latvian NO Yes NO Netherlands 148 Dutch Yes Yes Yes Norway 8 Norwegian Yes Yes Yes Poland 66 Polish Yes Yes Yes Portugal 13 Portuguese NO Yes Yes Spain 53 Spanish Yes Yes Yes Sweden 54 Swedish Yes Yes Yes United Kingdom 267 English Yes Yes Yes United States 245 English, Spanish Yes Yes Yes
SYNTAX QOL Supplementary Appendix- 7 Supplementary Table 2: Completeness of Follow-up by Individual Subscale Subscale Baseline 1 month 6 months 12 months SAQ Angina Frequency, % 95.1 89.4 89.0 88.8 SAQ Physical Limitation, % 91.9 77.2 85.2 85.6 SAQ Angina Stability, % 94.1 88.6 88.5 88.2 SAQ Treatment Satisfaction, % 93.0 88.0 86.0 85.8 SAQ Quality of Life, % 93.0 87.7 86.1 86.4 SAQ Any Scale, % 95.9 90.0 89.9 89.8 SF36 Physical Function, % 95.7 89.1 89.1 89.7 SF36 Role Physical, % 94.7 88.0 89.0 89.2 SF36 Role Emotional, % 94.4 87.6 88.7 88.7 SF36 Social Functioning, % 96.1 90.1 89.7 89.9 SF36 Bodily Pain, % 95.4 89.5 89.2 89.6 SF36 Mental Health Index, % 95.2 89.1 89.2 88.8 SF36 Vitality Index, % 95.4 89.3 89.3 88.8 SF36 General Health Perception, % 94.9 89.2 88.8 88.4 SF36 Any Scale, % 96.1 90.3 90.1 90.4 Overall Response Rate*, % 96.2 90.5 90.3 90.5 * Overall response rate is calculated as the proportion of patients with at least 1 evaluable scale at the specified time point.
SYNTAX QOL Supplementary Appendix- 8 Supplementary Table 3: Mean Values for SAQ Scale Scores at 1 Month, 6 Months, and 12 Months PCI Group CABG Group CABG-PCI Difference (95% CI)* P Value* Angina Frequency Baseline 69.6 ± 25.8 69.5 ± 26.7 0.91 1 month 90.2 ± 17.6 88.7 ± 18.9-1.3 (-3.1 to 0.5) 0.17 6 months 91.1 ± 17.3 92.8 ± 14.5 1.7 (0.1 to 3.3) 0.04 12 months 92.4 ± 15.9 93.8 ± 14.2 1.7 (0.2 to 3.2) 0.03 Physical Limitations Baseline 65.5 ± 24.7 65.7 ± 25.0 0.89 1 month 78.7 ± 23.2 66.5 ± 25.1-12.2 (-14.5 to -9.8) <0.001 6 months 81.6 ± 20.3 79.8 ± 21.6-1.5 (-3.5 to 0.5) 0.13 12 months 80.8 ± 20.9 81.9 ± 21.2 1.1 (-0.9 to 3.1) 0.21 Treatment Satisfaction Baseline 85.8 ± 17.4 84.4 ± 17.3 0.09 1 month 91.7 ± 12.5 88.5 ± 15.4-2.7 (-4.0 to -1.3) <0.001 6 months 92.0 ± 13.1 90.0 ± 15.2-1.5 (-3.0 to 0.0) 0.04 12 months 91.1 ± 13.9 90.7 ± 14.8 0.1 (-1.4 to 1.6) 0.87 Quality of Life Baseline 45.6 ± 23.0 44.8 ± 22.8 0.46 1 month 71.3 ± 21.8 66.3 ± 23.7-4.6 (-6.9 to -2.4) <0.001 6 months 75.0 ± 22.6 76.4 ± 21.5 1.6 (-0.7 to 3.8) 0.13 12 months 76.0 ± 21.0 77.9 ± 20.7 2.4 (0.3 to 4.6) 0.03 Angina Stability Baseline 43.3 ± 26.8 44.4 ± 27.4 0.39 1 month 60.9 ± 23.1 61.4 ± 24.0 0.5 (-1.9 to 2.9) 0.67 6 months 56.3 ± 20.6 58.0 ± 19.8 1.6 (-0.5 to 3.7) 0.11 12 months 55.6 ± 18.7 56.3 ± 18.0 0.6 (-1.4 to 2.6) 0.50 * Mean treatment effect, confidence intervals and p-values based on ANCOVA
SYNTAX QOL Supplementary Appendix- 9 Supplementary Table 4: Use of Anti-Anginal Medications over Time PCI CABG P Value Beta Blocker 1 month, % 78.5 78.9 0.84 6 months, % 78.8 74.7 0.04 12 months, % 78.7 76.4 0.26 Calcium Channel Blocker 1 month, % 25.0 16.5 <0.001 6 months, % 24.0 18.5 0.005 12 months, % 25.5 18.9 0.001 Long-Acting Nitrates 1 month, % 20.6 10.6 <0.001 6 months, % 18.6) 6.9 <0.001 12 months, % 17.4 7.5 <0.001 * Rates reflect proportion of all patients undergoing follow-up and do not exclude patients with contraindications to the specific medication
SYNTAX QOL Supplementary Appendix- 10 Supplementary Table 5: Mean Values for SF-36 Scale Scores and EQ-5D at 1 Month, 6 Months, and 12 Months PCI Group CABG Group CABG-PCI Difference (95% CI)* P Value* SF-36 Physical Function Baseline 57.9 ± 26.6 57.1 ± 26.8 0.53 1 month 73.0 ± 24.9 59.1 ± 24.6-14.1 (-16.2 to -11.9) <0.001 6 months 75.1 ± 24.1 75.4 ± 23.2 0.4 (-1.7 to 2.5) 0.74 12 months 74.3 ± 24.6 75.4 ± 24.7 1.6 (-0.5 to 3.7) 0.14 SF-36 Role Physical Baseline 53.6 ± 29.3 53.9 ± 29.8 0.83 1 month 63.6 ± 28.3 39.6 ± 27.2-24.3 (-27.0 to -21.6) <0.001 6 months 71.0 ± 27.2 66.8 ± 27.2-3.7 (-6.3 to -1-1) <0.001 12 months 71.8 ± 26.2 71.2 ± 27.0-0.1 (-2.6 to 2.4) 0.89 SF-36 Bodily Pain Baseline 55.2 ± 27.4 56.2 ± 27.4 0.44 1 month 75.3 ± 24.8 53.0 ± 24.5-22.8 (-25.1 to -20.3) <0.001 6 months 75.8 ± 25.5 73.9 ± 24.1-2.2 (-4.6 to 0.2) 0.07 12 months 75.9 ± 24.9 76.4 ± 24.1 0.4 (-1.9 to 2.8) 0.82 SF-36 Vitality Baseline 51.8 ± 23.4 51.7 ± 22.9 0.94 1 month 62.8 ± 21.4 51.9 ± 22.0-10.8 (-12.7 to -8.9) <0.001 6 months 64.0 ± 20.7 63.2 ± 20.1-0.9 (-2.7 to 1.0) 0.48 12 months 64.9 ± 20.8 64.7 ± 19.6 0.3 (-1.6 to 2.1) 0.73 SF-36 General Health Baseline 56.1 ± 19.8 55.6 ± 20.0 0.57 1 month 65.0 ± 19.5 63.8 ± 18.3 1.5 (-3.1 to 0.1) 0.12 6 months 65.1 ± 20.4 65.4 ± 20.1 0.3 (-1.6 to 2.1) 0.79 12 months 63.8 ± 20.1 66.1 ± 20.3 2.5 (0.7 to 4.3) <0.001 SF-36 Social Function Baseline 68.8 ± 28.2 68.3 ± 28.1 0.70 1 month 78.8 ± 24.2 63.9 ± 27.8-15.2 (-17.7 to -12.8) <0.001 6 months 82.5 ± 22.9 80.2 ± 23.5-2.3 (-4.5 to -0.1) 0.06 12 months 83.8 ± 21.4 83.3 ± 20.9-0.5 (-2.5 to 1.6) 0.76 SF-36 Role Emotional Baseline 66.7 ± 29.2 66.4 ± 29.2 0.81 1 month 74.2 ± 27.6 62.7 ± 31.2-11.6 (-14.4 to -8.7) <0.001 6 months 77.7 ± 26.1 75.9 ± 26.3-1.1 (-3.6 to 1.5) 0.33 12 months 79.2 ± 24.7 78.6 ± 24.7-0.4 (-2.9 to 2.0) 0.81
SYNTAX QOL Supplementary Appendix- 11 PCI Group CABG Group CABG-PCI Difference (95% CI)* P Value* SF-36 Mental Health Baseline 64.9 ± 22.1 65.1 ± 21.1 0.83 1 month 75.1 ± 19.1 69.6 ± 20.4-5.6 (-7.4 to -3.9) <0.001 6 months 74.6 ± 18.9 73.8 ± 19.9-1.0 (-2.7 to 0.7) 0.39 12 months 75.2 ± 18.7 75.0 ± 18.2-0.2 (-1.9 to 1.4) 0.87 SF-36 PCS Baseline 40.4 ± 10.0 40.4 ± 10.2 0.97 1 month 46.7 ± 9.3 39.1 ± 8.8-7.8 (-8.6 to 6.9) <0.001 6 months 47.9 ± 9.7 47.5 ± 8.8-0.3 (-1.2 to 0.6) 0.32 12 months 47.5 ± 9.5 48.1 ± 9.3 0.8 (-0.1 to 1.7) 0.12 SF-36 MCS Baseline 45.2 ± 12.4 45.2 ± 12.0 0.99 1 month 49.2 ± 11.0 45.9 ± 11.7-3.2 (-4.3 to -2.2) <0.001 6 months 49.7 ± 10.6 49.1 ± 11.1-0.6 (-1.7 to 0.4) 0.26 12 months 50.5 ± 10.3 50.0 ± 9.9-0.4 (-1.4 to 0.6) 0.50 EQ-5D Utility Weights Baseline 0.755 ± 0.186 0.740 ± 0.192 0.11 1 month 0.853 ± 0.156 0.769 ± 0.171-0.08 (-0.10 to -0.06) <0.001 6 months 0.861 ± 0.149 0.847 ± 0.153-0.01 (-0.03 to 0.00) 0.09 12 months 0.855 ± 0.155 0.850 ± 0.158 0.00 (-0.02 to 0.02) 0.92 PCS = physical component summary; MCS = mental component summary * Mean treatment effect, confidence intervals and p-values based on ANCOVA
SYNTAX QOL Supplementary Appendix- 12 Supplementary Table 6: Adjusted Effect of CABG vs. PCI on Disease- Specific Health Status Measures with Imputation of Worst Case Values to Patients with Missing Data* Treatment Difference (CABG-PCI)** Scales Difference Lower 95% CI Upper 95% CI P Value SAQ Physical Limitation 1 month -13.3-15.8-10.7 <0.001 6 months -2.1-4.3 0.1 0.068 12 months 0.1-2.1 2.3 0.939 SAQ Angina Stability 1 month 0.2-2.3 2.7 0.879 6 months 1.5-0.7 3.7 0.176 12 months 0.0-2.1 2.0 0.982 SAQ Angina Frequency 1 month -1.7-3.8 0.4 0.116 6 months 1.2-0.5 3.0 0.154 12 months 1.0-0.6 2.8 0.182 SAQ Treatment Satisfaction 1 month -2.9-4.6-1.1 0.001 6 months -2.0-3.7-0.2 0.031 12 months -0.9-2.7 0.9 0.310 SAQ Disease Perception 1 month -4.9-7.3-2.5 <0.001 6 months 1.4-1.0 3.8 0.262 12 months 1.7-0.6 4.0 0.155 * Patients with interval stroke or MI and missing data had the worst case value for each scale imputed ** Treatment differences estimated on the basis of longitudinal random effect growth curve models
SYNTAX QOL Supplementary Appendix- 13 Supplementary Table 7: Adjusted Effect of CABG vs. PCI on Generic Health Status Measures with Imputation of Worst Case Values to Patients with Missing Data* Treatment Difference (CABG-PCI)** Scales Difference Lower 95% CI Upper 95% CI P Value SF36 Physical Function 1 month -14.1-16.4-11.9 <0.001 6 months 0.1-2.1 2.3 0.896 12 months 0.9-1.4 3.2 0.447 SF36 Role Physical 1 month -24.1-26.8-21.4 <0.001 6 months -4.3-6.9-1.6 0.002 12 months -0.8-3.4 1.8 0.531 SF36 Bodily Pain 1 month -22.8-25.3-20.4 <0.001 6 months -2.5-5.0 0.0 0.052 12 months -0.6-3.0 1.9 0.662 SF36 Vitality Index 1 month -10.8-12.8-8.7 <0.001 6 months -1.0-3.0 1.0 0.324 12 months -0.5-2.4 1.5 0.649 SF36 General Health Perception 1 month -1.5-3.2 0.3 0.107 6 months 0.0-2.0 1.9 0.963 12 months 2.1 0.1 4.0 0.038 SF36 Social Functioning 1 month -15.2-17.7-12.7 <0.001 6 months -2.5-4.8-0.1 0.039 12 months -1.3-3.5 0.9 0.241 SF36 Role Emotional 1 month -11.7-14.6-8.8 <0.001 6 months -1.5-4.2 1.1 0.260 12 months -1.0-3.5 1.5 0.436 SF36 Mental Health Index 1 month -5.9-7.8-4.0 <0.001 6 months -1.2-3.1 0.7 0.205 12 months -0.1-1.8 1.6 0.875 SF36 Physical Component Scale 1 month -7.9-8.9-6.9 <0.001 6 months -0.6-1.6 0.4 0.269 12 months 0.3-0.7 1.3 0.587 SF36 Mental Component Scale 1 month -3.5-4.7-2.2 <0.001 6 months -0.8-1.9 0.4 0.196 12 months -0.9-2.0 0.3 0.133
SYNTAX QOL Supplementary Appendix- 14 * Patients with interval stroke or MI and missing data had the worst case value for each scale imputed ** Treatment differences estimated on the basis of longitudinal random effect growth curve models
SYNTAX QOL Supplementary Appendix- 15 References for the Supplementary Appendix 1. Spertus JA, Winder JA, Dewhurst TA, Deyo RA, Fihn SD. Monitoring the quality of life in patients with coronary artery disease. Am J Cardiol 1994;74:1240-4. 2. Spertus JA, Winder JA, Dewhurst TA, et al. Development and evaluation of the Seattle Angina Questionnaire: a new functional status measure for coronary artery disease. J Am Coll Cardiol 1995;25:333-41. 3. Shaw JW, Johnson JA, Coons SJ. US valuation of the EQ-5D health states: development and testing of the D1 valuation model. Med Care 2005;43:203-20. 4. Ware JE, Kosinski M, Dewey J. How to Score Version 2 of the SF-36 Health Survey. Lincoln RI: QualityMetric, Inc. 2000.
SYNTAX QOL Supplementary Appendix- 16 Supplementary Figure 1. Estimated effect of CABG versus PCI on the SAQ angina frequency subscale at 6 months, by subgroups. Treatment effects and interaction P values are derived from longitudinal random effect growth curve models. The SYNTAX (Synergy between PCI with Taxus and Cardiac Surgery) Score is an anatomical assessment of coronary disease severity based on the diagnostic angiogram, ranging from 0 to 115 with higher scores indicating more complex disease. For the SYNTAX Score subgroup analysis, patients were grouped by tertile of the score (0 to 22, 23 to 32, and 33 to 83).
SYNTAX QOL Supplementary Appendix- 17 Supplementary Figure 2. Estimated effect of CABG versus PCI on the SAQ angina frequency subscale at 12 months, by subgroups. Treatment effects and interaction P values are derived from longitudinal random effect growth curve models. The SYNTAX (Synergy between PCI with Taxus and Cardiac Surgery) Score is an anatomical assessment of coronary disease severity based on the diagnostic angiogram, ranging from 0 to 115 with higher scores indicating more complex disease. For the SYNTAX Score subgroup analysis, patients were grouped by tertile of the score (0 to 22, 23 to 32, and 33 to 83).