- Email: [email protected]
Racial Differences in Cardiac Catheterization Use and Appropriateness
Racial Differences in Cardiac Catheterization Use and Appropriateness JEFFREY A. FERGUSON, MD, MPH,*t:J: MORRIS WEINBERGER, PHD*t:J:
TERRYL A. ADAMS, RN,*
ABSTRACT: The authors sought to investigate the role of medical appropriateness as a potential explanatory factor in previously observed interracial cardiac procedure rate differences. A retrospective cohort study using RAND appropriateness criteria was conducted at a Veterans Affairs medical center among a sample of patients who were evaluated for cardiovascular disease during 1993 (n = 200). All participants were men and 50% were black (mean age = 61.8 years). Blacks were less likely than whites to undergo cardiac catheterizations (CC) (odds ratio [OR] = 0.23, P < 0.01). When RAND criteria were applied, blacks were found to have fewer indications that made them appropriate candidates for CC and more indications making them inappropriate candidates for CC (chi-square test, P < 0.05). No CC procedure underuse was found among blacks, whereas 10% of CC overuse was found among whites. Interracial CC procedure use differences were not due to procedure underuse among blacks but were in part due to overuse among whites. KEY INDEXING TERMS: Cardiovascular disease; Cardiac therapy; Retrospective studies (blacks, whites, veterans). [Am J Med Sci 1998;315(5):302-306.]
C
ardiovascular disease remains the leading cause of morbidity and mortality in the United
From the *Center for Health Services Research, Roudebush Veterans Affairs Medical Center; the tDivision of General Internal Medicine, Department of Medicine, Indiana University School of Medicine; and the Wegenstrief Institute for Health Care, Indianapolis, Indiana. Submitted September 15, 1997; accepted in revised form December 15, 1997. This study was funded in part by SDR 95-002 from the Health Services Research and Development Service, Department ofVeterans Affairs. Presented as an abstract at the annual meeting of the Society of General Internal Medicine, May 3, 1997, Washington, DC. Correspondence: Jeffrey A. Ferguson, MD, MPH, Richard L. Roudebush VAMC, HSR&D (lIB), 1481 West 10th Street, Indianapolis, IN 46202. Email: [email protected]
302
States despite significant technological advances in its management. For many patients in whom conservative management fails, optimal treatment modalities require the use of invasive cardiac procedures: cardiac catheterization (CC), percutaneous transluminal coronary angioplasty (PTCA), and coronary artery bypass graft (CABG) surgery. Although numerous previous studies suggested that blacks undergo fewer of these invasive cardiac procedures than their white counterparts,1-1O it is not known whether treatment differences are due to overuse among whites, underuse among blacks, neither of these reasons, or both. Criteria for determining invasive cardiac procedure overuse and underuse have been established by researchers at the RAND Corporation in collaboration with the Cardiac Advisory Committee of the State of New York. 11 - 13 Subsequently, these criteria have been used to determine rates of overuse of invasive cardiac procedures within New York State and among institutions participating in the Academic Medical Center Consortium study.14-17 Of importance, these previous studies have not focused on interracial treatment differences, rates of procedure underuse, or procedure use among veteran populations. Our previous retrospective study suggested that interracial differences in cardiac procedure use may have been influenced by relevant comorbidities and disease severity.18 To extend this research, we applied RAND appropriateness criteria to report rates of underuse and overuse of invasive cardiac procedures among black and white patients who were admitted to a veterans hospital for evaluation of cardiovascular disease. Methods Study Site. This study was conducted at the Roude-
bush Veterans Affairs Medical Center, a 400-bed medical-surgical hospital that provides both primary and tertiary care. At the time of this study, this institution provided care for approximately 7,600 hospitalized patients annually. Patients received primary care from approximately 84 house-staff physicians May 1998 Volume 315 Number 5
Ferguson, Adams, and Weinberger
and received cardiology consultation from six cardiology fellows and three faculty cardiologists. The study protocol was approved by the institutional review board at the Indiana University Medical Center, Indianapolis, and the Roudebush Veterans Mfairs Medical Center. PaHent Eligibility and Identification. Eligible inpatients identified by the Department of Veterans Mfairs inpatient administrative database, Patient Treatment File, were discharged between January 1 and December 31,1993, with a primary discharge diagnosis of cardiovascular disease or chest pain (International Classification of Diseases, 9th Revision, Clinical Modification codes, 390-459 or 786.5786.59). Eligibility criteria were male gender and age older than 30 years. 2 Patients who died during their index admissions were eligible for study inclusion. Patients were excluded if they were ineligible for Department of Veterans Affairs care, they had undergone an invasive cardiac procedure within 90 days before index admission, their race was coded as other than black or white, or they resided outside Indianapolis. We excluded patients who were nonlocal residents due to the unavailability of these medical records for chart review and the increased likelihood that these patients had scheduled admissions for cardiac procedures. A random sample of 100 patients per race was selected from a total of 470 eligible patients. For all patients, the index event was defined as first hospitalization for one of the target conditions during the study period. Measures and Procedures. Our primary outcome variable, invasive cardiac procedure use within prespecified periods after the index event (60 days for CC and PTCA, 90 days for CABG), was identified by both computer and chart audit. Chart audit data were considered the "gold standard" if discrepancies occurred. For each relevant cardiac procedure (ICD9-CM procedure codes: CC, 37.21-37.23, 88.5588.57; PTCA, 36.00-36.03, 36.05-36.09; CABG, 36.10-36.19), we recorded its occurrence and date. Due to the small number of patients eligible for PTCA and CABG, we report results for CC procedures only. Chart review was performed by a trained research nurse blinded to the study objectives who used a modified version of the RAND Medical Record Abstraction Form 19 to abstract patient-specific information. Abstracted data included patients' demographic and clinical characteristics (including risk factors for cardiac disease), comorbid conditions and disease severity, response to pharmaceutical therapies, physicians' recommendations for treatment and patients' agreements or refusals, and results of noninvasive and invasive cardiac assessments. A study investigator (JAF) blinded to patients' race and cardiac procedure status recommended patients for discrete cardiac procedure clinical indication catTHE AMERICAN JOURNAL OF THE MEDICAL SCIENCES
egories and assigned their corresponding appropriateness scores, which ranged from 1 to 9, in accordance with published RAND instructions and guidelines. 20 Patient scores were aggregated into three categories: inappropriate (1-3), of uncertain appropriateness (4-6), or appropriate (7-9) for undergoing an invasive cardiac procedure. If more than one clinical indication applied to a patient, the indication for which the procedure was more appropriate was used. Analysis. We used Fisher's exact tests to compare rates ofCC use, recommendations, and refusals. We used chi-square tests to compare aggregated appropriateness ratings between races, followed by descriptive statistics to estimate rates of cardiac procedure underuse and overuse for blacks and whites. Underuse rates were calculated as follows: number of patients who did not undergo a procedure while having an appropriate score divided by all patients who did not undergo a procedure. Overuse rates were calculated as follows: number of patients who underwent a procedure while having an inappropriate score divided by all patients who underwent a procedure. Results
Patients' mean age was 61.8 years and their diagnoses as determined by clinical indication criteria are listed by race in Table 1. Overall, the most common clinical categories were asymptomatic disease or chronic stable angina (38%), followed by unstable angina (19%), miscellaneous diagnoses (17%), and chest pain of uncertain origin (16%). Blacks were more likely to have chest pain of uncertain origin and asymptomatic disease or chronic stable angina, whereas whites were more likely to have unstable angina. Overall, 105 patients (52%) had ratings of inappropriate; 69 (35%) had ratings of uncertain appropriateness; and 26 (13%) had ratings of appropriate (Table 1). Blacks had more ratings of inappropriate and fewer ratings of appropriate than whites (chi-square, P < 0.05) (Table 1). Blacks underwent fewer CCs than whites: 14% versus 41%, respectively (Fishers exact test, OR = 0.23, P < 0.01) (Table 2). Blacks were also offered fewer CCs than whites: 20% versus 42%, respectively (OR = 0.34, P < 0.01) (Table 2). Procedure refusals were more frequent in blacks: 6 of20 recommendations versus 1 of 42 recommendations, respectively (OR = 17.5, P < 0.01) (Table 2). When patients who underwent CC were considered, it was determined that 1 (7%) of 14 black patients had a rating of inappropriate (overuse) compared with 4 (10%) of 41 white patients (Table 3). When patients who did not undergo CC were considered, it was found that 0 (0%) of 86 black patients had a rating of appropriate (underuse) compared with 2 (3%) of 59 whites (Table 4).
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Interracial CC Appropriateness
Table 1. Frequency of Various Cardiac Procedure Clinical Indication Categories and Appropriateness by Race Blacks Cardiac Procedure Clinical Indication Category
No.
A
Asymptomatic disease or chronic stable angina Unstable angina Chest pain of uncertain origin Acute myocardial infarction Postcoronary bypass Within 12 weeks of myocardial infarction Other cardiac diagnoses* Totals
45 12 18 8 0 0 17 100
0 3 1 1 1 6
Whites
?
No.
A
43 0 17 1
2 9 0 6
1 62
15 32t
30 25 13 11 3 1 17 100
2 12 1 1 1 0 3 20
? 26 1 9 3 1 1 2 43
2 12 3 7 1 0 12 37t
Patients were determined to be appropriate candidates for cardiac catheterization (A), inappropriate candidates for cardiac catheterization (1), or of uncertain appropriateness for cardiac catheterization (?). * Examples include preoperative evaluations, arrhythmias, and unexplained congestive heart failure. t Chi-square test, P < 0.05.
Of those who underwent CC, 7 of 14 blacks subsequently underwent a revascularization procedure (PTCA = 4, CABG = 3) and 17 of 41 whites underwent a revascularization procedure (PTCA = 6, CABG = 11) (data not shown). Discussion Overview. Our study had several important find-
ings. First, despite confirming earlier reports of lower invasive CC procedure use among minority veterans, we found no evidence of discriminatory underuse of this procedure among blacks. In fact, among blacks in our cohort, only one patient underwent care "outside the boundaries" of appropriate care as determined by previously validated RAND criteria; this occurred in a patient who underwent a procedure for which a clinical indication was lacking, an example of clinical overuse. In contrast, we found greater variability of cardiac procedure use among whites in our cohort. Of importance, 10% of whites undergoing CC had an inappropriate score (overuse), whereas 3% of whites not undergoing CC had an appropriate score (underuse). Therefore, these data suggest that previously observed interracial differences in invasive cardiac procedure use may be a
Table 2. Rates of Cardiac Catheterization Use, Recommendations, and Refusals by Race Treatment Variable
Blacks (n = 100)
Whites (n = 100)
Received CC Offered CC Refused CC Not offered CC
14 20 6 60
41 42 1 16
Values were obtained using Fisher's exact tests. CC = cardiac catheterization.
304
function of overuse among whites rather than underuse among blacks. Second, our study underscores the importance of heterogeneity in cardiac disease symptom severity between ethnic groups presenting for evaluation of cardiovascular disease. In general, blacks in our cohort had less severe cardiac disease presentations. Only 6% of black patients had symptom severity that placed them in the category appropriate for undergoing CC, whereas 62% were in the inappropriate category. In contrast, 20% of whites had symptom severity that placed them in the category appropriate for undergoing CC, whereas 43% were in the category meeting criteria making them inappropriate candidates for CC. Previous researchers have documented that although blacks and whites have similar prevalences of coronary artery disease, blacks often present with less severe symptoms and whites have a greater number of diseased arteries found during a subsequent CC. 21 Thus, it is not surprising to find that blacks in our cohort had less severe disease presentations overall, and when found to have disease requiring revascularization, they were more likely to undergo PTCA, whereas whites were more likely to undergo CABG. Third, our study supports earlier reports of more
Table 3. Appropriateness Ratings for Patients Who Received Cardiac Catheterization by Race and Corresponding Rates of Cardiac Catheterization Overuse P Value <0.01 <0.01 <0.01
Appropriateness Rating Inappropriateness Uncertain Appropriate
Blacks (n = 14)
Whites (n = 41)
1 7 6
4 19 18
Overuse by blacks was 7% (1114) and by whites was 10% (4141). May 1998 Volume 315 Number 5
Ferguson, Adams, and Weinberger
Table 4. Appropriateness Ratings for Patients Who Did Not Receive Cardiac Catheterization by Race and Corresponding Rates of Cardiac Catheterization Underuse Appropriateness Rating
Blacks (n = 86)
Whites (n = 59)
Inappropriate Uncertain Appropriate
61 25 0
39 18 2
Underuse by blacks was 0% (0/86) and by whites was 3% (2/59).
procedure refusals among blacks (6/20 [30%]) than whites (1/42 [2%]).5 Of note, all refusals occurred among patients who received a rating of uncertain appropriateness for CC. We cannot infer from our data the underlying mechanisms in patient decision making that would account for this difference. We previously conducted a study using patient focus group methodology that identified more distrust of the medical community by blacks22 ; however, these and additional factors must be more fully explored to address this complex issue in patient care properly. Last, our study provides an example of the inadequacy of an administrative database in making a quality of care assessment. In the absence of critical clinical data such as symptom severity, response to medical therapy, and patient preferences, blacks in our cohort could be perceived as recipients of suboptimal care compared with whites. However, when the clinical data that are necessary for judging the appropriateness of undergoing a cardiac procedure are considered, these interracial treatment differences are consistent with high-quality care and the desire of patients for treatment. Limitations. Our study had several limitations. This investigation was carried out at a single institution and may not be representative of patients and practices present throughout the entire Department of Veterans Affairs system. However, our population demographics and unadjusted cardiac procedure rates were similar to those reported within the Department of Veterans Affairs, suggesting that our institution is not significantly different from others within this healthcare setting. 2 Second, our findings may not be applicable in healthcare settings with financial reimbursement incentives that may influence the use of invasive, costly procedures. Third, our sample size was small. Although we have not reported appropriateness results for PTCA and CABG procedures, repeated analyses combining all three cardiac procedures (n = 255) yielded nearly identical underuse and overuse rates. In addition, our estimates of cardiac procedure overuse are congruent with previously reported rates. 14 - 17 With regard to these estimates of underuse, we are aware of no comparison study investigating CC use. Last, our study design did not allow us to capture data THE AMERICAN JOURNAL OF THE MEDICAL SCIENCES
prospectively. We relied on the accuracy of medical record notes that were not recorded for the purpose of a research study, and we could not directly assess physician or patient decision-making parameters, such as preferences for care. However, the RAND chart abstraction form has undergone rigorous testing and validation to verify its ability to capture information intended for our purpose. 23 Conclusions
In summary, we have contributed to research attempting to understand interracial treatment differences in cardiovascular disease. We were the first to use a validated chart abstraction instrument to determine the appropriateness of CC procedure use among blacks and whites as a potential explanation for previously reported treatment differences. We found that treatment differences in our cohort were not due to underuse of this procedure among blacks but were due in part to modest overuse among whites. Furthermore, we found that whites presented with greater cardiac symptom severity than blacks and that blacks were more likely to refuse recommendations for invasive cardiac procedure use than whites. Additional studies are needed to confirm these findings in other settings and among larger population samples. References 1. Peterson ED, Wright SM, Daley J, Thibault GE. Racial variation in cardiac procedure use and survival following acute myocardial infarction in the Department of Veterans Affairs. JAMA. 1994;271:1175-80. 2. Whittle J, Conigliaro J, Good CB, Lofgren RP. Racial differences in the use of invasive cardiovascular procedures in the Department of Veterans Affairs medical system. N Engl J Med. 1993;329:621-7. 3. Johnson PA, Lee TB, Cook F, Rouan GW, Goldman L. Effect of race on the presentation and management of patients with acute chest pain. Ann Intern Med. 1993; 118:593601. 4. Udvarhelyi IS, Gatsonis C, Epstein AM, Pashos CL, Newhouse JP, McNeil BJ. Acute myocardial infarction in the Medicare population: Process of care and clinical outcomes. JAMA. 1992;268:2530-6. 5. Maynard C, Fisher LD, Passanlani ER, Pullum T. Blacks in the Coronary Artery Surgery Study (CASS): Race and clinical decision making. Am J Public Health. 1986; 76:1446-8. 6. Wenneker MB, Epstein AM. Racial Inequalities in the use of procedures for patients with ischemic heart disease in Massachusetts. JAMA. 1989;261:253-7. 7. Goldberg KC, Bartz AJ, Jacobsen SJ, Krakauer B, Rimm AA. Racial and community factors influencing coronary artery bypass graft surgery rates for all 1986 Medicare patients. JAMA. 1992;267:1473-7. 8. Ayanian JZ, Udvarhelyi IS, Gatsonis CA, Pashos CL, Epstein AM. Racial differences in the use of revascularization procedures after coronary angiography. JAMA. 1993; 269:2642-6. 9. Giles WH, Anda RF, Caspar ML, Escobedo LG, Taylor HA. Race and sex differences in rates of invasive cardiac procedures in US hospitals: Data from the National Hospital Discharge Survey. Arch Intern Med. 1995; 155:318-24. 10. Ford E, Cooper R, Castaner A, Simmons B, Mar M. Coro-
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11.
12.
13.
14.
15.
16.
17.
nary arteriography and coronary bypass survey among whites and other racial groups relative to hospital-based incidence rates for coronary artery disease: Findings from NHDS. Am J Public Health. 1989;79:437-40. Leape LL, Hilborne LH, Kahan JP, Stason WH, Park RE, Kamberg CJ, et al. Coronary Artery Bypass Graft: A Literature Review and Ratings of Appropriateness and Necessity. Santa Monica, CA: RAND; 1991. Hilborne LH, Leape LL, Kahan JP, Park RE, Kamberg CJ, Brook RH. Percutaneous Transluminal Coronary Angioplasty: A Literature Review and Ratings of Appropriateness and Necessity. Santa Monica, CA: RAND; 1991. Bernstein SJ, Laouri M, Hilborne LH, Leape LL, Kahan JP, Park RE, et al. Coronary Angiography: A Literature Review and Ratings of Appropriateness and Necessity. Santa Monica, CA: RAND; 1992. Leape LL, Hilborne LH, Schwartz JS, Bates DW, Rubin HR, Slavin P, et al. The appropriateness of coronary artery bypass graft surgery in academic medical centers. Ann Intern Med. 1996; 125:8-18. Leape LL, Hilborne LH, Park RE, Bernstein SJ, Kamberg CJ, Sherwood M, et al. The appropriateness of use of Coronary artery bypass graft surgery in New York State. JAMA. 1993;269:753-60. Hilborne LH, Leape LL, Bernstein SJ, Park RE, Fiske ME, Kamberg CJ, et aI. The appropriateness of use of percutaneous transluminal coronary angioplasty in New York State. JAMA. 1993;269:761-65. Bernstein SJ, Hilborne LH, Leape LL, Fiske ME, Park RE, Kamber CJ, et al. The appropriateness of use of coro-
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18.
19.
20.
21.
22.
23.
nary angiography in New York State. JAMA. 1993;269: 766-9. Ferguson JA, Tierney WM, Westmoreland GR, MamHn LA, Segar DS, Eckert GJ, et al. Examining racial differences in management of cardiovascular disease. J Am ColI Cardiol. 1997;30:1707-13. Rand Corporation. Coronary artery bypass surgery and percutaneous transluminal coronary angioplasty and coronary angiography: Medical record abstraction form. Santa Monica, CA: RAND Corporation for the Cardiac Advisory Committee of New York; 1991. Rand Corporation. Coronary artery bypass surgery and percutaneous transluminal coronary angioplasty and coronary angiography: Guidelines. Santa Monica, CA: RAND Corporation for the Cardiac Advisory Committee of New York; 1991. Stone PH, Thompson B, Anderson HV, Kronenberg MW, Gibson RS, Rogers WJ, et al. Influence of race, sex, and age on management of unstable angina and non-Q-wave myocardial infarction: The TIMI III registry. JAMA. 1996; 275:1104-12. Tierney WM, Ferguson, JA, Westmoreland GR, MamHn GR, Segar DS, Eckert GJ, et al. Bridging quantitative and qualitative methods: Can raters consistently evaluate the content of focus groups (abstract)? J Gen Intern Med. 1996; 11(suppl): 1. Kravitz RL, Laouri M, Kahan JP, Guzy P, Sherman S, Hilborne L, et al. Validity of criteria used for detecting underuse of coronary revascularization. JAMA. 1995;274: 632-8.
May 1998 Volume 315 Numbel5
TERRYL A. ADAMS, RN,*
ABSTRACT: The authors sought to investigate the role of medical appropriateness as a potential explanatory factor in previously observed interracial cardiac procedure rate differences. A retrospective cohort study using RAND appropriateness criteria was conducted at a Veterans Affairs medical center among a sample of patients who were evaluated for cardiovascular disease during 1993 (n = 200). All participants were men and 50% were black (mean age = 61.8 years). Blacks were less likely than whites to undergo cardiac catheterizations (CC) (odds ratio [OR] = 0.23, P < 0.01). When RAND criteria were applied, blacks were found to have fewer indications that made them appropriate candidates for CC and more indications making them inappropriate candidates for CC (chi-square test, P < 0.05). No CC procedure underuse was found among blacks, whereas 10% of CC overuse was found among whites. Interracial CC procedure use differences were not due to procedure underuse among blacks but were in part due to overuse among whites. KEY INDEXING TERMS: Cardiovascular disease; Cardiac therapy; Retrospective studies (blacks, whites, veterans). [Am J Med Sci 1998;315(5):302-306.]
C
ardiovascular disease remains the leading cause of morbidity and mortality in the United
From the *Center for Health Services Research, Roudebush Veterans Affairs Medical Center; the tDivision of General Internal Medicine, Department of Medicine, Indiana University School of Medicine; and the Wegenstrief Institute for Health Care, Indianapolis, Indiana. Submitted September 15, 1997; accepted in revised form December 15, 1997. This study was funded in part by SDR 95-002 from the Health Services Research and Development Service, Department ofVeterans Affairs. Presented as an abstract at the annual meeting of the Society of General Internal Medicine, May 3, 1997, Washington, DC. Correspondence: Jeffrey A. Ferguson, MD, MPH, Richard L. Roudebush VAMC, HSR&D (lIB), 1481 West 10th Street, Indianapolis, IN 46202. Email: [email protected]
302
States despite significant technological advances in its management. For many patients in whom conservative management fails, optimal treatment modalities require the use of invasive cardiac procedures: cardiac catheterization (CC), percutaneous transluminal coronary angioplasty (PTCA), and coronary artery bypass graft (CABG) surgery. Although numerous previous studies suggested that blacks undergo fewer of these invasive cardiac procedures than their white counterparts,1-1O it is not known whether treatment differences are due to overuse among whites, underuse among blacks, neither of these reasons, or both. Criteria for determining invasive cardiac procedure overuse and underuse have been established by researchers at the RAND Corporation in collaboration with the Cardiac Advisory Committee of the State of New York. 11 - 13 Subsequently, these criteria have been used to determine rates of overuse of invasive cardiac procedures within New York State and among institutions participating in the Academic Medical Center Consortium study.14-17 Of importance, these previous studies have not focused on interracial treatment differences, rates of procedure underuse, or procedure use among veteran populations. Our previous retrospective study suggested that interracial differences in cardiac procedure use may have been influenced by relevant comorbidities and disease severity.18 To extend this research, we applied RAND appropriateness criteria to report rates of underuse and overuse of invasive cardiac procedures among black and white patients who were admitted to a veterans hospital for evaluation of cardiovascular disease. Methods Study Site. This study was conducted at the Roude-
bush Veterans Affairs Medical Center, a 400-bed medical-surgical hospital that provides both primary and tertiary care. At the time of this study, this institution provided care for approximately 7,600 hospitalized patients annually. Patients received primary care from approximately 84 house-staff physicians May 1998 Volume 315 Number 5
Ferguson, Adams, and Weinberger
and received cardiology consultation from six cardiology fellows and three faculty cardiologists. The study protocol was approved by the institutional review board at the Indiana University Medical Center, Indianapolis, and the Roudebush Veterans Mfairs Medical Center. PaHent Eligibility and Identification. Eligible inpatients identified by the Department of Veterans Mfairs inpatient administrative database, Patient Treatment File, were discharged between January 1 and December 31,1993, with a primary discharge diagnosis of cardiovascular disease or chest pain (International Classification of Diseases, 9th Revision, Clinical Modification codes, 390-459 or 786.5786.59). Eligibility criteria were male gender and age older than 30 years. 2 Patients who died during their index admissions were eligible for study inclusion. Patients were excluded if they were ineligible for Department of Veterans Affairs care, they had undergone an invasive cardiac procedure within 90 days before index admission, their race was coded as other than black or white, or they resided outside Indianapolis. We excluded patients who were nonlocal residents due to the unavailability of these medical records for chart review and the increased likelihood that these patients had scheduled admissions for cardiac procedures. A random sample of 100 patients per race was selected from a total of 470 eligible patients. For all patients, the index event was defined as first hospitalization for one of the target conditions during the study period. Measures and Procedures. Our primary outcome variable, invasive cardiac procedure use within prespecified periods after the index event (60 days for CC and PTCA, 90 days for CABG), was identified by both computer and chart audit. Chart audit data were considered the "gold standard" if discrepancies occurred. For each relevant cardiac procedure (ICD9-CM procedure codes: CC, 37.21-37.23, 88.5588.57; PTCA, 36.00-36.03, 36.05-36.09; CABG, 36.10-36.19), we recorded its occurrence and date. Due to the small number of patients eligible for PTCA and CABG, we report results for CC procedures only. Chart review was performed by a trained research nurse blinded to the study objectives who used a modified version of the RAND Medical Record Abstraction Form 19 to abstract patient-specific information. Abstracted data included patients' demographic and clinical characteristics (including risk factors for cardiac disease), comorbid conditions and disease severity, response to pharmaceutical therapies, physicians' recommendations for treatment and patients' agreements or refusals, and results of noninvasive and invasive cardiac assessments. A study investigator (JAF) blinded to patients' race and cardiac procedure status recommended patients for discrete cardiac procedure clinical indication catTHE AMERICAN JOURNAL OF THE MEDICAL SCIENCES
egories and assigned their corresponding appropriateness scores, which ranged from 1 to 9, in accordance with published RAND instructions and guidelines. 20 Patient scores were aggregated into three categories: inappropriate (1-3), of uncertain appropriateness (4-6), or appropriate (7-9) for undergoing an invasive cardiac procedure. If more than one clinical indication applied to a patient, the indication for which the procedure was more appropriate was used. Analysis. We used Fisher's exact tests to compare rates ofCC use, recommendations, and refusals. We used chi-square tests to compare aggregated appropriateness ratings between races, followed by descriptive statistics to estimate rates of cardiac procedure underuse and overuse for blacks and whites. Underuse rates were calculated as follows: number of patients who did not undergo a procedure while having an appropriate score divided by all patients who did not undergo a procedure. Overuse rates were calculated as follows: number of patients who underwent a procedure while having an inappropriate score divided by all patients who underwent a procedure. Results
Patients' mean age was 61.8 years and their diagnoses as determined by clinical indication criteria are listed by race in Table 1. Overall, the most common clinical categories were asymptomatic disease or chronic stable angina (38%), followed by unstable angina (19%), miscellaneous diagnoses (17%), and chest pain of uncertain origin (16%). Blacks were more likely to have chest pain of uncertain origin and asymptomatic disease or chronic stable angina, whereas whites were more likely to have unstable angina. Overall, 105 patients (52%) had ratings of inappropriate; 69 (35%) had ratings of uncertain appropriateness; and 26 (13%) had ratings of appropriate (Table 1). Blacks had more ratings of inappropriate and fewer ratings of appropriate than whites (chi-square, P < 0.05) (Table 1). Blacks underwent fewer CCs than whites: 14% versus 41%, respectively (Fishers exact test, OR = 0.23, P < 0.01) (Table 2). Blacks were also offered fewer CCs than whites: 20% versus 42%, respectively (OR = 0.34, P < 0.01) (Table 2). Procedure refusals were more frequent in blacks: 6 of20 recommendations versus 1 of 42 recommendations, respectively (OR = 17.5, P < 0.01) (Table 2). When patients who underwent CC were considered, it was determined that 1 (7%) of 14 black patients had a rating of inappropriate (overuse) compared with 4 (10%) of 41 white patients (Table 3). When patients who did not undergo CC were considered, it was found that 0 (0%) of 86 black patients had a rating of appropriate (underuse) compared with 2 (3%) of 59 whites (Table 4).
303
Interracial CC Appropriateness
Table 1. Frequency of Various Cardiac Procedure Clinical Indication Categories and Appropriateness by Race Blacks Cardiac Procedure Clinical Indication Category
No.
A
Asymptomatic disease or chronic stable angina Unstable angina Chest pain of uncertain origin Acute myocardial infarction Postcoronary bypass Within 12 weeks of myocardial infarction Other cardiac diagnoses* Totals
45 12 18 8 0 0 17 100
0 3 1 1 1 6
Whites
?
No.
A
43 0 17 1
2 9 0 6
1 62
15 32t
30 25 13 11 3 1 17 100
2 12 1 1 1 0 3 20
? 26 1 9 3 1 1 2 43
2 12 3 7 1 0 12 37t
Patients were determined to be appropriate candidates for cardiac catheterization (A), inappropriate candidates for cardiac catheterization (1), or of uncertain appropriateness for cardiac catheterization (?). * Examples include preoperative evaluations, arrhythmias, and unexplained congestive heart failure. t Chi-square test, P < 0.05.
Of those who underwent CC, 7 of 14 blacks subsequently underwent a revascularization procedure (PTCA = 4, CABG = 3) and 17 of 41 whites underwent a revascularization procedure (PTCA = 6, CABG = 11) (data not shown). Discussion Overview. Our study had several important find-
ings. First, despite confirming earlier reports of lower invasive CC procedure use among minority veterans, we found no evidence of discriminatory underuse of this procedure among blacks. In fact, among blacks in our cohort, only one patient underwent care "outside the boundaries" of appropriate care as determined by previously validated RAND criteria; this occurred in a patient who underwent a procedure for which a clinical indication was lacking, an example of clinical overuse. In contrast, we found greater variability of cardiac procedure use among whites in our cohort. Of importance, 10% of whites undergoing CC had an inappropriate score (overuse), whereas 3% of whites not undergoing CC had an appropriate score (underuse). Therefore, these data suggest that previously observed interracial differences in invasive cardiac procedure use may be a
Table 2. Rates of Cardiac Catheterization Use, Recommendations, and Refusals by Race Treatment Variable
Blacks (n = 100)
Whites (n = 100)
Received CC Offered CC Refused CC Not offered CC
14 20 6 60
41 42 1 16
Values were obtained using Fisher's exact tests. CC = cardiac catheterization.
304
function of overuse among whites rather than underuse among blacks. Second, our study underscores the importance of heterogeneity in cardiac disease symptom severity between ethnic groups presenting for evaluation of cardiovascular disease. In general, blacks in our cohort had less severe cardiac disease presentations. Only 6% of black patients had symptom severity that placed them in the category appropriate for undergoing CC, whereas 62% were in the inappropriate category. In contrast, 20% of whites had symptom severity that placed them in the category appropriate for undergoing CC, whereas 43% were in the category meeting criteria making them inappropriate candidates for CC. Previous researchers have documented that although blacks and whites have similar prevalences of coronary artery disease, blacks often present with less severe symptoms and whites have a greater number of diseased arteries found during a subsequent CC. 21 Thus, it is not surprising to find that blacks in our cohort had less severe disease presentations overall, and when found to have disease requiring revascularization, they were more likely to undergo PTCA, whereas whites were more likely to undergo CABG. Third, our study supports earlier reports of more
Table 3. Appropriateness Ratings for Patients Who Received Cardiac Catheterization by Race and Corresponding Rates of Cardiac Catheterization Overuse P Value <0.01 <0.01 <0.01
Appropriateness Rating Inappropriateness Uncertain Appropriate
Blacks (n = 14)
Whites (n = 41)
1 7 6
4 19 18
Overuse by blacks was 7% (1114) and by whites was 10% (4141). May 1998 Volume 315 Number 5
Ferguson, Adams, and Weinberger
Table 4. Appropriateness Ratings for Patients Who Did Not Receive Cardiac Catheterization by Race and Corresponding Rates of Cardiac Catheterization Underuse Appropriateness Rating
Blacks (n = 86)
Whites (n = 59)
Inappropriate Uncertain Appropriate
61 25 0
39 18 2
Underuse by blacks was 0% (0/86) and by whites was 3% (2/59).
procedure refusals among blacks (6/20 [30%]) than whites (1/42 [2%]).5 Of note, all refusals occurred among patients who received a rating of uncertain appropriateness for CC. We cannot infer from our data the underlying mechanisms in patient decision making that would account for this difference. We previously conducted a study using patient focus group methodology that identified more distrust of the medical community by blacks22 ; however, these and additional factors must be more fully explored to address this complex issue in patient care properly. Last, our study provides an example of the inadequacy of an administrative database in making a quality of care assessment. In the absence of critical clinical data such as symptom severity, response to medical therapy, and patient preferences, blacks in our cohort could be perceived as recipients of suboptimal care compared with whites. However, when the clinical data that are necessary for judging the appropriateness of undergoing a cardiac procedure are considered, these interracial treatment differences are consistent with high-quality care and the desire of patients for treatment. Limitations. Our study had several limitations. This investigation was carried out at a single institution and may not be representative of patients and practices present throughout the entire Department of Veterans Affairs system. However, our population demographics and unadjusted cardiac procedure rates were similar to those reported within the Department of Veterans Affairs, suggesting that our institution is not significantly different from others within this healthcare setting. 2 Second, our findings may not be applicable in healthcare settings with financial reimbursement incentives that may influence the use of invasive, costly procedures. Third, our sample size was small. Although we have not reported appropriateness results for PTCA and CABG procedures, repeated analyses combining all three cardiac procedures (n = 255) yielded nearly identical underuse and overuse rates. In addition, our estimates of cardiac procedure overuse are congruent with previously reported rates. 14 - 17 With regard to these estimates of underuse, we are aware of no comparison study investigating CC use. Last, our study design did not allow us to capture data THE AMERICAN JOURNAL OF THE MEDICAL SCIENCES
prospectively. We relied on the accuracy of medical record notes that were not recorded for the purpose of a research study, and we could not directly assess physician or patient decision-making parameters, such as preferences for care. However, the RAND chart abstraction form has undergone rigorous testing and validation to verify its ability to capture information intended for our purpose. 23 Conclusions
In summary, we have contributed to research attempting to understand interracial treatment differences in cardiovascular disease. We were the first to use a validated chart abstraction instrument to determine the appropriateness of CC procedure use among blacks and whites as a potential explanation for previously reported treatment differences. We found that treatment differences in our cohort were not due to underuse of this procedure among blacks but were due in part to modest overuse among whites. Furthermore, we found that whites presented with greater cardiac symptom severity than blacks and that blacks were more likely to refuse recommendations for invasive cardiac procedure use than whites. Additional studies are needed to confirm these findings in other settings and among larger population samples. References 1. Peterson ED, Wright SM, Daley J, Thibault GE. Racial variation in cardiac procedure use and survival following acute myocardial infarction in the Department of Veterans Affairs. JAMA. 1994;271:1175-80. 2. Whittle J, Conigliaro J, Good CB, Lofgren RP. Racial differences in the use of invasive cardiovascular procedures in the Department of Veterans Affairs medical system. N Engl J Med. 1993;329:621-7. 3. Johnson PA, Lee TB, Cook F, Rouan GW, Goldman L. Effect of race on the presentation and management of patients with acute chest pain. Ann Intern Med. 1993; 118:593601. 4. Udvarhelyi IS, Gatsonis C, Epstein AM, Pashos CL, Newhouse JP, McNeil BJ. Acute myocardial infarction in the Medicare population: Process of care and clinical outcomes. JAMA. 1992;268:2530-6. 5. Maynard C, Fisher LD, Passanlani ER, Pullum T. Blacks in the Coronary Artery Surgery Study (CASS): Race and clinical decision making. Am J Public Health. 1986; 76:1446-8. 6. Wenneker MB, Epstein AM. Racial Inequalities in the use of procedures for patients with ischemic heart disease in Massachusetts. JAMA. 1989;261:253-7. 7. Goldberg KC, Bartz AJ, Jacobsen SJ, Krakauer B, Rimm AA. Racial and community factors influencing coronary artery bypass graft surgery rates for all 1986 Medicare patients. JAMA. 1992;267:1473-7. 8. Ayanian JZ, Udvarhelyi IS, Gatsonis CA, Pashos CL, Epstein AM. Racial differences in the use of revascularization procedures after coronary angiography. JAMA. 1993; 269:2642-6. 9. Giles WH, Anda RF, Caspar ML, Escobedo LG, Taylor HA. Race and sex differences in rates of invasive cardiac procedures in US hospitals: Data from the National Hospital Discharge Survey. Arch Intern Med. 1995; 155:318-24. 10. Ford E, Cooper R, Castaner A, Simmons B, Mar M. Coro-
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May 1998 Volume 315 Numbel5