Gregory PM, Rhoads GG, Wilson AC, O’Dowd KJ, Kostis JB.
Impact of availability of hospital-based invasive cardiac services on racial differences in the use of services.
Am Heart J 1999;138(3 Pt 1):505-17. (Comment in: Am Heart J 1999;138(3 Pt 1):396-9.)

This study found that black patients in New Jersey acute care facilities were more likely to be admitted to hospitals where catheterization was available (52.2% of the blacks were admitted to such hospitals versus 46.1% of the whites) and where revascularization procedures – percutaneous transluminal coronary angioplasty (PCTA) and coronary-artery bypass surgery (CABG) – were available (50.3% of the blacks versus 41.8% of the whites).

However, blacks were less likely to undergo invasive procedures within 90 days of hospitalization: 62.4% of blacks versus 69.8% of whites received catheterization; PCTA, 21.0% of blacks versus 28.9% of whites; CABG, 10.4% of blacks versus 15.5% of whites; PCTA or CABG, 30.1% of blacks versus 42.9% of whites; and PCTA or CABG among those who received catheterization, 45.9% of blacks versus 58.1% of whites. For both racial groups, the use of procedures was more frequent during the 90-day follow-up when more services were available at first admission.

After adjusting for age, sex, health insurance status, clinical characteristics, and availability of services, the following odds ratios (OR, 95% confidence intervals) were reported for receiving procedures during 90-day follow-up:
OR for catheterization for blacks under 65 years versus whites=0.74 (0.61, 0.90)
OR for catheterization for blacks over 65 years versus whites=0.68 (0.36, 0.83)
OR for PTCA/CABG for blacks under 65 years versus whites=0.63 (0.52, 0.76)
OR for PTCA/CABG for blacks over 65 years versus whites=0.69 (0.54, 0.86)
OR for PTCA/CABG for blacks under 65 years who received catheterization=0.67 (0.54, 0.84) and OR for PTCA/CABG for blacks over 65 years who received catheterization =0.82 (0.61, 1.12).

For patients under 65 years, availability of cardiac services at first admission was associated with the racial differences in revascularization. The authors suggest that “it seems possible that some of the racial disparities in procedure use after AMI might diminish if availability of invasive cardiac services were increased.” Additionally, since blacks were less likely to be readmitted over the year after initial hospitalization, the authors suggest that the racial pattern in service use might also be explained partially by the intensity of treatment after initial hospitalization.

Possible reasons for racial differences were listed but could not be tested with the data in this study. Those listed included physician referral, patient preferences, physician-patient communication, and racial bias. It should be noted that overuse in cardiac service among white patients is another possibility.

There were no significant race differences in one-year mortality, but there was a trend for a higher mortality rate for blacks under 65 years compared with whites. The power of this study to find a statistically significant difference was low (43%). “It is plausible that outcomes other than death (quality of life and financial status) might have been different for blacks than for whites.”

Sheifer SE, Schulman KA.
Racial differences in the use of invasive cardiac procedures: A continuous quality improvement approach.
American Heart Journal 1999; 138 (3):398-399.

(Editorial in response to Gregory et al.)

The authors outline three potential explanations for the racial differences found in use of invasive procedures for patients with cardiovascular disease. First, availability of services and intensity of treatment after the initial hospitalization might partially, but not fully, explain the racial patterns. Second, socioeconomic issues like insurance coverage might be important. Third, interactions between patient and physician, patient and health care system, and prejudices that might influence physician decision-making are likely to help explain the observed racial differences.

“The challenge now is to modify data collection efforts to gather information on several of the more complex issues that may underlie racial differences in the use of invasive cardiac procedures.”

Suggestions for improved data collection in administrative data sets include:
1. Additional clinical data - track the intensity of post-myocardial infarction care, the frequency of transfers to a second institution for procedures, and the frequency of post hospitalization visits; physicians could complete care maps; data on contraindications for surgery and severity of illness could be recorded; and results of other objective clinical tests could be included in data set.
2. Additional socioeconomic data - services covered by insurance for each patient.
3. Data on physician-patient interactions - patients’ like/trust of their physicians, sufficiency of are procedure explanations; patients’ personal beliefs regarding medical procedures.