In the mid-1990s, several studies demonstrated clear disparities in receipt of recommended AMI treatments between rural and urban Medicare beneficiaries, with small rural and isolated small rural hospitals least likely to offer most recommended care in both adjusted and unadjusted analyses.9–11
Also notable were deficits in receipt of the most basic recommended AMI treatments at both urban and rural hospitals. This study’s reexamination of rural-urban differences in AMI care 6 years later suggests overall improvement in several quality measures. Additional good news is that admissions to large rural hospitals received virtually equivalent care to admissions to urban hospitals. However, small rural and isolated small rural hospitals were still the least likely to offer most recommended AMI treatments, though adjusted analyses demonstrated only a few disparities in prescription of recommended discharge medications between these rural and urban hospitals.
In 2000–2001, the recommended treatment used most frequently in the care of AMI admissions was aspirin, both within the first 24 hours (76.4%–83.0% depending on hospital geographic area) and on hospital discharge (64.7%–82.0%). With only about half of AMI admissions receiving early aspirin in the mid-1990s,9
receipt rates between 76.4% and 83.0% in 2000–2001 represent an overall increase in early aspirin use of 1.5 times that of the earlier period. In the mid-1990s, small rural and isolated small rural hospital admissions were significantly less likely to receive aspirin at admission and discharge than urban admissions, while by 2000–2001, the only rural-urban disparity in aspirin use was at discharge among isolated small rural hospital admissions. This is a significant success story for the quality improvement programs working with patients, physicians, and hospitals to disseminate the guidelines for simple and effective treatments such as aspirin.
Beta-blocker prescription at hospital discharge also improved in most geographic areas over time. In the mid-1990s, about half of eligible AMI admissions received beta-blockers at discharge,9
compared to between 59.9% and 69.2% of AMI admissions to urban, large rural, and small rural hospitals in 2000–2001. There was still room for improvement in receipt of this treatment, however, especially in isolated small rural hospitals, where there was no improvement in discharge beta-blocker prescription over time. Notably, there was no rural-urban disparity in discharge beta-blocker prescription in the mid-1990s. However, because urban hospital admissions had substantial increases in discharge beta-blocker prescription, significant rural-urban disparities in this treatment developed by 2000–2001.
Of interest, in the adjusted analyses of 2000–2001 data, the disparities between small rural and isolated small rural hospitals and urban hospitals were in discharge medication prescription. Discharge medications may reflect physician discretion to a greater degree than other treatments, which may be directed by emergency room or hospital protocols. Emergency room and hospital systems may be influenced more easily than individual physicians.
An important finding is the essentially equivalent care received in large rural and urban hospitals. One contributing factor may be the higher volume of AMI patients at large rural hospitals. The median average daily census of large rural hospitals has been reported at 49, compared to 18 for small rural hospitals and 10 for isolated small rural hospitals.9
Studies have shown that hospitals with higher AMI patient volumes have lower mortality rates and are more likely to provide guideline-recommended care.20,21
However, these studies have demonstrated that overall, rural hospitals had lower survival and lower likelihood of providing guideline-recommended AMI care even after controlling for AMI patient volume, suggesting that other characteristics contribute to AMI care processes and outcomes in rural hospitals.
This project is limited by the age of its data, though it has used the richest national data sources available on AMI care in rural hospitals. However, several quality improvement projects, such as the AHA’s “Get With The Guidelines” program,22
became widely available shortly before this study’s data were gathered. Thus, changes in adherence to AMI care guidelines in rural and urban hospitals may not be reflected in these findings. We found 1 study using recent data to examine differences in quality between a limited set of rural critical access hospitals and urban hospitals, and its findings were consistent with this study’s findings.23
Although our study database included a full range of clinical variables, there are data limitations. First, we could not measure the severity of the patients’ comorbidities. This and other unmeasured factors, such as patient preference or functional status, could influence our study findings, though all patients in our analyses were screened as ideally eligible for these treatments, and published guidelines suggest they should be receiving this care. Second, timing of reperfusion (percutaneous transluminal coronary angioplasty, thrombolysis) was missing from many records, making it impossible to examine a reperfusion outcome. Third, the data did not include hospital characteristics such as size or volume, so we were unable to explore the relationship between hospital volume, rural-urban location, and our study outcomes. Another study limitation is that the small number of study patients in the isolated small rural hospitals could result in a lack of statistically significant findings despite clinically significant outcome differences (type II error).
Our comparison of 1995–1996 and 2000–2001 data must be interpreted with caution because of differences in AMI case ascertainment in the 2 time periods. In addition, the 2000–2001 data required weighting, while 1995–1996 data did not, and there may be some error related to our weighting scheme. The consistency of our data with other published AMI treatment rates is reassuring, however.
This study supports the need for continued monitoring of guideline adherence in caring for AMI patients. Many simple, evidence-based guidelines that can improve AMI outcomes are not adequately implemented. In small rural and isolated small rural areas, special attention should be paid to identifying and addressing barriers to underutilized, life saving AMI care such as aspirin and beta-blockers at discharge. To improve care for AMI patients, we need to explore the strategies used by institutions with the greatest improvements. If best practices in quality improvement can be identified, efforts to translate these practices to the broadest range of institutions and providers can be mounted, ensuring that individuals with AMI receive the highest quality care regardless of geographic location.