Many therapies for AMI have been shown to lower mortality. After careful review, the AHA and ACC compiles those therapies into published guidelines.2,3
Despite the wide availability of these guidelines, the Institute of Medicine, in the book Crossing the Quality Chasm: A New Health System for the 21st Century, indicated that apparently there was universally low compliance with evidence-based therapies.5
Despite this history of poor performance, recent evidence indicates that adherence to guidelines is beginning to improve11
; however, there is considerable variation, even among “top hospitals.”6,12
A variety of methods for increasing adherence to guidelines have been initiated. These methods use 3 different approaches. The first approach has been to increase the reporting of data. The Centers for Medicare and Medicaid Services began publically reporting data on guideline adherence in 2004. The second approach has been to provide hospitals and physicians with the tools and infrastructure that are necessary to improve guideline adherence. Programs such as the ACC GAP program7
and the AHA GWTG program9
are examples of quality improvement programs that are designed to improve guideline adherence through tools and system redesign strategies. The third approach is to provide incentives to improve guideline adherence. Therefore, a hospital's financial success may be dependent on improved guideline adherence. Lindenauer et al13
showed that financial incentives in a Medicare “pay-for-performance” demonstration project can increase guideline adherence.
In the present study, a number of hospital characteristics were associated with improved adherence to published guidelines. Centers with higher volume of AMI, academic medical centers, and centers in the northeastern United States all demonstrated a significantly higher adherence. These findings are consistent with those of Bradley et al,14
who also demonstrated that higher-volume centers adhere better to the AMI guidelines.
However, because there are many factors that play a role in treating patients with AMI, it would be inaccurate to imply that volume alone leads to better adherence. In fact, the findings of our study are consistent with those of other studies that demonstrated that variables such as teaching status and region (Northeast) can predict higher guideline adherence.6,14
This variation emphasizes the complexity and team approach to AMI care. The complexity of guideline adherence was emphasized in a study by Pearson et al15
that showed that 95% of physicians questioned knew the National Cholesterol Education Program guidelines; however, only 18% of high-risk patients were treated according to the guidelines. Excellent guideline adherence requires a systematic, coordinated program involving the entire medical team using tools such as care pathways and preprinted order sets.
Our study suggests that the GWTG-CAD program was able to encompass all these needs and was associated with improved guideline adherence. It is one of the first studies to demonstrate that a quality improvement program is independently associated with increased adherence using an external, concurrent national database. The small absolute differences in quality observed in this study may be attributable to many factors. National adherence to quality measures is increasing owing to public reporting, payfor-performance projects, and participation in other quality improvement programs. As certain measures were at levels above 90% in HC, a “ceiling effect” may exist, making further improvements in adherence more difficult. It is possible that a study limited to poor-performing hospitals would show much more dramatic improvements. Although the improvements in adherence observed in our study were small in absolute terms, with more than 1 million patients hospitalized with AMI each year, these differences in performance would still translate to tens of thousands of more patients treated with recommended therapies each year if all US hospitals provided the same level of performance as those of GWTG-CAD hospitals.
LaBresh et al8
demonstrated that the GWTG-CAD program was associated with increased adherence to smoking cessation counseling, lipid treatment, and β-blocker, aspirin, and ACE inhibitor therapy as well as cardiac rehabilitation enrollment. The GWTG-CAD program uses an infrastructure of data collection and rapid improvement cycles. Therefore, data and individual hospital improvement systems are revised periodically using a “plan, do, study, act” approach, as described by Deming.16
Similar quality improvement programs have demonstrated improved guideline adherence over time on a smaller scale. The Cardiac Hospitalization Arteriosclerosis Management Program of UCLA Medical Center, Los Angeles, California, reported increased adherence in aspirin, β-blocker, ACE inhibitor, and statin treatment adherence when the preimplementation (1992–1993) and the postimplementation (1994–1995) years were compared.17
Similarly, the ACC GAP program showed improvement in aspirin and ACE inhibitor use on discharge and in tobacco cessation counseling.7
Both of these programs were limited to a small number of hospitals. The present study has demonstrated that a quality improvement program can be successfully implemented in a large number of hospitals on a national basis.
Guidelines are based on therapies that have been proved to reduce mortality. The present study did not evaluate whether improvement in guideline adherence was associated with improved mortality, as previous studies have already demonstrated this association. The Cardiac Hospitalization Arteriosclerosis Management Program was associated with improved reinfarction rates and a 2.7% reduction in 1-year mortality.17
In multivariate analysis, the GAP program was associated with a 26% reduction in 30-day mortality and a 22% reduction in 1-year mortality.18
Further study is necessary to determine if the GWTG-CAD program results in improved outcomes.
Despite the increase in technology and treatments that are available to patients, cardiovascular disease remains the leading cause of death in the United States. The AHA has set a goal to reduce death due to cardiovascular disease by 25% by 2010.1
Adherence to evidence-based guidelines remains a critical component in achieving this goal. In fact, the AHA/ACC guidelines for secondary prevention in patients with CAD recommends participation in a quality improvement program, such as GAP or GWTG.3
There are several limitations to this study. The AMI volume was estimated by using the number of cases that were eligible for aspirin therapy on admission. The estimation is likely accurate because this parameter represented the largest category of eligible patients. It is possible that contraindications to aspirin use could have reduced the number of patients in the eligible category, resulting in an underestimation of AMI volume. We were unable to evaluate other important quality-of-care metrics, including use of lipid-lowering therapy and referral to cardiac rehabilitation, as this information is not collected in the HC database. Reperfusion measures were optional at the time these data were analyzed. They may have been selectively reported, which could have influenced the findings. Also, in 2004, the HC measure for percutaneous coronary intervention to occur was within 120 minutes. The GWTG-CAD standard was 90 minutes. While this measure is not identical in both groups, higher-quality hospitals would be expected to have better adherence at both 90 and 120 minutes. Our study did not control for the patient case mix; however, given the broad nature of the GWTG-CAD program, it is unlikely that significant differences in the types of patients occurred. Based on these data, it is not clear whether participation in the GWTG-CAD program resulted in improved adherence or whether higher-quality hospitals participate in GWTG-CAD. This concern is mitigated by the observation that improved adherence occurred in HC core measures for CAD but not for pneumonia care in GWTG-CAD hospitals. The HC data relied on self-reporting by hospitals as opposed to abstraction from medical records by independent operators; however, random sample charts were independently validated by the Centers for Medicare and Medicaid. This study was not a randomized clinical trial, and the improvements in quality measures may have been influenced by factors other than GWTG-CAD participation. Despite multivariable adjustment, we cannot exclude the possibility that residual measured and unmeasured confounding might account for these observations.
In conclusion, GWTG-CAD is the largest hospital-based program dedicated to quality-of-care improvement for patients hospitalized with CAD in the United States. Hospitals participating in GWTG-CAD demonstrated improved adherence to national guideline-recommended therapies compared with other US hospitals that were publicly reporting data at the same time. The results of this study and other health care improvement programs suggest that the quality of care provided to patients with cardiovascular disease can be further enhanced by using Web-based patient data submission and performance feedback as well as collaborative care models and by concentrating on those processes of care that have proved to improve outcomes.