Effect of the Six Sigma Protocol on the Time Required to get STEMI Patients to Reperfusion Therapy Via PTCA

Kang, Kyeong Won; Kim, Ok Jun; Choi, Sung Wook; Kim, Eui chung; Park, Yeong Tae; Cho, Yun Kyung; Hwang, Hee Jeong; Ko, Tae I

Abstract

PURPOSE: To minimize the process that acute myocardial infarction (AMI) patients have to go through when visiting the emergency room (ER), and thus to provide prompt reperfusion therapy using the six sigma protocol, a business management renovation strategy to standardize the clinical process.
METHODS
Analysis was done on data obtained both before and after implementation of the six sigma protocol. Data were collected from ST segment elevation myocardial infarction (STEMI) patients who visited the ER between February 2006 and March 2009 and received reperfusion therapy. For statistical analysis used we used an unpaired t-test.
RESULTS
After the six sigma protocol was put into practice, total visiting time was reduced from 124.4+/-76.1 minutes to 91.5+/-50.3 minutes, and the reduction was statistically significant (p<0.0045). Six sigma (6 sigma) means 3.4 PPM, that is, among 1 million cases no more than 3.4 cases should exceed the time limit of 90 minutes from the arrival of the patient to the needle puncture, making the task hard to achieve. sigma score was greatly elevated-from 1.48 sigma to 2.48 sigma and the sigma error rate (the proportion of cases that exceeded 90 min) improved from 62% to 45% .
CONCLUSION
In this study we verified that applying the six Sigma protocol significantly reduced the time to reperfusion therapy for AMI patients. The reduction in time was due to changes in software (developed from the existing system) rather than to hardware improvements such as changes in test facilities or manpower amplification. The entire process, from a patient arriving at the ER until the patient received reperfusion therapy was viewed as one systemic flow and applying the six Sigma protocol to such flow was successful as shown by the result of this study. This shows that the six sigma protocol can be applied to a medical system if configured effectively. Further, this method can be useful not only for AMI patients, but also for many other urgent procedures such as acute cerebral infarction patients who require prompt diagnosis and hemolytic therapy, when the definition of the error rate is corrected according to the specific patients groups.