Predicting acute myocardial infarction (AMI) 30-days mortality: Using standardised mortality ratio (SMR) as the hospital performance measure

Background: A standardised mortality ratio (SMR) is the hospital observed mortality divided by its predicted mortality and has been used as an indicator to monitor hospital performance.Objectives: This study developed a model that predicted 30-day mortality for acute myocardial infarction (AMI) and compared the SMR among 41 Malaysian public hospitals using statistical process control charts.Methods & results: Data from referral centres and specialist hospitals with cardiology services were analysed. Both referral centres and specialist hospitals had comparable mortality, except for Hospitals A and B, which the study considered outliers. Two-thirds of the remaining hospitals had an SMR of above one (SMR 1.05-1.51), but the indices were still within the expected variations.Conclusion: The SMR coupled with a funnel plot and variable life adjusted display (VLAD) can identify hospitals with potentially higher than expected mortality rates.