Survival after acute myocardial infarction (SAMI) study: the design and implementation of a positive deviance study

Positive deviance studies combining qualitative and quantitative designs-a mixed-methods approach-can discover strategies to produce exemplary performance. We present the SAMI study, a national positive deviance study to discover hospital strategies associated with lower 30-day hospital risk-standardized mortality rates (RSMRs). There is marked variation across hospitals in 30-day hospital RSMRs for patients with acute myocardial infarction and little information about what accounts for differences in performance. We first conducted a qualitative study of hospitals in the United States (n = 11; 158 key staff) that ranked in the top 5% of RSMRs for each of the 2 most recent years of data (2005-2006 and 2006-2007) from the Centers for Medicare & Medicaid Services at the time of sample selection and in the bottom 5% for contrast, with diversity among hospitals in key characteristics. Using hypotheses generated in this qualitative stage, we constructed a quantitative survey that was administered in a cross-sectional study of acute care hospitals in the United States operating from July 1, 2005, through June 30, 2008, that publicly reported Centers for Medicare & Medicaid Services data for RSMRs during this time. We included hospitals with at least 75 acute myocardial infarction discharges during the 3-year period. Of the 600 hospitals we attempted to contact, 10 had closed, leaving a final sample of 590, of which 537 responded (91%). This type of study, using a positive deviance approach and mixed-methods design, can generate and test hypotheses about factors most strongly associated with exemplary performance based on practices currently in use.