Methods:

The study investigators conducted a cluster randomized, stepped-wedge clinical trial on patients presenting with an acute myocardial infarction (AMI) between November 10, 2014, and November 9, 2016, in 63 hospitals in a southern Indian state, with a last date of follow-up of December 31, 2016. The investigators randomly selected hospitals in a one-way crossover from the control group to the intervention group during five predefined steps over the study period. The hospitals provided either usual care (control group; n = 10,066 participants [step 0: n = 2,915; step 1: n = 2,649; step 2: n = 2,251; step 3: n = 1,422; step 4; n = 829; step 5: n = 0]) or care using a quality improvement tool kit (intervention group; n = 11,308 participants [step 0: n = 0; step 1: n = 662; step 2: n = 1,265; step 3: n = 2,432; step 4: n = 3,214; step 5: n = 3,735]) that consisted of audit and feedback, checklists, patient education materials, and linkage to emergency cardiovascular care and quality improvement training. The primary outcome was the composite of all-cause mortality, re-infarction, stroke, or major bleeding using standardized definitions at 30 days. Secondary outcomes included the primary outcome’s individual components, 30-day cardiovascular mortality, medication use, and tobacco cessation counseling. The authors utilized mixed-effects logistic regression models to account for clustering and temporal trends.