The interobserver agreement of ECG abnormalities using Minnesota codes in people with type 2 diabetes

Objectives To assess the interobserver agreement in categories of electrocardiogram (ECG) abnormalities using the Minnesota Code criteria. Methods We used a random sample of 180 ECGs from people with type 2 diabetes. ECG abnormalities were classified and coded using the Minnesota ECG Classification. Each ECG was independently rated on several abnormalities by an experienced rater (rater 1) and by two cardiologists (raters 2 and 3) trained to apply the Minnesota codes on four Minnesota codes; 1-codes as an indication for myocardial infarction, 4 en 5-codes as an indication for ischemic abnormalities, 3-codes as an indication for left ventricle hypertrophy, 7-1-codes as an indication for ventricular conduction abnormalities, and 8-3-codes as an indication for atrial fibrillation / atrial flutter. After all pairwise tables were summed, the overall agreement, the specific positive and negative agreement were calculated with a 95% confidence interval (CI) for each abnormality. Also, Kappa's with a 95% CI were calculated. Results The overall agreement (with 95% CI) were for myocardial infarction, ischemic abnormalities, left ventricle hypertrophy, conduction abnormalities and atrial fibrillation/atrial flutter respectively: 0.87 (0.84-0.91), 0.79 (0.74-0.84), 0.81 (0.76-0.85), 0.93 (0.90-0.95), 0.96 (0.93-0.97). Conclusion This study shows that the overall agreement of the Minnesota code is good to excellent.

Automated summary

The study demonstrates good to excellent interobserver agreement in categorizing ECG abnormalities using the Minnesota Code criteria.