Measure of inter-rater agreement for categorical data; accounts for chance agreement
Expansion
Cohen’s Kappa
Purpose
Quantifies observer agreement beyond chance
Clinical Context
Kappa equals (observed agreement minus expected agreement) divided by (1 minus expected agreement). Kappa greater than 0.75 indicates excellent agreement. Preferred for categorical data (positive, negative, indeterminate).
Related Terms
- Intraclass correlation coefficient
- Agreement
Key Points
- Kappa 0.81 to 1.0 excellent, 0.61 to 0.80 good, 0.41 to 0.60 moderate, 0.21 to 0.40 fair, less than 0.20 poor agreement