Objectives: To use a human reliability assessment tool to identify commonly occurring errors during myringotomy and ventilation tube (VT) insertion and to quantify the likelihood of error occurrence.
Methods: Error-free task analysis for myringotomy and VT insertion was defined at the outset. Fifty-five consecutive myringotomy and VT insertion procedures were videotaped. The operator was either the senior author (S.S.M.H.) or a trainee in the specialist registrar or senior house officer grade. Three assessors (M.-L.M., M.S.W.L, and S.S.M.H.) blinded to operator identity independently evaluated each procedure. Interobserver agreement was calculated (kappa values).
Results: Twelve potential error types were identified. A total of 87 errors were observed in 55 procedures. In 53% of procedures (n = 29) multiple errors were identified. Seven percent of procedures (n = 4) were error free. The 4 most frequent errors identified were (1) failure to perform a unidirectional myringotomy incision (n = 37; 43%); (2) multiple attempts to place VT (n = 14; 16%); (3) multiple attempts to complete the myringotomy (n = 11; 13%); and (4) magnification setting too high (n = 11; 13%). The human error probability was 0.13. Interobserver agreement as expressed by kappa statistics was high.
Conclusions: Human error identification in this most common of otologic procedures is crucial to future error avoidance. Eliminating the 2 most common errors in this model will halve the human error probability. Extending the role of error analysis to error-based teaching as an educational tool has potential.