Development and validation of an endoscopic ear surgery classification system

Abstract

Objectives/hypothesis: To design and validate a classification system for endoscopic ear surgery.

Study design: Validation study.

Methods: A classification system was devised that quantifies use of the endoscope during middle ear surgery. Otologic operative reports were reviewed by attending surgeons and trainees. A power analysis was performed to determine number of cases needed to review. The following categories were used: class 0 is defined by using the microscope only; class 1 describes the use of endoscope for inspection without dissection; and class 2 describes mixed use of the endoscope and the microscope. It is further subdivided into 2a and 2b, where the endoscope is used for less than 50% of dissection and more than 50% of dissection, respectively. Class 3 describes the use of the endoscope for the entire surgery. Fifty cases were reviewed by three attending otologic surgeons, one resident, and one medical student.

Results: Weighted Cohen's Kappa for inter-rater agreement between the two institutional surgeons was 0.79 (95% bias corrected [BC] confidence interval [CI]: 0.58-0.93). Agreement between the external surgeon and the two institutional surgeons was 0.77 (95% BC CI: 0.58-0.89) and 0.76 (95% BC CI: 0.57-0.88). Weighted Kappa between institutional surgeons and a resident was 0.73 (95% BC CI: 0.53-0.88) and 0.62 (95% BC CI: 0.38-0.80), and between institutional surgeons and a medical student was 0.75 (95% BC CI: 0.56-0.89) and 0.70 (95% BC CI: 0.49-0.85).

Conclusions: There was substantial inter-rater agreement. This classification system can be used as a simple and reliable tool to describe the extent to which an endoscope was used during ear surgery.

Level of evidence: NA. Laryngoscope, 128:967-970, 2018.

Keywords: Endoscopic ear surgery; classification; validation.