Narrow band imaging improves observer reliability in evaluation of upper aerodigestive tract lesions

Objectives/Hypothesis: Visualization by endoscopy is essential in the diagnosis of upper aerodigestive tract lesions. Recent studies showed that narrow band imaging (NBI) increases the diagnostic potential of conventional white light imaging (WLI) by highlighting the superficial vessels. The objective of this study was to evaluate whether the use of NBI would influence inter- and intraobserver agreement while making diagnostic decisions using rigid endoscopy of the upper aerodigestive tract. Study Design: Retrospective study. Methods: One hundred routinely collected pictures of laryngeal, hypopharyngeal, and oropharyngeal lesions were used. Rigid endoscopies and patient data collection were performed according to standard protocol. Twelve observers, grouped in different levels of experience, assessed all lesions twice with a 2 to 4 week interval. Fleiss and Cohen's kappa (kappa) values were calculated to assess inter- and intraobserver agreement. Results: Overall interobserver agreement increased from kappa = 0.34 to kappa = 0.40 by adding NBI to WLI (WLI and WLI + NBI, respectively). In experienced observers, an improvement from kappa = 0.39 to kappa = 0.43 was observed; in less-experienced observers an improvement from kappa = 0.30 to kappa = 0.37 was observed. Overall intraobserver agreement increased from moderate (kappa = 0.54) to substantial (kappa = 0.63) with addition of NBI. lntraobserver agreement for less -experienced observers improved remarkably when WLI was combined with NBI (kappa = 0.51 vs. kappa = 0.67). Conclusions: Addition of NBI during rigid endoscopies of the upper aerodigestive tract led to improvement of both inter- and intraobserver agreement.