Intra-observer and inter-observer variability in two grading systems for oral epithelial dysplasia: A multi-centre...

Area of Science:

• Oral Pathology
• Histopathology
• Oncology

Background:

• Oral epithelial dysplasia (OED) grading is crucial for predicting malignant risk in oral potentially malignant disorders.
• Current OED grading systems suffer from significant inter-observer and intra-observer variability, impacting reliability.

Purpose of the Study:

• To evaluate observer variability in OED grading using the WHO (2005) and a binary system.
• To assess the impact of a simplified two-grade system on OED reporting agreement.

Main Methods:

• A multi-centre study involving six Indian oral pathologists.
• Comparison of OED grading using the WHO (2005) system and a binary system.
• Observer variability assessed using kappa statistics.

Main Results:

• Grouping OED into two grades (no/mild vs. moderate/severe) significantly improved intra-observer agreement (κw = 0.5012) compared to the binary (κ = 0.1563) and WHO (κw = 0.4297) systems.
• Inter-observer agreement was poor to fair across both WHO and binary grading systems, with agreement rates ranging from 35% to 65%.

Conclusions:

• Standardized reporting of OED requires improvement for accurate risk assessment of oral potentially malignant disorders.
• External quality assessment programs are recommended for pathologists reporting OED in India to enhance diagnostic consistency.