Objectives: To assess the accuracy and correlation between Colposcopically Directed Biopsy (CDB) and Large Loop Excision of the Transformation Zone (LLETZ) and the influence of age.
Material and Method: A comparative analysis was conducted from the 352 women referred to Rajavithi Hospital from January 1998 to December 2003, to compare between CDB and LLETZ. Correlation was assessed by the percentage of concordance (accuracy), Spearman’s rank correlation coefficient (r) and Kappa statistics (K). A subgroup analysis was performed in women aged ≥ 50 years to evaluate the influence of age on the correlation.
Results: A 66.2% concordance was found between CDB and LLETZ. The correlation and agreement between the two procedures were low (r = 0.32, p < 0.0001; K = 0.24, p < 0.0001). In women aged ≥ 50 years, the accuracy was 60.7% and stronger correlation and agreement were noted (r = 0.50, p < 0.0001; K = 0.31, p = 0.001).
Conclusion: CDB is an inadequate diagnosis tool for Squamous Intraepithelial Lesion (SIL) in woman below 50 years of age. In women aged 50 years or more with satisfactory colposcopy, the accuracy and correlation between two procedures are not compromised.

Keywords: LLETZ, Correlation, Colposcopically directed biopsy