Table 3.

Relative Effectiveness of Ablation to Prevent Progression of LGD to HGD or Cancer in the Full Cohort and Subgroups

	Hazard Ratio (95% CI)	P value	Adjusted Hazard Ratio (95% CI)*	P value
Risk of Progression After RFA	0.08 [0.01–0.61]	0.02	0.06 [0.008–0.48]**	0.008
Sensitivity Analysis, Variable Tested on Effect of RFA
Only patients with LGD diagnosed from 2006 to end of study period (excluded all cases diagnosed before 2006)#			0.09 [0.01–0.73]	0.02
Flat LGD (excluded all patients with nodularity)¶			0.10 [0.01–0.76]	0.03
Progressors after >1 year (excluded all patients who progressed within the 1st year in surveillance group)^			0.13 [0.02–0.95]	0.04

^*Cox proportional hazard model after adjusting for incident diagnosis, confirmation with second pathology specimen, and multifocality. Incident diagnosis and confirmed LGD (with second specimen) were both confounders on progression and remained in the final model.

^**Year of diagnosis was not found to be an effect modifier nor a confounder. aHR=0.05; 95% CI, 0.007 – 0.43; P = 0.006 after adjusting for year of diagnosis in addition to incident diagnosis, confirmed with second pathology, and multifocality.

^#Sensitivity analysis on time of diagnosis and follow-up after excluding patients who had LGD diagnosed before 2006 (0/5 RFA and 27/89 surveillance progressed for those diagnosed before 2006). Of patients diagnosed in or after 2006, 1/40 RFA and 9/36 surveillance progressed.

^¶Sensitivity analysis on flat LGD after excluding patients who had presence of nodularity on index endoscopy. Of patients with flat LGD, 1/42 RFA and 29/112 surveillance progressed. 18.6% of the patients with flat, unifocal LGD progressed in the surveillance group.

^{^}Sensitivity analysis on early progressors. Of patients with at least one year follow-up and excluding patients in surveillance who progressed within the first year from initial surveillance, 1/33 RFA and 20/92 surveillance progressed.