Table 4.

Unadjusted and adjusted association between LN yield (≥ 10 vs. < 10) and detection of LNM in T1 CRC

	Odds ratio (95% CI)	P value	Maximum (97.5th percentile) IPWc	Post-IPW c-indexd	Complete case (%)e	Observed data points (%)f
Unadjusted	2.04 (1.30–3.20)	0.002	–	–	100	100
Adjusted for clinical factorsa	2.09 (1.28–3.42)	0.003	5.1 (4.2)	0.48	88	98
Adjusted for clinical and histological factorsb	2.27 (1.39–3.69)	0.001	6.6 (4.3)	0.49	18	85

CI confidence interval, CRC: colorectal cancer,IPW inverse probability weighting, LN lymph node, LNM lymph node metastasis

^aAge (continuously), sex (male vs. female), tumor location (right colon vs. left colon vs. rectum), tumor size (continuously), and tumor morphology (pedunculated vs. non-pedunculated)

^bAge (continuously), sex (male vs. female), tumor location (right colon vs. left colon vs. rectum), tumor size (continuously), tumor morphology (pedunculated vs. non-pedunculated), invasion depth (deep vs. superficial submucosal invasion), lymphovascular invasion (presence vs. absence), and differentiation grade (poor vs. moderate vs. good)

^cThe maximum weight of a single patient used in the IPW adjusted analysis to obtain balance in potential confounders. This is a quality instrument to assess whether a single or a few cases influence the risk estimate excessively. As a rule of thumb this should be lower than 10% of the analyzed dataset (i.e., smaller than 100)

^dThis is an estimate of the balance of confounders after adjusting by inverse probability weighting (0.50 complete balance, 1.00 complete unbalance)

^ePercentage of complete cases (i.e., cases with no imputed values for any of the evaluated variables of that analysis). Note: analysis was performed on the imputed dataset concerning all cases

^fPercentage of available data points before imputation. Note: analysis was performed on the imputed dataset concerning all cases