Association of a multiple-step action with cervical lymph node yield of oral cancer patients in an Asian country

BMC Oral Health

Table 5 Difference-in-differences analysis for lymph node yield and regional recurrence

	Lymph node yield		Regional recurrence
	Coefficient*	p value	Coefficient** (%)	p value
All patient
Time effect	1.82	0.291	− 2.4	0.488
Difference-in-difference (net) impact	13.78	< 0.001	− 3.9	0.448
END
Time effect	3.84	0.057	5.1	0.205
Difference-in-difference (net) impact	9.68	0.001	− 11.6	0.072
RND
Time effect	− 0.61	0.849	− 11.7	0.081
Difference-in-difference (net) impact	19.25	< 0.001	5.6	0.534

END, elective neck dissection; RND, radical neck dissection
^*Regressions controlled for sex, age, differentiation, tumor sub-site (tongue vs non-tongue), cT, and cN
^**Regressions controlled for sex, age, cT, cN, differentiation, tumor sub-site (tongue vs non-tongue), margin status, and adjuvant treatment modality (without vs with adjuvant treatment)

ISSN: 1472-6831