Table 1.

Comparison of incidence rate estimation and treatment effect evaluation per linkage level

Treatment by Cancer Type	Incidence rate per 100,000 person-years (95% CI)				Adjusted HR* (95% CI)
	DBIII	DBDII	Effect size		DBIII	DBDII	Effect size
Thyroid cancer
No Vitamin D	1.3 (1.2–1.4)	1.5 (1.5–1.6)	0.02		1 (Reference)	1 (Reference)
Vitamin D	1.1 (0.9–1.2)	1.4 (1.3–1.5)	0.00		0.83 (0.70–0.99)	0.83 (0.75–0.91)	0.00
Gastric cancer
Total gastrectomy	2.6 (2.4–2.9)	3.2 (3.0–3.4)	0.02
Subtotal gastrectomy	2.1 (2.0–2.2)	2.7 (2.6–2.8)	0.04		1.24 (1.10–1.39)	1.26 (1.15–1.37)	0.01
ESD/EMR	1.8 (1.6–1.9)	2.3 (2.2–2.5)	0.02		1 (Reference)	1 (Reference)
Breast cancer
Non-HT	2.2 (2.1–2.4)	2.2 (2.1–2.4)	0.00		1 (Reference)	1 (Reference)
AI-only	3.5 (3.2–3.7)	3.6 (3.4–3.8)	0.00		0.95 (0.85–1.07)	1.03 (0.94–1.14)	0.04
TAM-only	1.2 (1.1–1.3)	1.2 (1.1–1.3)	0.00		0.77 (0.69–0.87)	0.80 (0.73–0.89)	0.02
AI + TAM	1.3 (0.6–2.4)	2.9 (1.9–3.9)	0.01		0.42 (0.21–0.85)	0.94 (0.66–1.35)	0.44
Prostate cancer
Non-ADT	1.3 (1.2–1.4)	1.9 (1.8–2.1)	0.05		1 (Reference)	1 (Reference)
ADT	4.1 (3.8–4.5)	5.4 (5.1–5.7)	0.04		2.14 (1.85–2.48)	1.96 (1.76–2.17)	0.05
Cervical cancer
Non-RT	0.4 (0.3–0.5)	0.5 (0.4–0.6)	0.01		1 (Reference)	1 (Reference)
RT	1.1 (0.8–1.6)	1.0 (0.7–1.3)	0.01		2.62 (1.63–4.23)	1.80 (1.18–2.73)	0.21

Abbreviations: ADT: androgen deprivation therapy; AI: aromatase inhibitors; CI: confidence interval; DB: data base; DII: directly identifiable information; III: indirectly identifiable information; ESD: Endoscopic submucosal dissection; EMR: Endoscopic mucosal resection; HR: hazard ratio; HT: hormone therapy; III: indirectly identifiable information; RT: radiation therapy

*Adjusted HR was computed after all covariates excluding the treatment group variable