Table 3.

Sensitivity analyses.

Category	No. of persons at risk	No. of deaths	HR (95% CI)	P value
Disease-specific survival considering competing event
No cholera vaccine	1194	90	–	–
Cholera vaccine use	603	28	0.55 (0.37–0.81)	0.0026
Overall survival after 1 year
No cholera vaccine	1180	104	–	–
Cholera vaccine use	597	33	0.57 (0.38–0.88)	0.0101
Disease-specific survival after 1 year
No cholera vaccine	1180	72	–	–
Cholera vaccine use	597	23	0.56 (0.33–0.95)	0.0323
Disease-specific survival regarding cholera vaccine use before breast cancer diagnosisa
No cholera vaccine	1983	123	–	–
Cholera vaccine use	998	45	1.04 (0.66–1.64)	0.8751
Disease-specific survival after antimalarial medicationb
No antimalarial medication	873	48	–	–
Antimalarial medication	444	18	1.14 (0.57–2.29)	0.7141
Disease-specific survival in patients with stages I and II
No cholera vaccine	1166	78
Cholera vaccine use	589	26	0.59 (0.41–0.91)	0.0271
Disease-specific survival in patients with hormone therapy
No cholera vaccine	892	56
Cholera vaccine use	452	20	0.60 (0.34–1.04)	0.0711

^aNumber of breast cancer patients with pre-diagnostic use of cholera vaccine was 1013. Similar matching conditions were performed and 998 exposed patients were paired with 1983 unexposed patients.

^bNumber of breast cancer patients with post-diagnostic use of antimalarial medication was 598, among which 468 were without cholera vaccine administration. Similar matching conditions were performed for the exposed patients. In the final matched setting, there were 444 patients exposed to post-diagnostic use of antimalarial treatment as well as 873 patients without.