Table 1.

Characteristics of matched breast cancer patients diagnosed from 2005 to 2014.

Characteristics	No use		Cholera vaccine use		P value for Chi-square test
	N	%	N	%
Age at diagnosis (years)
≤65	954	79.9	482	79.9	0.9864
>65	240	20.1	121	20.1
Year of diagnosis
2005–2010	944	79.1	477	79.1	0.9833
2011–2014	250	20.9	126	20.9
Birth country
Sweden	1105	92.6	556	92.2	0.9651
Other European countries	78	6.5	41	6.8
Non-European countries	11	0.9	6	1.0
Education level, years
1–9	99	8.3	51	8.5	0.9912
10–11	440	36.8	221	36.6
≥12	655	54.9	331	54.9
Disposable income
Lowest	149	12.5	76	12.6	0.9456
Middle–low	230	19.3	115	19.1
Middle–high	323	27.0	162	26.9
Highest	489	41.0	247	41.0
Missing value	3	0.2	3	0.5
Place of residence
Big cites	630	52.8	321	53.2	0.7158
Southern Sweden	338	28.3	177	29.4
Northern Sweden	226	18.9	105	17.4
Comorbiditya
No	1031	86.4	519	86.1	0.8713
Yes	163	13.6	84	13.9
Aspirin use
No	993	83.2	512	84.9	0.1205
Yes	201	16.8	91	15.1
Clinical stage
I	413	33.1	239	39.6	0.1538b
I	750	62.8	352	57.4
III	24	2.0	8	1.3
IV	7	0.6	4	0.7
Hormone therapyc
No	281	23.5	147	24.4	0.6917
Yes	913	76.5	456	75.6
Total	1194	100	603	100

^aDiseases for the calculation of Charlson Comorbidity Index considered: myocardial infarction, congestive heart failure, peripheral vascular disease, cerebrovascular disease, dementia, chronic pulmonary disease, rheumatic disease, peptic ulcer disease, mild liver disease, diabetes, hemiplegia or paraplegia, renal disease, any malignancy (including lymphoma and leukaemia, except malignant neoplasm of skin), moderate-to-severe liver disease, metastatic solid tumour and AIDS/HIV.¹⁵

^bFisher Exact test was performed. Matching variables included year of diagnosis, age at diagnosis (5-year gap), education level, comorbidity (yes or no), income and birth country. One vaccinated patient was matched with at most two patients without vaccine use. In the final regression model, place of residence, use of aspirin and clinical stage were adjusted.

^cHormone therapy included anti-oestrogens (ATC, L02BA), aromatase inhibitors (L02BG) and gonadotropin-releasing hormone analogues (L02AE).