Table 1. Demographic and clinical characteristics of patients by extended-spectrum β-lactamase-producing Enterobacterales infection status, University Hospital Basel, Switzerland, January 2010–December 2016 (n = 376).

Characteristic	Cases (ESBL-positive) (n = 94)		Controls (ESBL-negative) (n = 282)		p valuea
	n	%	n	%
Age (years) (median, IQR)	69	57–76	73	59–81	0.060
Female	48	51	161	57	0.338
Male	46	49	121	43
Ward					0.642
- Medicine	74	79	218	77
- Surgery	9	10	38	13
- Gynaecology	2	2	7	2
- Intensive care unit	9	10	19	7
Source of bacteraemia					0.253
- Urinary tract	47	50	168	60
- Intra-abdominal	12	13	43	15
- Immunosuppressive diseases	12	13	25	9
- Pulmonary	3	3	6	2
- Gynaecologic diseases	2	2	2	1
- Indwelling hardware	4	4	10	4
- Wound infection	3	3	6	2
- Other	0	0	6	2
- Unknown	11	12	16	6

ESBL: extended-spectrum β-lactamase; IQR: interquartile range.

^a p values were calculated by chi-squared or Fisher’s exact test (as appropriate) for categorical variables and by the Student’s t-test or Mann–Whitney U test (as appropriate) for continuous variables. For categorical variables with more than two categories, we present overall p values.