. 2020 Jul 31;9:120. doi: 10.1186/s13756-020-00780-z

Table 3.

Risk factors for insufficient reduction of microbial skin counts after two paints of preoperative skin antisepsis

Variable	Level	Crude^a OR	Crude^aP-value
Age^b	Per 1-year increase	1.0 (1.0─1.1)	0.3
Sex	Female	1	0.2
Sex	Male	0.3 (0.04─1.8)	0.2
BMI^b	Per 1-kg/m² increase	1.0 (0.8─1.2)	0.2
Diabetes mellitus^c	No	1	0.3
Diabetes mellitus^c	Yes	2.6 (0.3─16.4)	0.3
Antimicrobial treatment prior to surgery^d	No	1	0.2
Antimicrobial treatment prior to surgery^d	Yes	3.8 (0.2─28.0)	0.2
Adequate antimicrobial prophylaxis^e	No	1	Not estimable
Adequate antimicrobial prophylaxis^e	Yes	─	Not estimable
Type of surgery	Cardiac	1	0.9
Type of surgery	Abdominal	0.8 (0.1─5.4)	0.9
Type of disinfectant	Chlorhexidine	1	Not estimable
Type of disinfectant	Povidone iodine	─	Not estimable
Overall exposure time of antiseptic product^f	Per 0.5-min increase	1.1 (0.9─1.3)	0.6
Microbial skin counts prior to skin antisepsis	Per 100-CFU increase	1.0 (1.0─1.0)	0.9

We performed all univariable analyses on the complete case population (n = 230 patients)

BMI body mass index, CFU colony forming unit, OR odds ratio

^aCalculated by use of univariable logistic regression models with fixed effects

^bAt day of surgery

^cPrevious diagnosis of diabetes mellitus type 2 according to medical records

^dAny antimicrobial treatment within the last 2 weeks prior to surgery and excluding peri-interventional antimicrobial prophylaxis

^eAntimicrobial prophylaxis administered within 120 min prior to incision

^fTime period from start of skin antisepsis until the applied antiseptic has dried out after paint 2