Table 5.

Multivariable logistic regression analysis: overall hospital acquired infection

		OR	95% CI	P-value
Admission year	2019	Ref
	2020	0.93	0.74–1.16	0.530
Age category (years)	40	Ref
	40–59	1.22	0.85–1.74	0.275
	≥ 60	1.67	1.19–2.35	0.003
Sex	Male	Ref
	Female	1.12	0.89–1.41	0.343
ASA score	Low (1–2)	Ref
	High (3–5)	1.44	1.05–1.98	0.023
	Not recorded	1.38	0.93–2.05	0.106
CCI	0	Ref
	1	1.37	0.97–1.95	0.074
	≥ 2	1.67	1.25–2.21	< 0.001
Admission type	Elective	Ref
	Emergency	1.33	1.02–1.74	0.035
Anaesthetic type	Regional/sedation	Ref
	General anaesthetic	1.13	0.60–2.16	0.701
	Not recorded	1.23	0.58–2.63	0.588
Length of index procedure (hours)	≤ 1	Ref
	1–4	1.73	1.25–2.38	0.001
	> 4	2.24	1.45–3.46	< 0.001
	Not recorded	1.44	0.77–2.67	0.253
ICU/CCU Admission	No	Ref
	Yes	3.71	2.76–4.99	< 0.001
No. of separate theatre visits	1	Ref
	2	1.69	1.19–2.40	0.004
	> 2	4.16	2.65–6.53	< 0.001
Length of stay	Day case	Ref
	Overnight	0.98	0.45–2.15	0.965
	> 2 days	3.62	1.85–7.08	< 0.001
Specialty unit	Plastic surgery	Ref
	Breast & Endocrine	1.33	0.53–3.38	0.546
	Cardiothoracics	0.74	0.40–1.36	0.331
	Colorectal	2.63	1.31–5.30	0.007
	Head & Neck & Plastics	4.59	1.93–10.95	0.001
	Emergency General Surgery	1.19	0.65–2.17	0.574
	Head, Neck & Otolaryngology	1.03	0.41–2.61	0.938
	Hepatobiliary & Upper Gastrointestinal	1.67	0.74–3.77	0.218
	Nephrology Surgical	1.02	0.52–2.00	0.947
	Neurosurgery	1.00	0.57–1.76	0.993
	Oral & Maxillofacial	0.81	0.23–2.92	0.753
	Orthopaedic	2.03	1.22–3.36	0.006
	Thoracics	0.77	0.33–1.79	0.541
	Urology	1.31	0.68–2.53	0.424
	Vascular	0.97	0.51–1.83	0.925
No. of admission episodes per patient	1	Ref
	> 1	2.35	1.72–3.21	< 0.001

OR: odds ratio, 95% CI: 95% Confidence interval, ASA score: American society of anesthesiology physical classification status score, CCI: Charlson comorbidity index, ICU: intensive care unit, CCU: coronary care unit. Ref: Referent