Appendix E.

Conditional logistic models to examine the relationship between obesity and post-operative AKI with adjustment for potential confounders, excluding the patients with missing creatinine.

	Complete Match
	OR	CI	p-value
BMI Only
<20	0.95	0.48–1.89	0.89
20–30 (reference)	--	--	--
30–35	0.81	0.58–1.13	0.21
≥35	1.62	1.09–2.39	0.02
BMI and complications excluding hypotension
<20	0.86	0.40–1.83	0.69
20–30 (reference)	--	--	--
30–35	0.96	0.67–1.37	0.82
≥35	1.73	1.12–2.66	0.01
Bleeding	1.22	0.89–1.69	0.22
Sepsis	4.55	2.77–7.48	<0.005
Cardiac Emergency	2.29	1.41–3.71	<0.005
Cardiac Event	1.75	0.94–3.25	0.08
BMI and complications including hypotension
<20	0.88	0.39–2.01	0.77
20–30 (reference)	--	--	--
30–35	0.95	0.65–1.39	0.78
≥35	1.56	0.99–2.47	0.06
Bleeding	1.14	0.81–1.62	0.46
Sepsis	3.41	2.00–5.82	<0.005
Cardiac Emergency	1.59	0.92–2.73	0.10
Cardiac Event	1.78	0.92–3.44	0.09
Hypotension	4.46	2.95–6.73	<0.005

Bolded odds ratios denote significant results. Basic match on age, sex, race, emergency status, transfer status, baseline eGFR and procedure type with fine balance on hospitals. Complete match on age, sex, race, emergency status, transfer status, baseline eGFR, procedure type, admission APACHE score, the risk of death score and pre-operative kidney dysfunction and end-stage kidney disease with fine balance on hospitals.