Table 2.

Team familiarity and other determinants associated with adjusted surgical outcomes

	Composite adverse event		Major surgical complication		Unplanned reoperation		Extended ICU stay		Death
Characteristic	Odds ratio (95% CI)c	P value	Odds ratio (95% CI)c	P value	Odds ratio (95% CI)c	P value	Odds ratio (95% CI)c	P value	Odds ratio (95% CI)c	P value
Surgical team familiaritya	0.92 (0.87–0.98)	0.007	0.93 (0.88–0.99)	0.015	0.88 (0.78–0.99)	0.027	0.88 (0.75–1.04)	0.132	0.87 (0.74–1.03)	0.101
Attending surgeon age	1.00 (0.99–1.02)	0.807	1.00 (0.99–1.02)	0.570	1.00 (0.98–1.02)	0.906	1.00 (0.98–1.02)	0.987	0.99 (0.96–1.02)	0.505
Attending surgeon status
Non-professor	-		-		-		-		-
Associate/full professor	0.95 (0.74–1.23)	0.717	0.95 (0.73–1.24)	0.696	0.92 (0.66–1.28)	0.615	1.07 (0.72–1.59)	0.723	0.85 (0.57–1.27)	0.435
Assisting surgeon status	-		-		-		-		-
Junior
Senior	1.35 (1.01–1.79)	0.041	1.35 (1.00–1.82)	0.049	1.22 (0.88–1.70)	0.229	1.14 (0.84–1.56)	0.393	1.25 (0.62–2.54)	0.528
Patient risk score quartile by surgical specialtyb
Cardiac and thoracic (Q1)	-		-		-		-		-
Cardiac and thoracic (Q2)	1.22 (0.64–2.29)	0.545	1.29 (0.69–2.43)	0.420	1.05 (0.31–3.57)	0.940	1.07 (0.50–2.29)	0.858	2.71 (1.19–6.16)	0.017
Cardiac and thoracic (Q3)	1.69 (1.25–2.29)	<0.001	1.59 (1.20–2.09)	0.001	2.90 (1.09–7.74)	0.033	2.69 (1.16–6.24)	0.021	6.16 (3.50–10.8)	<0.001
Cardiac and thoracic (Q4)	3.49 (2.35–5.17)	<0.001	3.21 (2.19–4.71)	<0.001	5.91 (1.94–18.0)	0.002	5.81 (2.65–12.7)	<0.001	16.4 (10.9–24.5)	<0.001
General and endocrine (Q1)	0.22 (0.15–0.32)	<0.001	0.22 (0.14–0.33)	<0.001	0.38 (0.11–1.26)	0.115	0.02 (0.00–0.13)	<0.001	0.23 (0.05–1.04)	0.056
General and endocrine (Q2)	0.56 (0.36–0.85)	0.006	0.56 (0.36–0.87)	0.010	0.64 (0.18–2.29)	0.495	0.11 (0.03–0.37)	<0.001	0.12 (0.02–0.88)	0.037
General and endocrine (Q3)	0.92 (0.62–1.36)	0.676	0.98 (0.66–1.44)	0.912	1.16 (0.37–3.63)	0.795	0.39 (0.15–1.01)	0.052	0.99 (0.44–2.26)	0.989
General and Endocrine (Q4)	3.25 (2.26–4.68)	<0.001	3.28 (2.29–4.70)	<0.001	4.02 (1.34–12.1)	0.013	2.35 (1.01–5.47)	0.048	5.24 (2.72–10.1)	<0.001
Orthopedic and urogynecologic (Q1)	0.08 (0.05–0.12)	<0.001	0.07 (0.04–0.11)	<0.001	0.13 (0.04–0.45)	0.001	0.00 (0.00–0.00)	<0.001	0.08 (0.01–0.82)	0.033
Orthopedic and urogynecologic (Q2)	0.17 (0.11–0.25)	<0.001	0.14 (0.09–0.22)	<0.001	0.38 (0.12–1.27)	0.116	0.02 (0.00–0.17)	<0.001	0.13 (0.04–0.45)	0.001
Orthopedic and urogynecologic (Q3)	0.33 (0.23–0.48)	<0.001	0.31 (0.22–0.45)	<0.001	0.62 (0.19–2.02)	0.431	0.00 (0.00–0.00)	<0.001	0.00 (0.00–0.00)	<0.001
Orthopedic and urogynecologic (Q4)	0.96 (0.64–1.44)	0.842	0.94 (0.62–1.42)	0.767	1.64 (0.52–5.15)	0.397	0.25 (0.07–0.93)	0.039	1.16 (0.51–2.63)	0.720

^aSurgical team familiarity was measured based on the number of previous collaborations between the attending and assisting surgeon and modeled using a logarithmic transformation.

^bPreoperative risk scores were developed for the five outcomes across the surgical specialties using a dataset of 3644 operations. The variables included demographics, surgical details, and comorbidities. Categories were based on quartiles (Q1-Q4) representing increasing adverse event rates by surgical specialty.

^cAbbreviations: CI = confidence interval.

We employed a multivariable generalized estimating equations (GEE) with an independent correlation matrix to model the association between patient outcomes and surgical team familiarity. The attending surgeon identity was considered in the models as a random effect, and possible interactions between the covariates were examined.