New perspectives on robotic pancreaticoduodenectomy: An analysis of the National Cancer Database

Table 4 Cox proportional hazards model of mortality after surgery for patients with pancreatic cancer

Characteristic	Parameter estimate	Hazard ratio	95%CI	P value
Age (yr)	0.01621	1.02	1.01-1.02	< 0.0001
Male sex	0.02903	1.03	0.98-1.08	0.20
Race: White	ref
Black	-0.0599	0.94	0.87-1.02	0.13
Other	-0.15749	0.85	0.76-0.96	0.009
Unknown	-0.16688	0.85	0.65-1.10	0.21
Hispanic ethnicity: No	ref
Yes	-0.15238	0.86	0.78-0.95	0.0037
Unknown	-0.03096	0.97	0.82-1.15	0.72
Tumor grade: 1	ref
2	0.45571	1.58	1.45-1.72	< 0.0001
3	0.70413	2.02	1.85-2.21	< 0.0001
4	0.80073	2.23	1.82-2.73	< 0.0001
Not determined, unknown	0.35723	1.43	1.28-1.60	< 0.0001
Surgical approach: Open	ref
MIS, MIS to open	-0.0402	0.96	0.90-1.02	0.19
Robotic, robotic to open	0.00838	1.01	0.88-1.15	0.90
Surgical margins: No residual tumor	ref
Macroscopic residual tumor	0.44741	1.56	1.19-2.05	0.0013
Microscopic residual tumor	0.34752	1.42	1.34-1.49	< 0.0001
Unknown, indeterminate	0.40122	1.49	1.15-1.94	0.0026
AJCC Pathological stage: 0	ref
1/1A/1B	0.49238	1.64	1.22-2.18	0.0008
2/2A/2B	0.90708	2.48	1.86-3.29	< 0.0001
3	1.10653	3.02	2.21-4.14	< 0.0001
Census block median income quartile: > 63332
$50354-$63332	0.06511	1.07	1.01-1.13	0.027
$40227-$50353	0.17171	1.19	1.12-1.26	< 0.0001
< $40227	0.19323	1.21	1.14-1.30	< 0.0001
Unknown	0.12115	1.13	0.61-2.10	0.70
Histology: Adenocarcinoma	ref
Duct carcinoma	-0.05251	0.95	0.91-0.99	0.027
All others	-0.72939	0.48	0.44-0.52	< 0.0001
Charlson-Deyo score: 0
1	0.10936	1.12	1.06-1.17	< 0.0001
2	0.18942	1.21	1.11-1.32	< 0.0001
3 or more	0.35643	1.43	1.26-1.62	< 0.0001
Lymph nodes examined	-0.01026	0.99	0.99-0.99	< 0.0001
Lymph nodes positive for cancer	0.05025	1.05	1.04-1.06	< 0.0001
Tumor size (mm)1	0.00479	1.01	1.00-1.01	< 0.0001
Year of diagnosis	-0.03434	0.97	0.96-0.98	< 0.0001
Weeks between diagnosis and surgery	0.00702	1.01	1.01-1.01	< 0.0001

¹Tumors greater than 200 were recoded to 200.

MIS: Minimally invasive surgery; AJCC: American Joint Committee on Cancer.