Table 2.

Baseline characteristics for cohort CRT

	Before matching					After matching
	CRT		C + CRT		P	CRT		C + CRT		P
	N	%	N	%		N	%	N	%
Facility
Nonacademic	848	65	789	59	0.0085	548	62	539	61	0.70
Academic	452	35	521	39		339	38	348	39
NA	7	1	19	1		0	0	0	0
Age
<66	674	52	762	57	0.0030	472	53	498	56	0.23
≥66	633	48	567	43		415	47	389	44
NA	0	0	0	0		0	0	0	0
Gender
Female	645	49	663	50	0.79
Male	662	51	666	50
NA	0	0	0	0
Race
White	1141	87	1148	86	0.19
Black	119	9	121	9
Other	32	2	49	4
NA	15	1	11	1
Insurance
None	31	2	34	3	0.071
Nonprivate	728	56	684	51
Private	533	41	601	45
NA	15	1	10	1
Income
Above median	733	56	870	65	<0.001	547	62	563	63	0.46
Below median	544	42	441	33		340	38	324	37
NA	30	2	18	1		0	0	0	0
Residential setting
Metro	1023	78	1086	82	0.049
Urban	201	15	181	14
Rural	31	2	18	1
NA	52	4	44	3
Charlson‐Deyo Score
0‐1	1235	94	1248	94	0.56	836	94	841	95	0.68
≥2	72	6	81	6		51	6	46	5
NA	0	0	0	0		0	0	0	0
Year of diagnosis
2004‐2007	210	16	74	6	<0.001	69	8	47	5	0.11
2008‐2011	680	52	696	52		458	52	467	53
2012‐2015	417	32	559	42		360	41	373	42
NA	0	0	0	0		0	0	0	0
Primary tumor site
Head	1076	82	1105	83	0.015
Body	78	6	105	8
Tail	153	12	119	9
NA	0	0	0	0
Tumor grade
Well diff	108	8	112	8	0.64	75	8	79	9	0.13
Mod diff	629	48	652	49		460	52	478	54
Poor diff	455	35	448	34		346	39	315	36
Other	13	1	20	2		6	1	15	2
NA	102	8	97	7		0	0	0	0
Tumor size (cm)
<3.1	575	44	657	49	0.0050	410	46	410	46	1
≥3.1	697	53	636	48		477	54	477	54
NA	35	3	36	3		0	0	0	0
Clinical T stage
1	158	12	195	15	0.15
2	517	40	509	38
3	632	48	625	47
NA	0	0	0	0
Clinical N stage
0	874	67	871	66	0.48
1	433	33	458	34
NA	0	0	0	0
Pathologic T stage
0	1	0	1	0	0.61	1	0	1	0	0.95
1	49	4	45	3		30	3	36	4
2	169	13	153	12		108	12	105	12
3	980	75	1056	79		731	82	729	82
4	22	2	22	2		17	2	16	2
Other	0	0	0	0		0	0	0	0
NA	86	7	52	4		0	0	0	0
Pathologic N stage
0	338	26	293	22	0.0075	228	26	226	25	0.96
1	874	67	971	73		659	74	661	75
NA	95	7	65	5		0	0	0	0
Number of positive lymph nodes
0	363	28	297	22	<0.001
1‐3	585	45	585	44
4+	324	25	415	31
NA	35	3	32	2
Surgery
Whipple variant	342	26	397	30	0.10	253	29	256	29	0.98
Whipple	668	51	650	49		437	49	436	49
Other	297	23	282	21		197	22	195	22
NA	0	0	0	0		0	0	0	0
Surgical margin
Negative	891	68	968	73	0.012	643	72	637	72	0.79
Positive	386	30	336	25		244	28	250	28
NA	30	2	25	2		0	0	0	0
Chemotherapy
Single agent	824	63	766	58	0.0047	536	60	515	58	0.33
Multi agent	483	37	563	42		351	40	372	42
NA	0	0	0	0		0	0	0	0
Radiation dose (Gy)
Median	50.4		50.4		0.18	50.4		50.4		0.17
IQR	50.0‐54.0		50.0‐50.4			50.0‐54.0		50.0‐50.4

C, chemotherapy; CRT, chemoradiation; diff, differentiated; IQR, interquartile range; mod, moderately; NA, not available; poor, poorly.