Days alive and out of hospital following primary surgery for oral cavity squamous cell carcinoma

Figures & data

Table 1. DAOH₃₀ and DAOH₃₆₅ of patient characteristics.

	DAOH30			DAOH365
Variate	Count, n (%)	Median (IQR)	p-value	Count, n (%)	Median (IQR)	p-value
Gender
Male	549 (63.3%)	24 (21–26)	Ref	549 (63.3%)	355 (330–360)	ref
Female	318 (36.7%)	25 (21–27)	0.125	318 (36.7%)	357 (340.25–361)	0.01
Age (at date of surgery)
<50	92 (10.6%)	25 (23–27)	ref	92 (10.6%)	358 (343.75–361)	ref
50–59	238 (27.5%)	25 (21–27)	0.115	238 (27.5%)	355 (336–360)	0.16
60–69	305 (35.2%)	25 (21–26)	0.014	305 (35.2%)	356 (336–360)	0.136
≥70	232 (26.8%)	24 (20–26)	0.002	232 (26.8%)	354.5 (318–360)	0.045
Pack years
0	108 (12.5%)	25 (21–27)	Ref	108 (12.5%)	357 (346.5–360)	ref
1–40	266 (30.7%)	24.5 (21–27)	0.82	266 (30.7%)	356 (338–360)	0.44
>40	266 (30.7%)	24 (20.25–26)	0.244	266 (30.7%)	354 (337.25–360)	0.084
Unknown	227 (26.2%)	25 (21–27)	0.068	227 (26.2%)	354 (320–361)	0.265
Daily units of alcohol
0	261 (30.1%)	24 (21–27)	Ref	261 (30.1%)	355 (340–360)	ref
1–4	258 (29.8%)	25 (21–27)	0.775	258 (29.8%)	356.5 (341.25–360)	0.511
>4	198 (22.8%)	24 (20–26)	0.303	198 (22.8%)	352 (327.5–359)	0.039
Unknown	150 (17.3%)	25 (22–27)	0.195	150 (17.3%)	356.5 (300.5–360)	0.007
T-stage
T1	311 (35.9%)	26 (24–27)	Ref	311 (35.9%)	359 (352–362)	ref
T2	293 (33.8%)	24 (21–26)	<0.001	293 (33.8%)	355 (321–359)	<0.001
T3	45 (5.2%)	21 (19–24)	<0.001	45 (5.2%)	345 (314–354)	<0.001
T4	107 (12.3%)	18 (12–21)	<0.001	107 (12.3%)	331 (253–351.5)	<0.001
Unknown	111 (12.8%)	26 (23–28)	<0.001	111 (12.8%)	356 (342–360)	0.017
N-stage
N0	536 (61.8%)	25 (22–27)	Ref	536 (61.8%)	357 (346–361)	ref
N1	124 (14.3%)	24 (20–26)	0.011	124 (14.3%)	350 (308.5–358)	<0.001
Unknown	207 (23.9%)	24 (20–26)	0.028	207 (23.9%)	348 (313.5–358)	<0.001
UICC disease stage
I	251 (29%)	26 (24–27)	Ref	251 (29%)	360 (355.5–362)	ref
II	188 (21.7%)	25 (22–26)	<0.001	188 (21.7%)	357 (344–360)	<0.001
III	121 (14%)	24 (21–26)	<0.001	121 (14%)	351 (314–358)	<0.001
IV	199 (23%)	20 (14.5–23)	<0.001	199 (23%)	336 (279.5–352)	<0.001
Unknown	108 (12.5%)	26 (23.75–28)	0.073	108 (12.5%)	356 (343.75–360)	<0.001
Treatment
Surgery	497 (57.3%)	25 (23–27)	Ref	497 (57.3%)	358 (349–361)	ref
Surgery + RT	370 (42.7%)	22.5 (19–26)	<0.001	370 (42.7%)	347 (310.25–357)	<0.001
CCI at date of surgery
2	531 (61.2%)	25 (21–27)	Ref	531 (61.2%)	357 (342–361)	ref
3	194 (22.4%)	24 (20–26)	0.034	194 (22.4%)	354 (323–359)	0.002
4	71 (8.2%)	24 (20.5–26.5)	0.12	71 (8.2%)	351 (321.5–360)	0.038
5	31 (3.6%)	22 (15–26.5)	0.074	31 (3.6%)	339 (282–356)	<0.001
>5	40 (4.6%)	24 (19.5–26)	0.012	40 (4.6%)	347.5 (223.3–357.3)	<0.001
LOS
<3	151 (17.4%)	28 (28–28)	Ref	151 (17.4%)	361 (357–363)	ref
3–5	355 (40.9%)	26 (25–27)	<0.001	355 (40.9%)	359 (349–361)	<0.001
6–8	161 (18.6%)	23 (22–24)	<0.001	161 (18.6%)	353 (334–357)	<0.001
>8	200 (23.1%)	17 (12–20)	<0.001	200 (23.1%)	336 (248.75–350)	<0.001
Readmission <30 days
No	730 (84.2%)	25 (21–27)	Ref
Yes	137 (15.8%)	22 (18–24)	<0.001
Readmission <365 days
No				705 (81.3%)	357 (341–361)	ref
Yes				162 (18.7%)	347 (311–357)	<0.001
Re-surgery
No	818 (94.3%)	25 (21–27)	Ref	799 (92.2%)	356 (336–360)	ref
Yes	49 (5.7%)	23 (18–24)	<0.001	68 (7.8%)	352 (332.25–358)	0.016
Recurrence
No	862 (99.4%)	25 (21–27)	Ref	726 (83.7%)	357 (344–361)	ref
Yes	5 (0.6%)	22 (19–24)	0.14	141 (16.3%)	336 (275–352)	<0.001
Days dead
0	861 (99.3%)	25 (21–27)	Ref	756 (87.2%)	357 (347–360)	ref
1–30	6 (0.7%)	0 (0–0)	<0.001
1–180				73 (8.4%)	219 (172–261)	<0.001
>180				38 (4.4%)	49 (3.5–91.5)	<0.001

Count, n (%); IQR: Inter-quartile-range; UICC: Union for international Cancer Control; RT: Radiotherapy; CCI: Charlson Comorbidity Index; LOS: Length of (hospital) stay; Days dead: mortality and related DAOH within period.

Figure 1. Boxplot of Median DAOH₃₀ for Patients- and Postoperative Characteristics. UICC: Union for international Cancer Control; CCI: Charlson Comorbidity Index; LOS: Length of (hospital) stay.

Table 2. Quantile linear regression of patient characteristics and DAOH₃₀ and DAOH₃₆₅.

	DAOH30			DAOH365
Variable	Median (IQR)	Estimate	p-value	Median (IQR)	Estimate	p-value
Age	62.7 (62.7–62.7)	–0.08	<0.001	62.7 (62.7–62.7)	–1.02	<0.001
Pack years (smoking)	47 (47–47)	–0.01	0.24	47 (47–47)	–0.12	0.08
Daily units of alcohol	3 (3–3)	0	0.62	3 (3–3)	–0.21	<0.01
T-stage	2 (2–2)	0.02	<0.001	2 (2–2)	0.03	<0.01
N-stage	0 (0–0)	0.02	0.01	0 (0–0)	0.01	0.89
UICC stage	2 (2–2)	0.02	0.01	2 (2–2)	0.03	<0.01
Charlson Comorbidity Index (CCI)	2 (2–2)	–0.71	<0.001	2 (2–2)	–11.6	<0.001
Length of stay (LOS)	5 (5–5)	–0.97	<0.001	5 (5–5)	–2.14	<0.001

IQR: Inter-quartile-range stay; UICC: Union for international Cancer Control; CCI: Charlson Comorbidity Index; LOS: Length of (hospital); Estimate, regression model output for how much outcome (DAOH) changes per single change in variable grouping.

Figure 2. Boxplot of Median DAOH₃₆₅ for Patients- and Postoperative Characteristics. UICC: Union for international Cancer Control; CCI: Charlson Comorbidity Index; LOS: Length of (hospital) stay.

Table 3. Readmission causes within 30- and 365 days following surgery.

	Readmission within 30 days			Readmission within 365 days
Category	Admission count (%)	Median inpatient days (IQR)	Relative impact	Admission count (%)	Median inpatient days (IQR)	Relative impact
Postoperative complication	41 (14.8%)	4 (2–6)	0.592	158 (17.2%)	5 (2–8)	0.86
Bleeding	12 (4.3%)	2.5 (2–4.25)	0.108	18 (2%)	2 (1.25–4)	0.039
Infection, other	9 (3.2%)	5 (4–8)	0.162	50 (5.4%)	4 (2–8)	0.218
Infection, respiratory	6 (2.2%)	5 (3.25–6.75)	0.108	29 (3.2%)	7 (5–13)	0.221
Infection, systemic	3 (1.1%)	3 (2.5–13)	0.032	13 (1.4%)	6 (3–12)	0.085
Other	11 (4%)	2 (1–4)	0.079	48 (5.2%)	4 (1–7)	0.209
Malignancy	179 (64.6%)	7 (3–11)	4.523	368 (40%)	8 (4–15)	3.203
Head and neck	172 (62.1%)	7 (3.75–11)	4.347	301 (32.8%)	8 (4–16)	2.62
Metastatic	6 (2.2%)	3 (1.5–3.75)	0.065	14 (1.5%)	9.5 (3.25–19.5)	0.145
Lung				29 (3.2%)	5 (3–7)	0.158
Other location	1 (0.4%)	4 (4–4)	0.014	24 (2.6%)	4.5 (3–9)	0.118
Cardiopulmonary	24 (8.7%)	4.5 (3–7.25)	0.39	101 (11%)	4 (2–9)	0.44
Circulatory disease	8 (2.9%)	3 (2–4.25)	0.087	40 (4.4%)	3.5 (2–5.25)	0.152
Heart disease	3 (1.1%)	8 (6–10.5)	0.087	16 (1.7%)	3.5 (2–6.5)	0.061
Pulmonary disease	13 (4.7%)	5 (3–13)	0.235	45 (4.9%)	5 (3–9)	0.245
Digestive system disorder	16 (5.8%)	2 (1–4)	0.116	98 (10.7%)	4 (2–9)	0.427
Acute	12 (4.3%)	2 (1–4)	0.087	56 (6.1%)	4 (2–7)	0.244
Other	4 (1.4%)	1.5 (1–4.5)	0.022	42 (4.6%)	4 (2–13.5)	0.183
Other	17 (6.1%)	4 (2–7)	0.245	194 (21.1%)	3 (2–8)	0.633
Benign tumor				19 (2.1%)	4 (2.5–6)	0.083
Intoxication				17 (1.8%)	3 (2–5)	0.055
Neurological				27 (2.9%)	2 (1–6)	0.059
Orthopedic	5 (1.8%)	4 (4–7)	0.072	29 (3.2%)	4 (3–12)	0.126
Other	12 (4.3%)	3 (1.75–5.5)	0.13	102 (11.1%)	3 (2–8)	0.333

Total number of readmissions within 30 days: n = 277. Total number of readmissions within 365 days: n = 919. Admission count, n (%), IQR: Inter-quartile-range.

Data availability statement

Due to the nature of this research, participants of this study did not agree for their data to be shared publicly, so supporting data is not available.