Table 1 Comparison of early and late weekday groups (EW and LW) before and after propensity score matching
All patients (n = 554) | P value | Propensity score-matched patients (n = 432) | P value | |||
|---|---|---|---|---|---|---|
EW group (n = 239) | LW group (n = 315) | EW group (n = 216) | LW group (n = 216) | |||
Age, years (median, IQR) | 70 (62–77) | 70 (63–77) | 0.717 | 70 (62–77) | 69 (62–77) | 0.889 |
Gender (n, %) | 0.521 | 0.760 | ||||
Male | 159 (66.5%) | 218 (69.2%) | 145 (67.1%) | 141 (65.3%) | ||
Female | 80 (33.5%) | 97 (30.8%) | 71 (32.9%) | 75 (34.7%) | ||
Time period (n, %) | 0.103 | 0.101 | ||||
2004–2010 | 104 (43.5%) | 160 (50.8%) | 91 (42.1%) | 109 (50.5%) | ||
2011–2017 | 135 (56.5%) | 155 (49.2%) | 125 (57.9%) | 107 (49.5%) | ||
BMI, kg/m2 (median, IQR) | 22.7 (20.9–24.5) | 22.5 (20.3–24.4) | 0.161 | 22.8 (20.9–24.5) | 22.7 (20.7–24.9) | 0.806 |
Diabetes mellitus (n, %) | 1.000 | |||||
Absent | 202 (84.5%) | 267 (84.8%) | 182 (84.3%) | 182 (84.3%) | 1.000 | |
Present | 37 (15.5%) | 48 (15.2%) | 34 (15.7%) | 34 (15.7%) | ||
COPD (n, %) | 0.719 | 1.000 | ||||
Absent | 226 (94.6%) | 295 (93.7%) | 203 (94.0%) | 202 (93.5%) | ||
Present | 13 (5.4%) | 20 (6.3%) | 13 (6.0%) | 14 (6.5%) | ||
Hemoglobin, g/dl (median, IQR) | 12.7 (11.7–13.9) | 12.7 (11.1–13.7) | 0.167 | 12.7 (11.7–13.9) | 12.8 (11.6–13.9) | 0.803 |
Albumin, g/dl (median, IQR) | 4.1 (3.9–4.4) | 4.0 (3.7–4.3) | 0.021 | 4.1 (3.9–4.4) | 4.1 (3.8–4.4) | 0.750 |
CEA, ng/ml (median, IQR) | 1.6 (0.9–2.6) | 1.6 (1.0–2.5) | 0.834 | 1.6 (0.9–2.6) | 1.6 (0.9–2.5) | 0.983 |
CA19-9, U/ml (median, IQR) | 9.4 (6.0–15.6) | 10 (6.8–17.3) | 0.161 | 9.6 (6.4–15.8) | 10 (6.5–17.0) | 0.371 |
Impairment of respiratory function (n, %) | 0.271 | 1.000 | ||||
Absent | 156 (65.3%) | 220 (69.8%) | 141 (65.3%) | 140 (64.8%) | ||
Present | 83 (34.7%) | 95 (30.2%) | 75 (34.7%) | 76 (35.2%) | ||
Clinical tumor depth (n, %) | 0.399 | 0.881 | ||||
cT1 | 127 (53.1) | 154 (48.9) | 116 (53.7%) | 121 (56.0%) | ||
cT2 | 54 (22.6) | 65 (20.6) | 49 (22.7%) | 47 (21.8%) | ||
cT3 | 35 (14.6) | 53 (16.8) | 34 (15.7%) | 29 (13.4%) | ||
cT4 | 23 (9.6) | 43 (13.7) | 17 (7.9%) | 19 (8.8%) | ||
Clinical lymph node metastasis (n, %) | 0.056 | 0.545 | ||||
cN0 | 187 (78.2%) | 215 (68.3%) | 172 (80.0%) | 160 (74.1%) | ||
cN1 | 40 (16.7%) | 72 (22.9%) | 34 (15.7%) | 44 (20.4%) | ||
cN2 | 11 (4.6%) | 25 (7.9%) | 9 (4.2%) | 10 (4.6%) | ||
cN3 | 1 (0.4%) | 3 (1.0%) | 1 (0.5%) | 2 (0.9%) | ||
Clinical TNM stage (n, %) | 0.075 | 0.180 | ||||
I | 165 (69.0%) | 193 (61.3%) | 150 (69.4%) | 149 (69.0%) | ||
IIA | 16 (6.7%) | 26 (8.3%) | 15 (6.9%) | 19 (8.8%) | ||
IIB | 22 (9.2%) | 22 (7.0%) | 22 (10.2%) | 11 (5.1%) | ||
III | 36 (15.1%) | 73 (23.2%) | 29 (13.4%) | 36 (16.7%) | ||
IVA | 0 | 1 (0.3%) | 0 | 1 (0.5%) | ||
Operative procedure (n, %) | 0.448 | 0.915 | ||||
Distal gastrectomy | 168 (70.3%) | 222 (70.5%) | 155 (71.8%) | 153 (70.8%) | ||
Proximal gastrectomy | 3 (1.3%) | 1 (0.3%) | 0 | 0 | ||
Total gastrectomy | 68 (28.4%) | 92 (29.2%) | 61 (28.2%) | 63 (29.2%) | ||
Operative approach (n, %) | 0.059 | 0.176 | ||||
Open | 107 (44.8%) | 167 (53.0%) | 91 (42.1%) | 106 (49.1%) | ||
Laparoscopic | 132 (55.2%) | 148 (47.0%) | 125 (57.9%) | 110 (50.9%) | ||
Lymph node dissection (n, %) | 0.230 | 1.000 | ||||
D1/D1+ | 127 (53.1%) | 150 (47.6%) | 117 (54.2%) | 116 (53.7%) | ||
D2 or more | 112 (46.9%) | 165 (52.4%) | 99 (45.8%) | 100 (46.3%) | ||