Table 1 Baseline characteristics of the study population
Characteristic | Training Cohort (n = 10,796) | Validation Cohort (n = 4624) |  | |||
|---|---|---|---|---|---|---|
NV-HAP (n = 153) | Non-NV-HAP (n = 10,643) | P | NV-HAP (n = 72) | Non-NV-HAP (n = 4552) | P | |
Age(years), median (IQR†) | 79 (12) | 73 (12) |  < 0.001 | 78 (9) | 73 (12) |  < 0.001 |
Male, n (%) | 90 (58.8) | 5598 (52.6) | 0.126 | 34 (56.7) | 2351 (52.2) | 0.496 |
Drinking status, n (%) | Â | Â | 0.400 | Â | Â | 0.406 |
 Never drinker | 129 (84.3) | 8732 (82.0) |  | 61 (84.7) | 3769 (82.8) |  |
 Current drinker | 13 (8.5) | 1262 (11.9) |  | 5 (6.9) | 509 (11.2) |  |
 Former drinker | 11 (7.2) | 649 (6.1) |  | 6 (8.3) | 274 (6.0) |  |
Smoking status, n (%) | Â | Â | 0.597 | Â | Â | 0.417 |
 Never smoker | 124 (81.0) | 8535 (80.2) |  | 58 (80.6) | 3646 (80.1) |  |
 Current smoker | 13 (8.5) | 1142 (10.7) |  | 5 (6.9) | 486 (10.7) |  |
 Former smoker | 11 (7.2) | 966 (9.1) |  | 9 (12.5) | 420 (9.2) |  |
Comorbidities, n (%) | Â | Â | Â | Â | Â | Â |
 COPD | 5 (3.3) | 391 (3.7) | 0.791 | 2 (2.8) | 173 (3.8) | 0.652 |
 Swallow disability | 5 (3.3) | 57 (0.5) |  < 0.001 | 0 (0.0) | 29 (0.6) | 0.497 |
 Stroke | 67 (43.8) | 3027 (28.4) |  < 0.001 | 39 (54.2) | 1279 (28.1) |  < 0.001 |
 Diabetes mellitus | 49 (32.0) | 2963 (27.8) | 0.252 | 28 (38.9) | 1288 (28.3) | 0.048 |
 Peptic ulcer disease | 6 (3.9) | 352 (3.3) | 0.674 | 1 (1.4) | 191 (4.2) | 0.236 |
 Moderate or severe renal disease | 17 (11.1) | 667 (6.3) | 0.015 | 7 (9.7) | 280 (6.2) | 0.213 |
 Liver disease | 22 (14.4) | 2036 (19.1) | 0.137 | 16 (22.2) | 927 (20.4) | 0.698 |
 Congestive heart failure | 5 (3.3) | 129 (1.2) | 0.023 | 6 (8.3) | 79 (1.7) |  < 0.001 |
 Solid tumour | 36 (23.5) | 1400 (13.2) |  < 0.001 | 17 (23.6) | 572 (12.6) | 0.005 |
CCI (points), median (IQR) | 6(3) | 4 (3) |  < 0.001 | 6 (2) | 4(2) |  < 0.001 |
Time at risk(days) | Â | Â | 0.164 | Â | Â | 0.132 |
 ≤ 6 | 48 (31.4) | 3741 (35.1) |  | 21 (29.2) | 1672 (36.7) |  |
 7–11 | 49 (32.0) | 3758 (35.3) |  | 22 (30.6) | 1534 (33.7) |  |
 ≥ 12 | 56 (36.6) | 3144 (29.5) |  | 29 (40.3) | 1346 (29.6) |  |
Admission category, n (%) | Â | Â | 0.003 | Â | Â | 0.413 |
 Internal medicine | 90 (58.8) | 6856 (64.4) |  | 51 (70.8) | 2934 (64.5) |  |
 Surgery | 55 (35.9) | 2857 (26.8) |  | 20 (27.8) | 1239 (27.2) |  |
 Gynaecology | 4 (2.6) | 219 (2.1) |  | 1 (1.4) | 110 (2.4) |  |
 Emergency department | 1 (0.7) | 477 (4.5) |  | 0 (0.0) | 190 (4.2) |  |
 ICU | 3 (2.0) | 59 (0.6) |  | 0 (0.0) | 24 (0.5) |  |
 Others | 0 (0.0) | 175 (1.6) |  | 0 (0.0) | 55 (1.2) |  |
Clinical procedure, n (%) |  |  |  |  |  |  |
 Central venous catheter | 30 (19.6) | 526 (4.9) |  < 0.001 | 20 (27.8) | 249 (5.5) |  < 0.001 |
 Indwelling urinary catheter | 49 (32.0) | 1652 (15.5) |  < 0.001 | 22 (30.6) | 735 (16.1) | 0.001 |
 Surgery | 32 (20.9) | 1792 (16.8) | 0.181 | 13 (18.1) | 764 (16.8) | 0.775 |
 Parenteral nutrition | 18 (11.8) | 472 (4.4) |  < 0.001 | 10 (13.9) | 209 (4.6) |  < 0.001 |
 Enteral tube feeding | 57 (37.3) | 1165 (10.9) |  < 0.001 | 28 (38.9) | 524 (11.5) |  < 0.001 |
NRS-2002(points), median (IQR) | 2 (2) | 1 (2) |  < 0.001 | 2 (2) | 1(2) |  < 0.001 |
Barthel Index, n (%) |  |  |  < 0.001 |  |  |  < 0.001 |
 Independent | 51 (33.3) | 7338 (68.9) |  | 22 (30.6) | 3081 (67.7) |  |
 Slight dependency | 19 (12.4) | 1541 (14.5) |  | 12 (16.7) | 638 (14.0) |  |
 Moderate dependency | 20 (13.1) | 894 (8.4) |  | 6 (8.3) | 447 (9.8) |  |
 Severe dependency | 31 (20.3) | 528 (5.0) |  | 16 (22.2) | 241 (5.3) |  |
 Total dependency | 32 (20.9) | 342 (3.2) |  | 16 (22.2) | 145 (3.2) |  |
Morse Fall Scale, n (%) |  |  |  < 0.001 |  |  | 0.046 |
 No risk | 19 (12.4) | 1945 (18.3) |  | 7 (9.7) | 803 (17.6) |  |
 Low risk | 76 (49.7) | 6555 (61.6) |  | 44 (61.1) | 2872 (63.1) |  |
 High risk | 58 (37.9) | 2143 (20.1) |  | 21 (29.2) | 877 (19.3) |  |
Other nosocomial infections, n (%) | 4 (2.6) | 282 (2.6) | 0.978 | 3 (4.2) | 110 (2.4) | 0.340 |
Season of admission, n (%) | Â | Â | 0.437 | Â | Â | 0.141 |
 Spring | 42 (27.5) | 2684 (25.2) |  | 19 (26.4) | 1208 (26.5) |  |
 Summer | 33 (21.6) | 2813 (26.4) |  | 11 (15.3) | 1208 (26.5) |  |
 Fall | 38 (24.8) | 2245 (21.1) |  | 20 (27.8) | 970 (21.3) |  |
 Winter | 40 (26.1) | 2901 (27.3) |  | 22 (30.6) | 1166 (25.6) |  |
In-hospital medications, n (%) | Â | Â | Â | Â | Â | Â |
 Antacids | 119 (77.8) | 7362 (69.2) | 0.022 | 55 (76.4) | 3099 (68.1) | 0.133 |
 Sedatives | 40 (26.1) | 1521 (14.3) |  < 0.001 | 16 (22.2) | 650 (14.3) | 0.057 |
 NSAIDs | 45 (29.4) | 1350 (12.7) |  < 0.001 | 14 (19.4) | 565 (12.4) | 0.074 |
 Systemic steroids | 23 (15.0) | 1893 (17.8) | 0.376 | 18 (25.0) | 832 (18.3) | 0.144 |
 Inhaled steroids | 36 (23.5) | 1140 (10.7) |  < 0.001 | 18 (25.0) | 513 (11.3) |  < 0.001 |
 Anticoagulant | 50 (32.7) | 1685 (15.8) |  < 0.001 | 21 (29.2) | 745 (16.4) | 0.004 |
Laboratory values, median (IQR) | Â | Â | Â | Â | Â | Â |
 BUN, mmol/L | 11.0 (9.6) | 10.8 (7) | 0.584 | 9.4 (7.7) | 10.8 (6.9) | 0.079 |
 ALB,g/L | 36.0 (7) | 38.6 (6.3) |  < 0.001 | 35.3 (6.4) | 38.5 (6.1) |  < 0.001 |
 CRP, mg/L | 12.5 (31.9) | 3.4 (17.6) |  < 0.001 | 14.2 (38.5) | 3.7 (18.4) |  < 0.001 |
 LY,109 /L | 1.2 (0.7) | 1.4 (0.9) |  < 0.001 | 1.2 (0.8) | 1.4 (0.8) | 0.003 |
 WBC,109 /L | 7.7 (3.7) | 6.4 (2.9) |  < 0.001 | 7.4 (3.3) | 6.4 (2.9) | 0.006 |
 Hb,g/L | 118.0 (31.0) | 126.0 (23.0) |  < 0.001 | 111.5 (32.4) | 126.0 (22.0) |  < 0.001 |