Background
Methods
Data source and study sample
Ethics
Outcome measures
Independent variable
Covariates
Analytical approach
Results
Patient and hospital characteristics
No 30-day readmission | 30-day pneumonia- specific readmission | 30-day pneumonia-unrelated readmission | 30-day all-cause readmission | |||||||
---|---|---|---|---|---|---|---|---|---|---|
N, Mean | N(%), Mean ± SD |
p-value | N(%), Mean ± SD |
p-value |
N(%), Mean ± SD |
p-value | ||||
<Individual level> | ||||||||||
Sex | ||||||||||
Men | 3101 | 405 | (11.6) | 0.276 | 377 | (10.8) | 0.012 | 782 | (20.1) | 0.017 |
Women | 2924 | 351 | (10.7) | 288 | (9.0) | 639 | (17.9) | |||
Age | ||||||||||
65–69 | 1020 | 104 | (9.3) | 0.092 | 108 | (9.6) | 0.014 | 212 | (17.2) | 0.047 |
70–74 | 1319 | 186 | (12.4) | 173 | (11.6) | 359 | (21.4) | |||
75–79 | 1450 | 172 | (10.6) | 175 | (10.8) | 347 | (19.3) | |||
80–84 | 1240 | 156 | (11.2) | 125 | (9.2) | 281 | (18.5) | |||
≥ 85 | 996 | 138 | (12.2) | 84 | (7.8) | 222 | (18.2) | |||
Income | ||||||||||
Medical aid | 488 | 89 | (14.3) | 0.003 | 42 | (7.9) | 0.452 | 131 | (21.2) | 0.409 |
Low | 1538 | 171 | (9.1) | 172 | (10.1) | 343 | (18.2) | |||
Middle | 1783 | 229 | (10.3) | 202 | (10.2) | 431 | (19.5) | |||
High | 2216 | 267 | (9.8) | 249 | (10.1) | 516 | (18.9) | |||
Prior year LOS | 52.1 | 59.6 | ±70.8 | 0.006 | 60.5 | ±60.4 | 0.001 | 60.1 | ±66.1 | <.0001 |
Prior year number of primary care visits | 30.0 | 32.4 | ±35.6 | 0.082 | 34.4 | ±36.0 | 0.003 | 33.4 | ±35.8 | 0.001 |
Prior year number of emergency department (ED) visits | 0.4 | 0.7 | ±4.3 | 0.108 | 0.5 | ±1.5 | 0.059 | 0.6 | ±3.3 | 0.036 |
Prior year cost (1000won) | 3055.8 | 4488.9 | ±11,796.2 | 0.001 | 3742.9 | ±6367.7 | 0.010 | 4138.0 | ±9635.6 | <.0001 |
Pathway | ||||||||||
Outpatient | 2262 | 269 | (10.6) | 0.312 | 241 | (9.6) | 0.537 | 510 | (18.4) | 0.259 |
Emergency | 3763 | 487 | (11.5) | 424 | (10.1) | 911 | (19.5) | |||
LOS of the index hospitalization | 10.4 | 12.7 | ±131 | 0.144 | 10.8 | ±8.7 | 0.752 | 11.817 | ±11.3 | 0.415 |
Septicemia/shock | ||||||||||
Yes | 155 | 31 | (16.7) | 0.021 | 28 | (15.3) | 0.020 | 59 | (27.6) | 0.002 |
Cancer | ||||||||||
Yes | 452 | 65 | (12.6) | 0.319 | 138 | (23.4) | <.0001 | 203 | (31.0) | <.0001 |
Dementia | ||||||||||
Yes | 243 | 28 | (10.3) | 0.736 | 35 | (12.6) | 63 | (20.6) | ||
Heart failure | ||||||||||
Yes | 221 | 29 | (11.6) | 0.898 | 51 | (18.8) | <.0001 | 80 | (26.6) | 0.001 |
Vascular or circulatory disease | ||||||||||
Yes | 440 | 73 | (14.2) | 0.026 | 94 | (17.6) | <.0001 | 167 | (27.5) | <.0001 |
COPD | ||||||||||
Yes | 769 | 178 | (18.8) | <.0001 | 170 | (18.1) | <.0001 | 348 | (31.2) | <.0001 |
Asthma | ||||||||||
Yes | 796 | 198 | (19.9) | <.0001 | 158 | (16.6) | <.0001 | 356 | (30.9) | <.0001 |
Renal failure | ||||||||||
Yes | 182 | 28 | (13.3) | 0.363 | 40 | (18.0) | <.0001 | 68 | (27.2) | 0.001 |
Liver disease | ||||||||||
Yes | 152 | 32 | (17.4) | 0.009 | 31 | (16.9) | 0.002 | 63 | (29.3) | 0.000 |
<Hospital level> | ||||||||||
Hospital classification | ||||||||||
Teaching hospital or general hospital | 4331 | 498 | (10.3) | 0.001 | 500 | (10.4) | 0.079 | 998 | (18.7) | 0.227 |
Hospital | 1694 | 258 | (13.2) | 165 | (8.9) | 423 | (20.0) | |||
Ownership | ||||||||||
Public | 467 | 54 | (10.4) | 0.604 | 46 | (9.0) | 0.490 | 100 | (17.6) | 0.392 |
Private | 5558 | 702 | (11.2) | 619 | (10.0) | 1321 | (19.2) | |||
Number of beds | ||||||||||
Low | 1645 | 252 | (13.3) | <.0001 | 169 | (9.3) | 0.054 | 421 | (20.4) | 0.116 |
Middle | 1747 | 245 | (12.3) | 173 | (9.0) | 418 | (19.3) | |||
High | 2633 | 259 | (9.0) | 323 | (10.9) | 582 | (18.1) | |||
Number of physicians per bed | ||||||||||
Very low | 1232 | 188 | (13.2) | <.0001 | 134 | (9.8) | 0.269 | 322 | (20.7) | 0.002 |
Low | 1960 | 307 | (13.5) | 205 | (9.5) | 512 | (20.7) | |||
High | 1208 | 119 | (9.0) | 129 | (9.7) | 248 | (17.0) | |||
Very high | 1625 | 142 | (8.0) | 197 | (10.8) | 339 | (17.3) | |||
MRI | ||||||||||
Yes | 5179 | 634 | (10.9) | 0.134 | 579 | (10.1) | 0.433 | 1213 | (19.0) | 0.591 |
Year | ||||||||||
2003 | 189 | 12 | (6.0) | 0.002 | 16 | (7.8) | 0.355 | 28 | (12.9) | 0.004 |
2004 | 262 | 19 | (6.8) | 32 | (10.9) | 51 | (16.3) | |||
2005 | 338 | 51 | (13.1) | 32 | (8.7) | 83 | (19.7) | |||
2006 | 393 | 33 | (7.8) | 38 | (8.8) | 71 | (15.3) | |||
2007 | 421 | 44 | (9.5) | 46 | (9.9) | 90 | (17.6) | |||
2008 | 471 | 69 | (12.8) | 59 | (11.1) | 128 | (21.4) | |||
2009 | 526 | 57 | (9.8) | 45 | (7.9) | 102 | (16.2) | |||
2010 | 543 | 78 | (12.6) | 68 | (11.1) | 146 | (21.2) | |||
2011 | 855 | 120 | (12.3) | 86 | (9.1) | 206 | (19.4) | |||
2012 | 997 | 148 | (12.9) | 130 | (11.5) | 278 | (21.8) | |||
2013 | 1030 | 125 | (10.8) | 113 | (9.9) | 238 | (18.8) | |||
Total | 6025 | 756 | (11.2) | 665 | (9.9) | 1421 | (19.1) |
Kaplan-Meier curves of 30-day readmissions for pneumonia according to number of doctors per bed
Cox proportional hazard models of 30-day readmissions for pneumonia
30-day pneumonia-specific readmission | 30-day pneumonia-unrelated readmission | 30-day all-cause readmission | |||||||
---|---|---|---|---|---|---|---|---|---|
HR | 95% CI | HR | 95% CI | HR | 95% CI | ||||
<Individual level> | |||||||||
Sex | |||||||||
Men | 1.000 | 1.000 | 1.000 | ||||||
Women | 1.010 | 0.875 | 1.166 | 1.072 | 0.930 | 1.235 | 1.040 | 0.940 | 1.150 |
Age | |||||||||
65–69 | 1.000 | 1.000 | 1.000 | ||||||
70–74 | 1.223 | 0.968 | 1.547 | 1.128 | 0.903 | 1.410 | 1.174 | 0.999 | 1.380 |
75–79 | 1.069 | 0.843 | 1.355 | 1.093 | 0.875 | 1.364 | 1.090 | 0.927 | 1.282 |
80–84 | 1.101 | 0.864 | 1.402 | 1.046 | 0.830 | 1.318 | 1.086 | 0.918 | 1.283 |
≥ 85 | 1.175 | 0.907 | 1.522 | 0.919 | 0.703 | 1.201 | 1.058 | 0.879 | 1.274 |
Income | |||||||||
Medical aid | 1.323 | 1.020 | 1.717 | 0.796 | 0.586 | 1.080 | 1.048 | 0.861 | 1.276 |
Low | 1.037 | 0.864 | 1.245 | 1.089 | 0.916 | 1.294 | 1.064 | 0.938 | 1.205 |
Middle | 1.031 | 0.868 | 1.223 | 0.965 | 0.817 | 1.141 | 0.993 | 0.881 | 1.118 |
High | 1.000 | 1.000 | 1.000 | ||||||
Prior year LOS | 0.836 | 0.710 | 0.983 | 1.181 | 1.001 | 1.393 | 0.997 | 0.888 | 1.120 |
Prior year number of primary care visits | 0.919 | 0.823 | 1.027 | 0.945 | 0.846 | 1.056 | 0.929 | 0.859 | 1.005 |
Prior year number of emergency department (ED) visits | 1.008 | 0.990 | 1.025 | 0.995 | 0.965 | 1.025 | 1.003 | 0.988 | 1.019 |
Prior year cost (1000won) | 1.107 | 1.015 | 1.206 | 0.904 | 0.828 | 0.986 | 1.001 | 0.942 | 1.064 |
Pathway | |||||||||
Outpatient | 1.000 | 1.000 | 1.000 | ||||||
Emergency | 1.113 | 0.959 | 1.291 | 1.002 | 0.866 | 1.161 | 1.053 | 0.949 | 1.168 |
LOS of the index hospitalization | 1.250 | 1.149 | 1.360 | 1.262 | 1.162 | 1.370 | 1.236 | 1.165 | 1.311 |
Septicemia/shock | |||||||||
No | 1.000 | 1.000 | 1.000 | ||||||
Yes | 1.177 | 0.846 | 1.638 | 1.298 | 0.931 | 1.810 | 1.223 | 0.968 | 1.545 |
Cancer | |||||||||
No | 1.000 | 1.000 | 1.000 | ||||||
Yes | 0.540 | 0.424 | 0.687 | 1.212 | 1.015 | 1.447 | 0.877 | 0.762 | 1.009 |
Dementia | |||||||||
No | 1.000 | 1.000 | 1.000 | ||||||
Yes | 0.605 | 0.414 | 0.885 | 1.126 | 0.832 | 1.526 | 0.837 | 0.660 | 1.062 |
heart failure | |||||||||
No | 1.000 | 1.000 | 1.000 | ||||||
Yes | 0.695 | 0.492 | 0.980 | 1.181 | 0.904 | 1.544 | 0.930 | 0.754 | 1.148 |
Vascular or circulatory disease | |||||||||
No | 1.000 | 1.000 | 1.000 | ||||||
Yes | 0.749 | 0.584 | 0.961 | 1.155 | 0.938 | 1.422 | 0.968 | 0.826 | 1.134 |
COPD | |||||||||
No | 1.000 | 1.000 | 1.000 | ||||||
Yes | 0.897 | 0.760 | 1.059 | 1.171 | 1.003 | 1.367 | 1.029 | 0.919 | 1.152 |
Asthma | |||||||||
No | 1.000 | 1.000 | 1.000 | ||||||
Yes | 1.221 | 1.041 | 1.432 | 1.252 | 1.070 | 1.466 | 1.222 | 1.093 | 1.367 |
Renal failure | |||||||||
No | 1.000 | 1.000 | 1.000 | ||||||
Yes | 0.842 | 0.600 | 1.182 | 1.122 | 0.840 | 1.500 | 0.977 | 0.784 | 1.217 |
Liver disease | |||||||||
No | 1.000 | 1.000 | 1.000 | ||||||
Yes | 0.848 | 0.592 | 1.214 | 1.155 | 0.845 | 1.577 | 0.993 | 0.785 | 1.257 |
<Hospital level> | |||||||||
Hospital classification | |||||||||
Teaching hospital or general hospital | 1.000 | 1.000 | 1.000 | ||||||
Hospital | 1.078 | 0.845 | 1.373 | 0.929 | 0.706 | 1.223 | 1.005 | 0.839 | 1.205 |
Ownership | |||||||||
Public | 1.000 | 1.000 | 1.000 | ||||||
Private | 1.201 | 0.906 | 1.591 | 1.144 | 0.851 | 1.536 | 1.169 | 0.955 | 1.431 |
The number of beds | |||||||||
Low | 1.043 | 0.779 | 1.395 | 0.802 | 0.591 | 1.088 | 0.901 | 0.732 | 1.109 |
Middle | 0.945 | 0.746 | 1.198 | 0.754 | 0.597 | 0.953 | 0.835 | 0.708 | 0.984 |
High | 1.000 | 1.000 | 1.000 | ||||||
The number of doctors per bed | |||||||||
Q1 | 1.334 | 0.976 | 1.823 | 1.217 | 0.888 | 1.669 | 1.276 | 1.026 | 1.587 |
Q2 | 1.406 | 1.072 | 1.843 | 1.168 | 0.898 | 1.519 | 1.280 | 1.064 | 1.540 |
Q3 | 1.009 | 0.789 | 1.290 | 1.036 | 0.829 | 1.295 | 1.033 | 0.878 | 1.215 |
Q4 | 1.000 | 1.000 | 1.000 | ||||||
MRI | |||||||||
No | 1.000 | 1.000 | 1.000 | ||||||
Yes | 1.182 | 0.935 | 1.495 | 1.154 | 0.883 | 1.508 | 1.157 | 0.971 | 1.379 |
Year | |||||||||
2003 | 1.000 | 1.000 | 1.000 | ||||||
2004 | 1.065 | 0.563 | 2.014 | 1.318 | 0.759 | 2.289 | 1.234 | 0.813 | 1.875 |
2005 | 1.544 | 0.885 | 2.694 | 1.115 | 0.653 | 1.905 | 1.352 | 0.919 | 1.990 |
2006 | 1.065 | 0.563 | 2.014 | 0.874 | 0.508 | 1.505 | 0.863 | 0.575 | 1.294 |
2007 | 1.544 | 0.885 | 2.694 | 1.043 | 0.622 | 1.749 | 1.027 | 0.699 | 1.510 |
2008 | 1.065 | 0.563 | 2.014 | 1.181 | 0.715 | 1.950 | 1.203 | 0.829 | 1.744 |
2009 | 1.544 | 0.885 | 2.694 | 0.895 | 0.534 | 1.500 | 0.943 | 0.644 | 1.380 |
2010 | 1.065 | 0.563 | 2.014 | 1.043 | 0.634 | 1.716 | 1.085 | 0.751 | 1.568 |
2011 | 1.544 | 0.885 | 2.694 | 0.938 | 0.566 | 1.552 | 1.000 | 0.691 | 1.447 |
2012 | 1.065 | 0.563 | 2.014 | 1.197 | 0.736 | 1.948 | 1.182 | 0.825 | 1.693 |
2013 | 1.544 | 0.885 | 2.694 | 1.125 | 0.689 | 1.838 | 1.032 | 0.717 | 1.484 |