Background
Methods
Data source
Study Population
Demographics, comorbidities, and care settings
Medication-related adverse events
Readmissions
Statistical analyses
Results
Cohort characteristics
Characteristic | Index Events n (%) n = 439,682 |
---|---|
Age | |
< 40 | 12,878 (2.9) |
40–49 | 25,172 (5.7) |
50–59 | 64,364 (14.6) |
60–69 | 95,136 (21.6) |
70–79 | 103,821 (23.6) |
80–89 | 101,941 (23.2) |
90+ | 36,371 (8.3) |
Sex | |
Female | 225,570 (51.3) |
Male | 214,111 (48.7) |
Primary payera | |
Private insurance | 75,983 (17.3) |
Medicare | 295,655 (67.2) |
Medicaid | 39,091 (8.9) |
Self-pay | 16,303 (3.7) |
No charge | 2308 (0.5) |
Median household income | |
$66,000+ | 88,803 (20.2) |
$51,000 - $65,999 | 99,932 (22.7) |
$40,000 - $50,999 | 118,495 (27.0) |
$1 - $39,999 | 126,668 (28.8) |
Missing | 5783 (1.3) |
Length of stay | |
0–7 days | 306,786 (69.8) |
> 7 days | 132,896 (30.2) |
Discharge disposition | |
Routine | 174,933 (39.8) |
Transfer: short-term hospital | 8551 (1.9) |
Transfer: other type of facility | 164,884 (37.5) |
Home health care | 86,989 (19.8) |
Against medical advice | 3531 (0.8) |
Discharged alive, destination unknown | 794 (0.2) |
Comorbidities | |
0–2 | 110,756 (25.2) |
3–4 | 166,434 (37.9) |
5–6 | 107,199 (24.4) |
7+ | 55,292 (12.6) |
Bed size of hospital | |
Small | 64,949 (14.8) |
Medium | 120,363 (27.4) |
Large | 254,370 (57.9) |
Control/ownership of hospital | |
Government, non-federal (public) | 53,708 (12.2) |
Private, not-for-profit (voluntary) | 326,024 (74.1) |
Private, investor-owned (proprietary) | 59,950 (13.6) |
Teaching status of hospital | |
Metropolitan teaching | 278,770 (63.4) |
Metropolitan non-teaching | 118,548 (27.0) |
Non-metropolitan | 42,364 (9.6) |
Readmissions
All Index Encounters | Index Encounters With Medication-Related Adverse Event | Index Encounters Without Medication-Related Adverse Event | |||
---|---|---|---|---|---|
n = 47,170 / 439,682; Readmission Rate = 10.7% | n (%) | n = 3200 / 20,822; Readmission Rate = 15.4% | n (%) | n = 43,970 / 418,860; Readmission Rate = 10.5% | n (%) |
Acute cerebrovascular disease | 5833 (12.4) | Septicemia | 464 (14.5) | Acute cerebrovascular disease | 5591 (12.7) |
Septicemia | 5197 (11.0) | Acute cerebrovascular disease | 241 (7.5) | Septicemia | 4733 (10.8) |
Congestive heart failure; nonhypertensive | 1974 (4.2) | Congestive heart failure; nonhypertensive | 165 (5.1) | Congestive heart failure; nonhypertensive | 1809 (4.1) |
Acute and unspecified renal failure | 1852 (3.9) | Acute and unspecified renal failure | 131 (4.1) | Acute and unspecified renal failure | 1720 (3.9) |
Urinary tract infections | 1462 (3.1) | Pneumonia | 118 (3.7) | Urinary tract infections | 1356 (3.1) |
Cardiac dysrhythmias | 1412 (3.0) | Urinary tract infections | 106 (3.3) | Cardiac dysrhythmias | 1321 (3.0) |
Gastrointestinal hemorrhage | 1329 (2.8) | Cardiac dysrhythmias | 91 (2.8) | Gastrointestinal hemorrhage | 1252 (2.8) |
Pneumonia | 1272 (2.7) | Respiratory failure; insufficiency; arrest | 88 (2.7) | Late effects of cerebrovascular disease | 1158 (2.6) |
Aspiration pneumonitis; food/vomitus | 1223 (2.6) | Complications of surgical procedures or medical care | 86 (2.7) | Pneumonia | 1154 (2.6) |
Late effects of cerebrovascular disease | 1193 (2.5) | Aspiration pneumonitis; food/vomitus | 80 (2.5) | Aspiration pneumonitis; food/vomitus | 1143 (2.6) |
Medication-related adverse event | Time to Readmission Median (IQR) | Time to Readmission Quartiles | p valuea | |||
---|---|---|---|---|---|---|
Quartile 1 n (%) | Quartile 2 n (%) | Quartile 3 n (%) | Quartile 4 n (%) | |||
Any Readmission | 1.0–4.0 days | 4.1–10.0 days | 10.1–18.6 days | 18.7–30.0 days | ||
No | 10.0 (4.0–18.5) | 10,961 (24.9) | 11,050 (25.1) | 10,364 (23.6) | 11,595 (26.4) | 0.492 |
Yes | 10.4 (4.5–18.8) | 734 (22.9) | 815 (25.5) | 767 (24.0) | 883 (27.6) | |
AIS Readmission | 1.0–2.3 days | 2.4–6.8 days | 6.9–15.0 days | 15.1–30.0 days | ||
No | 6.9 (2.2–15.1) | 1396 (23.5) | 1329 (22.4) | 1720 (28.9) | 1499 (25.2) | 0.003 |
Yes | 6.7 (3.4–13.5) | 31 (11.8) | 83 (31.8) | 89 (34.1) | 58 (22.3) | |
Non-AIS Readmission | 1.0–4.4 days | 4.5–10.5 days | 10.6–18.9 days | 19.0–30.0 days | ||
No | 10.5 (4.4–18.9) | 8805 (23.2) | 9547 (25.1) | 9238 (24.3) | 10,436 (27.4) | 0.819 |
Yes | 10.7 (4.7–19.0) | 651 (22.1) | 731 (24.9) | 718 (24.5) | 837 (28.5) |
Factors associated with readmission
Medication-related adverse event | 30-Day Readmission | p valuea | AORb(95% CI) | |
---|---|---|---|---|
Yes n (%) | No n (%) | |||
Any Readmission | ||||
No | 43,970 (93.2) | 374,890 (95.5) | <.001 | Reference |
Yes | 3200 (6.8) | 17,622 (4.5) | 1.22 (1.14–1.30)*** | |
AIS Readmission | ||||
No | 5944 (95.8) | 412,916 (95.3) | 0.172 | Reference |
Yes | 261 (4.2) | 20,561 (4.7) | 0.91 (0.75–1.10) | |
Non-AIS Readmission | ||||
No | 38,026 (92.8) | 380,834 (95.5) | <.001 | Reference |
Yes | 2939 (7.2) | 17,883 (4.5) | 1.26 (1.17–1.35)*** |
Characteristic | Any Readmission | p valuea | AORb(95% CI) | AIS Readmission | p valuea | AORb(95% CI) | Non-AIS Readmission | p valuea | AORb(95% CI) | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Yes n (%) n = 47,170 | No n (%)n = 392,512 | Yes n (%)n = 6205 | No n (%)n = 433,477 | Yes n (%)n = 40,965 | No n (%)n = 398,717 | |||||||
Age | ||||||||||||
< 40 | 1311 (2.8) | 11,567 (2.9) | <.001 | 1.12 (1.00–1.26)* | 135 (2.2) | 12,743 (2.9) | <.001 | 0.76 (0.55–1.04) | 1176 (2.9) | 11,702 (2.9) | <.001 | 1.20 (1.06–1.36)** |
40–49 | 2379 (5.0) | 22,793 (5.8) | Reference | 365 (5.9) | 24,807 (5.7) | Reference | 2014 (4.9) | 23,158 (5.8) | Reference | |||
50–59 | 6212 (13.2) | 58,151 (14.8) | 0.97 (0.88–1.05) | 929 (15.0) | 63,434 (14.6) | 1.01 (0.83–1.21) | 5283 (12.9) | 59,080 (14.8) | 0.96 (0.87–1.05) | |||
60–69 | 9649 (20.5) | 85,487 (21.8) | 0.93 (0.85–1.01) | 1431 (23.1) | 93,705(21.6) | 1.08 (0.90–1.30) | 8218 (20.1) | 86,918 (21.8) | 0.90 (0.83–0.99)* | |||
70–79 | 11,992 (25.4) | 91,829 (23.4) | 0.97 (0.88–1.06) | 1590 (25.6) | 102,231 (23.6) | 1.12 (0.91–1.37) | 10,402 (25.4) | 93,419 (23.4) | 0.95 (0.86–1.05) | |||
80–89 | 11,861 (25.1) | 90,080 (22.9) | 0.93 (0.85–1.02) | 1389 (22.4) | 100,551 (23.2) | 0.99 (0.81–1.22) | 10,472 (25.6) | 91,469 (22.9) | 0.93 (0.84–1.02) | |||
90+ | 3766 (8.0) | 32,605 (8.3) | 0.82 (0.74–0.91)*** | 366 (5.9) | 36,005(8.3) | 0.72 (0.56–0.93)* | 3400 (8.3) | 32,971 (8.3) | 0.84 (0.75–0.94)** | |||
Sex | ||||||||||||
Female | 24,509 (52.0) | 201,061 (51.2) | 0.087 | Reference | 3024 (48.7) | 222,546 (51.3) | 0.013 | Reference | 21,485 (52.4) | 204,085 (51.2) | 0.005 | Reference |
Male | 22,661 (48.0) | 191,450 (48.8) | 1.03 (1.00–1.07) | 3181 (51.3) | 210,930 (48.7) | 1.07 (0.99–1.17) | 19,480 (47.6) | 194,631 (48.8) | 1.02 (0.99–1.06) | |||
Primary payerc | ||||||||||||
Private insurance | 5834 (12.4) | 70,149 (17.9) | <.001 | Reference | 1002 (16.1) | 74,981 (17.3) | 0.159 | Reference | 4832 (11.8) | 71,151 (17.8) | <.001 | Reference |
Medicare | 34,216 (72.5) | 261,439 (66.6) | 1.33 (1.26–1.40)*** | 4160 (67.0) | 291,495 (67.2) | 1.02 (0.90–1.16) | 30,057 (73.4) | 265,598 (66.6) | 1.39 (1.30–1.47)*** | |||
Medicaid | 4794 (10.2) | 34,297 (8.7) | 1.41 (1.32–1.51)*** | 636 (10.2) | 38,455 (8.9) | 1.20 (1.02–1.42)* | 4158 (10.2) | 34,933 (8.8) | 1.44 (1.34–1.55)*** | |||
Self-pay | 1264 (2.7) | 15,040 (3.8) | 1.04 (0.93–1.16) | 231 (3.7) | 16,072 (3.7) | 1.05 (0.81–1.37) | 1033 (2.5) | 15,270 (3.8) | 1.03 (0.92–1.16) | |||
No charge | 169 (0.4) | 2139 (0.5) | 1.01 (0.72–1.41) | 42 (0.7) | 2266 (0.5) | 1.38 (0.85–2.25) | 127 (0.3) | 2181 (0.5) | 0.92 (0.64–1.34) | |||
Median household income | ||||||||||||
$66,000+ | 9260 (19.6) | 79,543 (20.3) | <.001 | Reference | 1312 (21.1) | 87,492 (20.2) | 0.014 | Reference | 7948 (19.4) | 80,855 (20.3) | <.001 | Reference |
$51,000 - $65,999 | 10,175 (21.6) | 89,756 (22.9) | 0.97 (0.92–1.02) | 1327 (21.4) | 98,605 (22.7) | 0.90 (0.79–1.03) | 8848 (21.6) | 91,083 (22.8) | 0.99 (0.94–1.04) | |||
$40,000 - $50,999 | 12,546 (26.6) | 105,950 (27.0) | 1.01 (0.96–1.06) | 1544 (24.9) | 116,952 (27.0) | 0.88 (0.78–1.01) | 11,002 (26.9) | 107,493 (27.0) | 1.04 (0.98–1.09) | |||
$1 - $39,999 | 14,620 (31.0) | 112,048 (28.5) | 1.08 (1.03–1.14)** | 1952 (31.5) | 124,717 (28.8) | 1.03 (0.91–1.17) | 12,668 (30.9) | 114,000 (28.6) | 1.09 (1.03–1.15)** | |||
Missing | 569 (1.2) | 5214 (1.3) | n/a | 71 (1.1) | 5712 (1.3) | n/a | 498 (1.2) | 5285 (1.3) | n/a | |||
Length of stay | ||||||||||||
0–7 days | 27,070 (57.4) | 279,716 (71.3) | <.001 | Reference | 4557 (73.4) | 302,229 (69.7) | <.001 | Reference | 22,513 (55.0) | 284,273 (71.3) | <.001 | Reference |
> 7 days | 20,100 (42.6) | 112,796 (28.7) | 1.38 (1.33–1.43)*** | 1648 (26.6) | 131,248 (30.3) | 0.75 (0.68–0.83)*** | 18,452 (45.0) | 114,444 (28.7) | 1.50 (1.44–1.55)*** | |||
Discharge disposition | ||||||||||||
Routine | 13,069 (27.7) | 161,864 (41.2) | <.001 | Reference | 2265 (36.5) | 172,667 (39.8) | <.001 | Reference | 10,803 (26.4) | 164,129 (41.2) | <.001 | Reference |
Transfer: short-term hospital | 1306 (2.8) | 7245 (1.8) | 1.91 (1.70–2.14)*** | 327 (5.3) | 8224 (1.9) | 3.08 (2.44–3.90)*** | 979 (2.4) | 7571 (1.9) | 1.63 (1.44–1.84)*** | |||
Transfer: other type of facility | 22,491 (47.7) | 142,394 (36.3) | 1.52 (1.45–1.59)*** | 2168 (34.9) | 162,716 (37.5) | 1.06 (0.95–1.19) | 20,322 (49.6) | 144,562 (36.3) | 1.59 (1.51–1.67)*** | |||
Home health care | 9693 (20.5) | 77,296 (19.7) | 1.26 (1.20–1.32)*** | 1298 (20.9) | 85,691 (19.8) | 1.19 (1.07–1.33)** | 8395 (20.5) | 78,594 (19.7) | 1.27 (1.20–1.34)*** | |||
Against medical advice | 595 (1.3) | 2936 (0.7) | 2.41 (2.08–2.79)*** | ## | ## | 3.12 (2.29–4.23)*** | 450 (1.1) | 3081 (0.8) | 2.13 (1.83–2.47)*** | |||
Discharged alive, destination unknown | 16 (0.0) | 777 (0.2) | 0.20 (0.11–0.38)*** | ## | ## | 0.16 (0.02–1.08) | 15 (0.0) | 779 (0.2) | 0.21 (0.11–0.42)*** | |||
Comorbidities | ||||||||||||
0–2 | 7125 (15.1) | 103,632 (26.4) | <.001 | Reference | 1364 (22.0) | 109,392 (25.2) | 0.001 | Reference | 5761 (14.1) | 104,995 (26.3) | <.001 | Reference |
3–4 | 16,020 (34.0) | 150,414 (38.3) | 1.36 (1.30–1.43)*** | 2400 (38.7) | 164,034 (37.8) | 1.20 (1.07–1.34)** | 13,620 (33.2) | 152,814 (38.3) | 1.40 (1.32–1.47)*** | |||
5–6 | 14,413 (30.6) | 92,786 (23.6) | 1.78 (1.68–1.87)*** | 1629 (26.2) | 105,571 (24.4) | 1.31 (1.16–1.47)*** | 12,784 (31.2) | 94,415 (23.7) | 1.86 (1.75–1.97)*** | |||
7+ | 9612 (20.4) | 45,680 (11.6) | 2.20 (2.08–2.34)*** | 812 (13.1) | 54,479 (12.6) | 1.34 (1.15–1.55)*** | 8800 (21.5) | 46,492 (11.7) | 2.34 (2.19–2.49)*** | |||
Bed size of hospital | ||||||||||||
Small | 6334 (13.4) | 58,615 (14.9) | <.001 | Reference | 920 (14.8) | 64,028 (14.8) | 0.533 | Reference | 5414 (13.2) | 59,535 (14.9) | <.001 | Reference |
Medium | 12,747 (27.0) | 107,616 (27.4) | 1.04 (0.98–1.11) | 1762 (28.4) | 118,601 (27.4) | 1.02 (0.88–1.17) | 10,985 (26.8) | 109,379 (27.4) | 1.05 (0.97–1.12) | |||
Large | 28,089 (59.5) | 226,281 (57.6) | 1.08 (1.02–1.15)* | 3523 (56.8) | 250,847 (57.9) | 1.00 (0.88–1.13) | 24,566 (60.0) | 229,803 (57.6) | 1.10 (1.02–1.18)* | |||
Control/ownership of hospital | ||||||||||||
Government, non-federal (public) | 5348 (11.3) | 48,360 (12.3) | <.001 | Reference | 732 (11.8) | 52,976 (12.2) | 0.081 | Reference | 4616 (11.3) | 49,093 (12.3) | <.001 | Reference |
Private, not-for-profit (voluntary) | 34,592 (73.3) | 291,432 (74.2) | 1.04 (0.97–1.11) | 4529 (73.0) | 321,495 (74.2) | 1.00 (0.86–1.16) | 30,063 (73.4) | 295,961 (74.2) | 1.04 (0.97–1.12) | |||
Private, investor-owned (proprietary) | 7229 (15.3) | 52,720 (13.4) | 1.20 (1.12–1.29)*** | 944 (15.2) | 59,006 (13.6) | 1.09 (0.91–1.30) | 6286 (15.3) | 53,664 (13.5) | 1.21 (1.13–1.30)*** | |||
Teaching status of hospital | ||||||||||||
Metropolitan teaching | 30,821 (65.3) | 247,949 (63.2) | <.001 | Reference | 3856 (62.1) | 274,914 (63.4) | 0.161 | Reference | 26,965 (65.8) | 251,806 (63.2) | <.001 | Reference |
Metropolitan non-teaching | 12,662 (26.8) | 105,886 (27.0) | 0.97 (0.93–1.01) | 1786 (28.8) | 116,762 (26.9) | 1.08 (0.97–1.19) | 10,876 (26.5) | 107,671 (27.0) | 0.95 (0.91–1.00)* | |||
Non-metropolitan | 3687 (7.8) | 38,677 (9.9) | 0.79 (0.73–0.85)*** | 563 (9.1) | 41,801 (9.6) | 0.92 (0.77–1.11) | 3124 (7.6) | 39,240 (9.8) | 0.77 (0.71–0.84)*** |