Background
Methods
Study design and setting
Study population
Covariates
Outcome measures
Statistical analysis
Results
ED visits for AECOPD
Patient characteristics
1 ED visit | 2 ED visits | ≥ 3 ED visits | ||
---|---|---|---|---|
Variables* | (n = 69,398) | (n = 17,005) | (n = 11,877) | P value† |
Age (y), median (IQR) | 69 (58–79) | 69 (59–78) | 67 (58–76) | <0.001‡ |
40-54 years | 11,922 (17) | 2595 (15) | 2010 (17) | <0.001 |
55-64 years | 14,807 (21) | 3815 (22) | 3288 (28) | |
65-74 years | 17,049 (25) | 4575 (27) | 3287 (28) | |
75-84 years | 16,788 (24) | 4160 (24) | 2441 (21) | |
85 years and older | 8832 (13) | 1860 (11) | 851 (7) | |
Male sex | 30,633 (44) | 7632 (45) | 5527 (47) | <0.001 |
Race/ethnicity | <0.001 | |||
Non-hispanic white | 51,557 (74) | 12,746 (75) | 8713 (73) | |
Non-hispanic black | 6349 (9) | 1702 (10) | 1577 (13) | |
Hispanic | 7715 (11) | 1732 (10) | 1068 (9) | |
Other | 2484 (4) | 569 (3) | 337 (3) | |
Missing | 1303 (2) | 256 (2) | 182 (2) | |
Insurance status | ||||
Medicare | 46,174 (67) | 11,829 (70) | 7793 (66) | <0.001 |
Medicaid | 8092 (12) | 2417 (14) | 2413 (20) | |
Private | 7931 (11) | 1299 (8) | 729 (6) | |
Self-pay | 4322 (6) | 71 (4) | 431 (4) | |
Other | 2870 (4) | 699 (4) | 508 (4) | |
Quartiles for median household income of patient’s ZIP code | <0.001 | |||
1 (lowest) | 22,390 (32) | 5749 (34) | 4415 (37) | |
2 | 19,307 (28) | 4800 (28) | 3325 (28) | |
3 | 15,904 (23) | 3797 (22) | 2497 (21) | |
4 (highest) | 10,524 (15) | 2308 (14) | 1372 (12) | |
Missing | 1273 (2) | 351 (2) | 268 (2) | |
Patient residence | <0.001 | |||
Counties of ≥ 1 million population | 42,303 (61) | 10,245 (60) | 7123 (60) | |
Counties of 250,000-999,999 population | 17,379 (25) | 4319 (25) | 2983 (25) | |
Counties of 50,000-249,999 population | 4103 (6) | 1053 (6) | 750 (6) | |
Counties of < 50,000 population | 5590 (8) | 1335 (8) | 956 (8) | |
State | 0.02 | |||
California | 33,741 (49) | 8297 (49) | 5942 (50) | |
Florida | 35,657 (51) | 8708 (51) | 5935 (50) | |
Any comorbidities | 54,633 (79) | 13,888 (82) | 9644 (81) | <0.001 |
Selected comorbidities§ | ||||
Congestive heart failure | 13,607 (20) | 3831 (23) | 2708 (23) | <0.001 |
Pulmonary circulation disorders | 674 (1) | 269 (2) | 198 (2) | <0.001 |
Diabetes, uncomplicated | 14,813 (21) | 3931 (23) | 2939 (25) | <0.001 |
Obesity | 7195 (10) | 1935 (11) | 1437 (12) | <0.001 |
Depression | 6357 (9) | 1886 (11) | 1479 (12) | <0.001 |
Psychoses | 3233 (5) | 1001 (6) | 847 (7) | <0.001 |
Drug abuse | 1430 (2) | 458 (3) | 528 (4) | <0.001 |
2 (vs. 1) ED visits | ≥ 3 (vs. 1) ED visits | |||
---|---|---|---|---|
Variables | Odds ratio (95% CI) | P value | Odds ratio (95% CI) | P value |
Age, y | <0.001 | <0.001 | ||
40-54 years | 1 [reference] | 1 [reference] | ||
55-64 years |
1.15 (1.09-1.22)
| <0.001 |
1.31 (1.23-1.39)
| <0.001 |
65-74 years |
1.14 (1.07-1.22)
| <0.001 |
1.11 (1.03-1.20)
| 0.006 |
75-84 years | 1.05 (0.98-1.12) | 0.10 |
0.86 (0.79-0.93)
| <0.001 |
85 years and older |
0.90 (0.83-0.97)
| 0.03 |
0.58 (0.52-0.64)
| <0.001 |
Male sex |
1.04 (1.00-1.08)
| 0.048 |
1.12 (1.07-1.17)
| <0.001 |
Race/ethnicity | ||||
Non-hispanic white |
1.15 (1.08-1.21)
| <0.001 |
1.32 (1.23-1.41)
| <0.001 |
Non-hispanic black |
1.17 (1.09-1.27)
| <0.001 |
1.59 (1.46-1.73)
| <0.001 |
Hispanic | 1 [reference] | 1 [reference] | ||
Other | 1.07 (0.96-1.19) | 0.29 | 1.07 (0.96-1.19) | 0.33 |
Insurance status | ||||
Medicare |
1.58 (1.47-1.69)
| <0.001 |
2.10 (1.92-2.29)
| <0.001 |
Medicaid |
1.77 (1.64-1.92)
| <0.001 |
2.92 (2.66-3.20)
| <0.001 |
Private | 1 [reference] | 1 [reference] | ||
Self-pay |
1.11 (1.00-1.23)
| 0.046 | 1.05 (0.92-1.20) | 0.45 |
Other |
1.46 (1.32-1.62)
| <0.001 |
1.78 (1.57-2.02)
| <0.001 |
Quartiles for median household income of patient’s ZIP code | ||||
1 (lowest) |
1.13 (1.07-1.20)
| <0.001 |
1.29 (1.21-1.38)
| <0.001 |
2 |
1.11 (1.05-1.18)
| <0.001 |
1.22 (1.14-1.31)
| <0.001 |
3 |
1.08 (1.01-1.14)
| 0.01 |
1.14 (1.06-1.22)
| <0.001 |
4 (highest) | 1 [reference] | 1 [reference] | ||
Patient residence | ||||
Counties of ≥ 1 million population | 1.07 (1.00-1.15) | 0.06 |
1.09 (1.01-1.18)
| 0.03 |
Counties of 250,000-999,999 population | 1.07 (1.00-1.15) | 0.07 | 1.09 (1.00-1.18) | 0.06 |
Counties of 50,000-249,999 population | 1.09 (1.00-1.20) | 0.06 | 1.10 (0.99-1.23) | 0.09 |
Counties of < 50,000 population | 1 [reference] | 1 [reference] | ||
State | ||||
California | 1.01 (0.98-1.05) | 0.44 |
1.06 (1.02-1.11)
| 0.006 |
Florida | 1 [reference] | 1 [reference] | ||
Selected comorbidities* | ||||
Congestive heart failure |
1.17 (1.11-1.22)
| <0.001 |
1.24 (1.17-1.30)
| <0.001 |
Pulmonary circulation disorders |
1.41 (1.22-1.64)
| <0.001 |
1.39 (1.17-1.64)
| <0.001 |
Diabetes, uncomplicated |
1.05 (1.01-1.10)
| 0.02 |
1.13 (1.07-1.19)
| <0.001 |
Obesity | 0.99 (0.94-1.05) | 0.79 | 0.97 (0.91-1.03) | 0.31 |
Depression |
1.21 (1.14-1.28)
| <0.001 |
1.38 (1.30-1.47)
| <0.001 |
Psychoses |
1.17 (1.09-1.27)
| <0.001 |
1.27 (1.17-1.38)
| <0.001 |
Drug abuse |
1.22 (1.09-1.37)
| <0.001 |
1.66 (1.48-1.85)
| <0.001 |
California | Florida | |||||||
---|---|---|---|---|---|---|---|---|
2 (vs. 1) ED visits | ≥ 3 (vs. 1) ED visits | 2 (vs. 1) ED visits | ≥ 3 (vs. 1) ED visits | |||||
Variables | Odds ratio (95% CI) | P value | Odds ratio (95% CI) | P value | Odds ratio (95% CI) | P value | Odds ratio (95% CI) | P value |
Age, y | ||||||||
40-54 years | 1 [reference] | 1 [reference] | 1 [reference] | 1 [reference] | ||||
55-64 years |
1.20 (1.11-1.31)
| <0.001 |
1.32 (1.21-1.45)
| <0.001 |
1.11 (1.03-1.21)
| 0.008 |
1.28 (1.17-1.41)
| <0.001 |
65-74 years |
1.17 (1.07-1.29)
| 0.001 |
1.16 (1.04-1.29)
| 0.008 |
1.13 (1.03-1.23)
| 0.01 | 1.05 (0.95-1.17) | 0.34 |
75-84 years |
1.15 (1.04-1.27)
| 0.007 | 0.90 (0.80-1.01) | 0.08 | 0.98 (0.89-1.08) | 0.73 |
1.81 (0.73-0.91)
| <0.001 |
85 years and older | 0.99 (0.88-1.11) | 0.83 |
0.61 (0.53-0.70)
| <0.001 |
0.85 (0.76-0.96)
| 0.007 |
0.54 (0.47-0.63)
| <0.001 |
Male sex |
1.05 (1.00-1.10)
| 0.048 |
1.13 (1.06-1.19)
| <0.001 | 1.03 (0.98-1.08) | 0.30 |
1.11 (1.05-1.18)
| <0.001 |
Race/ethnicity | ||||||||
Non-hispanic white |
1.15 (1.06-1.25)
| 0.001 |
1.32 (1.20-1.46)
| <0.001 |
1.13 (1.03-1.23)
| 0.004 |
1.30 (1.17-1.44)
| <0.001 |
Non-hispanic black |
1.24 (1.11-1.38)
| 0.001 |
1.71 (1.51-1.93)
| <0.001 |
1.12 (1.01-1.25)
| 0.04 |
1.49 (1.31-1.69)
| <0.001 |
Hispanic | 1 [reference] | 1 [reference] | 1 [reference] | 1 [reference] | ||||
Other | 1.23 (1.00-1.28) | 0.06 | 1.16 (0.99-1.35) | 0.06 | 0.85 (0.65-1.10) | 0.21 | 0.80 (0.57-1.12) | 0.20 |
Insurance status | ||||||||
Medicare |
1.55 (1.41-1.71)
| <0.001 |
1.88 (1.67-2.11)
| <0.001 |
1.63 (1.47-1.81)
| <0.001 |
2.41 (2.11-2.75)
| <0.001 |
Medicaid |
1.65 (1.48-1.83)
| <0.001 |
2.58 (2.29-2.92)
| <0.001 |
1.96 (1.75-2.20)
| <0.001 |
3.38 (2.93-3.89)
| <0.001 |
Private | 1 [reference] | 1 [reference] | 1 [reference] | 1 [reference] | ||||
Self-pay | 1.10 (0.95-1.28) | 0.21 | 1.05 (0.87-1.27) | 0.62 | 1.13 (0.98-1.29) | 0.09 | 1.11 (0.92-1.33) | 0.29 |
Other |
1.34 (1.14-1.57)
| <0.001 |
1.34 (1.10-1.62)
| 0.004 |
1.58 (1.37-1.81)
| <0.001 |
2.25 (1.90-2.67)
| <0.001 |
Quartiles for median household income of patient’s ZIP code | ||||||||
1 (lowest) |
1.24 (1.13-1.37)
| <0.001 |
1.18 (1.09-1.28)
| <0.001 |
1.10 (1.01-1.19)
| 0.03 |
1.22 (1.11-1.34)
| <0.001 |
2 |
1.22 (1.12-1.32)
| <0.001 |
1.24 (1.13-1.37)
| <0.001 | 1.03 (0.95-1.11) | 0.49 |
1.19 (1.08-1.31)
| <0.001 |
3 |
1.12 (1.03-1.21)
| 0.001 |
1.20 (1.09-1.33)
| <0.001 | 1.04 (0.95-1.13) | 0.40 | 1.07 (0.97-1.19) | 0.19 |
4 (highest) | 1 [reference] | 1 [reference] | 1 [reference] | 1 [reference] | ||||
Patient residence | ||||||||
Counties of ≥ 1 million population | 1.00 (0.89-1.12) | 0.99 | 0.97 (0.86-1.11) | 0.69 |
1.10 (1.01-1.20)
| 0.03 |
1.16 (1.04-1.28)
| 0.005 |
Counties of 250,000-999,999 population | 1.06 (0.94-1.20) | 0.34 | 1.02 (0.89-1.17) | 0.78 | 1.07 (0.98-1.17) | 0.16 | 1.09 (0.98-1.22) | 0.10 |
Counties of 50,000-249,999 population | 1.01 (0.87-1.06) | 0.92 | 1.04 (0.89-1.22) | 0.65 |
1.16 (1.02-1.32)
| 0.02 | 1.10 (0.94-1.28) | 0.23 |
Counties of < 50,000 population | 1 [reference] | 1 [reference] | 1 [reference] | 1 [reference] | ||||
Selected comorbidities | ||||||||
Congestive heart failure |
1.16 (1.09-1.23)
| <0.001 |
1.27 (1.18-1.36)
| <0.001 |
1.18 (1.11-1.26)
| <0.001 |
1.22 (1.13-1.31)
| <0.001 |
Pulmonary circulation disorders |
1.51 (1.22-1.86)
| <0.001 |
1.34 (1.04-1.73)
| 0.02 |
1.29 (1.05-1.60)
| 0.02 |
1.37 (1.09-1.73)
| 0.008 |
Diabetes, uncomplicated | 1.02 (0.96-1.09) | 0.47 |
1.14 (1.06-1.23)
| <0.001 |
1.08 (1.02-1.15)
| 0.009 |
1.12 (1.05-1.20)
| <0.001 |
Obesity | 1.01 (0.92-1.10) | 0.85 | 0.96 (0.87-1.06) | 0.42 | 0.98 (0.91-1.06) | 0.60 | 0.97 (0.89-1.06) | 0.50 |
Depression |
1.22 (1.11-1.33)
| <0.001 |
1.39 (1.26-1.54)
| <0.001 |
1.19 (1.10-1.28)
| <0.001 |
1.37 (1.26-1.49)
| <0.001 |
Psychoses |
1.19 (1.07-1.32)
| 0.001 |
1.26 (1.13-1.42)
| <0.001 |
1.16 (1.04-1.29)
| 0.01 |
1.28 (1.14-1.45)
| <0.001 |
Drug abuse |
1.27 (1.10-1.47)
| 0.001 |
1.72 (1.49-1.97)
| <0.001 | 1.16 (0.97-1.39) | 0.10 |
1.55 (1.30-1.86)
| <0.001 |
Variables | Risk ratio (95% CI) | P value |
---|---|---|
Age, y | ||
40-54 years | 1 [reference] | |
55-64 years |
1.07 (1.06-1.09)
| <0.001 |
65-74 years |
1.02 (1.00-1.03)
| 0.04 |
75-84 years |
0.94 (0.92-0.96)
| <0.001 |
85 years and older |
0.86 (0.85-0.88)
| <0.001 |
Male sex | ||
Race/ethnicity | ||
Non-hispanic white |
1.08 (1.06-1.09)
| <0.001 |
Non-hispanic black |
1.15 (1.13-1.17)
| <0.001 |
Hispanic | 1 [reference] | |
Other | 1.01 (0.98-1.03) | 0.62 |
Insurance status | ||
Medicare |
1.21 (1.19-1.23)
| <0.001 |
Medicaid |
1.34 (1.32-1.36)
| <0.001 |
Private | 1 [reference] | |
Self-pay | 1.01 (0.99-1.03) | 0.45 |
Other |
1.13 (1.10-1.16)
| <0.001 |
Quartiles for median household income of patient’s ZIP code | ||
1 (lowest) |
1.06 (1.05-1.08)
| <0.001 |
2 |
1.05 (1.03-1.06)
| <0.001 |
3 |
1.03 (1.01-1.04)
| <0.001 |
4 (highest) | 1 [reference] | |
Patient residence | ||
Counties of ≥ 1 million population |
1.03 (1.01-1.05)
| <0.001 |
Counties of 250,000-999,999 population |
1.04 (1.02-1.05)
| <0.001 |
Counties of 50,000-249,999 population |
1.03 (1.01-1.06)
| 0.007 |
Counties of < 50,000 population | 1 [reference] | |
State | ||
California |
1.02 (1.02-1.03)
| <0.001 |
Florida | 1 [reference] | |
Selected comorbidities | ||
Congestive heart failure |
1.05 (1.04-1.06)
| <0.001 |
Pulmonary circulation disorders |
1.13 (1.09-1.17)
| <0.001 |
Diabetes, uncomplicated |
1.04 (1.03-1.05)
| <0.001 |
Obesity |
0.97 (0.96-0.99)
| <0.001 |
Depression |
1.08 (1.07-1.10)
| <0.001 |
Psychoses |
1.08 (1.06-1.10)
| <0.001 |
Drug abuse |
1.18 (1.15-1.21)
| <0.001 |
COPD 30-day ED revisits, hospitalizations, and near-fatal events
Variables | 1 ED visit | 2 ED visits | ≥ 3 ED visits | P value |
---|---|---|---|---|
Number of ED visits for COPD, no. | 69,398 | 34,010 | 51,328 | – |
30-day ED revisit rate for COPD, % (95% CI)* | – | 10.5 (10.1-10.8) | 30.0 (29.6-30.4) | <0.001 |
Hospitalization rate for COPD, % (95% CI) | 62.3 (62.0-62.7) | 64.9 (64.4-65.4) | 62.1 (61.6-62.5) | <0.001 |
Near-fatal event rate, % (95% CI) | 5.8 (5.6-6.0) | 8.2 (7.9-8.5) | 8.8 (8.6-9.1) | <0.001 |
Variables | 1 ED visit | 2 ED visits | ≥ 3 ED visits | P value |
---|---|---|---|---|
California
| ||||
Number of ED visits for COPD, no. | 33,741 | 16,594 | 26,100 | – |
30-day ED revisit rate for COPD, % (95% CI)* | – | 11.1 (10.6-11.6) | 31.7 (31.2-32.3) | <0.001 |
Hospitalization rate for COPD, % (95% CI) | 55.7 (55.2-56.2) | 54.6 (53.9-55.4) | 54.5 (53.9-55.1) | <0.001 |
Near-fatal event rate, % (95% CI) | 6.8 (6.5-7.1) | 9.2 (8.7-9.6) | 9.6 (9.2-9.9) | <0.001 |
Florida
| ||||
Number of ED visits for COPD, no. | 35,657 | 17,416 | 25,228 | – |
30-day ED revisit rate for COPD, % (95% CI)* | – | 9.8 (9.4-10.3) | 28.2 (27.6-28.8) | <0.001 |
Hospitalization rate for COPD, % (95% CI) | 68.6 (68.1-69.0) | 71.7 (71.0-72.3) | 69.9 (69.3-70.4) | <0.001 |
Near-fatal event rate, % (95% CI) | 4.9 (4.7-5.1) | 7.3 (6.9-7.7) | 9.9 (9.5-10.3) | <0.001 |
Nebraska
| ||||
Number of ED visits for COPD, no. | 2009 | 1060 | 1301 | |
30-day ED revisit rate for COPD, % (95% CI)* | – | 8.6 (7.0-10.4) | 27.2 (24.8-29.7) | <0.001 |
Hospitalization rate for COPD, % (95% CI) | 52.5 (50.3-54.7) | 56.6 (53.6-59.6) | 53.0 (50.2-55.7) | 0.08 |
Near-fatal event rate, % (95% CI) | 6.9 (5.8-8.1) | 7.9 (6.4-9.7) | 11.2 (9.6-13.1) | <0.001 |