Table 1.
Comparison of clinical characteristics between patients with ACO versus patients with COPD alone
| Category | No. of patients (%) | P value | Standardized differencea | |
|---|---|---|---|---|
| ACO (n = 7822) | COPD alone (n = 7822) | |||
| Age group (years) | ||||
| 40–64 | 3700(47.3) | 3718(47.53) | 0.7732 | 0.00461 |
| ≥ 65 | 4122(52.7) | 4104(52.47) | ||
| Sex | ||||
| Male | 4170(53.31) | 4176(53.39) | 0.9234 | 0.00154 |
| Female | 3652(46.69) | 3646(46.61) | ||
| Charlson comorbidity index | ||||
| 0 | 1436(18.36) | 1537(19.65) | 0.3501 | 0.03368 |
| 1 | 2645(33.81) | 2603(33.28) | ||
| 2 | 1649(21.08) | 1642(20.99) | ||
| 3 | 877(11.21) | 855(10.93) | ||
| ≥ 4 | 1215(15.53) | 1185(15.15) | ||
| History of comorbidities in previous year | ||||
| Hypertension | 2741(35.04) | 2671(34.15) | 0.2394 | 0.01881 |
| Diabetes | 1558(19.92) | 1519(19.42) | 0.4328 | 0.01254 |
| Hyperlipidaemia | 1319(16.86) | 1313(16.79) | 0.898 | 0.00205 |
| Ischaemic heart disease | 633(8.09) | 595(7.61) | 0.2586 | 0.01806 |
| Sleep disorder | 600(7.67) | 559(7.15) | 0.2107 | 0.02001 |
| Alcohol-related illness | 238(3.04) | 225(2.88) | 0.5397 | 0.00981 |
| Epilepsy | 67(0.86) | 62(0.79) | 0.6585 | 0.00707 |
| Cancer | 895(11.44) | 874(11.17) | 0.596 | 0.00848 |
| Arthritis | 1552(19.84) | 1537(19.65) | 0.7632 | 0.00482 |
| Parkinson’s disease | 41(0.52) | 42(0.54) | 0.9124 | 0.00176 |
| Dementia | 72(0.92) | 86(1.1) | 0.2629 | 0.0179 |
| Obesity | 3(0.04) | 7(0.09) | 0.2058 | 0.02023 |
| Cerebrovascular disease | 621(7.94) | 606(7.75) | 0.6555 | 0.00713 |
| Atherosclerosis | 168(2.15) | 160(2.05) | 0.6553 | 0.00714 |
| History of exacerbation in previous year | ||||
| 0 | 62(0.79) | 70(0.89) | 0.4844 | 0.01118 |
| 1 | 1636(20.92) | 1688(21.58) | 0.3095 | 0.01625 |
| ≥ 2 | 6124(78.29) | 6064(77.52) | 0.2476 | 0.01849 |
| Healthcare utilization in previous year | ||||
| Hospitalization | 1327(16.96) | 1347(17.22) | 0.671 | 0.00679 |
| ED visit | 723(9.24) | 701(8.96) | 0.5409 | 0.00978 |
| Outpatient visit | 7321(93.59) | 7302(93.35) | 0.5385 | 0.00983 |
| Insurance type | ||||
| Health insurance | 7529(96.25) | 7504(95.93) | 0.3022 | 0.0165 |
| Medical-aid beneficiary | 293(3.75) | 318(4.07) | ||
| Index year | ||||
| 2003 | 1483(18.96) | 1435(18.35) | 0.3245 | 0.01575 |
| 2004 | 1107(14.15) | 1032(13.19) | 0.0809 | 0.02791 |
| 2005 | 910(11.63) | 943(12.06) | 0.4142 | 0.01306 |
| 2006 | 847(10.83) | 916(11.71) | 0.0811 | 0.0279 |
| 2007 | 765(9.78) | 816(10.43) | 0.1761 | 0.02163 |
| 2008 | 770(9.84) | 809(10.34) | 0.3006 | 0.01655 |
| 2009 | 768(9.82) | 714(9.13) | 0.1404 | 0.02358 |
| 2010 | 565(7.22) | 547(6.99) | 0.5754 | 0.00896 |
| 2011 | 607(7.76) | 610(7.8) | 0.9286 | 0.00143 |
ACO asthma-COPD overlap, COPD chronic obstructive pulmonary disease, ED emergency department
aA standardized mean difference of greater than 0.1 represents significant difference between the two cohorts