Burden of asthma and COPD overlap (ACO) in Taiwan: a nationwide population-based study

Abstract

BackgroundPatients with symptoms of both asthma and chronic obstructive pulmonary disease (COPD) may be classified with the term asthma-COPD overlap (ACO). ACO is of considerable interest as it is currently poorly characterised and has been associated with worse health outcomes and higher healthcare costs compared with COPD or asthma alone. Patients with ACO in Asia remain poorly described, and there is limited information regarding their resource utilisation compared with patients with asthma or COPD only. This study investigated the characteristics, disease burden and medical resource utilisation of patients with ACO in Taiwan.MethodsThis was a retrospective cohort study of patients identified from National Health Insurance (NHI) claims data in Taiwan in 2009–2011. Patients were classified into incident ACO, COPD or asthma cohorts according to International Classification of Disease, ninth revision, clinical modification codes in claims. Eligible patients were ≥40 years of age with 12 months’ continuous enrolment in the NHI programme pre- and post-index date (date of the first relevant medical claim).ResultsPatients with ACO (N = 22,328) and COPD (N = 69,648) were older and more likely to be male than those with asthma (N = 50,293). Patients with ACO had more comorbidities and exacerbations, with higher medication use: short-acting β2-agonist prescriptions ranged from 30.4% of patients (asthma cohort) to 43.6% (ACO cohort), and inhaled corticosteroid/long-acting β2-agonist combination prescriptions ranged from 11.1% (COPD cohort) to 35.0% (ACO cohort) in the 12 months following index. Patients with ACO generally had the highest medication costs of any cohort (long-acting muscarinic antagonist costs ranged from $227/patient [asthma cohort] to $349/patient [ACO cohort]); they also experienced more respiratory-related hospital visits than patients with asthma or COPD (mean outpatient/inpatient visits per patient post-index: 9.1/1.9 [ACO cohort] vs 5.7/1.4 [asthma cohort] and 6.4/1.7 [COPD cohort]).ConclusionsPatients with ACO in Taiwan experience a greater disease burden with greater healthcare resource utilisation, and higher costs, than patients with asthma or COPD alone.Electronic supplementary materialThe online version of this article (10.1186/s12890-017-0571-7) contains supplementary material, which is available to authorized users.

Risk factors of chronic obstructive pulmonary disease exacerbations

“…Similar results were reported by other studies . Montes de Oca et al evidenced that the number of exacerbations was 4.9 times higher in patients with ACO, while Kang et al found that these patients suffered more frequent and more severe exacerbations, resulting in a higher number of hospital admissions.…”

“…A retrospective study carried out in Taiwan showed that patients with ACO had more exacerbations (35.3%) than patients with asthma (29.0%, P < 0.0001 vs ACO) or COPD alone (18.6%, P < 0.0001 vs ACO). ACO patients had a higher rate of exacerbations requiring emergency room visits (8.2% vs 2.7% for the patients with COPD, P < 0.0001 and 2.3% for the asthma patients, P < 0.0001) and intensive care unit treatment (4.3% vs 2.7% for the patients with COPD, P < 0.0001 and 0.5% for the patients with asthma, P < 0.0001) …”

“…In recent years, asthma‐COPD overlap (ACO) is of considerable interest worldwide as it is associated with worse health outcomes compared with COPD or asthma alone …”

Association between continuity of care and emergency department visits and hospitalization in senior adults with asthma-COPD overlap

“…Due to the relationship between socioeconomic status (SES) and health care outcomes [38,39], insurance premiums were used as a proxy for SES because the NHI claims data set does not provide patients' educational levels or household incomes. In addition, health status and disease severity may affect the measurement of health outcomes [6,9,16,39]; therefore, any history of hypertension (ICD-9-CM codes 401.xx-405.xx), and diabetes (ICD-9-CM codes 250.xx) [4,6,9], whether a patient had ED visits for COPD or asthma and whether a patient was hospitalized for COPD or asthma were included in the previous year of the index date. The Charlson comorbidity index (CCI) [4,5,7,40] that was calculated for each patient according to outpatient or inpatient care by using the Quan adaptation of the Elixhauser comorbidities [41] and the number of outpatient visits for COPD or asthma (3-12, 13-24, and ≥25 times) [16] was measured during the COC period.…”

“…Studies of ACO reported the prevalence ranges from 0.9% to 11.1% among general population around the world [3]. The disease burden and healthcare utilization such as emergency department (ED) visits and hospital admissions for patients with ACO has been found to be higher than those with asthma or COPD alone [4][5][6][7][8][9]. While the importance of caring for patients with ACO has become a critical issue, there is limited information regarding treatment in ACO patients to reduce the resulting healthcare utilization.…”