Disease Burden of Patients with Asthma/COPD Overlap in a US Claims Database: Impact of ICD-9 Coding-based Definitions

A Comorbidity Knowledge-Aware Model for Disease Prognostic Prediction

Prognostic prediction is the task of estimating a patient's risk of disease development based on various predictors. Such prediction is important for healthcare practitioners and patients because it reduces preventable harm and costs. As such, a prognostic prediction model is preferred if: 1) it exhibits encouraging performance and 2) it can generate intelligible rules, which enable experts to understand the logic of the model's decision process. However, current studies usually concentrated on only one of the two features. Toward filling this gap, in the present study, we develop a novel knowledge-aware Bayesian model taking into consideration accuracy and transparency simultaneously. Real-world case studies based on four years' territory-wide electronic health records are conducted to test the model. The results show that the proposed model surpasses state-of-the-art prognostic prediction models in accuracy and c-statistic. In addition, the proposed model can generate explainable rules.

Concurrent asthma and chronic obstructive pulmonary disease in adult ED patients: A national perspective

OBJECTIVES

Emergency department (ED) visits for Asthma and Chronic Obstructive Pulmonary Disease (COPD) are common. The designation of Asthma-COPD overlap (ACO) has been used to describe patients with features of both diseases. Studies show that ACO patients may be at increased risk of poor outcomes relative to patients with either disease alone. We sought to characterize ED visits and ED-related outcomes of patients with ACO compared to patients with Asthma or COPD alone.

METHODS

We conducted a secondary analysis of the National Hospital Ambulatory Medical Care Survey (NHAMCS, 2005-2018) characterizing ED visits in patients ≥35 years of age with Asthma Only, COPD Only or ACO. We performed univariable and multivariable analyses adjusting for demographics to assess relevant ED outcome variables.

RESULTS

From 2005 to 2018, there were an estimated 8.15, 17.78 and 0.56 million ED visits for Asthma Only, COPD Only and ACO, respectively. ACO patients were younger than COPD Only patients (mean age 50.18 versus 61.79; p < 0.001). ACO patients differed in terms of sex, race and ethnicity from patients with either disease alone. When triaged, Asthma Only (adjusted odds ratio (aOR) = 11.45; 95% confidence interval (CI), 1.20-109.38) patients were more likely to require immediate care than ACO patients. Although admission rates were comparable between groups, ACO patients had a decreased mean length of ED visit compared to both Asthma Only (p < 0.001) and COPD Only (p < 0.05) patients. COPD Only patients were less likely than ACO patients to be seen in the ED in the last 72 h (aOR = 0.22; 95% CI, 0.056-0.89), receive nebulizer therapy (aOR = 0.55; 95% CI, 0.31-0.97), bronchodilators (aOR = 0.24; 95% CI, 0.12-0.48) and systemic corticosteroids (aOR = 0.18; 95% CI, 0.091-0.35). Asthma Only patients were less likely than ACO patients to undergo any imaging (aOR = 0.55; 95% CI, 0.31-0.96) and receive antibiotics (aOR = 0.46; 95% CI, 0.23-0.93).

CONCLUSIONS

ACO patients appear to differ demographically from patients with either disease alone in the ED. After adjustment for these demographic differences, ACO patients appear to differ with respect to several ED variables, notably respiratory therapies; however, clinical outcomes including admission and mortality rates appear to be comparable between groups.

Economic Burden of Asthma-Chronic Obstructive Pulmonary Disease Overlap among Older Adults in the United States

The objective of this study is to estimate the excess economic burden of Asthma-COPD Overlap (ACO) among older adults in the United States. We used a cross-sectional study design with data from a nationally representative survey of Medicare beneficiaries (Medicare Current Beneficiary Survey) linked to Medicare fee-for-service claims. Older adults with ACO had higher average total healthcare expenditures ($45,532 vs. $12,743) and higher out-of-pocket spending burden (19% vs. 8.5%) compared to those with no-asthma no-COPD (NANC). Individuals with ACO also had almost two, and 1.5 times higher expenditures compared to individuals with asthma only and COPD only, respectively. Multivariable regression models indicated that the adjusted associations of ACO to economic burden remained positive and statistically significant. In comparison with NANC, nearly three-quarters of the excess total healthcare expenditures and 83% of the out-of-pocket spending burden of older adults with ACO were explained by differences in predisposing, enabling, need, personal healthcare practices, and external factors among the two groups. The higher number of unique medications and the increased incidence of fragmented care were the leading contributors to the excess economic burden among older adults with ACO comparing to NANC individuals. Interventions that reduce the number of medications and fragmented care have the potential to reduce the excess economic burden among older adults with ACO.

Asthma-COPD overlap: current understanding and the utility of experimental models

Pathological features of both asthma and COPD coexist in some patients and this is termed asthma-COPD overlap (ACO). ACO is heterogeneous and patients exhibit various combinations of asthma and COPD features, making it difficult to characterise the underlying pathogenic mechanisms. There are no controlled studies that define effective therapies for ACO, which arises from the lack of international consensus on the definition and diagnostic criteria for ACO, as well as scant in vitro and in vivo data. There remain unmet needs for experimental models of ACO that accurately recapitulate the hallmark features of ACO in patients. The development and interrogation of such models will identify underlying disease-causing mechanisms, as well as enabling the identification of novel therapeutic targets and providing a platform for assessing new ACO therapies. Here, we review the current understanding of the clinical features of ACO and highlight the approaches that are best suited for developing representative experimental models of ACO.

Understanding the pathogenesis of asthma-COPD overlap is critical for improving therapeutic approaches. We present current knowledge on asthma-COPD overlap and the requirements for developing an optimal animal model of disease.https://bit.ly/3lsjyvm

Asthma-chronic obstructive pulmonary disease overlap and cost-related medication non-adherence among older adults in the United States

BACKGROUND

Cost-related medication non-adherence (CRN) can negatively impact health outcomes in older adults with asthma and chronic obstructive pulmonary disease (COPD) overlap (ACO) by reducing access and adherence to essential medications. The objective of this study is to examine the association of ACO to any CRN and specific forms of CRN among a nationally representative sample of older (age ≥ 65 years) adults.

METHODS

We adopted a cross-sectional study design using data from pooled cross-sectional Medicare Current Beneficiary Surveys (MCBS) (2006-2013) and linked fee-for-service Medicare claims. Unadjusted and adjusted logistic regressions that accounted for the complex survey design examined the association of ACO to any CRN and specific forms of CRN.

RESULTS

Among older adults with ACO, 16% reported any CRN. The most common form of CRN was "failing to get prescription". As compared to older adults with no asthma and no COPD, those with ACO were more likely to report any CRN (adjusted odds ratios [AOR] = 1.50, 95%CI = [1.14, 1.96]) and all forms of CRN. However, when the number of unique medications was added to the model, there were no statistically significant differences in CRN between the two groups.

CONCLUSIONS

Older adults with ACO represent a vulnerable population with increased risk for CRN. Multiple factors can contribute to CRN including: a higher number of prescribed medications, multiple co-morbidities, and cost of therapies. Medication comprehensive review interventions have the potential of reducing the risk of CRN among the older Medicare beneficiaries with ACO.

The Identification and Cost of Acute Chronic Obstructive Pulmonary Disease Exacerbations in a United States Population Healthcare Claims Database

Almost half of chronic obstructive pulmonary disease (COPD) exacerbations are estimated to be inaccurately reported by patients, inconsistently recorded in medical records, or not measured due to coding errors inherent to administrative claims. This retrospective observational study aimed to develop an algorithm capable of detecting acute COPD exacerbations (AECOPD) in healthcare claims and estimate costs associated with AECOPD over a 12-month period. Commercial and Medicare Advantage healthcare plan members (≥40 years old) with evidence of COPD were identified from US healthcare-claims database. To refine the algorithm detecting AECOPD in claims data, sensitivity and positive-predictive value calculations were performed to compare AECOPD identification in healthcare claims versus medical charts. Analyses were also performed to examine total exacerbation-related costs for events identified with the new claims algorithm plus events missed. The final algorithm had a sensitivity of 84.9%, with a positive-predictive value of 67.5%. Medical records were abstracted for 402 patients. In the overall sample of healthcare claims (n = 243,998), the algorithm detected ≥1 AECOPD event in 61.3% of patients. The mean cost per patient during an AECOPD episode, identified by the final algorithm, was USD 6,760 (n = 301), with an incremental average cost of USD 607 (n = 122) to 'unobserved' episodes (not reported in claims data) among the chart sample. After multivariate modeling, predicted yearly exacerbation costs translated to USD 1.12 billion per 100,000 patients (USD 12,000 per patient), with 35.76 million associated with unobserved exacerbations. While the final algorithm warrants further validation and study, these findings highlight unobserved AECOPD and their economic burden.

Fractional Exhaled Nitric Oxide as an Inflammatory Biomarker in Chronic Obstructive Pulmonary Disease (COPD) with or without Concurrent Diagnosis of Asthma: The Canadian Cohort Obstructive Lung Disease (CanCOLD)

We studied whether fractional exhaled nitric oxide (F _ENO) can differentiate chronic obstructive pulmonary disease (COPD) with concurrent diagnosis of asthma from COPD-only as well as its ability to predict disease severity and progression. This study was embedded in the Canadian Cohort Obstructive Lung Disease (CanCOLD). Subjects of ≥40 years old completed F _ENO measurements were subdivided into four groups, including COPD (N = 86 [COPD-only (N = 35) and COPD with concurrent diagnosis of asthma (N = 51)], healthy (N = 72), and at risk (N = 151). Three of the most common clinical definitions were used for characterizing COPD with concurrent diagnosis of asthma: 1) atopy and self-reported physician diagnosis of asthma, 2) ≥12% and ≥200 ml post-bronchodilator FEV1; 3) self-reported physician diagnosis of asthma. F _ENO values were classified using quartiles and the American Thoracic Society (ATS) guideline 2011. Compared to COPD-only, more COPD with concurrent diagnosis of asthma had a significant F _ENO50 level of [Formula: see text] 33.5 ppb (fourth quartile) than COPD-only (p = 0.045, 0.011, and 0.006, for definition 1, 2, and 3, respectively). Considering the ATS guideline 2011, fewer COPD with concurrent diagnosis of asthma had F _ENO50 < 25 than COPD-only, which was statistically significant with definition 1 and 3 (p = 0.038 and 0.026, respectively). F _ENO as a biomarker has the potential to be used as a complementary value for differentiating COPD with concurrent diagnosis of asthma from COPD-only. Further studies should be conducted on validated definitions of COPD with concurrent diagnosis of asthma, which may include a reference to the type of airway inflammation in addition to the clinical definition.

Prevalence of chronic obstructive pulmonary disease at high altitude: a systematic review and meta-analysis

Background and objective

Recently, several studies have investigated the prevalence of chronic obstructive pulmonary disease (COPD) at high altitude (>1,500 m). However, much remains to be understood about the correlation between altitude and COPD. We aimed to summarize the prevalence of COPD at high-altitudes and find out if altitude could be a risk factor for COPD.

Methods

We searched PubMed/Medline, Cochrane Library, Web of Science, SCOPUS, OVID, Chinese Biomedical Literature Database (CBM) and Embase databases from inception to April 30th, 2019, with no language restriction. We used STATA 14.0 to analyze the extracted data. A random-effect model was used to calculate the combined OR and 95% CI. Heterogeneity was assessed by the I² statistic versus P-value. We performed a subgroup analysis to analyze possible sources of heterogeneity. The Egger’s test and the Begg’s test were used to assess any publication bias.

Results

We retrieved 4,574 studies from seven databases and finally included 10 studies (54,578 participants). Males ranged from 18.8% to 49.3% and the population who smoked ranged from 3.3% to 53.3%. The overall prevalence of COPD at high-altitude was 10.0% (95% CI [0.08–0.12], P < 0.001). In a subgroup analysis, based on different regions, the results showed that the prevalence in Asia was higher than that in Europe and America. Seven studies compared the relationship between the prevalence of COPD at high-altitudes and the lowlands. The results showed that altitude was not an independent risk factor for the prevalence of COPD (OR_adj = 1.18, 95% CI [0.85–1.62], P = 0.321). There was no publication bias among the studies.

Conclusions

Our study found a higher prevalence of COPD at high-altitudes than those from average data. However, altitude was not found to be an independent risk factor for developing COPD (PROSPERO Identifier: CRD42019135012).

The many faces of asthma-chronic obstructive pulmonary disease overlap

PURPOSE OF REVIEW

Asthma and chronic obstructive pulmonary disease (COPD) are common diseases that often overlap. The term asthma-COPD overlap (ACO) has been used to define this entity but there remain several speculations on its exact definition, impact, pathophysiology, clinical features, and management. We reviewed recent publications on ACO to obtain more insight of current knowledge and outline future needs.

RECENT FINDINGS

Criteria for ACO vary from one publication to another and the many variable features of these patients underline the need to reconsider the evaluation and approach of patients with overlapping features based on clinical traits and underlying biological mechanisms. Epidemiological studies reveal that ACO patients have generally an increased burden of illness and healthcare use in addition to poorer quality of life (QoL) compared with asthma and higher or equal to COPD. However, their long-term outcome seems better than patients with COPD alone. Various methods have been proposed to evaluate these patients but their usefulness compared to 'classical' investigation of obstructive lung diseases remains speculative and needs further evaluation. Furthermore, there are no formal studies that examined and compared the different treatment strategies of well-characterized patients with ACO as such patients are usually excluded from clinical trials.

SUMMARY

ACO is a common condition with variable features and a high burden of disease. There is no consensus on its definition, diagnostic, and clinical features and more research should be done on its optimal management and long-term outcomes.

Association between asthma/chronic obstructive pulmonary disease overlap syndrome and healthcare utilization among the US adult population

Objectives: Asthma/chronic obstructive pulmonary disease (COPD) overlap (ACO) is a recently described phenomenon defined as the coexistence of both asthma and COPD. Both asthma and COPD are known to result in increased emergency department (ED) visits and hospitalizations, but it is unclear how the ACO population utilizes these same healthcare resources. The objective of this study was to compare healthcare utilization in the ACO population versus the general population, the asthma population and the COPD population. Methods: We conducted a pooled cross-sectional statistical analysis using the 2012-2015 National Health Interview Survey (NHIS) data. We focused on adults 18 years of age and older and excluded pregnant women. We employed an adjusted logit regression model, where the primary outcomes were dichotomous indicators on healthcare utilizations including ED visits and hospital stays. A key covariate was a four-category variable: 1) no asthma or COPD; 2) asthma only; 3) COPD only; and 4) ACO. Other covariates included age, sex, race, education level, marital status, household income level, medical insurance status, smoking status, body mass index (BMI) category, region, year and comorbidities (cancer, diabetes, hypertension, coronary heart disease and ulcer). Results: Adults with ACO were 134%, 53% and 21% more likely to have ED visits than the general population, asthma group and COPD group, respectively. For hospital stay, the ACO group was 120% and 86% more likely to be hospitalized than the general population and the asthma group respectively. In addition, adults with ACO were 61% and 130% more likely to have asthma exacerbations and asthma-related ED visits than the asthma group. Conclusions: ACO is a considerable risk factor for healthcare utilization versus the general population, the asthma population and the COPD population. Future focus should be placed on the ACO population to identify ways to reduce their healthcare utilization.

Asthma-COPD Overlap-A Discordance Between Patient Populations Defined by Different Diagnostic Criteria

BACKGROUND

The concordance between asthma-chronic obstructive pulmonary disease overlap (ACO) defined according to Global Inititative for Asthma (GINA)/Global Initiative for Chronic Obstructive Lung Disease (GOLD) and other diagnostic criteria is unknown.

OBJECTIVE

To assess the concordance between different ACO definitions and to estimate the definition-based ACO prevalence and characteristics.

METHODS

A prospective, real-life study based on a 32-item data set was performed in a mixed population of patients with asthma and chronic obstructive pulmonary disease (COPD). Five different definitions of ACO, including the GINA/GOLD criteria, were analyzed.

RESULTS

A total of 1609 patients were included in the final analysis. Application of Venn diagram for ACO populations resulted in 31 ACO subpopulations, which were further reduced to 6 separate populations by introducing a rank order for the analyzed definitions to classify patients from intersecting groups. Overall, the level of agreement between different ACO definitions was poor. Cohen kappa coefficient for the agreement between ACO GINA/GOLD definition and other ACO definitions varied from 0.06 to 0.21. Only 2 patients (0.12%) met all the ACO definitions. Definition-based ACO prevalence ranged between 3.8% (Spanish criteria) and 18.4% (clinician's diagnosis). A total of 573 (33.4%) patients met the criteria from at least 1 ACO definition. Patients who could not be classified as suffering from "pure" asthma, "pure" COPD, or ACO accounted for as much as 27.5% of the whole investigated group. The most severe symptoms were observed in patients with ACO defined as COPD and asthma diagnosed at age less than 40 years.

CONCLUSIONS

The current ACO definitions identify distinct populations that share only a small number of common features and present with different disease phenotypes. ACO prevalence is highly variable, depending on the definition applied.

Associations between statins and coronary artery disease and stroke risks in patients with asthma-chronic obstructive pulmonary disease overlap syndrome: A time-dependent regression study

BACKGOUND AND AIMS

We aimed at determining the effects of statin use on coronary artery disease (CAD) and stroke risks in patients with asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS).

METHODS

We retrospectively enrolled patients with ACOS treated with (N = 916) and without (N = 6338) statins. The cumulative incidence of CAD and stroke (ischemic and hemorrhagic) was analyzed through time-dependent Cox proportional regression. After adjustment for sex, age, comorbidities, inhaled corticosteroid steroid (ICS) use, and oral steroid (OS) use, we calculated the adjusted hazard ratios (aHRs) and their 95% confidence intervals (CIs) for CAD or stroke in the statin users (long-term [>600 days] and short-term [≤600 days]) compared with the non-users.

RESULTS

Among the statin users, aHRs (95% CIs) for CAD and stroke were 0.50 (0.41-0.62) and 0.83 (0.63-1.09), respectively; moreover, aHRs were 0.30 (0.09-0.99) and 0.90 (0.68-1.20) for ischemic and hemorrhagic stroke, respectively. aHRs (95% CIs) for CAD and stroke were 0.58 (0.47-0.71) and 0.93 (0.70-1.23), respectively, in the short-term users and 0.23 (0.13-0.41) and 0.42 (0.19-0.89), respectively, in the long-term users.

CONCLUSIONS

CAD risk was lower in all statin users, regardless of the duration of use, whereas ischemic stroke risk was lower only in the long-term statin users. No association was observed between hemorrhagic stroke risk and statin use.

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

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COC enables healthcare more effectively and improves clinical outcomes.

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COC is also important for elderly ACO patients.

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Increasing COC is beneficial for elderly patients with ACO in disease management.

Objective

To investigate associations between continuity of care (COC) and emergency department (ED) visits and hospitalization for chronic obstructive pulmonary disease (COPD) or asthma among elderly adults with asthma-COPD overlap (ACO).

Methods

A retrospective cohort study was performed using the Taiwan National Health Insurance research database. A total of 1141 ACO patients aged ≥65 years during 2005–2011 were observed and followed for 2 years. The Bice and Boxerman COC index (COCI) was used to evaluate COC by considering ambulatory care visits duo to COPD or asthma in the first year; ED visits and hospitalization for COPD or asthma were identified in the subsequent year, respectively. The COCI was divided into three levels (COCI < 0.3= low, 0.3 ≤ COCI<1=medium, COCI = 1=high). The Cox model was used to estimate the hazard ratio (HR) for ED visits and hospital admissions due to COPD or asthma.

Results

The average COCI was 0.55. 21.3% patients received outpatient care from a single physician. Compared to patients with high COC, those with low and medium COC had a higher risk of ED visits (aHR = 2.80 and 2.69, P < .01) and admissions (aHR = 1.80 and 1.72, P < .05).

Conclusion

Increasing COC is beneficial for elderly patients with ACO in disease management. Policymakers could create effective pay-for-performance programs for the elderly ACO population to enhance COC and improve care outcomes.

Statin for Tuberculosis and Pneumonia in Patients with Asthma⁻Chronic Pulmonary Disease Overlap Syndrome: A Time-Dependent Population-Based Cohort Study

We investigated the effects of statins on tuberculosis (TB) and pneumonia risks in asthma⁻chronic pulmonary disease overlap syndrome (ACOS) patients. We extracted data of patients diagnosed as having ACOS during 2000⁻2010 from the Taiwan National Health Insurance Research Database and divided them into statin users and nonusers. All study participants were followed up from the index date until death, withdrawal from insurance, or TB and pneumonia occurred (31 December 2011). The cumulative TB and pneumonia incidence was analyzed using Cox proportional regression analysis with time-dependent variables. After adjustments for multiple confounding factors including age, sex, comorbidities, and use of medications [statins, inhaled corticosteroids (ICSs), or oral steroids (OSs)], statin use was associated with significantly lower TB [adjusted hazard ratio (aHR) 0.49, 95% confidence interval (CI) 0.34⁻0.70] and pneumonia (aHR 0.52, 95% CI 0.41⁻0.65) risks. Moreover, aHRs (95% CIs) for statins combined with ICSs and OSs were respectively 0.60 (0.31⁻1.16) and 0.58 (0.40⁻0.85) for TB and 0.61 (0.39⁻0.95) and 0.57 (0.45⁻0.74) for pneumonia. Thus, statin users had lower TB and pneumonia risks than did nonusers, regardless of age, sex, comorbidities, and ICS or OS use. Pneumonia risk was lower among users of statins combined with ICSs or Oss and TB risk was lower among the users of statins combined with OSs.

Overlap of Asthma and Chronic Obstructive Pulmonary Disease in Patients in the United States: Analysis of Prevalence, Features, and Subtypes

Background

Although asthma and chronic obstructive pulmonary disease (COPD) are clinically distinct diseases, they represent biologically diverse and overlapping clinical entities and it has been observed that they often co-occur. Some research and theorizing suggest there is a common comorbid condition termed asthma-chronic obstructive pulmonary disease overlap (ACO). However, the existence of ACO is controversial.

Objective

The objective of this study is to describe patient characteristics and estimate prevalence, health care utilization, and costs of ACO using claims-based diagnoses confirmed with medical record information.

Methods

Eligible patients were commercial US health plan enrollees; ≥40 years; had asthma, COPD, or ACO; ≥3 prescription fills for asthma/COPD medications; and ≥2 spirometry tests. Records for a random sample of 5000 patients with ACO were reviewed to validate claims-based diagnoses.

Results

The estimated ACO prevalence was 6% (estimated 10,250/183,521) among 183,521 full study patients. In the claims-based cohorts, the comorbidity burden for ACO was greater versus asthma but similar to COPD cohorts. Medication utilization was higher in ACO versus asthma and COPD. Mean total health care costs were significantly higher for ACO versus asthma but similar to COPD. In confirmed diagnoses cohorts, mean total health care costs (medical plus pharmacy) were lower for ACO versus COPD but similar to asthma (US $20,035; P=.56). Among confirmed cases, where there was medical record evidence, smoking history was higher in ACO (300/343, 87.5%) versus asthma cohorts (100/181, 55.2%) but similar to COPD (68/84, 81%).

Conclusions

ACO had more comorbidities, medication utilization, and costs than patients with asthma or COPD but differences were not seen after confirmation with medical records.

Understanding and measuring symptoms and health status in asthma COPD overlap: content validity of the EXACT and SGRQ

BACKGROUND

Asthma-chronic obstructive pulmonary disease overlap (ACO) differs from asthma and chronic obstructive pulmonary disease (COPD) in demographics, phenotypic characteristics and outcomes, yet the patient experience of ACO is poorly characterized. We aimed to understand and compare the patient experience of symptoms and domains of impact in ACO relative to COPD, and assess the content validity of existing patient-reported outcome (PRO) instruments in ACO.

METHODS

This US qualitative, interview study included patients who met American Thoracic Society/European Respiratory Society spirometric criteria for COPD. Additionally, patients with ACO demonstrated reversibility (forced expiratory volume in 1 s [FEV1] increase ≥ 12% and ≥ 200 mL) to albuterol/salbutamol and an FEV1/forced vital capacity ratio < 0.7. Patients took part in concept elicitation (CE) to explore symptoms and impacts of obstructive lung disease. The Exacerbations of Chronic Pulmonary Disease Tool (EXACT), St George's Respiratory Questionnaire (SGRQ) and a daily wheeze assessment were cognitively debriefed to assess relevance and comprehensiveness. Interviews were analyzed using Atlas.Ti. Concept saturation was evaluated at the symptom level.

RESULTS

Twenty patients with ACO and 10 patients with COPD were recruited. Patients from both groups indicated that shortness of breath was their most frequent and bothersome symptom. The most frequently reported symptoms in both groups were shortness of breath, cough, wheezing, difficulty breathing, mucus/phlegm, chest tightness, and tiredness, weakness or fatigue. The onset, severity, frequency and duration of symptoms were consistently described across both groups, although a higher proportion of patients with ACO experienced exacerbations versus those with COPD. Impacts on daily living, physical impacts and emotional impacts were commonly described (ACO: 90-100%, COPD: 80-100%). Concept saturation was achieved in both groups. Overall, the EXACT, SGRQ and daily wheeze assessment were well understood and relevant to most patients with ACO or COPD (50-100%) and patients generally found the assessments easy to complete. The PRO instruments adequately captured symptoms described during CE, demonstrating high content validity in ACO and COPD.

CONCLUSIONS

Patients with ACO and COPD experienced similar symptoms and impacts. The EXACT, SGRQ and assessment of wheeze were well understood and captured concepts relevant to patients with ACO.

Association of asthma-chronic obstructive pulmonary disease overlap syndrome with coronary artery disease, cardiac dysrhythmia and heart failure: a population-based retrospective cohort study

OBJECTIVES

Patients with asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) and cardiovascular diseases (CVDs) share common risk factors. However, the association between ACOS and the incidence of CVDs has not been reported. This study investigated the relationship between CVDs and ACOS in the general population.

SETTING

Data were obtained from Taiwan's National Health Insurance Research Database for the period 2000 to 2010.

PARTICIPANTS

The ACOS cohort comprised patients (n=5814) who had received a diagnosis of asthma and COPD. The non-ACOS cohort comprised patients who had not received a diagnosis of asthma or COPD and were matched to the ACOS cohort (2:1) by age, sex and index date (n=11 625).

PRIMARY AND SECONDARY OUTCOME MEASURES

The cumulative incidence of CVDs-coronary artery disease (CAD), cardiac dysrhythmia (CD) and heart failure (HF)-was calculated. Cox proportional regression analysis was employed to examine the relationship between ACOS and CVDs.

RESULTS

After adjustment for multiple confounding factors-age, sex, comorbidities and medications-patients with ACOS were associated with a significantly higher risk of CVDs; the adjusted HRs (aHRs; 95% CI) for CAD, CD and HF were 1.62 (1.50 to 1.76), 1.44 (1.30 to 1.61) and 1.94 (1.73 to 2.19), respectively, whereas those of beta-blockers treatment for CAD, CD and HF were 1.19 (0.92 to 1.53), 0.90 (0.56 to 1.45) and 0.82 (0.49 to 1.38). The aHR of atenolol treatment for CD was 1.72 (1.01 to 2.93). The aHRs (95% CIs) of ACOS without acute exacerbation of COPD (AE-COPD) for CAD, CD and HF were 1.85 (1.70 to 2.01), 1.57 (1.40 to 1.77) and 2.07 (1.82 to 2.35), respectively.

CONCLUSION

ACOS was associated with higher CVD risk, even without the presence of previous comorbidities or AE-COPD. No significant differences in CVD events were observed in the ACOS cohort using beta-blockers, except for those using atenolol for treating CD.

Understanding COPD-overlap syndromes

INTRODUCTION

Chronic obstructive pulmonary disease accounts for a large burden of lung disease. It can 'overlap' with other respiratory diseases including bronchiectasis, fibrosis and obstructive sleep apnea (OSA). While COPD alone confers morbidity and mortality, common features with contrasting clinical outcomes can occur in COPD 'overlap syndromes'. Areas covered: Given the large degree of heterogeneity in COPD, individual variation to treatment is adopted based on its observed phenotype, which in turn overlaps with features of other respiratory disease states such as asthma. This is coined asthma-COPD overlap syndrome ('ACOS'). Other examples of such overlapping clinical states include bronchiectasis-COPD ('BCOS'), fibrosis-COPD ('FCOS') and OSA-COPD ('OCOS'). The objective of this review is to highlight similarities and differences between the COPD-overlap syndromes in terms of risk factors, pathophysiology, diagnosis and potential treatment differences. Expert commentary: As a consequence of COPD overlap syndromes, a transition from the traditional 'one size fits all' treatment approach is necessary. Greater treatment stratification according to clinical phenotype using a precision medicine approach is now required. In this light, it is important to recognize and differentiate COPD overlap syndromes as distinct disease states compared to individual diseases such as asthma, COPD, fibrosis or bronchiectasis.