Underdiagnosis in COPD: a battle worth fighting

From illness management to quality of life: rethinking consumer health informatics opportunities for progressive, potentially fatal illnesses

OBJECTIVES

Investigate how people with chronic obstructive pulmonary disease (COPD)-an example of a progressive, potentially fatal illness-are using digital technologies (DTs) to address illness experiences, outcomes and social connectedness.

MATERIALS AND METHODS

A transformative mixed methods study was conducted in Canada with people with COPD (n = 77) or with a progressive lung condition (n = 6). Stage-1 interviews (n = 7) informed the stage-2 survey. Survey responses (n = 80) facilitated the identification of participants for stage-3 interviews (n = 13). The interviews were thematically analyzed. Descriptive statistics were calculated for the survey. The integrative mixed method analysis involved mixing between and across the stages.

RESULTS

Most COPD participants (87.0%) used DTs. However, few participants frequently used DTs to self-manage COPD. People used DTs to seek online information about COPD symptoms and treatments, but lacked tailored information about illness progression. Few expressed interest in using DTs for self- monitoring and tracking. The regular use of DTs for intergenerational connections may facilitate leaving a legacy and passing on traditions and memories. Use of DTs for leisure activities provided opportunities for connecting socially and for respite, reminiscing, distraction and spontaneity.

DISCUSSION AND CONCLUSION

We advocate reconceptualizing consumer health technologies to prioritize quality of life for people with a progressive, potentially fatal illness. "Quality of life informatics" should focus on reducing stigma regarding illness and disability and taboo towards death, improving access to palliative care resources and encouraging experiences to support social, emotional and mental health. For DTs to support people with fatal, progressive illnesses, we must expand informatics strategies to quality of life.

Direct Medical Costs of COPD in the USA: An Analysis of the Medical Expenditure Panel Survey 2017-2018

AIM

In this study, we aimed to provide a nationally representative estimate of the economic burden of chronic obstructive pulmonary disease (COPD) by examining direct medical costs among individuals aged 45 years and older in the USA.

METHODS

Medical Expenditure Panel Survey (2017-2018) data were used to estimate the direct medical costs associated with COPD. All-cause (unadjusted) cost and COPD-specific (adjusted) cost were determined for the various service categories using a regression-based approach among patients with COPD. We developed a weighted two-part model and adjusted for various demographic, socioeconomic, and clinical characteristics.

RESULTS

The study sample consisted of 23,590 patients, of which 1073 had COPD. Patients with COPD had a mean age of 67.4 years (standard error (SE): 0.41), and the total all-cause mean medical cost per patient per year (PPPY) was 2018 US $19,449 (SE: US $865), of which US $6145 (SE: US $295) was for prescription drugs. Using the regression approach, the mean total COPD-specific cost was US $4322 (SE: US $577) PPPY, with prescription drugs contributing US $1887 (SE: 216) PPPY. These results represented an annual total COPD-specific cost of US $24.0 billion, with prescription drugs contributing US $10.5 billion. The mean annual out-of-pocket spending accounted for 7.5% (mean: US $325) of the total COPD-specific cost; for COPD-specific prescription drug cost, 11.3% (mean: US $212) was out-of-pocket cost.

CONCLUSION

COPD poses a significant economic burden on healthcare payers and patients 45 years of age and older in the USA. While prescription drugs accounted for almost half of the total cost, more than 10% of the prescription drug cost was out-of-pocket.

Impact of COVID-19 pandemic on incidence of long-term conditions in Wales: a population data linkage study using primary and secondary care health records

BACKGROUND

The COVID-19 pandemic has directly and indirectly had an impact on health service provision owing to surges and sustained pressures on the system. The effects of these pressures on the management of long-term or chronic conditions are not fully understood.

AIM

To explore the effects of COVID-19 on the recorded incidence of 17 long-term conditions.

DESIGN AND SETTING

This was an observational retrospective population data linkage study on the population of Wales using primary and secondary care data within the Secure Anonymised Information Linkage (SAIL) Databank.

METHOD

Monthly rates of new diagnosis between 2000 and 2021 are presented for each long-term condition. Incidence rates post-2020 were compared with expected rates predicted using time series modelling of pre-2020 trends. The proportion of annual incidence is presented by sociodemographic factors: age, sex, social deprivation, ethnicity, frailty, and learning disability.

RESULTS

A total of 5 476 012 diagnoses from 2 257 992 individuals are included. Incidence rates from 2020 to 2021 were lower than mean expected rates across all conditions. The largest relative deficit in incidence was in chronic obstructive pulmonary disease corresponding to 343 (95% confidence interval = 230 to 456) undiagnosed patients per 100 000 population, followed by depression, type 2 diabetes, hypertension, anxiety disorders, and asthma. A GP practice of 10 000 patients might have over 400 undiagnosed long-term conditions. No notable differences between sociodemographic profiles of post- and pre-2020 incidences were observed.

CONCLUSION

There is a potential backlog of undiagnosed patients with multiple long-term conditions. Resources are required to tackle anticipated workload as part of COVID-19 recovery, particularly in primary care.

Impact of Spirometrically Confirmed Chronic Obstructive Pulmonary Disease on Arterial Stiffness and Surfactant Protein D After Percutaneous Coronary Intervention. The CATEPOC Study

Background

Several mechanisms have been proposed to explain why chronic obstructive pulmonary disease (COPD) impairs the prognosis of coronary events. We aimed to explore COPD variables related to a worse prognosis in patients undergoing percutaneous coronary intervention (PCI).

Methods

Patients with an acute coronary event treated by PCI were prospectively included. One month after discharge, clinical characteristics, comorbidities measured with the Charlson index, and prognostic coronary scales (logistic EuroSCORE; GRACE 2.0) were collected. Post-bronchodilator spirometry, arterial stiffness, and serum inflammatory and myocardial biomarkers were measured. Lung plasmatic biomarkers (Surfactant protein D, desmosine, and Clara cell secretory protein-16) were determined with ELISA. COPD was defined by the fixed ratio (FEV1/FVC <70%). Spirometric values were also analyzed as continuous variables using adjusted and non-adjusted ANCOVA analysis. Finally, we evaluated the presence of a respiratory pattern defined by non-stratified spirometric values and pulmonary biomarkers.

Results

A total of 164 patients with a mean age of 65 (±10) years (79% males) were included. COPD was diagnosed in 56 (34%) patients (68% previously undiagnosed). COPD patients had a longer smoking history, higher scores on the EuroSCORE (p < 0.0001) and GRACE 2.0 (p < 0.001) scales, and more comorbidities (p = 0.006). Arterial stiffness determined by pulse wave velocity was increased in COPD patients (7.35 m/s vs 6.60 m/s; p = 0.006). Serum values of high sensitive T troponin (p = 0.007) and surfactant protein D (p = 0.003) were also higher in COPD patients. FEV1% remained significantly associated with arterial stiffness and surfactant protein D in the adjusted ANCOVA analysis. In the cluster exploration, 53% of the patients had a respiratory pattern.

Conclusion

COPD affects one-third of patients with an acute coronary event and frequently remains undiagnosed. Several mechanisms, including arterial stiffness and SPD, were increased in COPD patients. Their relationship with the prognosis should be confirmed with longitudinal follow-up of the cohort.

Case-finding and improving patient outcomes for chronic obstructive pulmonary disease in primary care: the BLISS research programme including cluster RCT

Background

Chronic obstructive pulmonary disease is a major contributor to morbidity, mortality and health service costs but is vastly underdiagnosed. Evidence on screening and how best to approach this is not clear. There are also uncertainties around the natural history (prognosis) of chronic obstructive pulmonary disease and how it impacts on work performance.

Objectives

Work package 1: to evaluate alternative methods of screening for undiagnosed chronic obstructive pulmonary disease in primary care, with clinical effectiveness and cost-effectiveness analyses and an economic model of a routine screening programme. Work package 2: to recruit a primary care chronic obstructive pulmonary disease cohort, develop a prognostic model [Birmingham Lung Improvement StudieS (BLISS)] to predict risk of respiratory hospital admissions, validate an existing model to predict mortality risk, address some uncertainties about natural history and explore the potential for a home exercise intervention. Work package 3: to identify which factors are associated with employment, absenteeism, presenteeism (working while unwell) and evaluate the feasibility of offering formal occupational health assessment to improve work performance.

Design

Work package 1: a cluster randomised controlled trial with household-level randomised comparison of two alternative case-finding approaches in the intervention arm. Work package 2: cohort study – focus groups. Work package 3: subcohort – feasibility study.

Setting

Primary care settings in West Midlands, UK.

Participants

Work package 1: 74,818 people who have smoked aged 40–79 years without a previous chronic obstructive pulmonary disease diagnosis from 54 general practices. Work package 2: 741 patients with previously diagnosed chronic obstructive pulmonary disease from 71 practices and participants from the work package 1 randomised controlled trial. Twenty-six patients took part in focus groups. Work package 3: occupational subcohort with 248 patients in paid employment at baseline. Thirty-five patients took part in an occupational health intervention feasibility study.

Interventions

Work package 1: targeted case-finding – symptom screening questionnaire, administered opportunistically or additionally by post, followed by diagnostic post-bronchodilator spirometry. The comparator was routine care. Work package 2: twenty-three candidate variables selected from literature and expert reviews. Work package 3: sociodemographic, clinical and occupational characteristics; occupational health assessment and recommendations.

Main outcome measures

Work package 1: yield (screen-detected chronic obstructive pulmonary disease) and cost-effectiveness of case-finding; effectiveness of screening on respiratory hospitalisation and mortality after approximately 4 years. Work package 2: respiratory hospitalisation within 2 years, and barriers to and facilitators of physical activity. Work package 3: work performance – feasibility and acceptability of the occupational health intervention and study processes.

Results

Work package 1: targeted case-finding resulted in greater yield of previously undiagnosed chronic obstructive pulmonary disease than routine care at 1 year [n = 1278 (4%) vs. n = 337 (1%), respectively; adjusted odds ratio 7.45, 95% confidence interval 4.80 to 11.55], and a model-based estimate of a regular screening programme suggested an incremental cost-effectiveness ratio of £16,596 per additional quality-adjusted life-year gained. However, long-term follow-up of the trial showed that at ≈4 years there was no clear evidence that case-finding, compared with routine practice, was effective in reducing respiratory admissions (adjusted hazard ratio 1.04, 95% confidence interval 0.73 to1.47) or mortality (hazard ratio 1.15, 95% confidence interval 0.82 to 1.61). Work package 2: 2305 patients, comprising 1564 with previously diagnosed chronic obstructive pulmonary disease and 741 work package 1 participants (330 with and 411 without obstruction), were recruited. The BLISS prognostic model among cohort participants with confirmed airflow obstruction (n = 1894) included 6 of 23 candidate variables (i.e. age, Chronic Obstructive Pulmonary Disease Assessment Test score, 12-month respiratory admissions, body mass index, diabetes and forced expiratory volume in 1 second percentage predicted). After internal validation and adjustment (uniform shrinkage factor 0.87, 95% confidence interval 0.72 to 1.02), the model discriminated well in predicting 2-year respiratory hospital admissions (c-statistic 0.75, 95% confidence interval 0.72 to 0.79). In focus groups, physical activity engagement was related to self-efficacy and symptom severity. Work package 3: in the occupational subcohort, increasing dyspnoea and exposure to inhaled irritants were associated with lower work productivity at baseline. Longitudinally, increasing exacerbations and worsening symptoms, but not a decline in airflow obstruction, were associated with absenteeism and presenteeism. The acceptability of the occupational health intervention was low, leading to low uptake and low implementation of recommendations and making a full trial unfeasible.

Limitations

Work package 1: even with the most intensive approach, only 38% of patients responded to the case-finding invitation. Management of case-found patients with chronic obstructive pulmonary disease in primary care was generally poor, limiting interpretation of the long-term effectiveness of case-finding on clinical outcomes. Work package 2: the components of the BLISS model may not always be routinely available and calculation of the score requires a computerised system. Work package 3: relatively few cohort participants were in paid employment at baseline, limiting the interpretation of predictors of lower work productivity.

Conclusions

This programme has addressed some of the major uncertainties around screening for undiagnosed chronic obstructive pulmonary disease and has resulted in the development of a novel, accurate model for predicting respiratory hospitalisation in people with chronic obstructive pulmonary disease and the inception of a primary care chronic obstructive pulmonary disease cohort for longer-term follow-up. We have also identified factors that may affect work productivity in people with chronic obstructive pulmonary disease as potential targets for future intervention.

Future work

We plan to obtain data for longer-term follow-up of trial participants at 10 years. The BLISS model needs to be externally validated. Our primary care chronic obstructive pulmonary disease cohort is a unique resource for addressing further questions to better understand the prognosis of chronic obstructive pulmonary disease.

Trial registration

Current Controlled Trials ISRCTN14930255.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 13. See the NIHR Journals Library website for further project information.

Prevalence and Determinants of COPD in Spain: EPISCAN II

BACKGROUND

Two previous national epidemiological studies, IBERPOC in 1997 and EPISCAN in 2007, determined the COPD burden in Spain. Changes in demographics and exposure to risk factors demand the periodic update of COPD prevalence and its determinants.

METHODS

EPISCAN II aimed to estimate the prevalence of COPD in the general population aged 40 years or older in all 17 regions of Spain. A random population screening sample, requiring 600 participants per region performed a questionnaire plus post-bronchodilator (post-BD) spirometry.

RESULTS

A total of 12,825 subjects were initially contacted, and 9433 (73.6%) agreed to participate, of whom 9092 performed a valid spirometry. Baseline characteristics were: 52.6% women, mean±SD age 60±11 years, 19.8% current- and 34.2% former-smokers. The prevalence of COPD measured by post-BD fixed ratio FEV₁/FVC<0.7 was 11.8% (95% C.I. 11.2-12.5) with a high variability by region (2.4-fold). Prevalence was 14.6% (95% C.I. 13.5-15.7) in males and 9.4% (95% C.I. 8.6-10.2) in females; according to the lower limit of normal (LLN) was 6.0% (95% C.I. 5.5-6.5) overall, by sex being 7.1% (95% C.I. 6.4-8.0) in males and 4.9% (95% C.I. 4.3-5.6) in females. Underdiagnosis of COPD was 74.7%. Cases with COPD were a mean of seven years older, more frequently male, of lower attained education, and with more smokers than the non-COPD population (p<0.001). However, the number of cigarettes and pack-years in non-COPD participants was substantial, as it was the reported use of e-cigarettes (7.0% vs. 5.5%) (p=0.045). There were also significant social and clinical differences including living alone, previous respiratory diagnoses, more comorbidities measured with the Charlson index, greater BODE and COTE scores, cognitive impairment, and depression (all p<0.001).

CONCLUSIONS

COPD remains prevalent in Spain and frequently underdiagnosed.

Clinical Application of Forced Oscillation Technique (FOT) in Early Detection of Airway Changes in Smokers

The forced oscillation technique (FOT) is a non-invasive method to assess airway function by emitting oscillatory signals into the respiratory tract during tidal ventilation. This opinion piece discusses the current use, trialled modification and future directions in utilizing FOT as a novel diagnostic tool for early detection of small airway changes in smokers. The published evidence to date has shown that FOT parameters could be a sensitive diagnostic tool to detect early respiratory changes in smokers. Multiple frequencies and the frequency dependence of resistance and reactance can provide the most valuable and early information regarding smoking induced changes in airways. Considering its non-invasiveness, lower level of discomfort to patients than spirometry, feasibility, and cost effectiveness, it could be the first-choice diagnostic technique for detection of early respiratory changes in smokers. The finding of FOT could further be supported and correlated with inflammatory markers.

Highlights of an Expert Advisory Board on Acute Exacerbations of Chronic Obstructive Pulmonary Disease (AE-COPD) in Latin America

Background

Chronic obstructive pulmonary disease (COPD) is a preventable and usually progressive lung disease that affects millions of people worldwide and is the sixth leading cause of death in the Americas. Viral and bacterial respiratory tract infections and air pollution may cause acute exacerbations of COPD (AE-COPD) ranging from mild, moderate to severe. The greatest proportion of the overall COPD burden on the health system is due to disease exacerbations. There is limited evidence regarding the etiology and burden of AE-COPD in Latin America (LATAM).

Methods

To respond to this gap in evidence, an Advisory Board with regional pneumologists and infectious disease experts was convened in September 2018 in Panama City, Panama, to: 1) review the burden of AE-COPD in LATAM; 2) evaluate the etiology of AE-COPD in LATAM; and 3) assess and compare the local/regional guidelines to confirm the etiology, characterize, and manage AE-COPD.

Results

The results of the meeting showed that there is a high prevalence of AE-COPD in LATAM countries, limited evidence on etiology data, and discrepancies in the case definitions and symptomology (ie, severity) classifications used in LATAM.

Conclusion

The Advisory Board discussions further resulted in recommendations for future research on the impact on the epidemiology and burden of disease, on establishing standardized AE-COPD case definition guidelines, and on studying the etiology of both moderate and severe AE-COPD cases.

Fixed Ratio versus Lower Limit of Normality for Diagnosing COPD in Primary Care: Long-Term Follow-Up of EGARPOC Study

Purpose

The best criterion for diagnosing airway obstruction in COPD, fixed ratio (FR: FEV1/FVC<0.7) or lower limit of normality (LLN), remains controversial. We compared the long-term evolution of COPD patients according to the initial obstruction criteria.

Patients and Methods

Between 2005 and 2008, we evaluated 1728 subjects over 45 years of age with smoking history, pertaining to a primary care center. A total of 424 patients were obstructive by FR, after a bronchodilator test. Of those, 289 patients met obstruction criteria for both FR and LLN and were considered concordant patients (FR+LLN+), while 135 patients were obstructive by FR but non-obstructive by LLN and were defined as discordant patients (FR+LLN-).

Results

Forty-eight patients (11.3%) were lost in follow-up, and 158 died (37.3%). After a median time of 120.4 months (IQR 25-75%: 110.2-128.8), 215 patients were spirometrically reevaluated. The annualized loss of FEV1/FVC was greater in discordant (FR+LLN-) patients [0.54 (0.8) vs 0.82 (0.7); p = 0.008], while 81% became concordant (FR+LLN+) during the follow-up. Hospitalization for COPD exacerbations was more frequent in concordant (FR+LLN+) patients (1.57±3.51 vs 0.77±2.29; p = 0.002). Adjusting for age, concordant (FR+LLN+) patients had greater COPD mortality (HR: 2.97; CI 95%: 1.27-7.3; p = 0.02).

Conclusion

LLN seems to be less useful for COPD diagnosis in primary care. Discordant (FR+LLN-) patients lost more FEV1/FVC during their evolution and tended to become concordant. LLN predicted COPD hospitalizations and mortality more poorly.

Validation of Questionnaire-based Case Definitions for Chronic Obstructive Pulmonary Disease

BACKGROUND

Various questionnaire-based definitions of chronic obstructive pulmonary disease (COPD) have been applied using the US representative National Health and Nutrition Examination Survey (NHANES), but few have been validated against objective lung function data. We validated two prior definitions that incorporated self-reported physician diagnosis, respiratory symptoms, and/or smoking. We also validated a new definition that we developed empirically using gradient boosting, an ensemble machine learning method.

METHODS

Data came from 7,996 individuals 40-79 years who participated in NHANES 2007-2012 and underwent spirometry. We considered participants "true" COPD cases if their ratio of postbronchodilator forced expiratory volume in 1 second to forced vital capacity was below 0.7 or the lower limit of normal. We stratified all analyses by smoking history. We developed a gradient boosting model for smokers only; predictors assessed (25 total) included sociodemographics, inhalant exposures, clinical variables, and respiratory symptoms.

RESULTS

The spirometry-based COPD prevalence was 26% for smokers and 8% for never smokers. Among smokers, using questionnaire-based definitions resulted in a COPD prevalence ranging from 11% to 16%, sensitivity ranging from 18% to 35%, and specificity ranging from 88% to 92%. The new definition classified participants based on age, bronchodilator use, body mass index (BMI), smoking pack-years, and occupational organic dust exposure, and resulted in the highest sensitivity (35%) and specificity (92%) among smokers. Among never smokers, the COPD prevalence ranged from 4% to 5%, and we attained good specificity (96%) at the expense of sensitivity (9-10%).

CONCLUSION

Our results can be used to parametrize misclassification assumptions for quantitative bias analysis when pulmonary function data are unavailable.

Impact of chronic obstructive pulmonary disease on mortality: A large national cohort study

BACKGROUND AND OBJECTIVE

The global burden of chronic obstructive pulmonary disease (COPD) is increasing and COPD patients are at higher risk for all-cause mortality. We aimed to evaluate the impact of COPD on specific-cause mortality using national data.

METHODS

This was nationwide retrospective cohort study of 340, 767 adults aged 40-84 years who lacked COPD diagnosis at baseline between 1 January 2003 and 31 December 2013. Incident COPD was defined by reference to COPD claim codes and prescription of COPD medication at least twice annually. Cox proportional hazard ratio (HR) for each cause of death in the COPD group was compared to that of the non-COPD group, with other causes of death accounted as the competing risk.

RESULTS

All-cause mortality was higher in the COPD (2,978 per 100, 000 person-years) than the non-COPD group (629 per 100, 000 person-years) and adjusted HR was 1.41 (95% CI = 1.32, 1.50). The association was particularly strong for chronic lower airway disease (adjusted sub-HR = 9.67; 95% CI = 7.21, 12.96) and lung cancer (adjusted sub-HR = 3.16; 95% CI = 2.68, 3.71), and the association was stronger in those aged <60 years.

CONCLUSION

In this large national cohort, COPD patients were at a statistically significant higher risk for all-cause mortality than those without COPD. They were more likely to die from chronic lower airway disease, lung cancer and pneumonia than subjects without COPD. The impact of COPD on specific mortalities was stronger in younger subjects.

Utility of FEV1/FEV6 index in patients with multimorbidity hospitalized for decompensation of chronic diseases

Spirometry remains essential for the diagnosis of airway obstruction. Nevertheless, its performance in elderly hospitalized patients with multimorbidity can be difficult. The aim of this study is to assess the utility of the COPD-6 portable device in this population. We included all patients hospitalized for exacerbation of chronic diseases in a medical ward specialized in the care of multimorbidity patients, between September 2017 and May 2018. A questionnaire including sociodemographic, cognitive and functional impairment, among other variables, was completed the last day of admission. Subsequently, patients attempted to perform three valid respiratory manoeuvres with the COPD-6 device and then conventional spirometry. A total of 184 patients were included (mean age of 79.61 years, 55% men). Forty-seven (25.54%) patients were able to perform complete spirometric manoeuvres and 99 (53.8%) could perform a valid FEV1/FEV6 determination. The inability to perform a valid spirometry was related with the patient’s age, functional physical disability, cognitive impairment or the presence of delirium or dysphagia during admission. Only 9% of patients with a Mini Mental Cognitive Examination (MMEC) lower than 24 points could perform a valid spirometry. Of the patients with an MMEC < 24 points and unable to perform spirometry, 34% were able to complete the FEV1/FEV6 manoeuvres. No differences were found in the Charlson index, multimorbidity scale, number of domiciliary drugs, or length of stay between those patients able and those not able to perform respiratory manoeuvres. The agreement between the values for FEV1 measured with COPD-6 and those observed in the spirometry was good (r: 0.71; p<0.0001). Inability to perform a valid spirometry during hospitalization in elderly patients with multimorbidity is frequent and related with functional and cognitive impairment. FEV1/FEV6 determination using the COPD-6 portable device allows an important percentage of the patients with limitations to complete spirometric measurement.

Most impactful predictors for hyperoxaemia in exacerbation of chronic obstructive pulmonary disease managed by Emergency Medical Services and Emergency Department

INTRODUCTION

Hyperoxemia in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) leads to adverse outcomes. It remains prevalent in the pre-hospital Emergency Medical Services (EMS) and Emergency Department (ED).

OBJECTIVE

To determine the key predictors for hyperoxemia in AECOPD in EMS and ED.

METHODS

This was a prospective observational study of AECOPD patients in EMS and two EDs. Hyperoxemia was defined as PaO₂ > 65 mm Hg (corresponds to SpO₂ > 92%). We determined apriori candidate factors in Patient, Organization and Staff domains. Primary outcomes were the key predictors for hyperoxemia. Secondary outcomes were in-hospital mortality and mechanical ventilation rates in hyperoxemic versus non-hyperoxemic groups. We generated a logistic regression model for each domain. We reported the adjusted odds ratios (AORs), 95% CIs and p values. We selected the output factors using AOR ≥2.0 and ≥2.5 for modifiable and non-modifiable factors, respectively. These selected factors were fed into a final model with eventual factors selected based on: threshold AORs as stated above and/or 95% CIs including these AORs.

RESULTS

Three hundred and twenty-six patients were analysed; 60.7% had hyperoxemia. We found three eventual modifiable factors; first, ED SpO₂ > 95% [AOR 2.62 (95% CIs: 1.61-4.33); P < 0.001], EMS non-rebreathing mask [AOR 2.01 (95% CIs: 1.06-3.97); P = 0.04]; and ED nasal cannula [AOR 1.69 (95% CIs: 1.05-2.72); P = 0.03]. Secondary outcomes did not differ between groups.

CONCLUSION

We identified three key modifiable predictors. We intend to conduct an interventional study using them to reduce hyperoxemia rate in AECOPD.

Daily Objective Physical Activity and Sedentary Time in Adults with COPD Using Spirometry Data from Canadian Measures Health Survey

Chronic obstructive pulmonary disease (COPD) is expected to be the third leading cause of premature death and disability in Canada and around the world by the year 2020. The study aims to compare objective physical activity (PA) and sedentary time in a population-based sample of adults with chronic obstructive pulmonary disease (COPD) and compare a group, and to investigate whether these behaviors differ according to COPD severity. From the 2007–2013 Canadian Health Measures Survey dataset, accelerometer and prebronchodilator spirometry data were available for 6441 participants, aged 35 to 79. Two weighted analyses of covariance were performed with adjustments for age, sex, body mass index, accelerometer wearing time, season, work, smoking (cotinine), education level, and income. A set of sensitivity analyses were carried out to examine the possible effect of COPD and type of control group. A cross-sectional weighted analysis indicated that 14.6% of study participants had a measured airflow obstruction consistent with COPD. Time in PA (moderate-vigorous and light PA), number of steps, and sedentary duration were not significantly different in participants with COPD, taken together, compared to controls. However, moderate to severe COPD participants (stages ≥2) had a significantly lower daily time spent in PA of moderate and vigorous intensity level compared to controls. Canadian adults with COPD with all disease severity levels combined did not show lower daily duration of light, moderate, and vigorous PA, and number of steps and higher daily sedentary time than those without airflow obstruction. Both groups are extremely sedentary and have low PA duration. Thus, “move more and sit less” public health strategy could equally target adults with or without COPD.

Forced oscillation technique for early detection of the effects of smoking and COPD: contribution of fractional-order modeling

Purpose

The aim of the present study was to evaluate the performance of the forced oscillation technique (FOT) for the early diagnosis of the effects of smoking and COPD. The contributions of the integer-order (InOr) and fractional-order (FrOr) models were also evaluated.

Patients and methods

In total, 120 subjects were analyzed: 40 controls, 40 smokers (20.3±9.3 pack-years) and 40 patients with mild COPD.

Results

Initially, it was observed that traditional FOT parameters and the InOr and FrOr models provided a consistent description of the COPD pathophysiology. Mild COPD introduced significant increases in the FrOr inertance, damping factor and hysteresivity (P<0.0001). These parameters were significantly correlated with the spirometric parameters of central and small airway obstruction (P<0.0001). The diagnostic accuracy analyses indicated that FOT parameters and InOr modeling may adequately identify these changes (area under the receiver operating characteristic curve – AUC >0.8). The use of FrOr modeling significantly improved this process (P<0.05), allowing the early diagnosis of smokers and patients with mild COPD with high accuracy (AUC >0.9).

Conclusion

FrOr modeling improves our knowledge of modifications that occur in the early stages of COPD. Additionally, the findings of the present study provide evidence that these models may play an important role in the early diagnosis of COPD, which is crucial for improving the clinical management of the disease.

What have we learned from observational studies and clinical trials of mild to moderate COPD?

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide. It is well established that patients with mild to moderate disease represent the majority of patients with COPD, and patients with mild COPD already have measurable physiological impairment with increased morbidity and a higher risk of mortality compared with healthy non-smoking individuals. However, this subpopulation is both underdiagnosed and undertreated. In addition, most clinical trials include cohorts of patients with worse lung function and quality of life, which are very different from the milder patients usually seen in primary care.

Clinical trials have shown that mild-moderate COPD patients present an improvement in lung function after treatment with long-acting bronchodilators (LABD). Inhaled therapy has also shown benefits in terms of symptoms, health-related quality of life (HRQL) and exacerbation prevention in this population. Early intervention might have also a positive effect to prevent functional impairment. Nevertheless, there is scarce evidence from randomised clinical trials and real-life studies about the importance of pharmacological treatment in early stages of COPD to improve long-term outcomes. New concepts such as clinically important deterioration may help to investigate the impact of interventions on the natural history of the disease.

Trends of testing for and diagnosis of α1-antitrypsin deficiency in the UK: more testing is needed

α₁-antitrypsin deficiency (AATD) significantly increases the risk of developing chronic obstructive pulmonary disease (COPD), and testing of all COPD patients for AATD is recommended by the World Health Organization, European Respiratory Society and Global Initiative for Chronic Obstructive Lung Disease (GOLD). We aimed to determine trends for testing and diagnosing AATD from 1990 to 2014.This study analysed all patients diagnosed with COPD from about 550 UK Optimum Patient Care Research Database general practices, including a subgroup of those diagnosed before the age of 60 years.We identified 107 024 COPD individuals, of whom 29 596 (27.6%) were diagnosed before 60 years of age. Of them, only 2.2% (95% CI 2.09-2.43%) had any record of being tested for AATD. Of those tested, 23.7% (95% CI 20.5-27.1%) were diagnosed with AATD. Between 1994 and 2013 the incidence of AATD diagnosis generally increased. A diagnosis of AATD was associated with being male, being an ex-smoker, more severe COPD with a lower forced expiratory volume in 1 s % pred and higher GOLD 2017 stages (all p<0.05).Despite an increase in the frequency of AATD testing since 1990, only 2.2% of patients diagnosed with COPD before the age of 60 years were tested. AATD prevalence was 23.7% in those tested. Thus, it appears that AATD remains markedly underdiagnosed in COPD patients.

Altitude and COPD prevalence: analysis of the PREPOCOL-PLATINO-BOLD-EPI-SCAN study

BACKGROUND

COPD prevalence is highly variable and geographical altitude has been linked to it, yet with conflicting results. We aimed to investigate this association, considering well known risk factors.

METHODS

A pooled analysis of individual data from the PREPOCOL-PLATINO-BOLD-EPI-SCAN studies was used to disentangle the population effect of geographical altitude on COPD prevalence. Post-bronchodilator FEV1/FVC below the lower limit of normal defined airflow limitation consistent with COPD. High altitude was defined as >1500 m above sea level. Undiagnosed COPD was considered when participants had airflow limitation but did not report a prior diagnosis of COPD.

RESULTS

Among 30,874 participants aged 56.1 ± 11.3 years from 44 sites worldwide, 55.8% were women, 49.6% never-smokers, and 12.9% (3978 subjects) were residing above 1500 m. COPD prevalence was significantly lower in participants living at high altitude with a prevalence of 8.5% compared to 9.9%, respectively (p < 0.005). However, known risk factors were significantly less frequent at high altitude. Hence, in the adjusted multivariate analysis, altitude itself had no significant influence on COPD prevalence. Living at high altitude, however, was associated with a significantly increased risk of undiagnosed COPD. Furthermore, subjects with airflow limitation living at high altitude reported significantly less respiratory symptoms compared to subjects residing at lower altitude.

CONCLUSION

Living at high altitude is not associated with a difference in COPD prevalence after accounting for individual risk factors. However, high altitude itself was associated with an increased risk of undiagnosed COPD.