Population-based case-finding to identify subjects with undiagnosed asthma or COPD

Early Diagnosis and Treatment of COPD and Asthma - A Randomized, Controlled Trial

BACKGROUND

Many persons with chronic obstructive pulmonary disease (COPD) or asthma have not received a diagnosis, so their respiratory symptoms remain largely untreated.

METHODS

We used a case-finding method to identify adults in the community with respiratory symptoms without diagnosed lung disease. Participants who were found to have undiagnosed COPD or asthma on spirometry were enrolled in a multicenter, randomized, controlled trial to determine whether early diagnosis and treatment reduces health care utilization for respiratory illness and improves health outcomes. Participants were assigned to receive the intervention (evaluation by a pulmonologist and an asthma-COPD educator who were instructed to initiate guideline-based care) or usual care by their primary care practitioner. The primary outcome was the annualized rate of participant-initiated health care utilization for respiratory illness. Secondary outcomes included changes from baseline to 1 year in disease-specific quality of life, as assessed with the St. George Respiratory Questionnaire (SGRQ; scores range from 0 to 100, with lower scores indicating better health status); symptom burden, as assessed with the COPD Assessment Test (CAT; scores range from 0 to 40, with lower scores indicating better health status); and forced expiratory volume in 1 second (FEV1).

RESULTS

Of 38,353 persons interviewed, 595 were found to have undiagnosed COPD or asthma and 508 underwent randomization: 253 were assigned to the intervention group and 255 to the usual-care group. The annualized rate of a primary-outcome event was lower in the intervention group than in the usual-care group (0.53 vs. 1.12 events per person-year; incidence rate ratio, 0.48; 95% confidence interval [CI], 0.36 to 0.63; P<0.001). At 12 months, the SGRQ score was lower than the baseline score by 10.2 points in the intervention group and by 6.8 points in the usual-care group (difference, -3.5 points; 95% CI, -6.0 to -0.9), and the CAT score was lower than the baseline score by 3.8 points and 2.6 points, respectively (difference, -1.3 points; 95% CI, -2.4 to -0.1). The FEV1 increased by 119 ml in the intervention group and by 22 ml in the usual-care group (difference, 94 ml; 95% CI, 50 to 138). The incidence of adverse events was similar in the trial groups.

CONCLUSIONS

In this trial in which a strategy was used to identify adults in the community with undiagnosed asthma or COPD, those who received pulmonologist-directed treatment had less subsequent health care utilization for respiratory illness than those who received usual care. (Funded by Canadian Institutes of Health Research; UCAP ClinicalTrials.gov number, NCT03148210.).

Proposing the potential of utilizing the CAT score for early detection of COPD in asymptomatic patients, shifting towards a patient-centered approach: A review

Chronic obstructive pulmonary disease (COPD) constitutes a significant public health challenge, with delayed diagnosis and underdiagnosis being pervasive issues. The United States Preventive Service Task Force recommends restricting COPD screening to symptomatic smokers, a focus that has exhibited limitations, leading to delayed diagnoses, and imposing a substantial burden on patients, their families, and the healthcare system. This paper explores an alternative approach, highlighting the potential utility of the COPD assessment test (CAT) score as a prescreening tool. A CAT score of 10 or higher could serve as an appropriate threshold for further diagnostic procedures, given its robust correlation with pulmonary function test parameters and is valuable capacity to quantify patients' symptoms. The utilization of CAT as a prescreening tool in primary care signifies a transition towards a more patient-centered and comprehensive approach to COPD diagnosis and care.

Impact of Undiagnosed Chronic Obstructive Pulmonary Disease and Asthma on Symptoms, Quality of Life, Healthcare Use, and Work Productivity

Rationale: A significant proportion of individuals with chronic obstructive pulmonary disease (COPD) and asthma remain undiagnosed. Objectives: The objective of this study was to evaluate symptoms, quality of life, healthcare use, and work productivity in subjects with undiagnosed COPD or asthma compared with those previously diagnosed, as well as healthy control subjects. Methods: This multicenter population-based case-finding study randomly recruited adults with respiratory symptoms who had no previous history of diagnosed lung disease from 17 Canadian centers using random digit dialing. Participants who exceeded symptom thresholds on the Asthma Screening Questionnaire or the COPD Diagnostic Questionnaire underwent pre- and post-bronchodilator spirometry to determine if they met diagnostic criteria for COPD or asthma. Two control groups, a healthy group without respiratory symptoms and a symptomatic group with previously diagnosed COPD or asthma, were similarly recruited. Measurements and Main Results: A total of 26,905 symptomatic individuals were interviewed, and 4,272 subjects were eligible. Of these, 2,857 completed pre- and post-bronchodilator spirometry, and 595 (21%) met diagnostic criteria for COPD or asthma. Individuals with undiagnosed COPD or asthma reported greater impact of symptoms on health status and daily activities, worse disease-specific and general quality of life, greater healthcare use, and poorer work productivity than healthy control subjects. Individuals with undiagnosed asthma had symptoms, quality of life, and healthcare use burden similar to those of individuals with previously diagnosed asthma, whereas subjects with undiagnosed COPD were less disabled than those with previously diagnosed COPD. Conclusions: Undiagnosed COPD or asthma imposes important, unmeasured burdens on the healthcare system and is associated with poor health status and negative effects on work productivity.

Anticipating undiagnosed asthma in symptomatic adults with normal pre- and post-bronchodilator spirometry: a decision tool for bronchial challenge testing

BACKGROUND

Some patients with asthma demonstrate normal spirometry and remain undiagnosed without further testing.

OBJECTIVE

To determine clinical predictors of asthma in symptomatic adults with normal spirometry, and to generate a tool to help clinicians decide who should undergo bronchial challenge testing (BCT).

METHODS

Using random-digit dialling and population-based case-finding, we recruited adults from the community with respiratory symptoms and no previous history of diagnosed lung disease. Participants with normal pre- and post-bronchodilator spirometry subsequently underwent BCT. Asthma was diagnosed in those with symptoms and a methacholine provocative concentration (PC20) of < 8 mg/ml. Sputum and blood eosinophils, and exhaled nitric oxide were measured. Univariate analyses identified potentially predictive variables, which were then used to construct a multivariable logistic regression model to predict asthma. Model sensitivity, specificity, and area under the receiver operating curve (AUC) were calculated.

RESULTS

Of 132 symptomatic individuals with normal spirometry, 34 (26%) had asthma. Of those ultimately diagnosed with asthma, 33 (97%) answered 'yes' to a question asking whether they experienced cough, chest tightness or wheezing provoked by exercise or cold air. Other univariate predictors of asthma included female sex, pre-bronchodilator FEV1 percentage predicted, and percent positive change in FEV1 post bronchodilator. A multivariable model containing these predictive variables yielded an AUC of 0.82 (95% CI: 0.72-0.91), a sensitivity of 82%, and a specificity of 66%. The model was used to construct a nomogram to advise clinicians which patients should be prioritized for BCT.

CONCLUSIONS

Four readily available patient characteristics demonstrated a high sensitivity and AUC for predicting undiagnosed asthma in symptomatic adults with normal pre- and post-bronchodilator spirometry. These characteristics can potentially help clinicians to decide which individuals with normal spirometry should be investigated with bronchial challenge testing. However, further prospective validation of our decision tool is required.

[The FEV1/VC ratio to define bronchial obstruction: Should we use a fixed ratio or the lower limit of normal?]

INTRODUCTION

While the screening of chronic obstructive lung diseases (COPD, asthma, etc.) constitutes a major public health issue in France and worldwide, simple spirometry appears currently as the key to meeting the challenge. Since description of the forced expiratory maneuver by Robert Tiffeneau in 1947, it has been admitted that the FEV1/VC ratio permits diagnosis obstructive pulmonary diseases. However, the diagnostic criteria for this ratio remain uncertain. The long-lasting debate between advocates of a 0.7 "fixed ratio" (FR) of 0.7 and advocates of the "lower limit of normal" (LLN) remains relevant.

STATE OF THE ARTS

In this general review, we describe the respective advantages of the FR and LLN criteria according to the most recently published studies, and characterize the conditions associated with discrepancies between these criteria.

PERSPECTIVES AND CONCLUSIONS

FR and LLN appear not to share similar diagnosis values and the use of both criteria facilitates proposal of an up-to-date interpretation and diagnosis strategy in the context of first-line spirometry, particularly for patients with FEV1/VC ratio in the "grey zone".

Current Progress of COPD Early Detection: Key Points and Novel Strategies

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide, with approximately 70% to 80% of adults with COPD being undiagnosed. Patients with undiagnosed COPD are at increased risk of poor outcomes and a worsened quality of life, making early detection a crucial strategy to mitigate the impact of COPD and reduce the burden on healthcare systems. In the past decade, increased interest has been focused on the development of effective strategies and instrument for COPD early detection. However, identifying undiagnosed cases of COPD is still challenging. Both screening and case-finding approaches have been adopted to identify undiagnosed COPD, with case-finding being recommended by the 2023 Global Initiative for Chronic Obstructive Lung Disease (GOLD) guideline and the updated United States Preventive Services Task Force (USPTF) recommendation. Nonetheless, the approaches, criteria, and instruments used for early detection of COPD are varied. However, advances in the taxonomy and risk factors of COPD are continuously being investigated. It is important to continuously assess the current state of knowledge on COPD early detection, given the challenges associated with identifying undiagnosed COPD. This review aims to highlight recent advances in early detection of COPD. To discuss the current challenge and opportunity in COPD early detection, providing an overview of existing literature on COPD case-finding strategies, including the approaches, criteria for subjects, and instruments. The review also summarizes the current progress in COPD case-findings and proposes a COPD case-finding flowchart as an efficient method for identifying at risk COPD patients.

The COVID-19 pandemic: asthma control, tobacco use, and mental health among African American and Latinx college students

OBJECTIVE

This study investigated the impact of COVID-19 on tobacco use and mental health in US African American and Latinx college students with asthma. Associations among asthma control, tobacco use, and mental health were also examined.

METHODS

105 African American and Latinx college students with asthma (18-23 years) completed two online questionnaires (June 2019-March 2020 for Time 1; August 2020-October 2020 for Time 2). Participants completed the Epidemic-Pandemic Impacts Inventory (measure of COVID-19 impact), Asthma Control Test, Generalized Anxiety Disorder scale, Patient Health Questionnaire (measure of depression), Perceived Stress Scale, and items related to tobacco use.

RESULTS

Asthma control improved (t = -3.326, p = 0.001) from Time 1 to 2, and e-vapor product use decreased (χ²₁₀₄ = 6.572, p = 0.010). COVID-19 impact was positively associated with students' symptoms of anxiety, depression, and perceived stress (B = 0.201, p < 0.001; B = 0.179, p < 0.001; and B = 0.199, p = 0.001, respectively) at Time 2. These results remained significant with the Benjamini-Hochberg correction. Asthma control at Time 1 was negatively associated with anxiety symptoms at Time 2 (B = -0.418, p = 0.023); however, associations with perceived stress (B = -0.514, p = 0.019) and all other tobacco product use (B = -0.233, p = 0.030) did not remain significant with the Benjamini-Hochberg correction.

CONCLUSIONS

As hypothesized, a higher COVID-19 impact score was associated with students endorsing more mental health symptoms. Better control of asthma symptoms before the pandemic predicted fewer anxiety symptoms during the pandemic.

Airway inflammation and hyperresponsiveness in subjects with respiratory symptoms and normal spirometry

BACKGROUND

Subjects without a previous history of asthma, presenting with unexplained respiratory symptoms and normal spirometry, may exhibit airway hyperresponsiveness (AHR) in association with underlying eosinophilic (type 2 (T2)) inflammation, consistent with undiagnosed asthma. However, the prevalence of undiagnosed asthma in these subjects is unknown.

METHODS

In this observational study, inhaled corticosteroid-naïve adults without previously diagnosed lung disease reporting current respiratory symptoms and showing normal pre- and post-bronchodilator spirometry underwent fractional exhaled nitric oxide (F _ENO) measurement, methacholine challenge testing and induced sputum analysis. AHR was defined as a provocative concentration of methacholine causing a 20% fall in forced expiratory volume in 1 s (PC₂₀) <16 mg·mL^-1 and T2 inflammation was defined as sputum eosinophils >2% and/or F _ENO >25 ppb.

RESULTS

Out of 132 subjects (mean±sd age 57.6±14.2 years, 52% female), 47 (36% (95% CI 28-44%)) showed AHR: 20/132 (15% (95% CI 9-21%)) with PC₂₀ <4 mg·mL^-1 and 27/132 (21% (95% CI 14-28%)) with PC₂₀ 4-15.9 mg·mL^-1. Of 130 participants for whom sputum eosinophils, F _ENO or both results were obtained, 45 (35% (95% CI 27-43%)) had T2 inflammation. 14 participants (11% (95% CI 6-16%)) had sputum eosinophils >2% and PC₂₀ ≥16 mg·mL^-1, suggesting eosinophilic bronchitis. The prevalence of T2 inflammation was significantly higher in subjects with PC₂₀ <4 mg·mL^-1 (12/20 (60%)) than in those with PC₂₀ 4-15.9 mg·mL^-1 (8/27 (30%)) or ≥16 mg·mL^-1 (25/85 (29%)) (p=0.01).

CONCLUSIONS

Asthma, underlying T2 airway inflammation and eosinophilic bronchitis may remain undiagnosed in a high proportion of symptomatic subjects in the community who have normal pre- and post-bronchodilator spirometry.

Patient and physician factors associated with symptomatic undiagnosed asthma or COPD

BACKGROUND

It remains unclear why some symptomatic individuals with asthma or COPD remain undiagnosed. Here, we compare patient and physician characteristics between symptomatic individuals with obstructive lung disease (OLD) who are undiagnosed and individuals with physician-diagnosed OLD.

METHODS

Using random-digit dialling and population-based case finding, we recruited 451 participants with symptomatic undiagnosed OLD and 205 symptomatic control participants with physician-diagnosed OLD. Data on symptoms, quality of life and healthcare utilisation were analysed. We surveyed family physicians of participants in both groups to elucidate differences in physician practices that could contribute to undiagnosed OLD.

RESULTS

Participants with undiagnosed OLD had lower mean pre-bronchodilator forced expiratory volume in 1 s percentage predicted compared with those who were diagnosed (75.2% versus 80.8%; OR 0.975, 95% CI 0.963-0.987). They reported greater psychosocial impacts due to symptoms and worse energy and fatigue than those with diagnosed OLD. Undiagnosed OLD was more common in participants whose family physicians were practising for >15 years and in those whose physicians reported that they were likely to prescribe respiratory medications without doing spirometry. Undiagnosed OLD was more common among participants who had never undergone spirometry (OR 10.83, 95% CI 6.18-18.98) or who were never referred to a specialist (OR 5.92, 95% CI 3.58-9.77). Undiagnosed OLD was less common among participants who had required emergency department care (OR 0.44, 95% CI 0.20-0.97).

CONCLUSIONS

Individuals with symptomatic undiagnosed OLD have worse pre-bronchodilator lung function and present with greater psychosocial impacts on quality of life compared with their diagnosed counterparts. They were less likely to have received appropriate investigations and specialist referral for their respiratory symptoms.

Accuracy and economic evaluation of screening tests for undiagnosed COPD among hypertensive individuals in Brazil

In Brazil, prevalence of diagnosed COPD among adults aged 40 years and over is 16% although over 70% of cases remain undiagnosed. Hypertension is common and well-recorded in primary care, and frequently co-exists with COPD because of common causes such as tobacco smoking, therefore we conducted a cross-sectional screening test accuracy study in nine Basic Health Units in Brazil, among hypertensive patients aged ≥40 years to identify the optimum screening test/combinations to detect undiagnosed COPD. We compared six index tests (four screening questionnaires, microspirometer and peak flow) against the reference test defined as those below the lower limit of normal (LLN-GLI) on quality diagnostic spirometry, with confirmed COPD at clinical review. Of 1162 participants, 6.8% (n = 79) had clinically confirmed COPD. Peak flow had a higher specificity but lower sensitivity than microspirometry (sensitivity 44.3% [95% CI 33.1, 55.9], specificity 95.5% [95% CI 94.1, 96.6]). SBQ performed well compared to the other questionnaires (sensitivity 75.9% [95% CI 65.0, 84.9], specificity 59.2% [95% CI 56.2, 62.1]). A strategy requiring both SBQ and peak flow to be positive yielded sensitivity of 39.2% (95% CI 28.4, 50.9) and specificity of 97.0% (95% CI 95.7, 97.9). The use of simple screening tests was feasible within the Brazilian primary care setting. The combination of SBQ and peak flow appeared most efficient, when considering performance of the test, cost and ease of use (costing £1690 (5554 R$) with 26.7 cases detected per 1,000 patients). However, the choice of screening tests depends on the clinical setting and availability of resources.ISRCTN registration number: 11377960.

Are we missing lifetime COPD diagnosis among people with COPD recorded death? A population-based retrospective cohort study

BACKGROUND

The British Lung Foundation (BLF) has previously estimated that there are 2.2 million people in the UK who have symptoms, but no diagnosis, of chronic obstructive pulmonary disease (COPD).

AIM

To investigate the proportion of patients with a missed COPD diagnosis among those with COPD as the cause of death on their death certificate, and how this has changed over a period of 17 years (2000-2017).

DESIGN & SETTING

Clinical Practice Research Datalink (CPRD) Aurum and GOLD primary care data were linked with Office for National Statistics (ONS) mortality data and Hospital Episode Statistics (HES) data. Adults who died between 2000 and 2017 with COPD as their main cause of death were included.

METHOD

Using a range of diagnostic COPD criteria, the proportion of patients with a missed COPD diagnosis was estimated, and the demographic and clinical characteristics of patients with and without prior COPD diagnosis were described, using a mixed-effect logistic regression model.

RESULTS

Depending on the COPD definition used, between 96% and 27% of the 78 621 patients included received a diagnosis of COPD before death. Using presence of a COPD Read or SNOMED CT code and performed spirometry as a main definition, just over half of the patients (52%) had received a COPD diagnosis overall, with a proportion of those who did not decreasing from 91% in 2000 to 31% in 2017 (P_trend <0.001).

CONCLUSION

The proportion of people with COPD-recorded death and who had received a diagnosis of COPD has improved (increased) over time, and currently represents the majority of them. This suggests that few patients are now being missed.

Derivation and Validation of the UCAP-Q Case-finding Questionnaire to Detect Undiagnosed Asthma and COPD

BACKGROUND

Many people with asthma and COPD remain undiagnosed. We developed and validated a new case-finding questionnaire to identify symptomatic adults with undiagnosed obstructive lung disease.

METHODS

Adults in the community with no prior history of physician-diagnosed lung disease who self-reported respiratory symptoms were contacted via random-digit dialing. Pre- and post-bronchodilator spirometry was used to confirm asthma or COPD. Predictive questions were selected using multinomial logistic regression with backward elimination. Questionnaire performance was assessed using sensitivity, predictive values, and area under the receiver operating curve (AUC). The questionnaire was assessed for test-retest reliability, acceptability, and readability. External validation was prospectively conducted in an independent sample and predictive performance re-evaluated.

RESULTS

A 13-item UCAP-Q case-finding questionnaire to predict undiagnosed asthma or COPD was developed. The most appropriate risk cut-off was determined to be 6% for either disease. Applied to the derivation sample (N=1615), the questionnaire yielded a sensitivity of 92% for asthma and 97% for COPD, specificity of 17%, with an AUC of 0.69 (95% CI: 0.64-0.74) for asthma and 0.82 (95% CI: 0.78-0.86) for COPD. Prospective validation using an independent sample (n=471) showed sensitivities of 93% and 92% for asthma and COPD, respectively, specificity of 19%, with AUC's of 0.70 (95% CI: 0.62-0.79) for asthma and 0.81 (95% CI: 0.74-0.87) for COPD. AUC's for UCAP-Q were higher compared to AUC's for currently recommended case-finding questionnaires for asthma or COPD.Conclusions:The UCAP-Q demonstrated high sensitivities and AUC's for identifying undiagnosed asthma or COPD. A web-based calculator allows for easy calculation of risk probabilities for each disease.

Prevalence and burden of obstructive lung disease in the urban poor population of Ottawa, Canada: a community-based mixed-method, observational study

BACKGROUND

Globally the burden of Obstructive Lung Diseases (OLD) is growing, however its effect on urban poor populations with the high prevalence of tobacco dependence is virtually unknown. The purpose of this project is to estimate the prevalence and burden of OLD in the urban, low-income populations of Ottawa, Canada.

METHODS

The study presented in this paper was part of the PROMPT (Management and Point-of-Care for Tobacco Dependence) project; a prospective cohort study in a community-based setting (n = 80) with meaningful Patient Engagement from design to dissemination. Spirometry data, standardized questionnaires and semi-structured interviews from PROMPT were interpreted to understand the lung function, disease burden and social determinants (respectively) in this population.

RESULTS

The prevalence of OLD among those who completed spirometry (N = 64) was 45-59%. Generic and disease-specific quality of life was generally poor in all PROMPT participants, even those without OLD, highlighting the higher disease burden this vulnerable population faces. Quality of life was impacted by two major themes, including i) socioeconomic status and stress and ii) social networks and related experiences of trauma.

CONCLUSION

The prevalence and disease burden of OLD is significantly higher in Ottawa's urban poor population than what is observed in the general Canadian population who smoke, suggesting an etiological role of the social determinants of health. This urges the need for comprehensive care programs addressing up-stream factors leading to OLDs, including poor access and utilization of preventive healthcare addressing the social determinants of health.

TRIAL REGISTRATION

ClinicalTrails.gov - NCT03626064 , Retrospective registered: August 2018.