It has been observed widely that, on average, Black individuals in the United States have lower FVC than White individuals, which is thought to reflect a combination of genetic, environmental, and socioeconomic factors that are difficult to disentangle. Debate therefore persists even after the American Thoracic Societys 2023 guidelines recommending race-neutral pulmonary function test (PFT) result interpretation strategies. Advocates of race-based PFT results interpretation argue that it allows for more precise measurement and will minimize disease misclassification. In contrast, recent studies have shown that low lung function in Black patients has clinical consequences. Furthermore, the use of race-based algorithms in medicine in general is increasingly being questioned for its risk of perpetuating structural health care disparities. Given these concerns, we believe it is time to adopt a race-neutral approach, but note that more research is urgently needed to understand how race-neutral approaches impact PFT results interpretation, clinical decision-making, and patient outcomes. In this brief case-based discussion, we offer a few examples of how a race-neutral PFT results interpretation strategy will impact individuals from racial and ethnic minority groups at different scenarios and stages of life.

COPD Genetic Epidemiology Study (COPDGene^®) manuscripts have provided important insights into chronic obstructive pulmonary disease (COPD) pathophysiology and outcomes, including a better understanding of COPD phenotypes relating computed tomography (CT) anatomic data to spirometric and patient-reported outcomes. Spirometry significantly underdiagnoses smoking-induced lung disease, and there is a marked improvement in sensitivity and specificity with CT scanning. This review also highlights the COPDGene^® exploration of specific spirometry phenotypes (e.g.,PRISm), contributors to spirometric decline, composite physiologic measures, asthma-COPD overlap (ACO) syndrome, consequences of bronchodilator responsiveness, newer methods to assess small airway dysfunction, and spirometric correlates of comorbid diseases such as obesity and diabetes.

The practice of using race or ethnicity in medicine to explain differences between individuals is being called into question because it may contribute to biased medical care and research that perpetuates health disparities and structural racism. A commonly cited example is the use of race or ethnicity in the interpretation of pulmonary function test (PFT) results, yet the perspectives of practicing pulmonologists and physiologists are missing from this discussion. This discussion has global relevance for increasingly multicultural communities in which the range of values that represent normal lung function is uncertain. We review the underlying sources of differences in lung function, including those that may be captured by race or ethnicity, and demonstrate how the current practice of PFT measurement and interpretation is imperfect in its ability to describe accurately the relationship between function and health outcomes. We summarize the arguments against using race-specific equations as well as address concerns about removing race from the interpretation of PFT results. Further, we outline knowledge gaps and critical questions that need to be answered to change the current approach of including race or ethnicity in PFT results interpretation thoughtfully. Finally, we propose changes in interpretation strategies and future research to reduce health disparities.

Background: Spirometry is the most common pulmonary function test. It is widely used in the assessment of lung function to provide objective information used in the diagnosis of lung diseases and monitoring lung health. In 2005, the American Thoracic Society and the European Respiratory Society jointly adopted technical standards for conducting spirometry. Improvements in instrumentation and computational capabilities, together with new research studies and enhanced quality assurance approaches, have led to the need to update the 2005 technical standards for spirometry to take full advantage of current technical capabilities.Methods: This spirometry technical standards document was developed by an international joint task force, appointed by the American Thoracic Society and the European Respiratory Society, with expertise in conducting and analyzing pulmonary function tests, laboratory quality assurance, and developing international standards. A comprehensive review of published evidence was performed. A patient survey was developed to capture patients experiences.Results: Revisions to the 2005 technical standards for spirometry were made, including the addition of factors that were not previously considered. Evidence to support the revisions was cited when applicable. The experience and expertise of task force members were used to develop recommended best practices.Conclusions: Standards and consensus recommendations are presented for manufacturers, clinicians, operators, and researchers with the aims of increasing the accuracy, precision, and quality of spirometric measurements and improving the patient experience. A comprehensive guide to aid in the implementation of these standards was developed as an online supplement.

Background

Diffusing capacity of the lung for carbon monoxide (Dlco) is inconsistently obtained in patients with COPD, and the added benefit of Dlco testing beyond that of more common tools is unknown.

Objective

The goal of this study was to determine whether lower Dlco is associated with increased COPD morbidity independent of emphysema assessed via spirometry and CT imaging.

Methods

Data for 1,806 participants with COPD from the Genetic Epidemiology of COPD (COPDGene) study 5-year visit were analyzed, including pulmonary function testing, quality of life, symptoms, exercise performance, and exacerbation rates. Dlco percent predicted was primarily analyzed as a continuous variable and additionally categorized into four groups: (1) Dlco and FEV₁ > 50% (reference); (2) only Dlco ≤ 50%; (3) only FEV₁ ≤ 50%; and (4) both ≤ 50% predicted. Outcomes were modeled by using multivariable linear and negative binomial regression, including emphysema and FEV₁ percent predicted among other confounders.

Results

In multivariable analyses, every 10% predicted decrease in Dlco was associated with symptoms and quality of life (COPD Assessment Test, 0.53 [P < .001]; St. George's Respiratory Questionnaire, 1.67 [P < .001]; Medical Outcomes Study Short Form 36 Physical Function, -0.89 [P < .001]), exercise performance (6-min walk distance, -45.35 feet; P < .001), and severe exacerbation rate (rate ratio, 1.14; P < .001). When categorized, severe impairment in Dlco alone, FEV₁ alone, or both Dlco and FEV₁ were associated with significantly worse morbidity compared with the reference group (P < .05 for all outcomes).

Conclusions

Impairment in Dlco was associated with increased COPD symptoms, reduced exercise performance, and severe exacerbation risk even after accounting for spirometry and CT evidence of emphysema. These findings suggest that Dlco should be considered for inclusion in future multidimensional tools assessing COPD.

Background

The US Preventive Services Task Force (USPSTF) 2021 updated recommendations on lung cancer screening with chest computed tomography to apply to individuals 50-80 years of age (previously 55-80 years), with a ≥20 pack-year history (previously ≥30), whether currently smoking or quit ≤15 years ago. Despite being at higher risk for lung cancer, persons with HIV (PWH) were not well-represented in the National Lung Screening Trial, which informed the USPSTF 2013 recommendations. It is unknown or unclear how PWH are affected by the 2021 recommendations.

Setting

This study was a retrospective analysis of PWH with and without lung cancer in the Women's Interagency HIV Study and the Multicenter AIDS Cohort Study.

Methods

We identified PWH, ages 40-80 years, who currently or previously smoked, with (cases) and without lung cancer (noncases). The sensitivity and specificity of the old, new, and alternative screening criteria were evaluated in each cohort.

Results

We identified 52 women and 19 men with lung cancer and 1950 women and 1599 men without lung cancer. Only 11 women (22%) and 6 men (32%) with lung cancer met 2013 screening criteria; however, more women (22; 44%) and men (12; 63%) met 2021 criteria. Decreased age and tobacco exposure thresholds in women further increased sensitivity of the 2021 criteria.

Conclusions

The 2021 USPSTF lung cancer screening recommendations would have resulted in more PWH with lung cancer being eligible for screening at the time of their diagnosis. Further investigation is needed to determine optimal screening criteria for PWH, particularly in women.

Rationale: Chronic obstructive pulmonary disease (COPD) mortality risk is often estimated using the BODE (body mass index, obstruction, dyspnea, exercise capacity) index, including body mass index, forced expiratory volume in 1 second, dyspnea score, and 6-minute walk distance. Diffusing capacity of the lung for carbon monoxide (DlCO) is a potential predictor of mortality that reflects physiology distinct from that in the BODE index. Objectives: This study evaluated DlCO as a predictor of mortality using participants from the COPDGene study. Methods: We performed time-to-event analyses of individuals with COPD (former or current smokers with forced expiratory volume in 1 second/forced vital capacity < 0.7) and DlCO measurements from the COPDGene phase 2 visit. Cox proportional hazard methods were used to model survival, adjusting for age, sex, pack-years, smoking status, BODE index, computed tomography (CT) percent emphysema (low attenuation areas below -950 Hounsfield units), CT airway wall thickness, and history of cardiovascular or kidney diseases. C statistics for models with DlCO and BODE scores were used to compare discriminative accuracy. Results: Of 2,329 participants, 393 (16.8%) died during the follow-up period (median = 4.9 yr). In adjusted analyses, for every 10% decrease in DlCO percent predicted, mortality increased by 28% (hazard ratio = 1.28; 95% confidence interval, 1.17-1.41, P < 0.001). When compared with other clinical predictors, DlCO percent predicted performed similarly to BODE (C statistic DlCO = 0.68; BODE = 0.70), and the addition of DlCO to BODE improved its discriminative accuracy (C statistic = 0.71). Conclusions: Diffusing capacity, a measure of gas transfer, strongly predicted all-cause mortality in individuals with COPD, independent of BODE index and CT evidence of emphysema and airway wall thickness. These findings support inclusion of DlCO in prognostic models for COPD.

Impaired single breath carbon monoxide diffusing capacity (DLCO) is associated with emphysema. Small airways disease (SAD) may be a precursor lesion to emphysema, but the relationship between SAD and DLCO is undescribed. We hypothesized that in mild COPD, functional SAD (fSAD) defined by computed tomography (CT) and Parametric Response Mapping methodology would correlate with impaired DLCO. Using data from ever-smokers in the COPDGene cohort, we established that fSAD correlated significantly with lower DLCO among both non-obstructed and GOLD 1-2 subjects. The relationship between DLCO with CT-defined emphysema was present in all GOLD stages, but most prominent in severe disease. TRIAL REGISTRATION: NCT00608764. Registry: COPDGene. Registered 06 February 2008, retrospectively registered.

Indoor sources of air pollution worsen indoor and outdoor air quality. Thus, identifying and reducing indoor pollutant sources would decrease both indoor and outdoor air pollution, benefit public health, and help address the climate crisis. As outdoor sources come under regulatory control, unregulated indoor sources become a rising percentage of the problem. This American Thoracic Society workshop was convened in 2022 to evaluate this increasing proportion of indoor contributions to outdoor air quality. The workshop was conducted by physicians and scientists, including atmospheric and aerosol scientists, environmental engineers, toxicologists, epidemiologists, regulatory policy experts, and pediatric and adult pulmonologists. Presentations and discussion sessions were centered on 1) the generation and migration of pollutants from indoors to outdoors, 2) the sources and circumstances representing the greatest threat, and 3) effective remedies to reduce the health burden of indoor sources of air pollution. The scope of the workshop was residential and commercial sources of indoor air pollution in the United States. Topics included wood burning, natural gas, cooking, evaporative volatile organic compounds, source apportionment, and regulatory policy. The workshop concluded that indoor sources of air pollution are significant contributors to outdoor air quality and that source control and filtration are the most effective measures to reduce indoor contributions to outdoor air. Interventions should prioritize environmental justice: Households of lower socioeconomic status have higher concentrations of indoor air pollutants from both indoor and outdoor sources. We identify research priorities, potential health benefits, and mitigation actions to consider (e.g., switching from natural gas to electric stoves and transitioning to scent-free consumer products). The workshop committee emphasizes the benefits of combustion-free homes and businesses and recommends economic, legislative, and education strategies aimed at achieving this goal.

Secondary polycythemia has long been recognized as a consequence of chronic pulmonary disease and hypoxemia and is associated with lower mortality and fewer hospitalizations among individuals with chronic obstructive pulmonary disease (COPD)-prescribed long-term oxygen therapy. This study investigates the association of polycythemia with COPD severity, phenotypic features, and respiratory exacerbations in a contemporary and representative sample of individuals with COPD. Current and former smokers with COPD (forced expiratory volume in 1 second [FEV1] to forced vital capacity [FVC] ratio <70%) without a history of hematologic/oncologic disorders were selected from the SubPopulations and InteRmediate Outcomes Measures In COPD Study (SPIROMICS), a multi-center observational cohort. Participants with polycythemia (hemoglobin ≥15g/dL [females] or ≥17g/dL [males]), were compared to individuals without anemia (hemoglobin ≥12g/dL [females] or ≥13g/dL [males]). Cross-sectional outcomes including percent predicted FEV1, respiratory symptoms, quality of life, exercise tolerance, and percentage and distribution of emphysema (voxels<-950 Hounsfield units [HU] at total lung capacity) were evaluated using linear or logistic regression. Longitudinal acute exacerbation of COPD (AECOPD) and severe AECOPD (requiring an emergency department visit or hospitalization) were assessed using zero-inflated negative binomial models. Among 1261 participants, 148 (11.7%) had polycythemia. Average follow-up was 4.2±1.7 years and did not differ by presence of polycythemia. In multivariate analysis, compared to participants with normal hemoglobin, polycythemia was associated with a reduced rate of severe AECOPD (adjusted incidence rate ratio 0.57, 95% CI: 0.33-0.98), lower percent predicted FEV1, lower resting oxygen saturation, increased upper to lower lobe ratio of emphysema, and a greater degree of emphysema, though the latter was attenuated after adjusting for lung function. There were no significant differences in total AECOPD, patient-reported outcomes, or exercise tolerance. These findings suggest that polycythemia, while associated with less favorable physiologic parameters, is not independently associated with symptoms, and is associated with fewer severe exacerbations. Future studies should explore the potentially protective role of increased hemoglobin beyond the correction of anemia.