[Validation of the Spanish version of the Chronic Obstructive Pulmonary Disease-Population Screener (COPD-PS). Its usefulness and that of FEV₁/FEV₆ for the diagnosis of COPD]

Assessment of inflammatory cytokines in exhaled breath condensate and exposure to mixtures of organic pollutants in brick workers

Brick production causes a lot of pollution in the form of dust, fumes, and toxic substances. Therefore, brick workers are highly exposed to pollutants and present a high risk of developing respiratory diseases. The objective of this research was to determine the exposure to polycyclic aromatic hydrocarbons (PAHs) and toluene in urine and evaluate the effects on health using markers of oxidative stress in exhaled breath condensate (EBC) as well as the exposure to pollutants in suspended particles of the studied area. Exposure to PAHs and toluene was evaluated using hydroxylated markers (OH) of PAHs and hippuric acid in urine, respectively. Cytokines like TNF-α, INF-y, IL-2, IL-4, IL-6, IL-8, IL-10 y GMCSF in EBC were also evaluated. PM_2.5 particles were measured during an 8-h work shift. The results in brick workers presented a total OH-PAHs concentration of 97.3 µg/L and hippuric acid concentration of 0.2 g/L. The environmental concentrations of suspended particles were found within a range of 41.67-3541.6 μg/m³. The median of cytokines oscillated between 11.8 pg/mL to 1041 pg/mL. In conclusion, these results are similar to those of occupations in which there is high exposure to pollutants and populations with lung diseases. For that reason, the brick production sector requires prevention and control strategies against the pollutants emitted.

Translation, cross-cultural adaptation and validation of the Computer Vision Syndrome Questionnaire into Persian (CVS-Q FA©)

Purpose

To translate, cross-culturally adapt and validate the Computer Vision Syndrome Questionnaire (CVS-Q^©) into Persian.

Methods

This study was carried out in 2 phases: (1) the CVS-Q^© was translated and cross-culturally adapted into Persian and (2) the validity and reliability of CVS-Q FA^© were assessed in a cross-sectional validation study. An expert committee composed of 15 optometrists evaluated content validity (item-level (I-CVI) and scale-level (S-CVI) content validity index were calculated). A pretest was performed (n = 20 participants) to verify the comprehensibility of the questionnaire. A total of 102 computer users completed the final questionnaire. Criterion validity and diagnostic performance of the CVS-Q FA^© were assessed by calculating sensitivity, specificity and receiver characteristic operator curve. Cronbach's alpha was calculated for the assessment of internal consistency and 46 participants refilled the questionnaire for the second time and the interclass correlation coefficient (ICC) and Cohen's kappa (κ) were evaluated for test–retest reliability.

Results

The translation and cross-cultural adaptation process was performed successfully according to accepted scientific recommendations without any major difficulties. The I-CVI was above 0.80 for all items (symptoms) except item 15 (feeling that sight is worsening) and the S-CVI was 0.92. The CVS-Q FA^© showed good sensitivity (81.1%) and acceptable specificity (69.2%). Also, it achieved good internal consistency (Cronbach's alpha = 0.80) and test–retest reliability (ICC = 0.81 and κ = 0.65).

Conclusion

The CVS-Q FA^© was successfully translated, cross-culturally adapted, and validated into Persian. This study provides a valid and reliable tool for the assessment of computer vision syndrome among the Iranian working population.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10792-022-02340-3.

Performance and Clinical Utility of Various Chronic Obstructive Pulmonary Disease Case-Finding Tools

BACKGROUND AND AIM

Chronic obstructive pulmonary disease (COPD) is frequently underdiagnosed because of the unavailability of spirometers, especially in resource-limited outpatient settings. This study provides real-world evidence to identify optimal approaches for COPD case finding in outpatient settings.

METHODS

This retrospective study enrolled individuals who were at risk of COPD (age ≥40 years, ≥10 pack-years, and ≥1 respiratory symptom). Eligible participants were examined using various COPD case-finding tools, namely the COPD Population Screener (COPD-PS) questionnaire, a COPD prediction (PCOPD) model, and a microspirometer, Spirobank Smart; subsequently, the participants underwent confirmatory spirometry. The definition and confirmation of COPD were based on conventional spirometry. Receiver operating characteristic curve (ROC), area under the curve (AUC), and decision curve analyses were conducted, and a clinical impact curve was constructed.

RESULTS

In total, 385 participants took part in the study [284 without COPD (73.77%) and 101 with COPD (26.23%)]. The microspirometer exhibited a higher AUC value than did the COPD-PS questionnaire and the PCOPD model. The AUC for microspirometry was 0.908 (95% confidence interval [CI] = 0.87-0.95), that for the PCOPD model was 0.788 (95% CI = 0.74-0.84), and that for the COPD-PS questionnaire was 0.726 (95% CI = 0.67-0.78). Decision and clinical impact curve analyses revealed that a microspirometry-derived FEV1/FVC ratio of <74% had superior clinical utility to the other measurement tools.

CONCLUSION

The PCOPD model and COPD-PS questionnaire were useful for identifying symptomatic patients likely to have COPD, but microspirometry was more accurate and had higher clinical utility. This study provides real-world evidence to identify optimal practices for COPD case finding; such practices ensure that physicians have convenient access to up-to-date evidence when they encounter a symptomatic patient likely to have COPD.

Evaluation of respiratory function and biomarkers of exposure to mixtures of pollutants in brick-kilns workers from a marginalized urban area in Mexico

Brick-kilns are polluted environments due to the use of low-quality technologies and fuels, which generates black fumes with a large number of pollutants. The objective of this research was to analyze environmental exposure and biomarkers of exposure to polycyclic aromatic hydrocarbons, metals, and respiratory health in brickmakers to assess the baseline state of contamination in a brick-kiln area of San Luis Potosi, Mexico. Lead was quantified in soil and particulate matter of 2.5 μm (PM_2.5) and 10 μm (PM₁₀) in brick-kiln areas. In brickmakers, lead was evaluated in whole blood and 10 hydroxylated metabolites of polycyclic aromatic hydrocarbons were determined in urine. Respiratory health was assessed by spirometry, exhaled breath condensate, and a COPD-PS questionnaire. Data association was performed by Spearman correlation. Environmental concentrations and biomarkers of exposure are presented as medians, for lead, it was 60.4 mg/kg, for PM10, it was 2663.1 μg/m³, and for PM2.5, it was 166.6 μg/m³. For blood lead, it was 1.06 μg/dL, and the summed concentration of OH-PAHs in urine was 16.1 μg/L. Spirometry values were 2.8 ± 0.6 L and 2.9 ± 1.3 L/s FEV1 and FEV 25-75 respectively. The correlation results indicate that the older the age of the workers is and the extensive period they have been working, their lung function is affected the most. The health vulnerability present in these occupational activities is high, so it is necessary to make visible, address these economic activities in Mexico, and apply surveillance systems based on the health of the worker.

Validity of the Handheld Expiratory Flowmeter for COPD Screening in the Primary Care Setting of China

Purpose

The use of simple and affordable screening tools for chronic obstructive pulmonary disease (COPD) is limited. We aimed to assess the validity of a handheld expiratory flowmeter (Vitalograph Ltd., COPD-6^®, Ireland) for COPD screening in Chinese primary care settings.

Methods

In our cross-sectional study, subjects were randomly selected in eight primary care settings. Tests with the handheld expiratory flowmeter and the conventional spirometry were sequentially performed on all participants. The correlation between the handheld expiratory flowmeter and the conventional spirometry was determined. Validity was determined by the area under the receiver operator characteristic curve (AUC) of the forced expiratory volume in one second (FEV₁)_/forced expiratory volume in six seconds (FEV₆) that used to detect airway obstruction. The sensitivity, specificity, predictive values, and likelihood ratio were calculated according to different FEV₁/FEV₆ cut-off points.

Results

A total of 229 subjects (15.4%) were diagnosed with airflow limitation by conventional spirometry. FEV₁, FEV₆, and FEV₁/FEV₆ measured by the handheld expiratory flowmeter were correlated with FEV₁, FVC, and FEV₁/FVC measured by the conventional spirometry (r=0.889, 0.835 and 0.647, p<0.001), respectively. AUC of the FEV₁/FEV₆ to determine airflow obstruction was 0.857 (95% CI: 0.826 to 0.888). No significant difference of AUC was observed between the symptomatic group and the asymptomatic group (AUC=0.869 vs 0.843, P=0.425). A similar phenomenon was found in the AUC of smokers and never-smokers (AUC=0.862 vs 0.840; P=0.515). The cut-off point for FEV₁/FEV₆ was 0.77 and the corresponding sensitivity and specificity were 71.2% and 89.8%, respectively.

Conclusion

The handheld expiratory flowmeter might be used as a screening device for COPD in Chinese primary care settings.

Precision and accuracy of FEV1 measurements from the Vitalograph copd-6 mini-spirometer in a healthy Ugandan population

Objective

Evaluate the accuracy and precision of the copd-6 mini-spirometer for FEV₁ in a rural Ugandan population.

Methods

In a cross-sectional study, 171 smallholder farmers performed spirometry with copd-6, and a diagnostic-quality spirometer.

Results and discussion

The copd-6 underestimated FEV₁ at low flows and overestimated FEV₁ at high flows. Across all participants, the device slightly overestimated FEV₁ by 0.04 [0.02; 0.06] L. Calibration data showed similar patterns.

Conclusion

The copd-6 could be considered as an affordable tool for research on lung function impairment in resource-constrained settings. However, further validation in a study population with obstructive lung disease is needed.

Performance of alternative COPD case-finding tools: a systematic review and meta-analysis

RATIONALE

Guidelines recommend pre-/post-bronchodilator spirometry for diagnosing COPD, but resource constraints limit the availability of spirometry in primary care in low- and middle-income countries. Although spirometry is the diagnostic gold standard, we shall assess alternative tools for settings without spirometry.

METHODS

A systematic literature review and meta-analysis was conducted, utilising Cochrane, CINAHL, Google Scholar, PubMed and Web of Science (search cut-off was May 01, 2020). Published studies comparing the accuracy of diagnostic tools for COPD with post-bronchodilator spirometry were considered. Studies without sensitivity/specificity data, without a separate validation sample and outside of primary care were excluded. Sensitivity, specificity and area under the curve (AUC) were assessed.

RESULTS

Of 7578 studies, 24 were included (14 635 participants). Hand devices yielded a larger AUC than questionnaires. The meta-analysis included 17 studies and the overall AUC of micro-spirometers (0.84, 95% CI 0.80-0.89) was larger when compared to the COPD population screener (COPD-PS) questionnaire (0.77, 95% CI 0.63-0.85) and the COPD diagnostic questionnaire (CDQ) (0.72, 95% CI 0.64-0.78). However, only the difference between micro-spirometers and the CDQ was significant.

CONCLUSIONS

The CDQ and the COPD-PS questionnaire were approximately equally accurate tools. Questionnaires ensured testing of symptomatic patients, but micro-spirometers were more accurate. A combination could increase accuracy but was not evaluated in the meta-analysis.

Respiratory health assessment and exposure to polycyclic aromatic hydrocarbons in Mexican indigenous population

Indoor air pollution is an important risk factor for the generation of lung diseases in developing countries. The indigenous population is particularly susceptible to be exposed to the mixture of pollutants from the biomass burning, among them, polycyclic aromatic hydrocarbons (PAHs). The objective of this study was to assess respiratory health and exposure to PAHs in indigenous populations of the Huasteca Potosina in Mexico. The urinary metabolite 1-hydroxypyrene (1-OHP) was evaluated by HPLC with fluorescence detector, the forced expiratory volume in one second (FEV₁) and the FEV₁/FVC ratio (forced vital capacity) by spirometry in the Teenek indigenous adult population of the communities from Tocoy (TOC), Xolol (XOL), and Tanjajnec (TAN). A total of 134 subjects participated in the study: 64 from TOC, 30 from XOL, and 40 from TAN; in all the communities, high percentages of overweight and obesity were presented (from 50 to 73%). The average hours of firewood usage per year were 281.06, 284.6, and 206.6 in TOC, XOL, and TAN, respectively. The average of the three communities of the % FEV₁ post-bronchodilator was 86.1%. There were identified from 4.5 to 6.6% and from 12.5 to 15.5% of spirometric obstructive and restrictive patterns respectively, in all communities. The highest exposure levels reported as median were found in TOC (1.15 μmol/mol of creatinine) followed by TAN (0.94 μmol/mol of creatinine) and XOL (0.65 μmol/mol of creatinine). Considering the magnitude of the indigenous population exposed to pollutants from the biomass burning and the possible effects on respiratory health, it is important to design strategies that mitigate exposure and evaluate the effectiveness through biological monitoring and effects.

Multicenter study of the COPD-6 screening device: feasible for early detection of chronic obstructive pulmonary disease in primary care?

Background and aim

Early detection of COPD may reduce the future burden of the disease. We aimed to investigate whether prescreening with a COPD-6 screening device (measuring FEV₁ and FEV₆) facilitates early detection of COPD in primary care.

Methods

In primary care, individuals at high risk of COPD (ie, age ≥35 years, relevant exposure, and at least one respiratory symptom) and no previous diagnosis of obstructive lung disease were examined with a COPD-6 screening device. In prioritized order, the criteria for proceeding to confirmatory spirometry were FEV₁/FEV₆ <0.7, FEV₁ <80%pred, or clinical suspicion of COPD regardless of test result (medical doctor’s [MD] decision). Based on spirometry, including bronchodilator (BD) reversibility test, individuals were classified as COPD (post-BD FEV₁/FVC <0.70), asthma (ΔFEV₁ ≥0.50 L), or no obstructive lung disease.

Results

A total of 2,990 subjects (54% men, mean age 59 years, and mean 28 pack-years) were enrolled, of whom 949 (32%) proceeded from COPD-6 screening to confirmative spirometry based on the following criteria: 510 (54%) FEV₁/FEV₆ <0.70, 382 (40%) FEV₁ <80%pred, and 57 (6%) MD decision. Following confirmative spirometry, the 949 individuals were diagnosed as having COPD (51%), asthma (3%), and no obstructive lung disease (45%). COPD was diagnosed in 487 (16%) of the enrolled subjects in whom confirmative spirometry was performed in 69% based on FEV₁/FEV₆ <0.7 and in 29% based on FEV₁ ≤80%pred.

Conclusion

Prescreening with the COPD-6 device showed acceptable specificity for the selection of subjects for diagnostic spirometry and is likely to be a useful alternative to current practice in primary care.

Which is the Best Screening Strategy for COPD among Smokers in Primary Care?

We developed a questionnaire to detect cases of chronic obstructive pulmonary disease (COPD) and compared its reliability with other strategies. In order to develop the new questionnaire (COPD screening questionnaire from Terrassa [EGARPOC]) we used data from an epidemiological study on the prevalence of COPD in smokers and calculated the odds ratio for each variable showing significance for the diagnosis of COPD on regression analysis. For comparison among questionnaires and the portable spirometer COPD-6, a cross-sectional multicenter study was performed. The study included 407 smokers or ex-smokers over the age of 40 years with no known diagnosis of COPD, who completed the different questionnaires (EGARPOC, Respiratory Health Screening Questionnaire, COPD-population screener and 2 questions) and underwent spirometry with the COPD-6. We determined the sensitivity, specificity, positive and negative predictive values (S, Sp, PPV and NPV, respectively) and the area under the receiver operating characteristic ROC curve (AUC ROC) of all the questionnaires and the different COPD-6 cut-offs. The prevalence of COPD was 26.3%. The EGARPOC questionnaire showed an S of 81.8%, an Sp of 70.6%, and an NPV of 91.8%; 73.3% of individuals were correctly classified, and the AUC ROC was 0.841. On comparing the questionnaires by the Chi-square test, the 2-question questionnaire showed the worst discrimination; while with an optimal cut-off of forced expiratory volume in one 1 second (FEV₁)/FEV₆ of 0.78, the COPD-6 was significantly better than the questionnaires in the detection of COPD. Using a cut-off of FEV₁/FEV₆ of 0.78 the COPD-6 was found to be the best screening tool for COPD in primary care compared to the questionnaires tested, which did not show differences among them.

Development of a simple binary response questionnaire to identify airflow obstruction in a smoking population in Argentina

The CODE questionnaire (COPD detection questionnaire), a simple, binary response scale (yes/no), screening questionnaire, was developed for the identification of patients with chronic obstructive pulmonary disease (COPD). We conducted a survey of 468 subjects with a smoking history in 10 public hospitals in Argentina. Patients with a previous diagnosis of COPD, asthma and other respiratory illness were excluded. Items that measured conceptual domains in terms of characteristics of symptoms, smoking history and demographics data were considered. 96 (20.5%) subjects had a diagnosis of COPD according to the 2010 Global Initiative for Chronic Obstructive Lung Disease strategy document. The variables selected for the final questionnaire were based on univariate and multivariate analyses and clinical criteria. Finally, we selected the presence or absence of six variables (age ≥50 years, smoking history ≥30 pack-years, male sex, chronic cough, chronic phlegm and dyspnoea). Of patients without any of these six variables (0 points), none had COPD. The ability of the CODE questionnaire to discriminate between subjects with and without COPD was good (the area under the receiver operating characteristic curve was 0.75). Higher scores were associated with a greater probability of COPD. The CODE questionnaire is a brief, accurate questionnaire that can identify smoking individuals likely to have COPD.

Screening for Chronic Obstructive Pulmonary Disease: Validity and Reliability of a Portable Device in Non-Specialized Healthcare Settings

Introduction and Objectives

The underdiagnosis of chronic obstructive pulmonary disease (COPD) could be improved through screening using portable devices simpler than conventional spirometers in specific healthcare settings to reach a higher percentage of the at-risk population. This study was designed to assess the validity and reliability of the COPD-6 portable device to screen for COPD in non-specialized healthcare settings.

Methods

Prospective cohort study to validate a diagnostic test. Three cohorts were recruited: primary care (PC), emergency services (ES) and community pharmacies (CPh). Study population: individuals with risk factors for COPD (>40 years, smoking >10 pack-years, with respiratory symptoms). The values measured using the COPD-6 were FEV1, FEV6 and the FEV1/FEV6 ratio. Subsequently, participants underwent conventional spirometry at hospital, using a post-bronchodilator FEV1/FVC value <0.7 as the gold standard criterion for the COPD diagnosis.

Results

437 participants were included, 362 were valid for the analysis. COPD was diagnosed in 114 patients (31.5%). The area under the ROC curve for the COPD-6 for COPD screening was 0.8.The best cut-off point for the FEV1/FEV6 ratio was 0.8 (sensitivity, 92.1%) using spirometry with the bronchodilator test as the gold standard. There were practically no differences in the COPD-6 performancein the different settings and also regarding age, gender and smoking status.

Conclusions

The COPD-6 device is a valid tool for COPD screening in non-specialized healthcare settings. In this context, the best cut-off point for the FEV1/FEV6 ratio is 0.8.

[Usefulness of the Chronic Obstructive Pulmonary Disease Assessment Test in chronic obstructive pulmonary disease with severe airflow limitation]

BACKGROUND AND OBJECTIVE

To evaluate the relationship between Chronic Obstructive Pulmonary Disease Assessment Test (CAT questionnaire) and chronic obstructive pulmonary disease (COPD) severity assessed by the multidimensional BODE index in patients with severe airflow obstruction (forced expiratory volume in one second [FEV1] post-bronchodilator<50%) in a stable state.

MATERIAL AND METHOD

Prospective observational study (2012). We classified the severity of COPD according to the BODE index in 3 subgroups: mild to moderate COPD (BODE<5 points), severe COPD (BODE 5-6 points) and very severe COPD (BODE ≥ 7 points).

RESULTS

We included 97 patients with a mean age of 67 (8) years, 96% were men. The mean FEV1 was 34.3% (9.8%) and mean BODE index was 4.8 (1.4). The mean CAT score was 20 (7.7). We found no significant differences in CAT score (total or by items) between the 3 groups of BODE assessed.

CONCLUSIONS

In patients with COPD and severe airflow obstruction, the CAT score reflects a moderate to severe impact of illness and does not allow to predict COPD severity assessed by the BODE index.

[Alveolar epithelial cell injury as an etiopathogenic factor in pulmonary fibrosis]

Idiopathic pulmonary fibrosis (IPF) is characterized by a progressive accumulation of extracellular matrix and an imbalance between profibrotic and antifibrotic mediators. In the last few years, understanding of the mechanisms of the biology of IPF has increased. One of the most significant discoveries is the finding that alveolar epithelial cell injury plays an important role in the pathogenesis of this disease. In this review, we describe some of the mechanisms involved in alveolar cell injury and their contribution to the development of IPF.

Design, rationale, and baseline demographics of SEARCH I: a prospective cluster-randomized study

Questionnaires are available to identify patients at risk for several chronic diseases, including COPD, but are infrequently utilized in primary care. COPD is often underdiagnosed, while at the same time the US Preventive Services Task Force recommends against spirometric screening for COPD in asymptomatic adults. Use of a symptom-based questionnaire and subsequent handheld spirometric device depending on the answers to the questionnaire is a promising approach to identify patients at risk for COPD. Screening, Evaluating and Assessing Rate CHanges of diagnosing respiratory conditions in primary care 1 (SEARCH I) was a prospective cluster-randomized study in 168 US primary care practices evaluating the effect of the COPD-Population Screener (COPD-PS™) questionnaire. The effect of this questionnaire alone or sequentially with the handheld copd-6^TM device was evaluated on new diagnoses of COPD and on respiratory diagnostic practice patterns (including referrals for pulmonary function testing, referrals to pulmonologists, new diagnoses of COPD, and new respiratory medication prescriptions). Participating practices entered a total of 9704 consecutive consenting subjects aged ≥ 40 years attending primary care clinics. Study arm results were compared for new COPD diagnosis rates between usual care and (1) COPD-PS plus copd-6 and (2) COPD-PS alone. A cluster-randomization design allowed comparison of the intervention effects at the practice level instead of individuals being the subjects of the intervention. Regional principal investigators controlled the flow of study information to sub-investigators at participating practices to reduce observation bias (Hawthorne effect). The results of SEARCH I, to be published subsequently, will provide insight into the real world utility of the COPD-PS as well as two-stage COPD case finding with COPD-PS and copd-6.