Diagnostic accuracy of FeNO [fractional exhaled nitric oxide] and asthma symptoms increased when evaluated with a superior reference standard

Objectives: The objective of the study is to determine the impact of changing reference standards (RS), namely spirometry vs. whole-body plethysmography (WBP), on estimation of the diagnostic accuracy of fractional exhaled nitric oxide (FeNO) and clinical signs and symptoms (CSS) as index tests regarding asthma diagnosis. Study Design and Setting: This was a diagnostic study conducted in 393 patients attending a private practice of pneumologists with complaints suspicious of asthma. First, the index tests were compared with the diagnostic results of spirometry in terms of forced expiratory volume in the first second (FEV1) responsiveness. Second, the index tests were compared with the results of WBP in terms of specific airway resistance and FEV1 responsiveness. Areas under the curve (AUC) were compared with a generalized estimating equation approach based on binary logistic regression. Results: FeNO values and CSS ‘wheezing’ and ‘allergic rhinitis’ showed higher specificities (P < 0.001) and sensitivities (not significant) when evaluated with WBP; also, Youden indices increased in these CSS (P < 0.05). AUC of FeNO in combination with ‘wheezing’ and ‘allergic rhinitis’ when WBP was used as RS (AUC = 0.724; 95% confidence interval 0.672 to 0.776) was higher compared with spirometry as RS (AUC = 0.654; 95% confidence interval 0.585 to 0.722) (P < 0.001). Conclusion: In case of asthma, superior RS led to more favorable assessment of index tests. FeNO measurement might have been underestimated in some previous studies

Diagnostic accuracy of capnovolumetry for the identification of airway obstruction - results of a diagnostic study in ambulatory care

BackgroundOne of the known weaknesses of spirometry is its dependence on patients' cooperation, which can only partially be alleviated by educational efforts. Therefore, procedures less dependent on cooperation might be of value in clinical practice. We investigated the diagnostic accuracy of ultrasound-based capnovolumetry for the identification of airway obstruction.MethodsConsecutive patients from a pulmonary outpatient clinic were included in the diagnostic study. As reference standard, the presence of airway obstruction was evaluated via spirometry and bodyplethysmography. Capnovolumetry was performed as index test with an ultrasound spirometer providing a surrogate measure of exhaled carbon dioxide. Receiver operating characteristic (ROC) analysis was performed using the ratio of slopes of expiratory phases 3 and 2 (s3/s2)0.10 as primary capnovolumetric parameter for the recognition of airway obstruction. Logistic regression was performed as secondary analysis to identify further useful capnovolumetric parameters. The diagnostic potential of capnovolumetry to identify more severe degrees of airway obstruction was evaluated additionally.ResultsOf 1400 patients recruited, 1287 patients were included into the analysis. Airway obstruction was present in 29% of patients. The area under the ROC-curve (AUC) of s3/s2 was 0.678 (95% CI 0.645, 0.710);sensitivity of s3/s20.10 was 47.7 (95% CI 42.7, 52.8)%, specificity 79.0 (95% CI 76.3, 81.6)%. When combining this parameter with three other parameters derived from regression analysis (ratio area/volume phase 3, slope phase 3, volume phase 2), an AUC of 0.772 (95% CI 0.743, 0.801) was obtained. For severe airway obstruction (FEV(1)50% predicted) sensitivity of s3/s20.10 was 75.9 (95% CI 67.1, 83.0)%, specificity 75.8 (95% CI 73.3, 78.1)%;for very severe airway obstruction (FEV(1)30% predicted) sensitivity was 86.7 (95% CI 70.3, 94.7)%, specificity 72.8 (95% CI 70.3, 75.2)%. Sensitivities increased and specificities decreased considerably when the combined capnovolumetric score was used as index test.ConclusionsCapnovolumetry by way of an ultrasound spirometer had a statistically significant albeit moderate potential for the recognition of airway obstruction in a heterogeneous population of patients typically found in clinical practice. Diagnostic accuracy of the capnovolumetric device increased with the severity of airway obstruction.Trial registrationThe study is registered under DRKS00013935 at German Clinical Trials Register (DRKS)

Prediction of air trapping or pulmonary hyperinflation by forced spirometry in COPD patients: results from COSYCONET

Background: Air trapping and lung hyperinflation are major determinants of prognosis and response to therapy in chronic obstructive pulmonary disease (COPD). They are often determined by body plethysmography, which has limited availability, and so the question arises as to what extent they can be estimated via spirometry. Methods: We used data from visits 1–5 of the COPD cohort COSYCONET. Predictive parameters were derived from visit 1 data, while visit 2–5 data was used to assess reproducibility. Pooled data then yielded prediction models including sex, age, height, and body mass index as covariates. Hyperinflation was defined as ratio of residual volume (RV) to total lung capacity (TLC) above the upper limit of normal. (ClinicalTrials.gov identifier: NCT01245933). Results: Visit 1 data from 1988 patients (Global Initiative for Chronic Obstructive Lung Disease grades 1–4, n=187, 847, 766, 188, respectively) were available for analysis (n=1231 males, 757 females; mean±SD age 65.1±8.4 years; forced expiratory volume in 1 s (FEV1) 53.1±18.4 % predicted (% pred); forced vital capacity (FVC) 78.8±18.8 % pred; RV/TLC 0.547±0.107). In total, 7157 datasets were analysed. Among measures of hyperinflation, RV/TLC showed the closest relationship to FEV1 % pred and FVC % pred, which were sufficient for prediction. Their relationship to RV/TLC could be depicted in nomograms. Even when neglecting covariates, hyperinflation was predicted by FEV1 % pred, FVC % pred or their combination with an area under the curve of 0.870, 0.864 and 0.889, respectively. Conclusions: The degree of air trapping/hyperinflation in terms of RV/TLC can be estimated in a simple manner from forced spirometry, with an accuracy sufficient for inferring the presence of hyperinflation. This may be useful for clinical settings, where body plethysmography is not available

Gender-specific differences in COPD symptoms and their impact for the diagnosis of cardiac comorbidities

Background In chronic obstructive pulmonary disease (COPD), gender-specifc diferences in the prevalence of symptoms and comorbidity are known. Research question We studied whether the relationship between these characteristics depended on gender and carried diag nostic information regarding cardiac comorbidities. Study design and methods The analysis was based on 2046 patients (GOLD grades 1–4, 795 women; 38.8%) from the COSYCONET COPD cohort. Assessments comprised the determination of clinical history, comorbidities, lung function, COPD Assessment Test (CAT) and modifed Medical Research Council dyspnea scale (mMRC). Using multivariate regres sion analyses, gender-specifc diferences in the relationship between symptoms, single CAT items, comorbidities and functional alterations were determined. To reveal the relationship to cardiac disease (myocardial infarction, or heart failure, or coronary artery disease) logistic regression analysis was performed separately in men and women. Results Most functional parameters and comorbidities, as well as CAT items 1 (cough), 2 (phlegm) and 5 (activities), dif fered signifcantly (p<0.05) between men and women. Beyond this, the relationship between functional parameters and comorbidities versus symptoms showed gender-specifc diferences, especially for single CAT items. In men, item 8 (energy), mMRC, smoking status, BMI, age and spirometric lung function was related to cardiac disease, while in women primarily age was predictive. Interpretation Gender-specifc diferences in COPD not only comprised diferences in symptoms, comorbidities and func tional alterations, but also diferences in their mutual relationships. This was refected in diferent determinants linked to cardiac disease, thereby indicating that simple diagnostic information might be used diferently in men and women. Clinical trial registration The cohort study is registered on ClinicalTrials.gov with identifer NCT01245933 and on Ger manCTR.de with identifer DRKS00000284, date of registration November 23, 2010. Further information can be obtained on the website http://www.asconet.net

Reduced decline of lung diffusing capacity in COPD patients with diabetes and metformin treatment

We studied whether in patients with COPD the use of metformin for diabetes treatment was linked to a pattern of lung function decline consistent with the hypothesis of anti-aging efects of metformin. Patients of GOLD grades 1–4 of the COSYCONET cohort with follow-up data of up to 4.5 y were included. The annual decline in lung function (FEV1, FVC) and CO difusing capacity (KCO, TLCO) in %predicted at baseline was evaluated for associations with age, sex, BMI, pack-years, smoking status, baseline lung function, exacerbation risk, respiratory symptoms, cardiac disease, as well as metformin-containing therapy compared to patients without diabetes and metformin. Among 2741 patients, 1541 (mean age 64.4 y, 601 female) fulflled the inclusion criteria. In the group with metformin treatment vs. non-diabetes the mean annual decline in KCO and TLCO was signifcantly lower (0.2 vs 2.3, 0.8 vs. 2.8%predicted, respectively; p < 0.05 each), but not the decline of FEV1 and FVC. These results were confrmed using multiple regression and propensity score analyses. Our fndings demonstrate an association between the annual decline of lung difusing capacity and the intake of metformin in patients with COPD consistent with the hypothesis of anti-aging efects of metformin as refected in a surrogate marker of emphysema

Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial

Background: Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke. Methods: We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30–50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515. Findings: Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68–0·90), which indicated that albiglutide was superior to placebo (p&lt;0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (&lt;1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (&lt;1%) deaths in the albiglutide group. Interpretation: In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes. Funding: GlaxoSmithKline

COVID-19 assessment in family practice—A clinical decision rule based on self-rated symptoms and contact history

The study aimed to evaluate the diagnostic accuracy of contact history and clinical symptoms and to develop decision rules for ruling-in and ruling-out SARS-CoV-2 infection in family practice. We performed a prospective diagnostic study. Consecutive inclusion of patients coming for COVID-PCR testing to 19 general practices. Contact history and self-reported symptoms served as index test. PCR testing of nasopharyngeal swabs served as reference standard. Complete data were available from 1141 patients, 605 (53.0%) female, average age 42.2 years, 182 (16.0%) COVID-PCR positive. Multivariable logistic regression showed highest odds ratios (ORs) for 'contact with infected person' (OR 9.22, 95% CI 5.61-15.41), anosmia/ageusia (8.79, 4.89-15.95), fever (4.25, 2.56-7.09), and 'sudden disease onset' (2.52, 1.55-4.14). Patients with 'contact with infected person' or 'anosmia/ageusia' with or without self-reported 'fever' had a high probability of COVID infection up to 84.8%. Negative response to the four items 'contact with infected person, anosmia/ageusia, fever, sudden disease onset' showed a negative predictive value (NPV) of 0.98 (95% CI 0.96-0.99). This was present in 446 (39.1%) patients. NPV of 'completely asymptomatic,' 'no contact,' 'no risk area' was 1.0 (0.96-1.0). This was present in 84 (7.4%) patients. To conclude, the combination of four key items allowed exclusion of SARS-CoV-2 infection with high certainty. With the goal of 100% exclusion of SARS-CoV-2 infection to prevent the spread of SARS-CoV-2 to the population level, COVID-PCR testing could be saved only for patients with negative response in all items. The decision rule might also help for ruling-in SARS-CoV-2 infection in terms of rapid assessment of infection risk

Evaluation of the diagnostic accuracy of fractional exhaled nitric oxide (FeNO) in patients with suspected asthma: study protocol for a prospective diagnostic study

Introduction The measurement of fractional exhaled nitric oxide (FeNO) is promising for diagnosing asthma and might substitute for bronchial provocation (BP) tests. To evaluate the diagnostic accuracy of FeNO within a confirmatory study, the following hypotheses will be tested: (1) A FeNO cut-off &gt;50 ppb (parts per billion) is suitable for diagnosing asthma (sensitivity 35%, specificity 95%); (2) If the clinical symptoms ‘allergic rhinitis’ and ‘wheezing’ are present, asthma can be diagnosed at FeNO &gt;33 ppb with a positive predictive value (PPV) &gt;70% and (3) A FeNO &gt;33 ppb can predict responsiveness to inhaled corticosteroid (ICS) with a PPV &gt;70%.Methods and analysis A prospective diagnostic study will be conducted in three practices of pneumologists in Germany. 300 patients suspected of suffering from asthma will be included. As an index test, patients perform FeNO measurement with the device NIOX VERO. As reference a test, patients are examined with whole bodyplethysmography and BP, if necessary. After 3 months, patients with an asthma diagnosis will be examined again to verify the diagnosis and evaluate ICS responsiveness. Patients who did not receive an asthma diagnosis at the initial examination will be phoned after 3 months and asked about persistent respiratory symptoms to exclude false negative findings. As a primary target, sensitivity and specificity of FeNO &gt;50 ppb will be determined. As a secondary target the PPV for asthma at FeNO &gt;33 ppb, when the symptoms ‘allergic rhinitis’ and ‘wheezing’ are present, will be calculated. Regarding ICS responsiveness, the PPV of FeNO &gt;33 ppb will be determined.Ethics and dissemination The study was approved by the Ethical Committee of the Technical University of Munich (Reference number 122/20 S). The major results will be published in peer-reviewed academic journals and disseminated through conferences.Trial registration number DRKS00021125