Prevalence and clinical associations of wheezes and crackles in the general population: the Tromsø study

Detection of heart failure in a general population not aware of having the disease

BACKGROUND

Heart failure (HF) is one of the most common causes of hospitalization and death worldwide. We aimed at identifying variables that can be helpful for early diagnosis of HF in primary care.

METHODS

In 2015-16, we included 2007 participants aged ≥ 40 years in the 7th Tromsø study. They underwent echocardiography and other examinations needed for establishing a diagnosis of HF according to European guidelines from 2016. We analyzed associations with HF among the 1863 participants who reported not to have HF. Variables significantly associated with HF were included in multivariable logistic regression analyses. Diagnostic models were further analyzed by ROC curves and areas under curve (AUC) were calculated, optimism corrected by bootstrapping.

RESULTS

The HF prevalence in the age groups 40-64 years, 65-74 years, and ≥ 75 years were 3.5%, 11.7% and 29.4%, respectively. A predictive model based on self-reported hypertension, myocardial infarction, atrial fibrillation, body-mass index and moderate to severe dyspnea had an AUC of 0.813 (95% CI 0.785-0.843). In a significantly stronger model, in which NT-proBNP was included and self-reported atrial fibrillation was replaced by atrial fibrillation on ECG, an AUC of 0.849 (95% CI 0.821-0.880) was reached.

CONCLUSION

Easily available clinical information may be used both to rule out HF an to identify patients needing further examinations. A direct referral to echocardiography should be considered for elderly patients in primary care with a known cardiovascular disease and severe shortness of breath. With less abundant history and symptoms, ECG and NT-proBNP can guide further investigations.

The unreliability of crackles: insights from a breath sound study using physicians and artificial intelligence

BACKGROUND AND INTRODUCTION

In comparison to other physical assessment methods, the inconsistency in respiratory evaluations continues to pose a major issue and challenge.

OBJECTIVES

This study aims to evaluate the difference in the identification ability of different breath sound.

METHODS/DESCRIPTION

In this prospective study, breath sounds from the Formosa Archive of Breath Sound were labeled by five physicians. Six artificial intelligence (AI) breath sound interpretation models were developed based on all labeled data and the labels from the five physicians, respectively. After labeling by AIs and physicians, labels with discrepancy were considered doubtful and relabeled by two additional physicians. The final labels were determined by a majority vote among the physicians. The capability of breath sound identification for humans and AI was evaluated using sensitivity, specificity and the area under the receiver-operating characteristic curve (AUROC).

RESULTS/OUTCOME

A total of 11,532 breath sound files were labeled, with 579 doubtful labels identified. After relabeling and exclusion, there were 305 labels with gold standard. For wheezing, both human physicians and the AI model demonstrated good sensitivities (89.5% vs. 86.0%) and good specificities (96.4% vs. 95.2%). For crackles, both human physicians and the AI model showed good sensitivities (93.9% vs. 80.3%) but poor specificities (56.6% vs. 65.9%). Lower AUROC values were noted in crackles identification for both physicians and the AI model compared to wheezing.

CONCLUSION

Even with the assistance of artificial intelligence tools, accurately identifying crackles compared to wheezing remains challenging. Consequently, crackles are unreliable for medical decision-making, and further examination is warranted.

Feasibility and Acceptability of Pediatric Smartphone Lung Auscultation by Parents: Cross-Sectional Study

Background

The use of a smartphone built-in microphone for auscultation is a feasible alternative to the use of a stethoscope, when applied by physicians.

Objective

This cross-sectional study aims to assess the feasibility of this technology when used by parents-the real intended end users.

Methods

Physicians recruited 46 children (male: n=33, 72%; age: mean 11.3, SD 3.1 y; children with asthma: n=24, 52%) during medical visits in a pediatric department of a tertiary hospital. Smartphone auscultation using an app was performed at 4 locations (trachea, right anterior chest, and right and left lung bases), first by a physician (recordings: n=297) and later by a parent (recordings: n=344). All recordings (N=641) were classified by 3 annotators for quality and the presence of adventitious sounds. Parents completed a questionnaire to provide feedback on the app, using a Likert scale ranging from 1 ("totally disagree") to 5 ("totally agree").

Results

Most recordings had quality (physicians' recordings: 253/297, 85.2%; parents' recordings: 266/346, 76.9%). The proportions of physicians' recordings (34/253, 13.4%) and parents' recordings (31/266, 11.7%) with adventitious sounds were similar. Parents found the app easy to use (questionnaire: median 5, IQR 5-5) and were willing to use it (questionnaire: median 5, IQR 5-5).

Conclusions

Our results show that smartphone auscultation is feasible when performed by parents in the clinical context, but further investigation is needed to test its feasibility in real life.

The seventh survey of the Tromsø Study (Tromsø7) 2015-2016: study design, data collection, attendance, and prevalence of risk factors and disease in a multipurpose population-based health survey

Aims:

The Tromsø Study is an ongoing population-based health study in Tromsø, Norway, initiated in 1974. The purpose of the seventh survey (Tromsø7) 2015–2016 was to advance the population risk factor surveillance and to collect new types of data. We present the study design, data collection, attendance, and prevalence of risk factors and disease.

Methods:

All inhabitants in Tromsø municipality, Norway, aged 40 years and older (N=32,591) were invited to a health screening including extensive questionnaires, face-to-face interviews, biological sampling (blood, urine, saliva, nasal/throat swabs, faeces), measurements (anthropometry, blood pressure, pulse, pulse oximetry) and clinical examinations (pain sensitivity, echocardiography, cognitive, physical, and lung function, accelerometer measurements, eye examinations, carotid ultrasound, electrocardiography, dual-energy X-ray absorptiometry, and heart, lung and carotid auscultation). New research areas in this round were dental and oral health examinations, collection of faecal samples for studies of normal bacterial flora and antibiotic resistance, and 24-hour urine samples for examination of sodium and iodine intakes.

Results:

Attendance was 65% (N=21,083), and was higher in women, age group 50–79 years, previous attenders, and Norwegian-born individuals. Cardiovascular risk factor levels and prevalence of chronic obstructive lung disease decreased since the last survey, while the prevalence of obesity and diabetes increased.

Conclusions:

Attendance was stable from the sixth survey. Interaction with participants might be key to maintain participation. Favourable trends in risk factors continue, except for a continued increase in obesity. Both new data collection technology and traditional physical examinations will be crucial for the impact of future population studies.

Digitally recorded and remotely classified lung auscultation compared with conventional stethoscope classifications among children aged 1-59 months enrolled in the Pneumonia Etiology Research for Child Health (PERCH) case-control study

BACKGROUND

Diagnosis of pneumonia remains challenging. Digitally recorded and remote human classified lung sounds may offer benefits beyond conventional auscultation, but it is unclear whether classifications differ between the two approaches. We evaluated concordance between digital and conventional auscultation.

METHODS

We collected digitally recorded lung sounds, conventional auscultation classifications and clinical measures and samples from children with pneumonia (cases) in low-income and middle-income countries. Physicians remotely classified recordings as crackles, wheeze or uninterpretable. Conventional and digital auscultation concordance was evaluated among 383 pneumonia cases with concurrently (within 2 hours) collected conventional and digital auscultation classifications using prevalence-adjusted bias-adjusted kappa (PABAK). Using an expanded set of 737 cases that also incorporated the non-concurrently collected assessments, we evaluated whether associations between auscultation classifications and clinical or aetiological findings differed between conventional or digital auscultation using χ2 tests and logistic regression adjusted for age, sex and site.

RESULTS

Conventional and digital auscultation concordance was moderate for classifying crackles and/or wheeze versus neither crackles nor wheeze (PABAK=0.50), and fair for crackles-only versus not crackles-only (PABAK=0.30) and any wheeze versus no wheeze (PABAK=0.27). Crackles were more common on conventional auscultation, whereas wheeze was more frequent on digital auscultation. Compared with neither crackles nor wheeze, crackles-only on both conventional and digital auscultation was associated with abnormal chest radiographs (adjusted OR (aOR)=1.53, 95% CI 0.99 to 2.36; aOR=2.09, 95% CI 1.19 to 3.68, respectively); any wheeze was inversely associated with C-reactive protein >40 mg/L using conventional auscultation (aOR=0.50, 95% CI 0.27 to 0.92) and with very severe pneumonia using digital auscultation (aOR=0.67, 95% CI 0.46 to 0.97). Crackles-only on digital auscultation was associated with mortality compared with any wheeze (aOR=2.70, 95% CI 1.12 to 6.25).

CONCLUSIONS

Conventional auscultation and remotely-classified digital auscultation displayed moderate concordance for presence/absence of wheeze and crackles among cases. Conventional and digital auscultation may provide different classification patterns, but wheeze was associated with decreased clinical severity on both.

Lung Auscultation Using the Smartphone-Feasibility Study in Real-World Clinical Practice

Conventional lung auscultation is essential in the management of respiratory diseases. However, detecting adventitious sounds outside medical facilities remains challenging. We assessed the feasibility of lung auscultation using the smartphone built-in microphone in real-world clinical practice. We recruited 134 patients (median[interquartile range] 16[11-22.25]y; 54% male; 31% cystic fibrosis, 29% other respiratory diseases, 28% asthma; 12% no respiratory diseases) at the Pediatrics and Pulmonology departments of a tertiary hospital. First, clinicians performed conventional auscultation with analog stethoscopes at 4 locations (trachea, right anterior chest, right and left lung bases), and documented any adventitious sounds. Then, smartphone auscultation was recorded twice in the same four locations. The recordings (n = 1060) were classified by two annotators. Seventy-three percent of recordings had quality (obtained in 92% of the participants), with the quality proportion being higher at the trachea (82%) and in the children's group (75%). Adventitious sounds were present in only 35% of the participants and 14% of the recordings, which may have contributed to the fair agreement between conventional and smartphone auscultation (85%; k = 0.35(95% CI 0.26-0.44)). Our results show that smartphone auscultation was feasible, but further investigation is required to improve its agreement with conventional auscultation.

Associations with antibiotic prescribing for acute exacerbation of COPD in primary care: secondary analysis of a randomised controlled trial

BACKGROUND

C-reactive protein (CRP) point-of-care testing can reduce antibiotic use in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in primary care, without compromising patient care. Further safe reductions may be possible.

AIM

To investigate the associations between presenting features and antibiotic prescribing in patients with AECOPD in primary care.

DESIGN AND SETTING

Secondary analysis of a randomised controlled trial of participants presenting with AECOPD in primary care (the PACE trial).

METHOD

Clinicians collected participants' demographic features, comorbid illnesses, clinical signs, and symptoms. Antibiotic prescribing decisions were made after participants were randomised to receive a point-of-care CRP measurement or usual care. Multivariable regression models were fitted to explore the association between patient and clinical features and antibiotic prescribing, and extended to further explore any interactions with CRP measurement category (CRP not measured, CRP <20 mg/l, or CRP ≥20 mg/l).

RESULTS

A total of 649 participants from 86 general practices across England and Wales were included. Odds of antibiotic prescribing were higher in the presence of clinician-recorded crackles (adjusted odds ratio [AOR] = 5.22, 95% confidence interval [CI] = 3.24 to 8.41), wheeze (AOR = 1.64, 95% CI = 1.07 to 2.52), diminished vesicular breathing (AOR = 2.95, 95% CI = 1.70 to 5.10), or clinician-reported evidence of consolidation (AOR = 34.40, 95% CI = 2.84 to 417.27). Increased age was associated with lower odds of antibiotic prescribing (AOR per additional year increase = 0.98, 95% CI = 0.95 to 1.00), as was the presence of heart failure (AOR = 0.32, 95% CI = 0.12 to 0.85).

CONCLUSION

Several demographic features and clinical signs and symptoms are associated with antibiotic prescribing in AECOPD. Diagnostic and prognostic value of these features may help identify further safe reductions.

Inspiratory crackles-early and late-revisited: identifying COPD by crackle characteristics

BACKGROUND

The significance of pulmonary crackles, by their timing during inspiration, was described by Nath and Capel in 1974, with early crackles associated with bronchial obstruction and late crackles with restrictive defects. Crackles are also described as 'fine' or 'coarse'. We aimed to evaluate the usefulness of crackle characteristics in the diagnosis of chronic obstructive pulmonary disease (COPD).

METHODS

In a population-based study, lung sounds were recorded at six auscultation sites and classified in participants aged 40 years or older. Inspiratory crackles were classified as 'early' or 'late and into the types' 'coarse' and 'fine' by two observers. A diagnosis of COPD was based on respiratory symptoms and forced expiratory volume in 1 s/forced inspiratory vital capacity below lower limit of normal, based on Global Lung Function Initiative 2012 reference. Associations between crackle characteristics and COPD were analysed by logistic regression. Kappa statistics was applied for evaluating interobserver agreement.

RESULTS

Of 3684 subjects included in the analysis, 52.9% were female, 50.1% were ≥65 years and 204 (5.5%) had COPD. Basal inspiratory crackles were heard in 306 participants by observer 1 and in 323 by observer 2. When heard bilaterally COPD could be predicted with ORs of 2.59 (95% CI 1.36 to 4.91) and 3.20 (95% CI 1.71 to 5.98), annotated by observer 1 and 2, respectively, adjusted for sex and age. If bilateral crackles were coarse the corresponding ORs were 2.65 (95% CI 1.28 to 5.49) and 3.67 (95% CI 1.58 to 8.52) and when heard early during inspiration the ORs were 6.88 (95% CI 2.59 to 18.29) and 7.63 (95%CI 3.73 to 15.62). The positive predictive value for COPD was 23% when early crackles were heard over one or both lungs. We observed higher kappa values when classifying timing than type.

CONCLUSIONS

'Early' inspiratory crackles predicted COPD more strongly than 'coarse' inspiratory crackles. Identification of early crackles at the lung bases should imply a strong attention to the possibility of COPD.

Prediction of chronic heart failure and chronic obstructive pulmonary disease in a general population: the Tromsø study

Aims

Heart failure (HF) and chronic obstructive pulmonary disease (COPD) are main causes of dyspnoea, and echocardiography and spirometry are essential investigations for these diagnoses. Our aim was to determine the prevalence of HF and COPD in a general population, also how the diseases may be identified, and to what extent their clinical characteristics differ.

Methods and results

In the seventh survey of Tromsø study (2015–16), subjects aged 40 years or more were examined with echocardiography, spirometry, lung sound recordings, questionnaires, including the modified Medical Research Council (mMRC) questionnaire on dyspnoea, and N‐terminal pro‐brain natriuretic peptide analysis. A diagnosis of HF (HF with reduced ejection fraction, HF with mid‐range ejection fraction, or HF with preserved ejection fraction) or COPD was established according to current guidelines. Predictors of HF and COPD were evaluated by logistic regression and receiver operating characteristic curve analysis. A total of 7110 participants could be evaluated for COPD, 1624 for HF, and 1538 for both diseases. Age‐standardized prevalence of HF was 6.8% for women and 6.1% for men; the respective figures for COPD were 5.2% and 5.1%. Among the 1538 evaluated for both diseases, 139 subjects fulfilled the HF criteria, but only 17.1% reported to have the disease. Of those fulfilling the COPD criteria, 31.6% reported to have the disease. Shortness of breath at exertion was a frequent finding in HF; 59% of those with mMRC ≥2 had HF, while such shortness of breath was found in 24% among those with COPD. Reporting mMRC ≥2 had an odds ratio for HF of 19.5 (95% confidence interval 11.3–33.7), whereas the odds ratio for COPD was 6.3 (95% confidence interval 3.5–11.6). Current smoking was the strongest predictor of COPD but did not predict HF. Basal inspiratory crackles were significant predictors of HF in multivariable analysis. Among the subtypes of HF, an age <70 years was most frequently found in HF with reduced ejection fraction, in 51.7%. Clinical scores based on the predictive value in multivariable analysis of history, symptoms, and signs predicted HF and COPD with areas under the curve of 0.833 and 0.829, respectively.

Conclusions

Study participants with HF and COPD were in most cases not aware of their condition. In general practice, when an elderly patient present with shortness of breath, both diseases should be considered. Previous cardiovascular disease points at HF, while a history of smoking points at COPD. The threshold should be low for ordering echocardiography or spirometry for verifying the suspected cause of dyspnoea.