Objective Assessment Of Cough Research Articles

Objective Assessment of Cough: An Early Marker of Response to Biological Therapies in Asthma?

Cough is an important symptom of asthma. The objective assessment of chronic cough has been enhanced by the development of ambulatory cough monitoring systems. Mepolizumab has been demonstrated to reduce exacerbations in eosinophilic asthmatics long-term. We evaluate the utility of objective cough count as an outcome measure in severe eosinophilic asthma treated with mepolizumab. Consecutive, consenting patients initiated on treatment with mepolizumab had a 24-h cough count recorded at baseline; this was repeated at 1, 3 and 6months. Asthma control questionnaire (ACQ) scores and exacerbation frequency were also recorded. The mean 24-h cough count in 11 subjects (8 females, mean age 53.6years) was 172.4 at baseline; at 1, 3 and 6months following initiation of treatment this decreased to 101.4, 92 and 70.8, respectively (p < 0.02). Significant improvements were also observed in mean ACQ score (3-1.6, p < 0.01) and exacerbation frequency (5.5 per year - 1.3, p < 0.01). Objective cough measurement could be used as an early, precise and clinically relevant endpoint in assessing response to asthma therapy.

Validity of Cough-Holter Monitoring for the Objective Assessment of Cough and Wheezing in Children with Respiratory Symptoms

목 적 : 임상에서 기침, 천명에 대한 평가는 환자나 보호자가 호소하는 주관적인 증상과 의사의 신체 진찰을 통해 주로 이루어지고 있다. 하지만 이러한 방법들은 일회성이며 주관적인 측면이 있어 기침이나 천명음의 양적인 평가나 지속적인 모니터링에 제한점이 많다. 이에 본 연구에서는 기침-홀터 모니터에서 측정된 기침, 천명음의 빈도 및 강도와 호소하는 증상 및 청진 결과의 일치도를 평가하여 이에 따른 임상적 이용 가치를 알아보고자 하였다. 방 법 : 기침이나 천명음을 주소로 2011년 2월 1일부터 2011년 10월 31일까지 고려대학교 안암병원 소아청소년과 호흡기 알레르기 클리닉을 방문하여 입원한 59명을 대상으로 시행하였다. 대상 환아들은 야간에 약 12시간 동안 기침-홀터 모니터를 사용하여 기침과 천명음의 빈도 및 강도를 분석하였으며, 측정된 결과와 보호자에 의해 설문 작성된 VAS score, 소아청소년과 의사의 청진 상 wheezing score 사이의 연관성을 분석하였다. 결 과: 전체 대상군에서 기침-홀터는 VAS score와 기침의 빈도, 강도에서 유의한 양의 상관 관계를 보였고, wheezing score도 천명음의 빈도와 강도에서 유의한 양의 상관 관계를 보였다. 천명군과 비천명군 모두에서 기침-홀터는 기침강도와 유의한 양의 상관 관계를 보였으나, 천명군에서 whee-zing score와 천명음의 빈도 및 강도는 모두 유의한 상관관계가 없었다. 결 론 : 본 연구에서 기침-홀터로 측정한 기침, 천명음은 환자 또는 보호자가 호소하는 기침 증상 및 소아청소년과 의사의 청진을 통한 주관적 평가 결과와 유의하게 일치하는 경향을 보였다. 기침-홀터는 임상에서 급, 만성 호흡기 증상을 호소하는 소아를 평가하는 객관적 평가 도구의 하나로서 유용하게 사용할 수 있을 것으로 판단된다.

A portable automatic cough analyser in the ambulatory assessment of cough

BackgroundCough is one of the main symptoms of advanced lung disease. However, the efficacy of currently available treatment remains unsatisfactory. Research into the new antitussives requires an objective assessment of cough.MethodsThe aim of the study was to test the feasibility of a new automatic portable cough analyser and assess the correlation between subjective and objective evaluations of cough in 13 patients with chronic cough. The patients' individual histories, a cough symptom score and a numeric cough scale (1-10) were used as a subjective evaluation of cough and a computerized audio-timed recorder was used to measure the frequency of coughing.ResultsThe pre-clinical validation has shown that an automated cough analyser is an accurate and reliable tool for the ambulatory assessment of chronic cough. In the clinical part of the experiment for the daytime, subjective cough scoring correlated with the number of all cough incidents recorded by the cough analyser (r = 0.63; p = 0.022) and the number of cough incidents per hour (r = 0.60; p = 0.03). However, there was no relation between cough score and the time spent coughing per hour (r = 0.48; p = 0.1). As assessed for the night-time period, no correlation was found between subjective cough scoring and the number of incidents per hour (r = 0.29; p = 0.34) or time spent coughing (r = 0.26; p = 0.4).ConclusionAn automated cough analyser seems to be a feasible tool for the ambulatory monitoring of cough. There is a moderate correlation between subjective and objective assessments of cough during the daytime, whereas the discrepancy in the evaluation of night-time coughing might suggest that subjective analysis is unreliable.

New Developments in the Objective Assessment of Cough

A variety of different methods are available for measuring cough. In clinical practice and most clinical trials subjective reporting of cough is relied upon, using scoring systems or visual analog scores (VAS). Although these measures give an indication of patients' perceptions of the severity of the symptom, they may be unreliable because they are influenced by other factors such as mood, vigilance, and expectations. An objective measure of cough would therefore be a valuable tool. In the last decade advances in computer technology and the availability of portable digital sound recording devices have resulted in a resurgence of interest in developing ambulatory systems for recording cough. The ultimate goal is an automated detection system of use in the wide variety of conditions that cause cough. Multidisciplinary teams of researchers around the world are applying techniques such as neural networks, voice recognition models, and other signal processing techniques to this problem. The main challenge is achieving high sensitivity with good discrimination of noncough signals. For cough sound detection, this is confounded by both the variability of the acoustics of cough sounds within and between individuals and the amount and variety of speech sounds that must be discriminated. Significant progress is being made and it is likely that accurate automated objective monitoring systems will be available in the near future. These systems have the potential to change the way cough is measured in clinical practice and clinical trials, allowing a better understanding of the effect of existing and novel treatments on this troublesome symptom.

Evaluation of an ambulatory system for the quantification of cough frequency in patients with chronic obstructive pulmonary disease.

BackgroundTo date, methods used to assess cough have been primarily subjective, and only broadly reflect the impact of chronic cough and/or chronic cough therapies on quality of life. Objective assessment of cough has been attempted, but early techniques were neither ambulatory nor feasible for long-term data collection. We evaluated a novel ambulatory cardio-respiratory monitoring system with an integrated unidirectional, contact microphone, and report here the results from a study of patients with COPD who were videotaped in a quasi-controlled environment for 24 continuous hours while wearing the ambulatory system.MethodsEight patients with a documented history of COPD with ten or more years of smoking (6 women; age 57.4 ± 11.8 yrs.; percent predicted FEV1 49.6 ± 13.7%) who complained of cough were evaluated in a clinical research unit equipped with video and sound recording capabilities. All patients wore the LifeShirt® system (LS) while undergoing simultaneous video (with sound) surveillance. Video data were visually inspected and annotated to indicate all cough events. Raw physiologic data records were visually inspected by technicians who remained blinded to the video data. Cough events from LS were analyzed quantitatively with a specialized software algorithm to identify cough. The output of the software algorithm was compared to video records on a per event basis in order to determine the validity of the LS system to detect cough in COPD patients.ResultsVideo surveillance identified a total of 3,645 coughs, while LS identified 3,363 coughs during the same period. The median cough rate per patient was 21.3 coughs·hr-1 (Range: 10.1 cghs·hr-1 – 59.9 cghs·hr-1). The overall accuracy of the LS system was 99.0%. Overall sensitivity and specificity of LS, when compared to video surveillance, were 0.781 and 0.996, respectively, while positive- and negative-predictive values were 0.846 and 0.994. There was very good agreement between the LS system and video (kappa = 0.807).ConclusionThe LS system demonstrated a high level of accuracy and agreement when compared to video surveillance for the measurement of cough in patients with COPD.

Objective assessment of cough.

Cough is a primitive reflex typically consisting of an initiating deep inspiration, glottal closure, and an explosive expiration accompanied by a sound. The flow characteristics of cough have been shown to differ between different pulmonary diseases. Cough sounds are generated at the larynx and in the lungs. Modern analysing techniques have also been applied in cough sound studies, and differences in cough sound duration and spectra have been found in pulmonary diseases with different bronchopulmonary pathophysiology. Since the objective assessment of cough is clinically important, automatic cough detectors and counters have been constructed, e.g. to assess the efficacy of antitussive drugs. Also, ambulatory methods for assessment of cough have been reported. This review includes a brief history of cough research and present methods available for objective assessment of cough.