For crackles, we observed k=0.22 and k=0.40 (p=<0.01) in the same order. Fleiss kappa values for the multirater agreement were k=0.51 and k=0.56 (p=.63) for wheezes without and with spectrogram, respectively. We conducted a study in which 23 medical students classified the same lung sounds with and without spectrograms. We also tested if the use of spectrograms could improve the classification of lung sounds. Four out of seven groups reached a k≥0.62. For wheezes, we observed a probability of agreement between 69% and 100% and kappa values from 0.09 to 0.97. Congers kappa ranged from 0.20 to 0.58 and four of seven groups reached a k ≥0.49. The probability of agreement for crackles varied between 65% and 87%. We asked seven groups with four doctors each to classify 120 lung sound recordings. We explored the variation of inter-observer agreement. In the case of inspiratory crackles, significant predictors were age, current smoking, rheumatoid arthritis mMRC ≥2, low oxygen saturation and FEV1 Z-score. Age, female sex, self-reported asthma, and current smoking predicted the occurrence of expiratory wheezes. We observed a crude prevalence of adventitious lung sounds in 28% of the participants 18 % had wheezes, 13% had crackles. We obtained lung sound recordings from 4033 participants in the 7th survey of the Tromsø.

The main goal of this work was to describe the prevalence of adventitious lung sounds (wheezes and crackles) in a general population.

Adventitious lung sounds