Concordance and discriminatory power of cough measurement devices for individuals with Parkinson disease.

BACKGROUND

Dysphagia and aspiration pneumonia are two causes of morbidity in Parkinson disease (PD). In PD, impaired airway clearance can lead to penetration of foreign material, resulting in a high prevalence of aspiration pneumonia and death. This study examines three different devices for measurement of peak airflow during voluntary cough in healthy control subjects and those with PD. Two simple and low-cost devices for measuring peak cough airflow were compared with the "gold standard" pneumotachograph.

METHODS

Thirty-five healthy control subjects and 35 individuals with PD produced voluntary cough at three perceived strengths (weak, moderate, and strong cough) for each of the three devices.

RESULTS

A significant difference in mean peak cough airflow was demonstrated for disease (F[1,56] = 4.0, P < .05) and sex (F[1,56] = 9.59, P < .003) across devices. The digital and analog meters were comparable to the gold standard demonstrating no significant difference (statistical) by device (digital vs analog) in receiver operating characteristic curve analysis. Both devices were discriminative of the presence of PD.

CONCLUSIONS

The analog and digital peak airflow meters are suitable alternatives to the gold standard pneumotachograph due to their low cost, portability, ease of use, and high sensitivity relative to normative peak cough airflows. Voluntary cough airflow measures may serve as a noninvasive means of screening for aspiration risk in target populations. Additionally, quantification of cough strength through use of predetermined limens for weak, moderate, and strong cough may assist clinicians in better describing and tracking cough strength as a contributing factor to aspiration risk.