Simplified cough test for screening silent aspiration

Objective: To simplify the cough test to screen silent aspiration without sacrificing accuracy.

Design: Criterion standard.

Setting: University dental hospital.

Participants: Consecutive patients (N=141; 92 men, 49 women; mean age 71±14y, range 23-94y) who had complained of some dysphagic symptoms between June 2008 and February 2010.

Interventions: All patients were administrated a simplified cough test and underwent the fiberoptic endoscopic evaluation of swallowing. Citric acid inhalation was terminated when the first cough occurred, and the time between the start of inhalation and the first cough was measured.

Main outcome measures: The time when the first cough was observed by the simplified cough test was compared with the results of the fiberoptic endoscopic evaluation of swallowing, which was used as a criterion standard.

Results: Receiver operating characteristic curve analysis was performed for 53 patients evaluated as having aspiration by fiberoptic endoscopic evaluation of swallowing. We found that 30 seconds or less was an appropriate cutoff value for detecting patients without silent aspiration, where the sensitivity was .92 and the specificity was .94. From the receiver operating characteristic curve analyses for all patients, 60 seconds or less was determined to be an appropriate cutoff, and the sensitivity and specificity were .81 and .65, respectively.

Conclusion: The simplified cough test is a useful screening tool for silent aspiration in patients with aspiration.