Inter- and intra-rater reliability of cervical auscultation to detect aspiration in patients with dysphagia

Abstract

Objective: To measure the inter- and intra-rater reliability of cervical auscultation used alone to detect aspiration in dysphagic patients.

Setting: A university teaching hospital.

Design: Comparison of the detection of aspiration in 16 recorded swallow sounds by five speech and language therapists on two occasions. Swallow sounds were recorded simultaneously with videofluoroscopy.

Subjects: Sixteen patients referred for assessment of dysphagia with videofluoroscopy.

Results: The kappa statistic for multiple raters showed fair agreement between raters (kappa = 0.28). There was high agreement when aspiration occurred but in non-aspirating swallows there was significant overdetection of aspiration (p < 0.001 McNemar's test). The intra-rater reliability within different individuals was widely variable (kappa = 0.55 (range 0.31-0.85)).

Conclusions: Presented with the swallowing sounds in isolation speech and language therapists cannot reliably classify swallows into those with accompanying aspiration and those without. There appears to be a problem of over detection of aspiration. Even in this small study, however, some individual therapists achieve such high reliability (kappa = 0.85) that they must be using successful internal criteria to interpret the swallow sounds correctly and further qualitative research may identify these.