Screening Accuracy for Aspiration Using Bedside Water Swallow Tests: A Systematic Review and Meta-Analysis

Hospitalizations for aspiration pneumonia have doubled among older adults. Using a bedside water swallow test (WST) to screen for swallowing-related aspiration can be efficient and cost-effective for preventing additional comorbidities and mortality. We evaluated screening accuracy of bedside WSTs used to identify patients at risk for dysphagia-associated aspiration.

Sixteen online databases, Google Scholar, and known content experts through May 2015 were searched. Only prospective studies with patients ≥ 18 years of age given WST screenings validated against nasoendoscopy or videofluoroscopy were included. Data extraction used dual masked extraction and quality assessment following Meta-analysis of Observational Studies in Epidemiology guidelines.

Airway response (eg, coughing/choking) with or without voice changes (eg, wet/gurgly voice quality) was used to identify aspiration during three different bedside WSTs. Pooled estimates for single sip volumes (1-5 mL) were 71% sensitive (95% CI, 63%-78%) and 90% specific (95% CI, 86%-93%). Consecutive sips of 90 to 100 mL trials were 91% sensitive (95% CI, 89%-93%) and 53% specific (95% CI, 51%-55%). Trials of progressively increasing volumes of water were 86% sensitive (95% CI, 76%-93%) and 65% specific (95% CI, 57%-73%). Airway response with voice change improved overall accuracy in identifying aspiration.

Currently used bedside WSTs offer sufficient, although not ideal, utility in screening for aspiration. Consecutive sips with large volumes in patients who did not present with overt airway responses or voice changes appropriately ruled out risk of aspiration. Small volumes with single sips appropriately ruled in aspiration when clinical signs were present. Combining these bedside approaches may offer improved screening accuracy, but further research is warranted.