Letter by Daniels Regarding Article "Silent Aspiration Risk is Volume-Dependent"

Abstract

Leder and Suiter [1] have proposed the 3-oz. water swallowchallenge as a screening tool for dysphagia in all patientpopulations. Their study was of a retrospective referral-based cohort, i.e., consecutive admissions were not tested.Studies on referral-based patients have the potential forbias. In addition, blinding was not part of this study as thesame investigator interpreted both the fiber-optic evalua-tion of swallowing (FEES) and the 3-oz water swallowchallenge. In their article it was stated that FEES wasperformed prior to the administration of the 3-oz. waterswallow challenge. In a most recent article [2], the sameauthors again studied a large cohort of referred patients,primarily the same patients in the previous study. As in theearlier study, FEES was conducted prior to the 3-oz. waterswallow challenge with the same examiner completingboth. This time, however, the authors reported that over400 patients were excluded from the 3-oz water swallowchallenge due to safety issues, e.g., aspiration of largeamounts of various consistencies on FEES. This detail callsinto question the authors entire body of work and raisesstrong safety concerns about the validity of the 3-oz. waterswallow challenge. When screening a patient, the potentialfor dysphagia and aspiration is unknown; this is the entirereason to screen. Given the information about the exclusionof patients from the 3-oz. water swallow challenge, howare clinicians to decide who is and is not a safety risk priorto actual screening? This methodological informationregarding patient exclusion begs the question: Werepatients excluded in initial study but not reported? Theauthors have not reported any negative consequences ofadministering the 3-oz. water swallow challenge. Theremay have been a lack of negative consequences due to thepreferential selection of patients who underwent thescreening. In order to clarify these issues, the authorsshould undertake a well-designed prospective study inwhich all patients, or a particular subpopulation of patients,are studied, not just referrals. Blinding must be in place;otherwise, the potential for bias will always exist. Lastly,the 3-oz. water swallow challenge MUST be administeredto all patients. In addition, morbidity of patients should bereported. Only after such a study is undertaken can health-care personnel be confident in using the 3-oz. water swal-low challenge as a screening tool.References