Reflux and Voice Disorders: Have We Established Causality?

Abstract

Purpose of Review

A trend of attributing abnormal voice changes to reflux has gained momentum among medical professionals over the last few decades. Evidence supporting the connection between reflux and voice and the use of anti-reflux medication in patients with dysphonia is conflicting and deserves careful examination. In the current health care environment, it is important that medical decisions be based on science rather than anecdote and practice patterns. The goal of this review is to investigate the evidence linking reflux and voice changes. Specifically, this association will be examined in the context of the Bradford Hill criteria to determine what evidence exists for a causal relationship between this exposure (reflux) and outcome (voice change).

Summary

Using the Bradford Hill criteria as a rubric, the evidence toward causality between reflux and voice is insufficient. The most compelling data derived from animal studies show biological plausibility, since an acidic environment does induce mucosal changes. However, evidence from human studies is largely associative. To date, neither clinical trials nor comparative observational studies have been able to demonstrate a strong dose–response relationship between reflux and voice disorders, temporality (reflux precedes dysphonia), consistent treatment effects, or strength of association between anti-reflux treatment and improved voice among patients with presumed laryngopharyngeal reflux (LPR). Nonetheless, a relationship does exist between LPR and voice and it deserves careful consideration. However, the strength and nature of that association remain unclear.

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