Laryngopharyngeal reflux (LPR) is characterized by non-specific symptoms such as hoarseness, cough, and throat clearing. Due to its lack of pathognomonic symptoms or exam findings, LPR is often overdiagnosed. The following blog post outlines a recent study published in May 2016 that examines the accuracy of LPR diagnosis and advocates for laryngeal stroboscopy as the diagnostic modality of choice for this condition.
Background:
More than half of all patients who present with a chief complaint of hoarseness are presumed to have reflux-related disease. Due to the prevalence of LPR, 64% of primary care physicians now feel comfortable diagnosing and empirically treating the condition for up to six weeks before referring a patient to an otolaryngologist. Alarmingly, patients with reflux who are not examined by a specialist are at risk for misdiagnosis, as reflux can mimic other etiologies of hoarseness, such as cancer, cysts, vocal cord paresis, and gastroesophageal reflux disease (GERD). Recent studies highlighting misdiagnosis of LPR among otolaryngologists suggest that laryngeal pathology can be missed even with direct visualization techniques.
Methods:
A healthcare record analysis was conducted with 1,077 patients, all of whom presented with laryngeal complaints from January 2010 through June 2013, from six tertiary academic laryngology practices. Each patient’s demographic information, referring physician, referring diagnosis, and history of prior flexible laryngoscopy was recorded. After each patient’s examination by the referred laryngologist, the patient’s final diagnosis and the key diagnostic test used were also recorded.
The objective of the study was twofold: (1) to determine the prevalence of the LPR referring diagnosis and compare this initial diagnosis with final diagnosis to determine accuracy; (2) to ascertain the best clinical test for diagnosing LPR in the tertiary laryngology practice setting.
Results:
Of the 132 patients who presented with a singular referring diagnosis of LPR, only 35.6% (47/132) were confirmed to have LPR as their primary diagnosis. Of these 47 patients, 28 (59.6%) had undergone a prior laryngoscopy. Transnasal flexible laryngoscopy (TFL) was the critical diagnostic test used to confirm LPR in 27 of 47 patients, followed by stroboscopy (8/47) and history (7/47).
Of the 64.4% (85/132) of patients whose primary diagnosis was found to differ from the referring diagnosis of LPR, stroboscopy was considered the key test used to establish the final diagnosis in 76.5% of them (65/85), followed by TFL (16.5%, 14/85) and history (2.4%, 2/85).
When these groups were compared (patients with confirmed LPR vs. those whose referral diagnosis of LPR was changed post-procedure), several factors were found to significantly affect diagnostic accuracy. 85.9% of patients (73/85) whose singular referral LPR diagnosis changed had a prior laryngoscopy, a significantly higher percentage than that of the confirmed LPR group (P< .001).
Stroboscopy was significantly (P< .001) better at suggesting an alternate diagnosis to LPR than at confirming an initial diagnosis of LPR. Of note, stroboscopy led to a diagnosis change in 83.1% (54/65) of the patients referred from another otolaryngologist.
Compared to the final diagnosis, the referral diagnosis was 72.84% sensitive and 90.66% specific, with a positive predictive value of 38.82% and negative predictive value of 97.62%.
Discussion:
Laryngopharyngeal reflux is commonly overdiagnosed in patients presenting with non-specific symptoms such as hoarseness, dysphagia, and cough. This can lead to potentially harmful outcomes such as inappropriate empiric therapy and delayed evaluation by a specialist. In accordance with the 2009 Clinical Practice Guideline on hoarseness and given the study findings above, any patient whose hoarseness occurs in the absence of GERD symptoms and causes significantly decreased quality-of-life should undergo laryngeal visualization by a specialist.
In this and other recent studies, stroboscopy has been shown to be invaluable in its ability to establish an alternate final diagnosis in cases where the referral diagnosis of LPR is incorrect.
Reference:
Fritz, MA., Persky, MJ., Fang, Y., Simpson, CB., Amin, MR., Akst, LM., Postma, GN. “The Accuracy of the Laryngopharyngeal Reflux Diagnosis: Utility of the Stroboscopic Exam.” Otolaryngol Head Neck Surg 2016 Jun 14. DOI: 10.1177/0194599816655143