A questionnaire on swallowing disturbance is somewhat predictive of aspiration on a barium swallow, but the predictive power wasn’t particularly strong, according to findings presented at the Triological Society Combined Sections Meeting. The findings suggest that the Swallowing Disturbance Questionnaire (SDQ) might not be the best option for clinicians to use for these evaluations.
Dysphagia is common in the United States, with up to one in 25 adults reporting swallowing difficulty each year, said Doreen Lam, BA, the presenter and a fourth-year medical student at the University of Pennsylvania (UPenn) in Philadelphia. It’s also a significant risk factor for aspiration pneumonia, malnutrition, and mortality.
“As a result, screening and early identification of patients with dysphagia is important,” she said. But whether surveys such as the SDQ can predict objective evidence of swallowing dysfunction hasn’t been well explored, Lam said. “To date, few studies have investigated whether the SDQ predicts objective findings of swallowing impairment in modified barium swallow studies, particularly in patients with no clear etiology to their symptoms.”
The SDQ is a survey of 15 questions that are self-completed and specific to dysphagia. It was developed for Parkinson’s disease patients but has been validated for patients with non-neurological disorders. An SDQ score of 12.5 or higher is believed to warrant further evaluation.
In the UPenn study, researchers assessed data from patients who underwent modified barium swallow studies (MBSS) from May 2019 to December 2020, not including patients who were being evaluated as part of a work-up for a lung transplant. The SDQ was completed at the same time as the barium swallow. The outcomes were MBSS findings as rated by the Penetration–Aspiration Scale and esophageal swallow physiology findings on an esophagram.
The study included 158 patients, 56% of whom were female, with a median age of 64. The top referring specialties were gastroenterology, otolaryngology, pulmonology, internal medicine, and neurology. The common reasons for referral were new or worsening dysphagia symptoms without an apparent cause and dysphagia related to head and neck cancer or neurological or GI comorbidities.
A positive SDQ is associated with aspiration findings on barium swallow, but outcomes of the SDQ should be carefully interpreted to consider aspects of a patient’s clinical history not captured in this survey. —Doreen Lam, BA
Researchers found that 41% of patients had a positive SDQ screen with a score of at least 12.5. On MBSS, 10% of patients were found to have penetration, 7.1% had aspiration, and 42% had an abnormal pharyngeal swallow. On esophagram, 76% of patients had reflux and 88% had esophageal abnormalities.
They also found that only patients with aspiration findings on MBSS had statistically significantly increased SDQ scores compared to those who did not aspirate—a score of 21.59 for those with abnormal aspiration findings, compared to 10.69 for those with normal aspiration findings. Those with a positive SDQ score were 6.5 times more likely to have aspiration events, but the 95% confidence interval for the relative risk value was wide, at 1.45 to 29.08, Lam said.
The positive predictive value of the SDQ for aspiration events was 14.3%, and the negative predictive value was 97.8%. Researchers also found a significant, but weak, linear correlation between the SDQ and Penetration–Aspiration Scale scores.
“We found a positive SDQ was associated with a higher risk of aspiration, [but] the wide confidence interval indicates statistical uncertainty due to a small sample size in our cohort,” she said. “And the low positive predictive value also highlights the need for careful clinical decision making when using this survey to minimize unnecessary testing and interventions.”
She added that the SDQ only assesses dysphagia symptoms related to the oropharyngeal phases of swallowing, but patients referred for work-up may have swallowing dysfunction with esophageal causes. Differences between oropharyngeal or esophageal symptoms can be hard to elucidate, which can make test selection difficult, she said. To date, there are few esophageal dysphagia-specific surveys to aid in clinical decision making.
Other patient-reported outcome measures, such as the MDADI and EAT-10, have also had varying success in identifying objective dysfunction on barium swallow, she said, and to date there’s no formally recommended dysphagia screening survey for the general population.
“A positive SDQ is associated with aspiration findings on barium swallow,” concluded Lam, “but outcomes of the SDQ should be carefully interpreted to consider aspects of a patient’s clinical history not captured in this survey.”
Thomas R. Collins is a freelance medical writer based in Florida.