Development and validation of an electronic version of Sydney Swallow Questionnaire

Background and Aims: Accurate assessment of patient-reported oropharyngeal dysphagia (OPD) is essential to guide appropriate management and evaluate response. The Sydney Swallow Questionnaire (SSQ) is a paper-based 17-item inventory developed and validated to objectively detect risk of OPD. An easy-to-use electronic version with digital output has significant potential in streamlining patient assessment. This study aims to develop and validate an electronic version of the SSQ (eSSQ) against the original paper version. 

Method: The English-based paper SSQ was adapted on the online REDcap (Research Electronic Data Capture) platform to be accessible on computer and mobile devices. Patients with OPD and asymptomatic controls completed both electronic and paper versions in randomized order. Patients with stable symptoms then repeated the eSSQ after ≥14 days for test–retest reliability. Paper-based and eSSQs were also collected from an independent cohort for external validation. Agreement of total scores between both versions and eSSQ test–retest reliability were calculated using two-way mixed-effects intra-class correlation coefficient (ICC). 

Results: 47 dysphagic patients, 32 controls, and 31 patients from an external validation cohort were recruited. The most common underlying etiology was head and neck cancer. Mean eSSQ total score was 789 in dysphagic patients, and 68 in controls. eSSQ had excellent agreement with paper SSQ in total scores among all participants, with ICC 0.97 (95% CI [0.93, 0.98]) in controls, 0.97 (95% CI [0.94, 0.98]) in dysphagic patients and 0.96 (95% CI [0.92, 0.98]) in validation cohort. Test–retest reliability was also excellent (ICC 0.96, 95% CI [0.90, 0.98]). 

Conclusion: The newly developed eSSQ shows excellent agreement with the paper version and test–retest reliability. Future applications of its use may allow for more efficient and accessible patient assessment.