Development and validation of a self-report symptom inventory to assess the severity of oral-pharyngeal dysphagia

Background & Aims: The aim of this study was to develop and evaluate the va lidity and reliability of a self-report inventory to measure symptomatic se verity of oral-pharyngeal dysphagia. Methods: Test-retest reliability and f ace, content, and construct validity of a prototype visual analogue scale i nventory were assessed in 45 patients who had stable, neuromyogenic dysphag ia, Results: Normalized scores varied over time by -0.5% +/- 17.6% (95% con fidence interval, -9.2% to 8.2%). Factor analysis identified a single facto r (dysphagia), to which 18 of 19 questions contributed significantly, that accounted for 56% of total variance (P < 0.0001). After deletion of 2 quest ions with poor face validity and patient compliance, this proportion increa sed to 59%; mean test-retest change was -2% (95% confidence interval, -11% to 7%); and total score correlated highly with an independent global assess ment severity score (r = 0.7; P < 0.0001). A mean 70% reduction in score (P < 0.0001) was observed after surgery in patients with Zenker's diverticulu m (discriminant validity). Conclusions: Applied to patients with neuromyoge nic dysphagia, the 17-question inventory shows strong test-retest reliabili ty over 2 weeks as well as face, content, and construct validity, Discrimin ant validity (responsiveness) has been demonstrated in a population with a correctable, structural cricopharyngeal disorder, Responsiveness of the ins trument to treatment in neuromyogenic dysphagia remains to be quantified.