Validation of instruments for the assessment of dysphagia due to malignancy of the esophagus

Abstract

The aim of the study was to validate the Watson scale, the Ogilvie scale, and the Goldschmid scale for assessment of dysphagia due to malignancy of the esophagus. After translation of the scales to Swedish, 35 patients with dysphagia due to esophageal malignancy were asked to participate. On day 1, patients were asked to fill in the questionnaires. The patients also kept a food diary for 4 consecutive days, for assessment of actual swallowing ability. On day 10, the patients were asked to fill in the scales again, to control for individual variability. As an external control group, 29 healthy volunteers were asked to fill in the questionnaires once. External validation was done against actual swallowing ability, and against the European Organization for Research and Treatment of Cancer scales QLQ-C30 and QLQ-OG25, which are already validated quality of life scales for malignancy. Reliability in the categorical variables (Ogilvie and Goldschmid) showed weighted kappa values of 0.52 and 0.54, respectively. For the Watson scale and the Dysphagia module of QLQ-OG25, the intraclass correlation coefficients were 0.68 and 0.80, respectively. Correlations between all scales were good to excellent with values of correlation coefficients (rs) between 0.69 and 0.88, with the strongest correlations between the Ogilvie score and the dysphagia module in QLQ-OG25. These latter two scales had the strongest correlation to the food diary (rs = 0.72). Although the Ogilvie scale was superior, all the three scales showed good reliability and are thus judged to have good validity for assessment of dysphagia due to esophageal malignancy.

Keywords: Watson score; dysphagia; esophageal cancer; health-related quality of life; palliative treatment; squamous cell carcinoma.