Back-translation process
SWAL-QOL. Issues related to semantic equivalence were observed when analyzing the French France version (VF2). As an example, the word “glaires [phlegm]” (item 11) is not used in spoken French in Quebec, and the word “gêne [distraction]” (item 31) is more employed to express shyness than inconvenience. Therefore, other terms were chosen for the reconciliation version (VF3). In addition, grammatical issues were encountered during reconciliation of VF1 and VF2. For example, it was particularly challenging to translate the Likert scale items for items 1 to 7, and the back-translation (VE1) showed that the intended meaning amongst each scale point was not reached at our first attempt. The original response options “Very much true, Quite a bit true, Somewhat true, A little true, Not at all true” were then adapted this way: “Tout à fait vrai, Très vrai, Plutôt vrai, Un peu vrai, Pas vrai du tout”. A better fit of the items with the original meaning was finally obtained, as shown by the second back-translation (VE2): Completely true, Very true, Quite true, Slightly true, Not at all true”.
SSQ. Experiential and conceptual equivalence issues were observed during reconciliation of VF1 and VF2, specifically with items 4 and 17. The problem with item 4 was that “Mornays” was mentioned as an example of soft food, which is a French sauce that is not typically part of the French Canadians diet and could not be known by patients. The author of the SSQ was contacted and “coquille St-Jacques” (a preparation of scallops in a creamy sauce topped with cheese) was chosen, instead of Mornays, because it is well-known by French-Canadians. Greater precision was also required for the wording of item 17 “How much does your swallowing problem interfere with your enjoyment or quality of life?” because the word “enjoyment” is expressed by different words in French, such as “plaisir [pleasure]” and “bonheur [happiness]”, which have subtly different conceptual meanings. The authors of the SSQ explained that this item was related to disruption of a patient’s ability to enjoy life because of swallowing dysfunction. By consensus, the word “bien-être [back-translation: well-being]” was retained. No grammatical difficulties were encountered in translating the SSQ into French.
Cross-sectional study for the assessment of known groups validity.
Table 1 summarizes the participants’ characteristics and mean scores for the SWAL-QOL scales, DSB, composite score, and SSQ. As hypothesized, the group with the lower mean drinking test time had a significantly lower mean FC SSQ score, with an effect size of 0.52 (Table 2). However, mean composite FC SWAL-QOL did not differ significantly, with an effect size of 0.41. Only 2 scales (burden and eating duration) showed significant differences; those scales had the larger effect sizes (0.60 and 0.75).
Cognitive debriefing
SWAL-QOL. Participants (n = 21) were age 60.7 ± 6.9 years and 9/21 were females. Mean dysphagia duration was 10.1 years ± 5.7. 25 % had some post-secondary education, 35 % were high school graduates, 25 % had less than a high school education and 15 % were college graduates. Each item was addressed by 5 to 7 participants. Semantic equivalence issues were found for item 12 and item 19. When asked the meaning of item 12 “Avoir des hauts-le-cœur [Gagging]”, most of the participants (6/7) understood it as vomiting and one participant referred to having food stuck in the throat causing a gag reflex. Item 19 “Avoir des aliments ou des liquides qui ressortent par la bouche [Food or liquid dribbling out of your mouth]” was misinterpreted by the participants as regurgitation. Experiential equivalence issues were also observed for two items. Items 9 and 26 were problematic as the term “s’étouffer” [choking]” was interpreted in two different ways. In the first case, participants identified situations in which food was blocking the airway, preventing them from breathing. In the second case, participants described the experience of having a blockage sensation in the throat causing them to spit out food, but they still can breathe. A conceptual equivalence issue was observed for item 33 “Mon problème de déglutition me frustre [My deglutition problem frustrates me]”. 3 out of 5 participants interpreted the word “frustrates” as “to be angry” and two participants described situations in which they would like to eat normally, like other people do. Lastly, problems inherent to the original questionnaire were observed, such as ambiguity and vagueness for some items. For example, participants did not consistently interpret item 1 “Gérer mes troubles de deglutition [Dealing with my swallowing problem]”. Some participants referred to the day-to-day coping strategies they use to avoid choking, while other participants referred to coping strategies in specific contexts, like eating in a restaurant. Two other items were found problematic because of their double-barreled nature (items 11 and 15). Finally, items 24, 37, 39, 40, and 41, pertaining to communication, social, fatigue and sleep scales were considered irrelevant to dysphagia by some participants.
SSQ. Mean age of participants (n = 7) was 62.7 years ± 6.4 and 4/7 were females. Mean dysphagia duration was 10.7 years ± 6.4. 1 had some post-secondary education, 4 were high-school graduates, 1 had less than a high school education and 1 was a college graduate. Item 8 was found to have a semantic equivalence issue because the term “amorcer la déglutition? [starting a swallow?]” is mostly a technical term and was not understood by many participants. The main issue with the SSQ was experiential equivalence, with the examples given for food textures and liquid consistencies in items 2 to 6. For example, when questioned about difficulty with hard foods (item 5), many people agree that they did have difficulty with steak and raw vegetables like carrots, but not with raw fruit, like an apple or a pear, which made it difficult for them to give an accurate answer. The term “difficulty” itself appears to be conceptually problematic because it can have subtly different meanings, such as not swallowing easily or having any problem when swallowing. For example, some participants acknowledged they did have difficulty because they use strategies to prevent swallowing problems with food and drink, such as taking small bites. On the other hand, other participants considered themselves as not having difficulty because they were using effective strategies. Vagueness was a problem for some items, such as items 12, 16 and 17, leading participants to various interpretations. For exemple, when asked “Aujourd’hui, comment évaluez-vous la gravité de votre problème de déglutition? [How do you rate the severity of your swallowing problem today?]” (item 16), participants thought about impacts on social life, severity of blockage in the throat, discomfort related to secretions, life-threatening symptoms and food limitations. No comment was raised about the relevance of the items. However, some participants felt that the questionnaire was incomplete because it had no question about pharyngo-oral secretions.
Finalization
In order to achieve better equivalent translations, revisions were made for items 12, 19 and 33 of the FC SWAL-QOL and item 8 of the FC SSQ). No changes were made for the other items, in order to respect the conceptual meaning of the original version. The final versions of the FC SWAL-QOL and the FC SSQ are available in Supplementary File S1 and S2.