Dysphagia‐related quality of life in oculopharyngeal muscular dystrophy: Psychometric properties of the SWAL‐QOL instrument

Abstract

Introduction The Swallowing Quality of Life instrument (SWAL-QOL) is a patient-reported outcome (PRO) measure of swallowing-related quality of life (SR-QoL). Its psychometric properties in oculopharyngeal muscular dystrophy (OPMD) are not known. Methods We administered the SWAL-QOL to U.S. OPMD Registry participants. We described SR-QoL profiles and assessed reliability and validity. Results Mean composite score in 113 individuals with OPMD was 54.4 ± 20.7, indicating moderate impairment. Severe impairments were observed in eating duration, burden, and fatigue scales. Internal consistency reliability of all scales was found to be satisfactory, and 9 of 10 scales demonstrated adequate test-retest reliability. Data confirmed 86% of hypotheses, supporting construct validity. The SWAL-QOL limitations in OPMD include: floor/ceiling effects in 7 of 10 scales and low specificity of sleep, fatigue, and communication scales for dysphagia. Discussion SR-QoL is reduced in OPMD. Given several limitations of the SWAL-QOL, development of an improved dysphagia-specific QoL instrument for OPMD is warranted.

The requirement for a disease‐specific patient‐reported outcome measure of dysphagia in oculopharyngeal muscular dystrophy

“…Six questionnaires focused on FHS, whereas 4 others were HR‐QOL related (Table ). The only questionnaire that included a validation process with an OPMD population was the Swallowing Quality‐of‐Life (SWAL‐QOL), a generic questionnaire . Although some evidence of reliability and validity is documented in OPMD, the SWAL‐QOL presents several weaknesses, including floor/ceiling effects that may diminish its discriminative power …”

“…Thus, this symptom's meaning is not clear and should be avoided in a questionnaire. Chewing and oral control difficulties were not reported by patients in the qualitative interviews and were disclosed only by rare patients in the OPMD SWAL‐QOL validation study (<20%, n = 113) . Oral impairments have not been extensively documented in OPMD, but dystrophic changes were found in the tongue and masseter muscles as well as reduced lingual pressure generation .…”

“…Blockage sensation can be expressed as food sticking or getting stuck in the throat. This symptom is usually reported by all patients and is in line with pharyngeal muscle weakness . Regarding swallowing difficulties, experts outlined the importance of difficulty with solid foods compared to liquids and distinguishing between different food textures in assessing difficulty with solid foods.…”

“…Major symptoms include eyelid ptosis, oropharyngeal dysphagia, and, later, limb weakness. Dysphagia‐related symptoms have been partially explored in OPMD by using semiquantitative measures, patient reported outcomes (PRO), and qualitative interviews . Difficulty swallowing is typically first noticed for solid foods and then progressively for liquids and even saliva .…”

“…Coping strategies are also adopted by patients in social contexts, such as eating before going to a restaurant . Health‐related quality of life is significantly impacted by the worsening of dysphagia …”