Validation of the Dutch version of the Swallowing Quality-of-Life Questionnaire (DSWAL-QoL) and the adjusted DSWAL-QoL (aDSWAL-QoL) using item analysis with the Rasch model: a pilot study.

BACKGROUND: The Swallowing Quality-of-Life Questionnaire (SWAL-QoL) is considered the gold standard for assessing health-related QoL in oropharyngeal dysphagia. The Dutch translation (DSWAL-QoL) and its adjusted version (aDSWAL-QoL) have been validated using classical test theory (CTT). However, these scales have not been tested against the Rasch measurement model, which is required to establish the structural validity and objectivity of the total scale and subscale scores. Thus, the purpose of this study was to examine the psychometric properties of these scales using item analysis according to the Rasch model. METHODS: Item analysis with the Rasch model was performed using RUMM2030 software with previously collected data from a validation study of 108 patients. The assessment included evaluations of overall model fit, reliability, unidimensionality, threshold ordering, individual item and person fits, differential item functioning (DIF), local item dependency (LID) and targeting. RESULTS: The analysis could not establish the psychometric properties of either of the scales or their subscales because they did not fit the Rasch model, and multidimensionality, disordered thresholds, DIF, and/or LID were found. The reliability and power of fit were high for the total scales (PSI = 0.93) but low for most of the subscales (PSI < 0.70). The targeting of persons and items was suboptimal. The main source of misfit was disordered thresholds for both the total scales and subscales. Based on the results of the analysis, adjustments to improve the scales were implemented as follows: disordered thresholds were rescaled, misfit items were removed and items were split for DIF. However, the multidimensionality and LID could not be resolved. The reliability and power of fit remained low for most of the subscales. CONCLUSIONS: This study represents the first analyses of the DSWAL-QoL and aDSWAL-QoL with the Rasch model. Relying on the DSWAL-QoL and aDSWAL-QoL total and subscale scores to make conclusions regarding dysphagia-related HRQoL should be treated with caution before the structural validity and objectivity of both scales have been established. A larger and well-targeted sample is recommended to derive definitive conclusions about the items and scales. Solutions for the psychometric weaknesses suggested by the model and practical implications are discussed.

Feasibility and Psychometric Properties of the Adjusted DSWAL-QoL Questionnaire for Dysphagic Patients with Additional Language and/or Cognitive Impairment: Part I.

The Swallowing Quality-of-Life questionnaire (SWAL-QoL) is considered the gold standard for assessing health-related quality of life in people with dysphagia. However, many dysphagic patients struggle to complete this questionnaire because of additional functional sequelae such as language impairment and cognitive disorders. In this study, we sought to develop an adjusted Dutch version of the SWAL-QoL (aDSWALQoL) and to evaluate its psychometric properties and feasibility compared with the original questionnaire. We developed the aDSWAL-QoL based on recommendations from previous literature. The feasibility, internal consistency, test-retest reliability, and criterion validity of the aDSWAL-QoL were evaluated in 78 dysphagic patients, among whom 43 had additional language and/or cognitive impairments (DysLC). Statistical analyses were performed using SPSS 20.0. The aDSWAL-QoL had a higher degree of feasibility for the DysLC group. We obtained high Cronbach's α coefficients for total scale and for almost all subscales. Total aDSWAL-QoL scores showed excellent testretest agreement and good criterion validity with respect to the DSWAL-QoL. Almost all subscales showed significantly moderate to good test-retest agreement and criterion validity. However, the psychometric properties of the 'Food selection' subscale were inadequate. The aDSWAL-QoL is a feasible, reliable, and valid tool for use with DysLC patients. Conversion of the aDSWAL-QoL into an audio computer-assisted self-administered format should be investigated. The construct validity of the aDSWAL-QoL will be evaluated in a separate report.

Oral health screening: feasibility and reliability of the oral health assessment tool as used by speech pathologists.

BACKGROUND: The aim of this study was to investigate the feasibility and reliability of the Oral Health Assessment Tool (OHAT) as used by speech pathologists, to become part of a comprehensive clinical swallowing examination. METHODS: A multicentre study in 132 elderly subjects was conducted by speech pathologists. The inter-rater, test-retest and intra-rater reliabilities of the OHAT were assessed in R statistics, version 3.0.1. Intraclass correlation coefficients (ICCs) were used for the total OHAT, and Kappa statistics were used for the individual categories. RESULTS: Total OHAT scores showed good inter-rater (ICC = 0.96), intra-rater (ICC ≥ 0.95) and test-retest (ICC ≥ 0.78) agreement. The inter-rater Kappa statistics were almost perfect (κ ≥ 0.83) for seven of the eight individual categories of the OHAT and perfect for 'dental pain' (κ = 1.00). The test-retest Kappa statistics indicated excellent agreement for 'natural teeth' and 'dentures' (κ ≥ 0.86). The intra-rater per cent agreement was excellent for all categories except 'gums and tissues'. CONCLUSIONS: This is the first study to examine the feasibility and reliability of the OHAT as used by speech pathologists. As the results showed both good feasibility and reliability, the OHAT has the potential to add to the clinical swallowing examination. However, future research investigating actual referral strategies and adaptation of care strategies following assessment with OHAT is needed.