Jan Vanderwegen

Effect of rate control on speech production and intelligibility in dysarthria.

The reported study investigated the effect of 7 rate control methods (RCM) on running speech intelligibility, speaking rate (SR), articulation rate (AR) and pause characteristics in 27 individuals with dysarthria. The data reveal that with the exception of slower on demand, each RCM resulted in lower mean SRs and ARs (p < 0.05). Clinically significant improvements in intelligibility were found in half of the participants with different types of dysarthria. The majority of them had normal or decreased ARs and SRs. The most effective methods were: alphabet board, hand tapping and pacing board. For the majority of speakers, the maximal decrease in speech rate was not associated with the maximal increase in intelligibility.

Outcome of vocal hygiene in singers

Purpose of reviewIn this article, we illustrate the evolution of studies that contribute to a better understanding of vocal care for professional voice users and singers in particular. Recent findingsResearch on vocal hygiene is specific, focusing on concrete solutions. It has commonly been believed that hydration and vocal rest are beneficial; recent research proves this supposition. An exhaustive medical diagnosis and careful therapy is stressed to detect and treat any micro-organic lesions caused by reflux, infection, allergy and environmental circumstances, which can harm a singers voice. The use of medication is reviewed and side effects are evaluated. SummaryVocal coaches, speech therapists and otolaryngologists need to focus more specifically on the management of vocal care. Accurate medical diagnosis and specific guidelines for singers must be provided as higher voice demands imply more profound and structured voice care. In the past, vocal hygiene had a negative connotation; a more positive and supporting approach to voice care, with more attention to the singer, is recommended.

The Validation and Psychometric Properties of the Dutch Version of the Swallowing Quality-of-Life Questionnaire (DSWAL-QOL)

The aim of this work was to evaluate the psychometric properties of the Dutch version of the Swallowing Quality-of-Life Questionnaire (DSWAL-QOL). A cross-sectional survey of 295 dysphagic patients and 124 healthy controls was studied to evaluate the validity and reliability of the DSWAL-QOL, and 50 patients were recruited for the test–retest reliability. Construct validity was validated through principal component analysis and a correlation study between the DSWAL-QOL and the SF-36. The psychometric properties of the DSWAL-QOL were found to be largely similar to those of the original SWAL-QOL, except the Sleep scale; the composite Symptoms score reaffirms its validity in this study. The DSWAL-QOL was able to differentiate between dysphagic and nondysphagic patients and is sensitive to disease severity as measured by known-groups validity, based on different food and liquid textures. The DSWAL-QOL is a clinically valid and reliable tool for assessing the quality of life in Dutch-speaking dysphagic patients, regardless of the cause or severity of the dysphagia.

Study protocol for a randomized controlled trial: tongue strengthening exercises in head and neck cancer patients, does exercise load matter?

BackgroundReduced tongue strength is an important factor contributing to early and late dysphagia in head and neck cancer patients previously treated with chemoradiotherapy. The evidence is growing that tongue strengthening exercises can improve tongue strength and swallowing function in both healthy and dysphagic subjects. However, little is known about the impact of specific features of an exercise protocol for tongue strength on the actual outcome (strength or swallowing function). Previous research originating in the fields of sports medicine and physical rehabilitation shows that the degree of exercise load is an influential factor for increasing muscle strength in the limb skeletal muscles. Since the tongue is considered a muscular hydrostat, it remains to be proven whether the same concepts will apply.Methods/DesignThis ongoing randomized controlled trial in chemoradiotherapy-treated patients with head and neck cancer investigates the effect of three tongue strengthening exercise protocols, with different degrees of exercise load, on tongue strength and swallowing. At enrollment, 51 patients whose dysphagia is primarily related to reduced tongue strength are randomly assigned to a training schedule of 60, 80, or 100 % of their maximal tongue strength. Patients are treated three times a week for 8 weeks, executing 120 repetitions of the assigned exercise once per training day. Exercise load is progressively adjusted every 2 weeks. Patients are evaluated before, during and after treatment by means of tongue strength measurements, fiber-optic endoscopic evaluation of swallowing and quality-of-life questionnaires.DiscussionThis randomized controlled trial is the first to systematically investigate the effect of different exercise loads in tongue strengthening exercise protocols. The results will allow the development of more efficacious protocols.Trial registrationCurrent Controlled Trials ISRCTN14447678.

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

BackgroundThe 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.MethodsItem 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.ResultsThe 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.ConclusionsThis 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.