The Applicability of the Dysphonia Severity Index and the Voice Handicap Index in Evaluating Effects of Voice Therapy and Phonosurgery

doi:10.1016/j.jvoice.2008.06.007

Journal of Voice

Volume 24, Issue 2, March 2010, Pages 199-205

https://doi.org/10.1016/j.jvoice.2008.06.007 Get rights and content

Summary

The objective was to investigate the applicability of the Dysphonia Severity Index (DSI) and the Voice Handicap Index (VHI) in evaluating effects of intervention between groups of patients and for intrasubject differences and whether DSI and VHI are complementing measurements. Analyses of measurement data before and after intervention of 171 patients with voice disorders. The voice quality was measured objectively with the DSI. The perceived voice handicap was measured with the VHI. Three groups of patients were used: patients who had voice therapy, phonosurgery, or no intervention. DSI and VHI improved significantly after intervention in the voice therapy and the surgery group (median difference DSI 1.19 and 3.03, VHI −8 and −26, respectively). The intrasubject results were analyzed based on the test-retest variability of DSI and VHI. Significant better DSI and VHI scores after intervention were found in, respectively, 22% and 38% of the patients with voice therapy, and 56% and 78% of the patients with surgery. In the no intervention group, this was 11% and 12%. In 37% of the patients, the differences before and after intervention in DSI and VHI were in discordance. The DSI and VHI are able to show significant differences after intervention for voice disorders between groups of patients. The DSI and VHI can be used to determine a significant intrasubject result of intervention. The DSI and VHI measure each different aspects of the voice and are complementing measurements. The DSI is therefore applicable in clinical practice for objective evaluation of voice quality and the VHI for subjective evaluation of the perceived handicap by the patient self.

Introduction

Evaluating effects of intervention is of growing importance in today's health care, because of the need for evidence-based intervention. For voice disorders also, research on the effects of intervention is needed. There are however not yet well-accepted standardized instruments that can be used to assess the effects of intervention for voice disorders. When evaluating effects of intervention, there are two different aspects to take into account: the differences between groups of patients (intersubject differences) and the difference within one patient before and after intervention (intrasubject differences). The differences in outcome between groups are needed for research purposes: to compare a new type of intervention with a commonly used type of intervention, or to determine what the best type of intervention is for a certain diagnosis. Therefore, the intersubject variance of the used measurements has to be known. In daily clinical practice, it is important to be able to interpret differences between measurements of one patient made on different points in time (eg, before and after intervention). To know whether differences are significant, the intrasubject variance of the used measurements has to be known.

Because voice disorders consist of different aspects (voice quality, voice handicap), several measurements should be used. Clinical assessment of voice disorders should consist of (video)laryngostroboscopy, perceptual voice assessment, objective measurements (acoustic analysis and aerodynamic measurements), and subjective self-evaluation of voice.¹ However, not all these aspects appear equally suitable for evaluating effects of intervention.

Although (video)laryngostroboscopy is a very important clinical tool for diagnosing and evaluating patients with voice disorders, it has not been widely used as a research tool because the interpretation is subjective and reliable and quantifiable tools for research purposes are not yet available.² For the perceptual voice assessment, the “GRBAS scale” as introduced by Hirano³ is widely used. The reliability of grade has been investigated.4, 5 However, these investigations are expressed as levels of agreement (kappa values) for inter- and intra-rater and test-retest reliabilities, and are not expressed as the intrasubject variance. The reason for this is probably that grade is scored on a categorical scale and consequently calculations cannot be made. Therefore, grade appears not to be suitable for evaluation of intervention effects, neither between groups of patients, nor for intrasubject differences.6, 7 There is no consensus on what objective measurements for voice quality are best suitable to measure effects of intervention. In studies describing effects of intervention for voice disorders, a variety of measurements are used. The choice for the used measurements in evaluation studies can be based on expected changes in specific aspects of voice quality.8, 9, 10, 11 However, in daily clinical practice it is most practical to use the same objective measurement for all voice disorders. It is already known that multiparametric measures are more suitable for evaluation of voice quality than single measures.12, 13, 14, 15 The Dysphonia Severity Index (DSI)¹⁴ is such a multiparametric measure. The DSI has a good relationship with the perceptual evaluation on grade of the GRBAS scale.¹⁶ An advantage of the DSI is that the parameters can be obtained relatively quick and easy by speech pathologists in daily clinical practice.

For the self-evaluation of voice, the Voice Handicap Index (VHI) is a widely used tool.¹⁷ The VHI is a subjective self-administered questionnaire addressing the patients perceived disability. The VHI and the DSI measure each different aspects of voice and the outcomes on both measurements are therefore not necessarily related. The patient's perception of the voice disorder is not only related to voice quality (as measured with the DSI) but is also related to, for example, professional and social vocal demands and personal aspects.

For both the DSI and VHI, the clinical significance (standard deviation [SD]) is known, obtained from test-retest variability investigations.18, 19 This clinical significance is necessary to interpret the differences between measurements before and after intervention. Therefore, these measurements could be suitable to evaluate effects of intervention. The VHI is already used for evaluation, the DSI however is until now only used on a very limited scale.

We hypothesized that it is possible to evaluate results of intervention for voice disorders with a widely applicable objective measurement. We also hypothesized that measurements of different aspects of voice disorders will complement each other. The purposes of this study were as follows:

To investigate whether the DSI and the VHI can be used to evaluate effects of different types of intervention for voice disorders between groups of patients.
To investigate whether the DSI and VHI can be used in daily clinical practice to determine a significant intrasubject effect of intervention for voice disorders.
To investigate whether the DSI and VHI are complementing measurements, by investigating the relationship between the differences before and after intervention on the DSI and the VHI.

Section snippets

Subjects

The measurements of the patients with voice disorders visiting the outpatient clinic of our department of Otorhinolaryngology are collected in a database. The measurements are done at the first visit and at follow-up visits. When patients have voice therapy, the follow-up measurements are done at least 3 months after the first therapy session. When patients have phonosurgery, the follow-up measurements are done at least 2 months after surgery. When there is no intervention, the minimum time

Results

The diagnoses and types of intervention of the 171 patients with voice disorders are shown in Table 1.

Discussion

In this clinical follow-up study, data of 171 patients were analyzed. The measurements took place at two different visits to our department, with a minimum time interval of 6 weeks. Between the two measurements, patients underwent surgery or had voice therapy. Part of the patients had no intervention. In most studies evaluating effects of intervention, only the results of a particular therapy for groups of patients are investigated, whereas the results for individual patients (intrasubject

Conclusion

In the evaluation of effects of intervention for voice disorders, two aspects are important: the intersubject and intrasubject differences. The intersubject differences are needed in research for evaluation of different types of intervention. The DSI and VHI are both able to show differences between groups of patients, and can therefore be used to evaluate effects of different types of intervention. The intrasubject differences are needed in clinical practice to determine whether measurements

References (24)

M.S. De Bodt et al.
Test-retest study of the GRBAS scale: influence of experience and professional background on perceptual rating of voice quality
J Voice
(1997)
G. Cantarella et al.
Vocal fold augmentation by autologous fat injection with lipostructure procedure
Otolaryngol Head Neck Surg
(2005)
J.C. Selby et al.
Perceptual and acoustic evaluation of individuals with laryngopharyngeal reflux pre- and post-treatment
J Voice
(2003)
P. Yu et al.
Objective voice analysis for dysphonic patients: a multiparametric protocol including acoustic and aerodynamic measurements
J Voice
(2001)
M.M. Hakkesteegt et al.
The relationship between perceptual evaluation and objective multiparametric evaluation of dysphonia severity
J Voice
(2008)
A. Schindler et al.
Voice quality after carbon dioxide laser and conventional surgery for T1A glottic carcinoma
J Voice
(2004)
B. Schneider et al.
Acoustic assessment of the voice quality before and after medialization thyroplasty using the titanium vocal fold medialization implant (TVFMI)
Otolaryngol Head Neck Surg
(2003)
P.H. Dejonckere et al.
A basic protocol for functional assessment of voice pathology, especially for investigating the efficacy of (phonosurgical) treatments and evaluating new assessment techniques. Guideline elaborated by the Committee on Phoniatrics of the European Laryngological Society (ELS)
Eur Arch Otorhinolaryngol
(2001)
C.A. Rosen
Stroboscopy as a research instrument: development of a perceptual evaluation tool
Laryngoscope
(2005)
M. Hirano
Clinical Examination of Voice
(1981)

A.L. Webb et al.

The reliability of three perceptual evaluation scales for dysphonia

Eur Arch Otorhinolaryngol

(2004)

R. Shrivastav et al.

Application of psychometric theory to the measurement of voice quality using rating scales

J Speech Lang Hear Res

(2005)

Cited by (76)

Experiences of Patients with Unilateral Vocal Fold Paralysis: A Mixed-Methods Study of the Insider's Perspective
2024, Journal of Voice
Unilateral vocal fold paralysis (UVFP) is often characterized by severe dysphonia and has a significant impact on a patient’s communication in daily and vocational situations. Having a better understanding of how UVFP influences quality of life and patient experiences can help improve patient-centered care in this population. Therefore, the purpose of this study was to explore the lived experiences of patients with UVFP.
Twenty-five adults with UVFP (age range: 39–84 years) participated in the study. Quantitative data were collected from 22 participants, using the Voice Handicap Index (VHI), Dysphonia Severity Index (DSI), and Acoustic Voice Quality Index (AVQI). Qualitative data were collected from 25 individual semistructured interviews, which were recorded, transcribed, and analyzed with the software program NVivo. The interviews were coded using an inductive thematic approach.
Quantitative results showed a mean DSI of − 1.6, mean AVQI of 3.80, and mean VHI of 45.8 in the participant group. A statistically significant, moderate (positive) correlation was found between VHI and time after onset (in years). From the qualitative analysis of the interviews, four main themes were identified: emotional impact, psychosocial impact, physical complaints, and coping strategies. Voice problems caused by UVFP generally had a negative impact on patients’ emotional and psychological well-being, with considerable effects on participation, self-identity, and professional activity. Participants demonstrated a combination of problem-focused and emotion-focused coping strategies to accommodate to these issues. Half of the participant group also showed avoidance as a coping style. VHI scores were significantly higher in participants who reported experiencing current emotional and participation problems due to UVFP, and who had not yet accepted their new voice.
The themes from this study emphasize the importance of focused anamnesis and emotive counseling in practice, with specific attention to the psychosocial and emotional impact of UVFP.
An eclectic Voice Therapy Program for the Treatment of Hyperfunctional Voice Disorders (HFVD)
2023, Journal of Voice
An eclectic voice therapy program includes sequenced and structured set of exercises combining direct and indirect intervention methods. Tailor-made exercise prescription with specific cultural adaptations are needed to provide a holistic change to voice quality.¹ This study detailed the construction of an exercise prescription for participants with hyperfunctional voice disorder [HFVD] in the Indian context.
The exercise program was developed based on literature related to vocal therapy approaches and delivery methods. Adaptations were introduced to a selected set of exercises. Five voice experts verified the exercises and their prescription for content and feasibility of use in the Indian context. Modification suggested by the experts were included for framing the final version of the exercise program. This structured therapy program was planned for 6 weeks (30 minutes duration/session offered individually twice per week, with a gap of two days between sessions in a week) with the goals to improve voice quality, flexibility, and endurance while speaking. Five participants with HFVD partook in the study for pilot testing. Stroboscopy, perceptual voice analysis, Dysphonia Severity Index (DSI) and Vocal Fatigue Index in Tamil (VFI-T) were used to report the therapy outcomes. Participants’ report on the learning process and generalization of the program were documented. Wilcoxon-signed rank test was used to test the pre-post outcome measures.
An eclectic voice therapy program, i.e., Comprehensive Voice Habilitation Program [CVHP] was constructed and it included vocal hygiene instructions, warm-up & cool-down, easy onset, resonant voice, and carry over exercises. Participants completed the program in 14-18 sessions (over 7 to 9 weeks of therapy). All participants showed significant changes in vocal fold movement patterns, reduction in ventricular hyperadduction, overall grade of voice quality, DSI and VFI-T. Participants reported that pictorial illustrations, feedback, and monitoring sheets were useful in learning the exercises.
CVHP showed significant change in the voice-related outcome measures and was a viable program for treating HFVD.
The Dysphonia Severity Index as a Mediator for the Relationship Between the Vocal Fatigue Index and the Voice-Related Quality of Life Among Elementary Teachers with Voice Complaint
2023, Journal of Voice
Citation Excerpt :
It is worth noting that, although these two parameters do not have a significant relationship with the model, they have a significant positive correlation with the Pearson correlation test. The results of this research on the correlation between these indicators are consistent with the results of studies done by Hakkesteegt et al. (2010),31 Norman et al. (2000),29 Ewa Niebudek-Bogusz et al. (2010),32 Timmermans et al (2002),26 Leonard et al. (2009),24 Aghadoost et al. (2013)33 and Ghaemi et al. (2015).30 Therefore, those with lower DSI scores, according to the Pearson correlation test, have lower quality of life and receive less scores in the VRQOL questionnaire.
The multi-causal nature of voice disorders is required to be evaluated systematically and in different ways to determine the exact nature of the disorder. Given the importance of voice for teachers, the present study was designed to investigate the causal relationship between vocal fatigue index (VFI) and the voice-related quality of life (VRQOL) with the mediating role of the dysphonia severity index (DSI) among teachers with voice complaints.
This analytical and non-interventional study examined 57 male and 122 female teachers with voice complaint. The study used DSI, VRQOL and VFI. Acoustic data were extracted using Praat software, and statistical analysis was performed using SPSS. Direct and indirect path testing of the proposed research model was performed using path analysis and bootstrapping, respectively.
Model fit indices showed that the proposed model is data fit (CFI = 0.998, GFI = 0.996, RMSEA = 0.072). Moreover, all subtests of the VFI had a significant direct relationship with VRQOL. The DSI, measured using the proposed model, does not have a significant relationship with VRQOL. Therefore, the indirect path of the present model (including tiredness of voice to VRQOL through DSI, physical discomfort to VRQOL through DSI and the improvement of symptoms with rest to VRQOL through DSI) did not show a significant relationship.
The vocal fatigue directly affects VRQOL. However, it does not affect it indirectly through DSI. Therefore, it can be concluded that although DSI and VRQOL are correlated, they do not have a causal relationship and DSI, as an acoustic parameter, cannot be an appropriate mediator for the relationship between the VFI and VRQOL.
Examining Relationships Between GRBAS Ratings and Acoustic, Aerodynamic and Patient-Reported Voice Measures in Adults With Voice Disorders
2023, Journal of Voice
To determine if auditory-perceptual voice ratings performed using the GRBAS scale correlate with acoustic and aerodynamic measures of voice. A secondary aim was to examine the relationship between GRBAS ratings and patient-reported quality of life scales.
GRBAS ratings, acoustic, aerodynamic and patient-reported quality of life ratings were collected from the University of Wisconsin Madison Voice and Swallow Outcomes Database for 508 adults with voice disorders. Acoustic measures included noise to harmonic ratio, jitter%, shimmer%, highest fundamental frequency (F0) of vocal range, lowest F0 of vocal range, maximum phonation time and dysphonia severity index. Aerodynamic measures included phonation threshold pressure, subglottal pressure, mean transglottal airflow and laryngeal airway resistance. Patient-reported quality of life measures included the Vocal Handicap Index (VHI) and Glottal Function Index (GFI).
GRBAS ratings were significantly correlated with several acoustic and aerodynamic measures, VHI and GFI. The strongest significant correlations for acoustic measures were observed between GRBAS ratings of overall voice quality and perturbation measures (jitter% r = 0.58, shimmer% r = 0.45, noise to harmonic ratio r = 0.36, Dysphonia Severity Index r = -0.56). The strongest significant correlation for aerodynamic voice measures was observed between GRBAS ratings of breathiness and transglottal airflow (r = 0.23), subglottal pressure (r = 0.49), and phonation threshold pressure (r = 0.26). GRBAS ratings were also significantly correlated with both VHI and the GFI scales. R values were higher for the VHI, but remained largely in low range for both scales.
Although GRBAS ratings were significantly correlated with multiple objective voice and patient related quality of life ratings, r values were low. These findings support the need for multiple voice measures when performing voice evaluations as no single voice measure was highly correlated with voice quality as measured by the GRBAS scale.
Methods of Measuring Laryngeal Muscle Tension in Patients with Muscle Tension Dysphonia: A Scoping Review
2023, Journal of Voice
In clinical practice and research relating to Muscle Tension Dysphonia (MTD), several laryngeal muscle tension measurement methods are used to diagnose, to identify specific muscle strengths and deficits, and to measure therapeutic outcomes. The variety and reliability of available measurement methods presents challenges within diagnosis and treatment. The lack of methodical standardization presents a barrier to homogeneous practice in this area. There is a need for a comprehensive scoping review of laryngeal muscle tension measurement methods.
Scoping review.
(1) To identify current methods of laryngeal muscle measurement which have been developed or tested with people with MTD; and (2) To identify the construct/s measured, reliability, validity, ability to detect change, efficiency and accessibility of identified methods.
This scoping review was conducted using the Arksey and O'Malley framework. Studies were identified through searches of 4 major databases. The reviewer independently assessed titles, abstracts, and full-text articles.
Twenty seven papers published from 2000 to 2022 that satisfied the inclusion criteria were selected from 194 studies. The papers showed a variety of approaches with regards to the measurement of laryngeal activity and tension in subjects with MTD. Just over a quarter (25.9%) were reviews of the validity of assessment methods of MTD, including surface electromyography (sEMG), while 22.2% discussed surface electromyography as a measurement of muscle activity in subjects with MTD. 96.3% used a published methodological framework.
Assessment methods for Primary MTD are multifaceted, including patient history, laryngoscopic examination, and voice-related musculoskeletal features. Potential use of objective measurement methods, including sEMG, Real Time Elastosonography, Magnetic Resonance Imaging was noted. Due to variability in assessment methods and results, there is a need for greater objective practical methodological standardization to ensure accurate diagnosis, appropriate care, and chart patient progress.
Accuracy Analysis of the Multiparametric Acoustic Indices AVQI, ABI, and DSI for Speech-Language Pathologist Decision-Making
2023, Journal of Voice
To investigate the accuracy of the Acoustic Voice Quality Index (AVQI), the Acoustic Breathiness Index (ABI), and the Dysphonia Severity Index (DSI) for speech-language pathologist (SLP) decision-making in the evaluation of teachers' voice conditions.
Cross-sectional observational study with a convenience sample composed of 21 teachers “fit” in carrying out their work activities as a teacher, and 21 considered “unfit” for the same. All teachers underwent a voice evaluation, carried out by a voice-specialized speech-language pathologist. Voice evaluation included the SLP's opinion on whether the teachers presented “fit” or “unfit” for work. The voice and speech samples used for the AVQI and ABI scores were the mid-three seconds of a sustained vowel /a/, and a spontaneous count from 1 to 10. The following parameters were used to extract the DSI score: mid-three seconds of a sustained vowel /a/, maximum phonation time of a sustained vowel /a/, ascending vocal glide on the vowel /a/ until reaching the highest pitch, and sustained vowel /a/ at the softest possible vocal intensity. The t-test was used to compare the difference between the AVQI and ABI indices. The Mann-Whitney test was used for the DSI index, with a confidence level of 95%. The receiver operating characteristic curve (ROC) was used for accuracy analysis.
There was a difference in AVQI values (P=0.008), ABI (P=0.014), and DSI (P=0.000) between groups. The cutoff points that revealed the highest specificity for the AVQI, ABI, and DSI respectively were 3.33 (sensitivity 57.1% and specificity 90.5%), 4 (sensitivity 57.1% and specificity 85.7%), and 1.62 (sensitivity 71.4% and specificity 90.5%).
The AVQI, ABI, and DSI are instruments that provide robust voice information and can help speech-language pathologists in their decision-making about whether teachers must or must not be restricted in their vocal activities at work.

View all citing articles on Scopus

View full text

The Applicability of the Dysphonia Severity Index and the Voice Handicap Index in Evaluating Effects of Voice Therapy and Phonosurgery

Summary

Introduction

Section snippets

Subjects

Results

Discussion

Conclusion

J Voice

Otolaryngol Head Neck Surg

J Voice

J Voice

J Voice

J Voice

Otolaryngol Head Neck Surg

A basic protocol for functional assessment of voice pathology, especially for investigating the efficacy of (phonosurgical) treatments and evaluating new assessment techniques. Guideline elaborated by the Committee on Phoniatrics of the European Laryngological Society (ELS)

Eur Arch Otorhinolaryngol

Stroboscopy as a research instrument: development of a perceptual evaluation tool

Laryngoscope

Clinical Examination of Voice

The reliability of three perceptual evaluation scales for dysphonia

Eur Arch Otorhinolaryngol

Application of psychometric theory to the measurement of voice quality using rating scales

J Speech Lang Hear Res