Abstract
Vestibular rehabilitation therapy (VRT) is an effective treatment for individuals experiencing imbalance and dizziness, helps to improve the quality of life. Lack of culturally valid questionnaires to assess the outcome from VRT necessitates the development of reliable and culturally valid questionnaire to measure the outcomes of VRT. Hence, the current study aimed to develop a culturally valid and reliable questionnaire for measuring the outcome of VRT in Indian population and to translate it into Malayalam and Kannada. This cross-sectional study was conducted at the department of Audiology and Speech Language Pathology of a tertiary care hospital. The questionnaire was constructed based on thorough literature search of existing questionnaires related to dizziness and vestibular disorders in relevant to the Indian context. Content validity was assessed by expert reviewers using a rating scale, and the questionnaire was translated into two south Indian languages (Malayalam and Kannada). The questionnaire was then administered on 12 patients undergoing VRT to assess its initial validation. The questionnaire was named as ‘Effect of Vestibular Rehabilitation Therapy Questionnaire (EVRT-Q)’, consisted of 25 questions divided into three domains: symptom, function, and emotion. The questionnaire demonstrated good content validity with a Content Validity Index greater than 0.8 for each question in all domains. The questionnaire possesses a high internal consistency when measured using Cronbach’s alpha. Hence, the EVRT-Q appears to be a valid and reliable tool to assess the outcome from VRT in Indian population.
Keywords: Dizziness, Imbalance, Vestibular rehabilitation therapy, Questionnaire, Outcome measure
Introduction
Dizziness is referred as sensation of spinning with disturbance of spatial orientation, light-headedness triggering imbalance, commonly observed in adult and geriatric populations. The prevalence of dizziness is about 25% in the general population and mostly 50% were old-aged adults [1]. Diagnostic information is provided with physiological tests however, most often it failed to correlate with subjective complaints of dizziness [2]. Most of the individuals who experience dizziness are also accompanied with anxiety, avoidance behaviour and handicap [2]. Overall, around 74% of individuals with dizziness reported avoiding certain circumstances or activities [3]. Following, a noticeable decline is being observed in quality of life due to long standing dizziness with a reduction in psychosocial aspects [4].
Vestibular rehabilitation therapy (VRT) has become the cornerstone in treating patients with balance disorders [5]. The VRT facilitates reducing the intensity and frequency of dizziness occurrence, thereby improving the quality of life. Vestibular rehabilitation incorporates the patient performing graded exercises, consisting of oculomotor, body balance, stance stability and head movements that stimulate the vestibular system [2]. Vestibular rehabilitation serves as a treatment compensating strategy by emphasising routine therapy rather than medication. Review studies have reported of compensatory achievement with VRT and repositioning manoeuvres in patients with a vestibular pathology [6].
A robust and scalable patient-focused measure is necessary to observe the progress and to learn the impact of the therapy program. Measuring the outcome of VRT is an important aspect for monitoring the prognosis, to hold track of the progress and to make the required adjustments in the therapy plan. The objective of the current study was to develop a reliable measure that can quantitatively assess the symptoms following therapy. A self-rated questionnaire allows the patient to rate their own level of progress following treatment, helping them to gain confidence and encouragement.
Several questionnaires were developed to evaluate the dizziness and its impacts on quality of life such as dizziness handicap inventory, vertigo handicap questionnaire, and vertigo symptom scale [7–9]. Whereas limited questionnaires and checklists are available for measuring the outcome of vestibular rehabilitation therapy, mainly focussing on the Western population. However, few questions in those materials were inappropriate for the Indian population because of cultural and lifestyle differences. Despite of several attempts to develop the indigenous quality of life questionnaires, most of question lack its utility to assess the VRT outcome [10, 11]. The quality of life questionnaire was framed based on emotional, physical and functional domains to check the individual’s performance in daily living activities. However, none of the questions were framed specifically to assess the improvement and deterioration before and after VRT exercises. Which would further help in remodelling the therapy plan based on the symptom betterment and the patient’s requirement. Also, there is an unavailability of culturally valid questionnaires in Indian languages to measure the outcome of VRT. Therefore, the present questionnaire was developed to qualitatively measure the outcome and effect of VRT focusing on Indian population. Initially the questionnaire was developed in English and the same was translated in two other Indian languages (Malayalam and Kannada).
Method
The study was conducted at the Department of Audiology and Speech-Language Pathology in a tertiary care hospital and was approved by the Institutional Ethics Committee. The current study includes three phases. Phase 1 was the development of the questionnaire. Phase 2 was the content validity of the developed questionnaire. The second phase also included translating the original questionnaire from Indian English to the other two languages i.e. Malayalam and Kannada. Phase 3 included the initial validation of the developed questionnaire among the clinical population who underwent VRT.
Phase 1: Construction of the Questionnaire
The first phase of the study began with a thorough literature search to gather questions from already existing questionnaires, inventories, and checklists related to dizziness and vestibular disorders. Some questions were taken as reference and were modified to make the questionnaire more relevant to the need of the study and also framed to the Indian context. The resulting list of questions were then divided into three domains, namely Symptom, Function, and Emotion. The first domain, ‘symptom (S)’ reflects on vestibular/dizziness symptoms. The domain ‘Function (F)’ included questions related to the daily physical activities of the participant. Third domain included questions on emotional aspects or feelings of participants related to dizziness.
Phase 2: Evaluation of Content Validity of Questionnaire
The constructed questionnaire was subsequently put through a content validity assessment. The questions were sent to five audiologists, who are experts in the field of vestibular science and practising vestibular rehabilitation therapy at least for the past 5 years. The specialists reviewed the entire questionnaire including the questions and the rating scale. The experts were instructed to rate each question on a five-point rating scale from 0 being “not relevant” to 4 being “highly relevant”. Additionally, the reviewers were requested to comment on the content’s relevance and clarity and to suggest any modifications to the questions. The classification of questions into three domains was also validated by the experts. Modifications in the questionnaire were done according to experts’ ratings and suggestions. After the review, the questionnaire was evaluated for its content validity using the Content Validity Index (CVI) [10]. It was calculated using the following equation:
where CVI is Content Validity Index, R is number of desired ratings obtained by the subject experts, and N is total number of experts. The CVI was carried out for each of the domain, Symptom, Function and Emotion separately as well as the questionnaire as a whole.
Phase III: Initial Validation of Questionnaire
Administration of the developed questionnaire on the selected clinical population marked phase three. Twelve patients (seven males and five females) with a mean (SD) age of 47.41 (12.83) years having a long-standing complaint of dizziness more than 3 months were included in this phase. The participants for the current study were selected from a group of subjects enrolled for the vestibular rehabilitation programme at the department of Audiology and Speech Language Pathology. Participants with a history/complaint of neurological disorder, autoimmune disorder, degenerative disorder and any systemic illness were excluded from the present study. The participants were initially informed about the motives for the study, the significance of their participation and the confidentiality of their personal data. Written informed consent form was obtained from each participant prior data collection.
To prevent bias in the scoring, the questionnaire was administered by an examiner who is blind to the patient’s progression or regression. When the patient has finished four weeks of VRT, the examiner of this kind is retained to administer the questionnaire. The chosen participants were instructed to answer each question by comparing the difficulty that occurred before and after regular VRT sessions. The questionnaire was provided with a four-point rating scale ranging from zero to three, where zero corresponds to ‘Never’, one to ‘Sometimes’, two to ‘Almost always’ and three to ‘Always’. To maximise the efficacy of the questionnaire, the participants were encouraged to rate their symptoms accurately. The questionnaire’s internal consistency was then determined using the information gathered from participant responses. The questionnaire included two categories of questions: those inquiring about the positive effects of exercise or therapy and those inquiring about the negative effects of exercise. Consequently, it is necessary to reverse the scoring for the latter category to accurately represent the improvement in the individual’s condition. Such questions are starred and a footnote on reverse scoring is provided with the questionnaire. The star marked questions had a scoring as follows. Score zero for ‘always’ and three for ‘never’. This kind of reverse scoring is used in four out of ten questions for the domain ‘Symptom’, six out of ten for the domain ‘Function’, and one out of five questions for the domain ‘Emotion’. The statistical analysis of the collected data was done using SPSS version 25.
Result
Phase 1 and Phase 2
The final questionnaire which was reviewed and rated by experts in the field was named as “Effect of Vestibular Rehabilitation Therapy Questionnaire” (EVRT-Q) containing a total of 25 questions (Table 1). The questionnaire is being divided into three domains: symptom, function and emotion with a four-point rating scale.
Table 1.
List of questions included in final questionnaire
| S. no. | Question |
|---|---|
| S01 | Do you feel the dizziness has reduced after regular therapy? |
| S02 | Do symptoms get reduced after therapy? |
| S03* | Do you feel dizzy after exercise? |
| S04* | Do you feel tired/fatigue after exercise? |
| S05 | Do you feel the blurring of vision have reduced after therapy? |
| S06 | Do you feel steady while walking after continuous therapy? |
| S07* | Do you have difficulty breathing or feel shortness of breath after exercise? |
| S08* | Do you have increased heart beat/palpitation after exercise? |
| S09 | Does the intensity and duration of dizziness reduce after therapy? |
| S10 | Does the frequency of dizziness reduce after therapy? |
| F01 | Do you feel comfortable doing your daily activities? |
| E01 | Do you feel improvement in confidence to perform task after regular therapy? |
| F02 | Are you able to concentrate and/or remember things better? |
| F03* | Do you need to hold on to something for support while walking, waking up, etc.? |
| E02 | Is there improvement in your lifestyle after regular therapy? |
| E03* | Do you hesitate to perform some functional activities even after regular therapy? |
| F04 | Do you feel stable in the dark or when your eyes are closed? |
| F05* | Do you have difficulty walking on flat/uneven surface (e.g.: stairs)? |
| F06* | Do you have difficulty taking lift/escalator? |
| F07* | Do you have difficulty while driving vehicle/travelling? |
| F08* | Do you have difficulty getting into bed or out of bed or turning over in bed? |
| F09* | Do you have difficulty doing focused activity like reading, writing etc? |
| F10* | Does quick head movement triggers/increases your dizziness? |
| E04 | Do you feel stress and anxiety has reduced after regular therapy? |
| E05 | Do you feel regular therapy is helpful to overcome the dizziness? |
*Questions with reverse scoring
Each item in the questionnaire were selected only if it had a CVI value of greater than 0.8 for each question under all of the domains. The rating by experts and CVI is given in Tables 2, 3, and 4. The domain Symptom had the highest CVI score of 1 for 6 out of 10 questions (Table 2). The domain Function with a total of 10 questions had a CVI score of 0.84 for F2, F4 and F9 questions and nearly a score of 1 for F1, F3, F5, F6, F7, F8 questions (Table 3). The last domain Emotion with a total of 5 questions had a CVI score of 0.9 for E1 and E4 questions and a CVI score of 1 for E2, E3, E5 questions (Table 4).
Table 2.
The number of desired ratings by the experts and the Content Validity Index obtained for each question under the ‘Symptom’ domain
| Questions | Number of desired ratings by the experts | Total number of experts | Content Validity Index |
|---|---|---|---|
| S1 | 5 | 5 | 1 |
| S2 | 5 | 5 | 1 |
| S3 | 5 | 5 | 1 |
| S4 | 4.6 | 5 | 0.92 |
| S5 | 4.8 | 5 | 0.96 |
| S6 | 5 | 5 | 1 |
| S7 | 4.4 | 5 | 0.88 |
| S8 | 4.6 | 5 | 0.92 |
| S9 | 5 | 5 | 1 |
| S10 | 5 | 5 | 1 |
Table 3.
The number of desired ratings by the experts and the Content Validity Index obtained for each question under the ‘Function’ domain
| Questions | Number of desired ratings by the experts | Total number of experts | Content Validity Index |
|---|---|---|---|
| F1 | 5 | 5 | 1 |
| F2 | 4.2 | 5 | 0.84 |
| F3 | 5 | 5 | 1 |
| F4 | 4.2 | 5 | 0.84 |
| F5 | 5 | 5 | 1 |
| F6 | 4.8 | 5 | 0.96 |
| F7 | 4.8 | 5 | 0.96 |
| F8 | 5 | 5 | 1 |
| F9 | 4.2 | 5 | 0.84 |
| F10 | 5 | 5 | 1 |
Table 4.
The number of desired ratings by the experts and the Content Validity Index obtained for each question under the ‘Emotion’ domain
| Questions | Number of desired ratings by the experts | Total number of experts | Content Validity Index |
|---|---|---|---|
| E1 | 4.8 | 5 | 0.96 |
| E2 | 5 | 5 | 1 |
| E3 | 5 | 5 | 1 |
| E4 | 4.6 | 5 | 0.92 |
| E5 | 5 | 5 | 1 |
Phase 3
To assess the internal consistency of the questionnaire, Cronbach’s alpha test was administered. As the questionnaire had three domains, i.e., symptom, function and emotion, the internal consistency analysis was performed for each of the domains separately. While analysing the internal consistency of the ‘Symptom’ based questions, Cronbach’s alpha value was observed as 0.865, indicating a high internal consistency. The internal consistency of the domain ‘Emotion’ had a Cronbach’s alpha value of 0.819, indicating high internal consistency. An excellent level of consistency was observed for the domain ‘Function’ as it had a Cronbach’s alpha value of 0.902. When taking the entire questionnaire into consideration, Cronbach’s alpha value was discovered to be 0.945, indicating an excellent consistency.
Discussion
Evaluations of content validity and internal consistency of questionnaire reveals its relevance and utility as an outcome measure of VRT. The CVI values showed good results for each domain ranging from 0.8 to 1 indicating relevance of each of the questions under their respective domains. The internal consistency analysis is done using Cronbach’s alpha. On evaluating the internal consistency, it was found that the domains, Function and Emotion had a high internal consistency whereas the domain Symptom had an excellent internal consistency. The overall questionnaire had an excellent internal consistency with a Cronbach’s alpha value of 0.945.
The questionnaire being divided into three domains helps the clinician gain an insight on the effectiveness of VRT on each of the different aspects affecting the individual’s quality of life. Furthermore, helping the clinician address each of it. The questionnaire is being administered to patients undergoing VRT from a period of at least four weeks making it possible for the patient to experience a significant difference in the symptoms. Immediate and long-term effects of different exercises used in VRT is being assessed and monitored with the help of the questionnaire.
The selection and duration of exercises to be included in the VRT programme varies depends on the various factors related to both clinician and patients. Such factors include the compliance of patient, effect of exercise on patient, and approach of clinician [12]. Some of the questions focusing on exercises used in EVRT-Q may help the clinician to be more objective during this process. The current effort of developing a questionnaire was also extended to translate the developed questionnaire to other languages with a familiarity check by the native proficient speakers who was asked to comment and rate based on the language clarity, comprehensiveness and relevance. This effort makes the present questionnaire accessible to individuals especially in the southern part of India.
Conclusion
The current study provides questionnaire in English, Kannada, and Malayalam helpful in clinical setup to assess the VRT outcome for patients experiencing imbalance and dizziness. The questionnaire had good CVI and internal consistency, which makes it an effective tool to administer and also helps different natives considering availability in additional languages.
Funding
No funds, grants, or other support was received for conducting this study.
Declarations
Conflict of interest
The authors have no competing interests to declare that are relevant to the content of this article.
Ethics Approval
Approval was obtained from the Institutional Ethics Committee of the Kasturba Medical College, Mangalore.
Informed Consent
Written informed consent was obtained from all participants.
Footnotes
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
References
- 1.Hannaford PC, Simpson JA, Bisset AF, Davis A, McKerrow W, Mills R. The prevalence of ear, nose and throat problems in the community: results from a national cross-sectional postal survey in Scotland. Fam Pract. 2005;22(3):227–233. doi: 10.1093/fampra/cmi004. [DOI] [PubMed] [Google Scholar]
- 2.Yardley L, Kirby S, Barker F, Little P, Raftery J, King D, Morris A, Mullee M. An evaluation of the cost-effectiveness of booklet-based self-management of dizziness in primary care, with and without expert telephone support. BMC Ear Nose Throat Disord. 2009;9:9–13. doi: 10.1186/1472-6815-9-13. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Hägnebo C, Melin L, Larsen HC, Lindberg P, Lyttkens L, Scott B. The influence of vertigo, hearing impairment and tinnitus on the daily life of Menière patients. Scand Audiol. 1997;26(2):69–76. doi: 10.3109/01050399709074978. [DOI] [PubMed] [Google Scholar]
- 4.Booth RL (2000) Dizziness and quality of life in clinic and general population samples of dizzy individuals. PhD dissertation, University of Southampton
- 5.Furman JM, Whitney SL. Central causes of dizziness. Phys Ther. 2000;80(2):179–187. doi: 10.1093/ptj/80.2.179. [DOI] [PubMed] [Google Scholar]
- 6.Boyer FC, Percebois-Macadré L, Regrain E, Lévêque M, Taïar R, Seidermann L, Belassian G, Chays A. Vestibular rehabilitation therapy. Neurophysiol Clin. 2008;38(6):479–487. doi: 10.1016/j.neucli.2008.09.011. [DOI] [PubMed] [Google Scholar]
- 7.Jacobson GP, Newman CW. The development of the dizziness handicap inventory. Arch Otolaryngol Head Neck Surg. 1990;116(4):424–427. doi: 10.1001/archotol.1990.01870040046011. [DOI] [PubMed] [Google Scholar]
- 8.Yardley L, Putman J. Quantitative analysis of factors contributing to handicap and distress in vertiginous patients: a questionnaire study. Clin Otolaryngol Allied Sci. 1992;17(3):231–236. doi: 10.1111/j.1365-2273.1992.tb01833.x. [DOI] [PubMed] [Google Scholar]
- 9.Yardley L, Masson E, Verschuur C, Haacke N, Luxon L. Symptoms, anxiety and handicap in dizzy patients: development of the vertigo symptom scale. J Psychosom Res. 1992;36(8):731–741. doi: 10.1016/0022-3999(92)90131-k. [DOI] [PubMed] [Google Scholar]
- 10.Ranjan R, Bhat J, Vas Naik PE. Quality of life rating for dizziness: a self-reporting questionnaire. Indian J Otolaryngol Head Neck Surg. 2019;71:1040–1046. doi: 10.1007/s12070-017-1090-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Neupane AK, Kapasi A, Patel N. Psychometric features of dizziness handicap inventory (DHI): development and standardization in Gujarati language. Int Tinnitus J. 2019;23(2):86–90. doi: 10.5935/0946-5448.20190015. [DOI] [PubMed] [Google Scholar]
- 12.Morris AE, Lutman ME, Yardley L. Measuring outcome from vestibular rehabilitation, part II: refinement and validation of a new self-report measure. Int J Audiol. 2009;48(1):24–37. doi: 10.1080/14992020802314905. [DOI] [PubMed] [Google Scholar]