Criterion-Related Validity of a Self-Administrated Modified Vertigo Symptom Scale (MVSS)

Vertigo Symptom Scale (VSS) by Yardley et al. (1992) is a disease specific questionnaire used widely in clinical settings. It is conducted in English and has been translated into seven other languages: Dutch, French, German, Spanish, Swedish, Turkish and Malay. It has been acknowledged as a good subjective tool to determine the severity of balance disorders. The aim of this study was to validate the English language version of the Modified VSS (MVSS) using criterion-related validity via Pearson’s correlation. Ninety seven patients were selected from an age range of 18-75 years, with a mean age of 47.92 (S.D=13.17). These patients were divided into two different groups: Group 1(Untreated patients, newly referred with dizziness symptom) and Group 2 (Treated dizzy patients, seen as follow-ups who have completed a minimum of 3 months balance exercises). They were asked to fill in the English language version of VSS and MVSS. Pearson’s correlation was used for concurrent validity. Significant positive correlations (p< 0.0001) between VSS and MVSS for both groups with r= 0.92 for group 1 and r = 0.93 for group 2 were found. In each version, significant and high, or positive correlations, between those three different subscales in group 1 and 2 consecutively, were observed: vertigo r= 0.87 and r=0.88, somatic anxiety r=0.76 and r= 0.85 and autonomic subscale r=0.82 and r= 0.91. For predictive validity of MVSS, dichotomous outcome measure was used to perform McNemar’s test. Both questionnaires were able to discriminate the clinical conditions of the patient’s symptom into mild or severe. In conclusion, MVSS, which is the shortened and simplified version of VSS, is simpler, easier to administer, and easier to Zuraida & Geshina 2016 Health and the Environment Journal, 2016, Vol 7 No 2 pp 102-115 103 understand. The findings herein also provide some good psychometric properties of the MVSS. It is suggested that this questionnaire be considered for use and implementation in clinical evaluation of vertigo and for future research purposes.