TRANSLATION AND VALIDATION OF VANDERBILT ATTENTION DEFICIT AND HYPERACTIVITY DISORDER DIAGNOSTIC PARENT RATING SCALE (VADPRS)IN TAMIL LANGUAGE AND DETERMINATION OF ITS PSYCHOMETRIC PROPERTIES
Authors: Neelakandan S. , Doshi V.Vimal , Nambi Shanthi , Valarmathi T. 
Published: December 2020

BACKGROUND: Attention Deficit Hyperactivity Disorder (ADHD) is a common neuro-developmental disorder with a prevalence range of 5-12% worldwide. The available diagnostic criteria are only qualitative measures to diagnose ADHD and not useful for quantifying the various dimensions and severity. The Vanderbilt Assessment scale (VADPRS) is designed for assessment of severity in individual symptom dimensions. As the majority of the population attending the tertiary care hospitals is Tamil speaking with lower educational background, there is need for a standardized Tamil version, so as to have uniformity in the assessment and follow up of ADHD children, simultaneously ensuring its comparability internationally. Thus the Tamil version is important for both clinical diagnosis, management and for research purposes.
AIMS: To translate and standardize the Tamil Language version of the Vanderbilt ADHD Diagnostic Parent Rating Scale (VADPRS) and determine its psychometric properties.
METHODS: The study design was of a cross sectional translation and validation study done in a setting of both community (n=100) and clinical (n=102) samples. The methodology involved
1. Translation process of five step: two forward translations->a composite prefinal version and pilot testing and a final translated version->two back translations->comparison of back translation with original version using Likert scales.
2. Adaptation in the whole sample for determination of psychometric properties:-
1. Intra and intercorrelations (using Pearson correlations) 2. Convergent validity with K-SADS PL ADHD Supplement scores and DSM-IV criteria 3. Internal consistency (using Cronbach’s alpha) 4. Split-Half Analyses and 5.comparison of back translation and original version (using Likert scales).
RESULTS: In descriptive analysis, in clinical sample, age distribution was almost 80% in the 5-10 years; male preponderance ; age of onset of ADHD 47% at 5 years and; duration of symptoms mostly 2 years(35.5%) to 3 years (28.4%); common type of ADHD was combined type (87.3%). In analysis of psychometric properties both school and hospital samples had significant Pearson’s correlation coefficients in intra and inter correlations between the original English and translated Tamil versions. In convergent validity analysis, the correlations between the K-SADS-ADHD Supplement scores and the Tamil version scores revealed high correlations. Split-half analyses of the two domains of VADPRS (Inattention vs Hyperactivity/Impulsivity) showed ‘r’ values of upto 0.798. In Reliability statistics (Internal consistency) the values of Cronbach’s alpha- 0.925. In Likert Scale analysis of the Expert reviews of the back translation vs original version showed scores mostly in the “extremely comparable/similar” range.
CONCLUSION: This study was done to translate VADPRS original English version to native Tamil language using internationally accepted guidelines and validated to have highly significant psychometric properties. This empowered us to conclude that this translated Tamil version is a valid and reliable instrument to screen, diagnose and assess severity of ADHD in Tamil population to aid effective clinical management and for research purposes.