Knowledge, Attitude, and Practices Among Clinical Physiotherapists Regarding Transcranial Direct Current Stimulation Application in Stroke Rehabilitation: Questionnaire Development and Validation via Multicenter Observations in Saudi Arabia

Transcranial direct current stimulation (tDCS) is known to modulate the brain excitability and enhance cognitive functions and neuroplasticity, although adherence to its administration in post-stroke rehabilitation is still being understudied. This study set out to develop and content validate a questionnaire to assess clinical physiotherapists’ knowledge, attitude, and practices regarding the use of tDCS following a stroke. In order to gather expert opinion and come to a consensus on a certain topic, the Delphi technique was employed. The measure was validated using both qualitative (cognitive interviewing) and quantitative (content validity) methods on a panel of 32 experts. Calculations were made for the content validity ratio (CVR), content validity index (CVI), item-level CVI (I-CVI), and scale-level CVI universal agreement (S-CVI/UA). A total of 48 interdisciplinary experts in the field of neurosciences were invited. In all, 32 specialists from Neurology, General Medicine, Neurophysiotherapy, and Physiology departments accepted the invitation and provided their opinion for instrument analysis. After two rounds, early iterations of this instrument demonstrated an acceptable CVR value of 1, high overall content validity (S-CVI/UA = 0.86), and high content validity of individual items (I-CVI range: 0.83-1.00). The kappa value varied between 0.75 and 1, which is excellent. Its content is therefore deemed validated. Through an iterative process, its development and assessment revealed strong item-content validity for determining the domains of the questionnaire. It is anticipated that this metric could be utilized to increase the adherence rate of post-stroke tDCS application in Saudi Arabia.