Content Validity and Test-retest Reliability Section of Self-reported Questionnaire Assessing Knowledge and Perception of SMS Thumb: A Cross-sectional Study

Introduction: Continuous texting is associated with more stress on the thumb, which may cause the onset of a variety of wrist and thumb conditions. Today’s youth spend the majority of their time on smartphones, which might cause texting thumb symptoms to occur. As there is a lack of a questionnaire that can evaluate their awareness and views, this was the first study that develops as well as evaluates the validity and reliability of a self-designed questionnaire.

Aim: To assess the validity and reliability of a self-designed questionnaire that measured knowledge and perception of Short Message Service (SMS) Thumb.

Materials and Methods: This cross-sectional pilot survey was conducted in Mangalore, Karnataka, India from June 2022 to July 2022. Validity and reliability were performed in two sections. A panel of four experts reviewed the questionnaire’s content validity to determine its Content Validity Index (CVI), while reliability was performed by using test-retest reliability method which was carried out through an online survey among 31 young individuals with the inclusion criteria of non medical students aged between 18 to 25 years. CVI was used to analyse the questionnaire’s validity. Test-retest statistical analysis was performed by Statistical Package for the Social Sciences (SPSS Inc; Chicago, IL), Version 26.0 and internal consistency were used to assess the reliability. Pearson correlation was used to perform the reliability.

Results: The item Content Validity Index (i-CVI) of the questionnaire was 1.00 for 20 of the 25 questions, while the average scale CVI of the questionnaire was 0.95. Test-retest reliability and internal consistency were both evaluated using Cronbach’s alpha coefficient and Pearson’s correlation ratio, respectively. The questionnaire was significantly reliable with a p-value <0.05.

Conclusion: The questionnaire showed acceptable test-retest reliability and content validity which can be a useful tool for measuring awareness and attitude about SMS Thumb.