Test-Retest Reliability of a Questionnaire to Assess the Knowledge and Attitude of Dental Students toward Tobacco Counseling Services

ABSTRACT

Objective: To determine the test-retest reliability of a new questionnaire designed to assess the attitude of students in a Nigerian dental school to tobacco cessation services. Materials and Methods: A self-administered questionnaire was administered twice at 4 weeks interval to the same set of final year dental students (N = 36) in one of the Nigerian dental schools. Ten questions were randomly selected from the 35-item questionnaire. Intra-class correlation (ICC) coefficients at 95confidence interval were computed for each selected item and the Cronbach's alpha coefficients were calculated to assess the internal consistency of the questionnaire. Results: The results showed that the least Cronbach's alpha value was 0.49 and the highest was 0.98. Only two items had less than a substantial agreement level (0.60) and seven items had an almost perfect agreement level (0.80). The results also indicated that the ICC coefficient is very highly statistically significant (P 0.001). Conclusion: The questionnaire demonstrated adequate test-retest reliability to assess the attitude of dental students to tobacco cessation services