Validation of an instrument to assess evidence-based practice knowledge, attitudes, access, and confidence in the dental environment.

This article reports the validation of an assessment instrument designed to measure the outcomes of training in evidence-based practice (EBP) in the context of dentistry. Four EBP dimensions are measured by this instrument: 1) understanding of EBP concepts, 2) attitudes about EBP, 3) evidence-accessing methods, and 4) confidence in critical appraisal. The instrument-the Knowledge, Attitudes, Access, and Confidence Evaluation (KACE)-has four scales, with a total of thirty-five items: EBP knowledge (ten items), EBP attitudes (ten), accessing evidence (nine), and confidence (six). Four elements of validity were assessed: consistency of items within the KACE scales (extent to which items within a scale measure the same dimension), discrimination (capacity to detect differences between individuals with different training or experience), responsiveness (capacity to detect the effects of education on trainees), and test-retest reliability. Internal consistency of scales was assessed by analyzing responses of second-year dental students, dental residents, and dental faculty members using Cronbach coefficient alpha, a statistical measure of reliability. Discriminative validity was assessed by comparing KACE scores for the three groups. Responsiveness was assessed by comparing pre- and post-training responses for dental students and residents. To measure test-retest reliability, the full KACE was completed twice by a class of freshman dental students seventeen days apart, and the knowledge scale was completed twice by sixteen faculty members fourteen days apart. Item-to-scale consistency ranged from 0.21 to 0.78 for knowledge, 0.57 to 0.83 for attitude, 0.70 to 0.84 for accessing evidence, and 0.87 to 0.94 for confidence. For discrimination, ANOVA and post hoc testing by the Tukey-Kramer method revealed significant score differences among students, residents, and faculty members consistent with education and experience levels. For responsiveness to training, dental students and residents demonstrated statistically significant changes, in desired directions, from pre- to post-test. For the student test-retest, Pearson correlations for KACE scales were as follows: knowledge 0.66, attitudes 0.66, accessing evidence 0.74, and confidence 0.76. For the knowledge scale test-retest by faculty members, the Pearson correlation was 0.79. The construct validity of the KACE is equivalent to that of instruments that assess similar EBP dimensions in medicine. Item consistency for the knowledge scale was more variable than for other KACE scales, a finding also reported for medically oriented EBP instruments. We conclude that the KACE has good discriminative validity, responsiveness to training effects, and test-retest reliability.