Abstract
Purpose: This article describes the systematic construction and psychometric analysis of a knowledge assessment instrument for phase II cardiac rehabilitation (CR) patients measuring risk modification disease management knowledge and behavioral outcomes derived from national standards relevant to secondary prevention and management of cardiovascular disease.
Methods: First, using adult curriculum based on disease-specific learning outcomes and competencies, a systematic test item development process was completed by clinical staff. Second, a panel of educational and clinical experts used an iterative process to identify test content domain and arrive at consensus in selecting items meeting criteria. Third, the resulting 31-question instrument, the Cardiac Knowledge Assessment Tool (CKAT), was piloted in CR patients to ensure use of application. Validity and reliability analyses were performed on 3638 adults before test administrations with additional focused analyses on 1999 individuals completing both pretreatment and posttreatment administrations within 6 months.
Results: Evidence of CKAT content validity was substantiated, with 85% agreement among content experts. Evidence of construct validity was demonstrated via factor analysis identifying key underlying factors. Estimates of internal consistency, for example, Cronbach's [alpha] = .852 and Spearman-Brown split-half reliability = 0.817 on pretesting, support test reliability. Item analysis, using point biserial correlation, measured relationships between performance on single items and total score (P < .01). Analyses using item difficulty and item discrimination indices further verified item stability and validity of the CKAT.
Conclusions: A knowledge instrument specifically designed for an adult CR population was systematically developed and tested in a large representative patient population, satisfying psychometric parameters, including validity and reliability.