Background: Physicians can play an important role in preventing and treating childhood obesity. There are currently no validated measures of medical students' self-efficacy in these skills; therefore, we sought to develop a valid and reliable computerized survey to measure medical students' self-efficacy in skills needed to prevent and treat childhood obesity.
Methods: We developed the Childhood Obesity Prevention Self-Efficacy (COP-SE) survey with input from two expert panels and cognitive interviews with medical students. We administered the 43-item COP-SE computerized survey to a nation-wide sample of medical students.
Results: The final sample consisted of 444 medical students from 53 medical schools. Exploratory factor analysis revealed a two-factor structure with a correlation of 0.637 between factors and high reliability within factors. The correlation between the COP-SE and a measure of general self-efficacy was moderate (0.648), and reliability within factors was high (Factor 1=0.946; Factor 2=0.927).
Conclusions: The 18-item COP-SE is a valid and reliable measure of childhood obesity prevention self-efficacy. Factor 1 assesses self-efficacy in nutrition counseling, and Factor 2 measures self-efficacy to assess readiness to change and initiate nutrition lifestyle changes. The correlation between the COP-SE and a measure of general self-efficacy indicates that the COP-SE is a distinct, valid assessment of domain-specific self-efficacy. The high reliability of items within factors indicates the items measure the same constructs. Therefore, medical schools can use this valid and reliable instrument as a formative or summative assessment of students' self-efficacy in childhood obesity prevention and treatment.