title: Case-based or non-case-based questions for teaching postgraduate physicians: a randomized crossover trial.
abstract: OBJECTIVE
  The comparative efficacy of case-based (CB) and non-CB self-assessment questions in Web-based instruction is unknown. The authors sought to compare CB and non-CB questions.
  
  
  METHODS
  The authors conducted a randomized crossover trial in the continuity clinics of two academic residency programs. Four Web-based modules on ambulatory medicine were developed in both CB (periodic questions based on patient scenarios) and non-CB (questions matched for content but lacking patient scenarios) formats. Participants completed two modules in each format (sequence randomly assigned). Participants also completed a pretest of applied knowledge for two modules (randomly assigned).
  
  
  RESULTS
  For the 130 participating internal medicine and family medicine residents, knowledge scores improved significantly (P < .0001) from pretest (mean: 53.5; SE: 1.1) to posttest (75.1; SE: 0.7). Posttest knowledge scores were similar in CB (75.0; SE: 0.1) and non-CB formats (74.7; SE: 1.1); the 95% CI was -1.6, 2.2 (P = .76). A nearly significant (P = .062) interaction between format and the presence or absence of pretest suggested a differential effect of question format, depending on pretest. Overall, those taking pretests had higher posttest knowledge scores (76.7; SE: 1.1) than did those not taking pretests (73.0; SE: 1.1; 95% CI: 1.7, 5.6; P = .0003). Learners preferred the CB format. Time required was similar (CB: 42.5; SE: 1.8 minutes, non-CB: 40.9; SE: 1.8 minutes; P = .22).
  
  
  CONCLUSIONS
  Our findings suggest that, among postgraduate physicians, CB and non-CB questions have similar effects on knowledge scores, but learners prefer CB questions. Pretests influence posttest scores.
authors.affiliation: Office of Education Research, Division of General Internal Medicine, College of Medicine, Mayo Clinic, Baldwin 4-A, 200 First Street SW, Rochester, MN 55905, USA. cook.david33@mayo.edu
authors.forename: David A
authors.initials: DA
authors.lastname: Cook
authors.forename: Warren G
authors.initials: WG
authors.lastname: Thompson
authors.forename: Kris G
authors.initials: KG
authors.lastname: Thomas
mesh_terms: D018592:Cross-Over Studies; D004502:Education, Medical, Continuing / Q000379:methods*; D005194:Family Practice / Q000193:education*; D006801:Humans; D007388:Internal Medicine / Q000193:education*; D020407:Internet; D013663:Teaching / Q000379:methods*