RESUMEN
OBJECTIVE: To compare the reliability, usability, and efficiency of video versus print instructions to teach parents a procedural measurement task. We hypothesized that videos would outperform print in all outcomes. STUDY DESIGN: This cross-sectional study included parents/caregivers of children aged 0-18 years with deep vein thrombosis attending the Thrombosis Clinic at The Hospital for Sick Children for post-thrombotic syndrome (PTS) assessment. Participants were randomly assigned to three instruction types: (i) video, which followed the technique used by clinicians; (ii) long pamphlet, which also followed the clinicians' technique; and (iii) short pamphlet, which explained a simplified technique. After measuring their children's arms or legs using the randomly assigned material, participants completed a usability questionnaire. The reliability of the instructions was estimated by comparing parents/caregivers versus clinicians' measurements using the intraclass correlation coefficient (ICC). Reliability, usability, and efficiency (time to task completion) were compared among the three instruction types. RESULTS: In total, 92 participants were randomized to video (n = 31), long pamphlet (n = 31), and short pamphlet (n = 30). While the video had the highest usability, the short pamphlet was the most reliable and efficient. ICCs were .17 (95% confidence interval [CI]: .00-.39) for the video, .53 (95% CI: .30-.72) for the long pamphlet, and .70 (95% CI: .50-.81) for the short pamphlet. CONCLUSION: Although the video had higher usability, the short/simplified print instruction was more reliable and efficient. However, the reliability of the short pamphlet was only moderate/good, suggesting that whenever possible, measurements should still be obtained by trained clinicians.