First-year medical students use of ultrasound or physical examination to diagnose hepatomegaly and ascites: a randomized controlled trial.

Purpose: To compare point-of-care ultrasound and physical examination (PEx), each performed by first-year medical students after brief teaching, for assessing ascites and hepatomegaly. Ultrasound and PEx were compared on: (1) reliability, validity and performance, (2) diagnostic confidence, ease of use, utility, and applicability.

Methods: A single-center, randomized controlled trial was performed at a tertiary centre. First-year medical students were randomized to use ultrasound or PEx to assess for ascites and hepatomegaly. Cohen's kappa and interclass coefficient (ICC) were used to measure interrater reliability between trainee assessments and the reference standard (a same day ultrasound by a radiologist). Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were compared. A ten-point Likert scale was used to assess trainee diagnostic confidence and perceptions of utility.

Results: There were no significant differences in interobserver reliability, sensitivity, specificity, accuracy, PPV, or NPV between the ultrasound and PEx groups. However, students in the ultrasound group provided higher scores for perceived utility (ascites 8.38 ± 1.35 vs 7.08 ± 1.86,  = 0.008; hepatomegaly 7.68 ± 1.52 vs 5.36 ± 2.48,  < 0.001) and likelihood of adoption (ascites 8.67 ± 1.61 vs 7.46 ± 1.79,  = 0.02; hepatomegaly 8.12 ± 1.90 vs 5.92 ± 2.32,  = 0.001).

Conclusions: When performed by first-year medical students, the validity and reliability of ultrasound is comparable to PEx, but with greater perceived utility and likelihood of adoption. With similarly brief instruction, point-of-care ultrasonography can be as effectively learned and performed as PEx, with a high degree of interest from trainees.