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

Abstract

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, p = 0.008; hepatomegaly 7.68 ± 1.52 vs 5.36 ± 2.48, p < 0.001) and likelihood of adoption (ascites 8.67 ± 1.61 vs 7.46 ± 1.79, p = 0.02; hepatomegaly 8.12 ± 1.90 vs 5.92 ± 2.32, p = 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.

Keywords: Ascites; Bedside ultrasound; Education; Hepatomegaly; Point-of-care ultrasound (POCUS); Rational physical examination.

Conflict of interest statement

Conflict of interest

All authors declare that they have no conflicts of interest related to this study.

Ethical standard

Our study has been reviewed by the Research Ethics Board of Saint Michael’s Hospital and the University Health Network (Toronto, Canada).

Informed consent

All patient participants and medical trainees gave their informed consent prior to their inclusion in the study and had the opportunity to withdraw consent at any time during the study. All details that might disclose the identity of patient and trainee participants have been omitted.