2018 FSA Posters

P053: CROSS-SECTIONAL LITERACY TRAINER: READINESS FOR USING ULTRASONOGRAPHY?
Samsun Lampotang, PhD¹, Tufan Sezer², David Lizdas¹, Baris Sezer³, Lou Ann Cooper, PhD¹; ¹University of Florida, ²Ankara University, ³Hacettepe University

Introduction/Background: Clinical use of ultrasonography (US) is spreading with advances in technology. Some schools issue hand-held, personal scanners to medical students. Ultrasonography produces a two-dimensional cross-section of a three-dimensional object as if “cut” along the US insonation plane. Cross-sectional literacy should facilitate interpretation and use of US. To date, cross-sectional literacy is not a formal part of medical school curricula.

We have developed a mixed reality cross-sectional literacy trainer1. As part of a validation study, we assessed the cross-sectional literacy of medical students at the end of their first year of training (MS1) with the Santa Barbara Solids Test (SBST)2.  In previous studies3, the most common incorrect responses involved making an egocentric error, i.e., failure to change one’s view perspective as if one were at the cutting plane, i.e., at the ultrasound probe. The ability to alter one’s perspective from where one stands is important in interpreting US images.

Methods: Participants completed a short demographic questionnaire and were administered the SBST2 (paper-and-pencil with color) in a classroom setting and no time limit. The SBST has 30 questions. Test-takers are instructed to choose the correct cross-section from 4 possible choices. Each set of answers incorporates an egocentric foil. Items are scored 1 if correct, 0 if incorrect/blank.  Responses were manually entered and scored using Excel. We used SPSS (v. 18.0) to compute descriptive statistics. Differences in SBST score by gender were tested with Student’s t-test.

Results: Of 135 first year medical students (MS1), 57 (42%) provided valid answer sheets for analysis. The mean and SD of the total score, expressed as percent correct, was 0.79±0.2 (range .07 – 1.00). Scores for females and males were 0.77±0.2 and 0.81±0.19 respectively. There was no significant difference between genders (p=0.46). 

The egocentric foil was the most common error (53.2%; 189 of 355 wrong answers). If we express the number of participants (n) and the number of egocentric errors (ee) as n:ee, then 22:0 means 22 students made no egocentric errors. The distribution was 22:0, 13:1, 3:2, 3:3, 2:4, 1:5, 1:6, 2:7, 4:8, 1:10, 1:12, 1:13, 1:17, 1:20 and 1:23. Two students earned perfect scores. For 3 participants, over half of the wrong answers were egocentric errors.  The mean (SD) proportion of egocentric errors was 0.33 ±0.33.  

Discussion/Conclusions:  Mean (SD) SBST scores of MS1s were 0.79 (.20) compared to 0.68 (0.23) for undergraduates in introductory chemistry classes3. While we might expect higher scores for medical students, egocentric errors were more common with larger variance in the incidence (0.33±0.33 vs. 0.19±0.113).

The results reported here are part of a larger program of learning outcome and simulator validation studies. We are beginning to explore whether technology (Ultrasonography) is ahead of pedagogy (cross-sectional literacy). The SBST evaluates only cognitive cross-sectional literacy. With clinical US, psychomotor skills are also required to orient the US probe to obtain a desired image. We will be exploring clinical cross-sectional literacy with a learning outcome study of a new simulator.