Background: Diagnostic errors are common, costly, and harmful. Cognitive biases and suboptimal clinical reasoning are contributing factors for diagnostic error. A diagnostic time-out (DTO) is a structured tool to optimize clinical reasoning, prioritize the differential diagnosis, and communicate diagnostic uncertainty in high-risk situations susceptible to diagnostic error.

Purpose: To design and implement an interactive educational curriculum to adopt the use of the DTO among house staff during night float at a large academic medical center.

Description: Methods: Based on literature review and expert discussion, we adapted a diagnostic time-out initially developed by Garber et al to reflect the principles of problem representation and prioritization of a differential diagnosis. We discussed with residents and hospitalists, situations where reconsidering the diagnosis would be most helpful and compiled a list of trigger events to take a DTO [see Figure 1a]. Using simulation and group thinking strategies, we developed an educational curriculum that we implemented during the night float rotation of Vanderbilt Internal Medicine residency at the Nashville VA Medical Center. During the first night of a two-week rotation, residents and the night hospitalist are introduced to the DTO through an online video showcasing a simulated case [Figure 1b]. On the following nights, the hospitalist on call and residents meet to take a DTO for one patient admitted that night. The hospitalist provides direct, in-person feedback on clinical reasoning and the proposed plan. Following each rotation block, we surveyed participants’ perceptions of diagnostic uncertainty and intention to change practice after using the DTO using an electronic data capture tool. Survey questions were structured on a Likert scale. We calculated Cohen’s D effect size to compare perceptions before and after using the DTO.Results: A total of 21 residents completed the DTO experience during a 4-month period. Survey response rate was 85%. Our preliminary data suggest that after learning and using the DTO during their night float rotation, residents were more likely to communicate diagnostic uncertainty to their patients (Cohen’s D 0.63) and reach out to their supervising physicians when feeling uncertain of the diagnosis (Cohen’s D 0.99). The majority of residents (88%) expressed their intent to take a DTO in future high-risk situations for diagnostic error or high levels of uncertainty. Some reported limitations in using the DTO included time constraints when teams have a high workload burden and perceived lack of utility in low-complexity cases.

Conclusions: The DTO was found to be a useful tool to address diagnostic uncertainty and to potentially optimize clinical reasoning among house staff in situations at high-risk for diagnostic error. Additionally, we are developing a digital tool to prompt clinicians to take a DTO and then to document the outcome in the electronic health record.

IMAGE 1: Table 1. Preliminary data on intention on perception on diagnostic uncertainty and intentions to change practice before and after workshop.

IMAGE 2: Graph 1. Training materials (a) Diagnostic time-out card (b) Interactive simulated training video.