A cohort study for the development and validation of a reflective inventory to quantify diagnostic reasoning skills in optometry practice

Abstract

Background Diagnostic reasoning is an essential skill for optometry practice and a vital part of the curriculum for optometry trainees but there is limited understanding of how diagnostic reasoning is performed in optometry or how this skill is best developed. A validated and reliable self-reflective inventory for diagnostic reasoning in optometry, would enable trainees and registered practitioners to benchmark their diagnostic reasoning skills, identify areas of strength and areas for improvement. Methods A 41 item self-reflective inventory, the Diagnostic Thinking Inventory, used extensively in the medical field was adapted for use in optometry and called the Diagnostic Thinking Inventory for Optometry (DTI-O). The inventory measures two subdomains of diagnostic reasoning, flexibility in thinking and structured memory. Context based changes were made to the original inventory and assessed for face and content validity by a panel of experts. The inventory was administered to two groups, experienced (qualified) optometrists and second-year optometry students to establish validity and reliability of the self-reflective tool in optometry. Results Exploratory Factor Analysis uncovered 13 domain specific items were measuring a single construct, diagnostic reasoning. One misfitting item was removed following Rasch analysis. Two unidimensional subdomains were confirmed in the remaining 12 items: Flexibility in Thinking (χ2 = 12.98, P = 0.37) and Structured Memory (χ2 = 8.74, P = 0.72). The ‘Diagnostic Thinking Inventory for Optometry Short’ (DTI-OS) tool was formed from these items with the total and subdomain scores exhibiting strong internal reliability; Total score Cα = 0.92. External reliability was established by test-retest methodology (ICC 0.92, 95% CI 0.83–0.96, P < .001) and stacked Rasch analysis (one-way ANOVA, F = 0.07, P = 0.80). Qualified optometrists scored significantly higher (P < .001) than students, demonstrating construct validity. Conclusion This study showed that the DTI-O and DTI-OS are valid and reliable self-reflective inventories to quantify diagnostic reasoning ability in optometry. With no other validated tool to measure this metacognitive skill underpinning diagnostic reasoning a self-reflective inventory could support the development of diagnostic reasoning in practitioners and guide curriculum design in optometry education.

Virtual simulated international placements as an innovation for internationalisation in undergraduate programs: a mixed methods study

“…Student experiences were evaluated as part of a quality assurance activity using a voluntary and anonymous survey instrument at the completion of the fifth week. Pre-existing scores from the Diagnostic Thinking Inventory for Optometry (DTI-O) before and after the learning activity were included in the study [ 7 ]. After the 5 th week, all students and facilitators were invited to participate in focus group discussions with two to four students or two to four facilitators.…”

“…The inventory has two subdomains, 21 items for Flexibility in Thinking (FT) and 20 items for Structured Memory (SM). Flexibility in thinking focuses on the skill of moving between different enquiry processes and structured memory relates to the ability to process possessed knowledge to solve clinical cases [ 7 ]. A higher score on the DTI-O represents greater diagnostic reasoning skills with a maximum score of 246 (126 in FT and 120 in SM).…”

“…A higher score on the DTI-O represents greater diagnostic reasoning skills with a maximum score of 246 (126 in FT and 120 in SM). The DTI-O has demonstrated ability to detect the difference between abilities in diagnostic reasoning in a validity study and was chosen to reflect the student’s level of diagnostic reasoning proficiency at a set point in time [ 7 ].…”

Validating the Korean shorter Diagnostic Thinking Inventory in medical education: a pilot study

“…Although DTI is a reliable tool for determining the level of FT and SM that experts and medical students use in clinical reasoning processes [ 1 , 7 , 12 ], it consists of 41 overlapping items that can be inconvenient to use. Edgar et al [ 7 ] recently adapted DTI for use in optometric education contexts through context-based changes. They created a shorter version of the DTI in optometric education contexts (DTI-OS) by reducing items from the original DTI.…”

“…The DTI-OS in their study demonstrated a high level of internal reliability, with a Cronbach’s α of 0.92, and its validity was established with significantly higher scores by qualified optometrists compared to second-year optometry students. Edgar et al [ 7 ] also measured the clinical reasoning abilities of second-year optometry students using the original DTI. Despite the different contexts, its mean value (155.6) of second-year optometry students in their study was comparable to the mean value (158.3) of third-year medical students in Bordage et al [ 1 ].…”