Real Patients, Real Reasoning: Karachi Surgeons Put Diagnostic Thinking to the Test

Diagnostic reasoning, the mental machinery that transforms a vague complaint into a precise diagnosis, has long been treated as something surgical trainees absorb by osmosis rather than something they are explicitly taught. A team of surgeons and education researchers at a tertiary teaching hospital in Karachi set out to challenge that assumption. In a study published in BMC Medical Education, they describe a 60-week program in which junior surgical residents worked through the cases of real patients with complex, undiagnosed conditions, under direct faculty observation, and were then formally evaluated on whether the intervention actually sharpened their diagnostic thinking. The results offer one of the first structured looks at how such an approach performs in a lower-middle-income country, where diagnostic errors carry a heavy toll and formal training in clinical reasoning has historically been scarce.

The intervention itself was deceptively simple in concept but demanding in execution. Small groups of residents encountered patients whose conditions had not yet been pinned down, so the educational stakes mirrored genuine clinical uncertainty. Faculty directly observed the residents as they gathered history, performed examinations, and analyzed the data they collected. Feedback focused not just on what conclusions the residents reached, but on how they structured their thinking along the way. A technique called concept mapping sat at the heart of the method: residents were required to lay out their problem representation, a concise summary of the patient’s clinical picture, and their differential diagnosis, the ranked list of possible explanations, in visual map form that made the architecture of their reasoning visible to teachers and to themselves.

The cognitive science behind this is well established. Expert clinicians do not simply accumulate facts; they build problem representations that bundle findings into coherent patterns, which then activate illness scripts, mental models of diseases that include typical presentations, plausible complications, and discriminating features. Novices tend to jump prematurely to a single hypothesis or to enumerate possibilities without coherent structure, a failure mode that concept mapping is designed to expose. In the Karachi program, residents refined their initial analyses through self-directed study, and once a definitive diagnosis was finally available, they reflected on where their reasoning had gone wrong and deliberately updated their mental models of the disease. This closing loop, from hypothesis to feedback to model revision, is the mechanism that educational theorists believe converts raw clinical exposure into durable expertise.

The scale of the program was modest but meaningful. Over 60 weeks, 11 residents encountered 51 patients with complex, undiagnosed conditions, a median of 20 cases per resident, with individual exposure ranging from 12 to 40 patients. Because the patients were real rather than simulated, the residents faced the full messiness of clinical medicine: incomplete histories, atypical presentations, and the psychological pressure of genuine stakes. That authenticity is precisely what simulation-based curricula often struggle to replicate, and it is what makes the Karachi experiment notable at a time when medical educators worldwide are debating how best to teach reasoning rather than merely test recall.

How do you measure whether an educational intervention actually improves something as intangible as thinking? The researchers used a layered evaluation. Questionnaires and focus group discussions probed residents’ perceptions of acceptability, relevance, and impact on their professional growth. Early outcomes were tracked by scoring how well residents’ problem representations and differential diagnoses aligned with the definitive diagnoses ultimately established. Strikingly, that alignment was achieved in 39 of 51 cases, or 76.5 percent, a figure the authors present as evidence that the residents’ structured reasoning frequently converged on the truth. To address the thornier question of attribution, whether any improvement was really due to the program rather than ordinary clinical maturation, the team compared Diagnostic Thinking Inventory scores between participants and non-equivalent controls using a quasi-experimental design. The DTI is a validated instrument that assesses the flexibility and structure of a clinician’s diagnostic thinking, and the comparison provided what the authors characterize as modest evidence that learning gains were attributable to the intervention itself.

The word modest matters. Quasi-experimental designs, which lack the randomization of a true trial, can never fully rule out confounding, and the control groups in this study were non-equivalent by construction. The new cohort of general surgery residents recently inducted into the program and residents from other surgical and surgical-related specialties served as comparators, but differences in experience, motivation, and exposure could all influence DTI scores. The authors are candid about this limitation, positioning their work as an early implementation evaluation rather than a definitive effectiveness trial. In implementation science, that is the appropriate posture: establish feasibility, acceptability, and a signal of promise before investing in the larger, more rigorous studies that would be needed to justify widespread adoption.

The qualitative findings add texture that the numbers alone cannot convey. Surveys and focus groups indicated that the program was acceptable and relevant to the trainees and supported their professional growth, which is no small achievement for a curriculum imposed on residents already stretched thin by clinical service. Yet the residents also reported anxiety tied to their knowledge gaps, a candid admission that grappling with undiagnosed patients is emotionally as well as intellectually taxing. Persistent deficiencies in data gathering and analysis surfaced even after the intervention, suggesting that structured reasoning does not automatically compensate for gaps in foundational knowledge. And residents pointed to limited faculty support amid heavy service demands, a chronic tension in teaching hospitals everywhere but especially acute in resource-constrained systems, which hindered consolidation of learning in the workplace.

These challenges are not incidental; they point to where the field must go next. The authors recommend three priorities for future efforts: structured illness script development, so that residents accumulate organized disease knowledge rather than fragmented facts; greater integration of supervised learning in the workplace, so that diagnostic reasoning is practiced and coached during routine care rather than only in dedicated teaching sessions; and the introduction of formal assessment with targeted feedback, so that progress in reasoning is measured and corrected as deliberately as surgical skill. Each recommendation addresses a failure point identified in the current program, and together they sketch a roadmap for embedding clinical reasoning into the mainstream of surgical training.

The context in Pakistan gives the study particular weight. Diagnostic reasoning remains insufficiently prioritized within medical education and clinical practice in the country, according to the researchers, and surgical residency has traditionally emphasized operative technique and service delivery over explicit cognitive training. Pakistan’s postgraduate surgical training is overseen by bodies such as the College of Physicians and Surgeons of Pakistan, and global movements toward competency-based medical education, championed by organizations like the Accreditation Council for Graduate Medical Education, are pressuring training programs everywhere to demonstrate outcomes rather than hours logged. In that environment, a low-cost, real-patient intervention that requires no expensive simulators, only committed faculty and a structured method, could be especially attractive for LMIC institutions, where budgets for simulation centers and dedicated educators are often thin.

What happens next will determine whether the Karachi experiment remains a promising case study or becomes a template. The program’s core insight deserves to travel: diagnostic reasoning is a skill that can be taught, observed, and improved, and the raw material for that teaching already walks through the doors of every teaching hospital in the world. The 76.5 percent alignment figure, the modest but positive DTI evidence, and the residents’ own testimony that the program fostered growth all suggest that the model works well enough to test at scale. The anxieties, knowledge gaps, and faculty shortages documented alongside those successes are equally instructive, reminding educators that a curriculum is only as strong as the clinical learning environment that surrounds it. For surgical residents in Karachi and beyond, the study’s message is quietly radical: the most powerful diagnostic teaching tool may be the undiagnosed patient, provided someone teaches you how to think about them.

Subject of Research: Teaching diagnostic reasoning to surgical residents through a real-patient educational intervention in Pakistan

Article Title: Teaching diagnostic reasoning to surgical residents: early evaluation of a real-patient intervention in an LMIC

Article References: Teaching diagnostic reasoning to surgical residents: early evaluation of a real-patient intervention in an LMIC. (n.d.). https://doi.org/10.1186/s12909-026-10607-x

Image Credits: AI Generated

DOI: 10.1186/s12909-026-10607-x

Keywords: diagnostic reasoning, surgical residency, medical education, Pakistan, concept mapping, problem representation, differential diagnosis, Diagnostic Thinking Inventory, LMIC, clinical training, quasi-experimental study, faculty feedback