Calibrating clinical reasoning under uncertainty: a qualitative study of expert physiotherapists in musculoskeletal practice

Background Clinical practice guidelines aim to reduce unwarranted variation in musculoskeletal physiotherapy, yet they cannot fully determine how clinicians should act when patient presentations are ambiguous, incomplete, or evolving. In such situations, expert reasoning may depend on how clinicians interpret, weight, and act upon uncertain clinical information.Objective To explore how expert physiotherapists transform clinical uncertainty into actionable clinical judgments when reasoning through musculoskeletal clinical vignettes.Materials and methods We conducted an interpretive qualitative study using 24 short musculoskeletal clinical vignettes that presented an uncertain clinical situation, a proposed diagnostic hypothesis or management decision, and new information whose impact experts judged and justified in writing. Ten expert physiotherapists, all Fellows of programs recognized by the International Federation of Manual and Musculoskeletal Physical Therapists Incorporated (IFOMPT), completed the vignettes and provided written justifications for their responses. The final qualitative dataset comprised 234 written expert justifications. Data were analyzed using codebook thematic analysis in ATLAS.ti 26.0.1, with attention to within-vignette variation, cross-vignette patterns, and divergent reasoning strategies.Results Three interrelated themes were generated. First, experts used clinical scripts as flexible interpretive structures, activating, questioning, or suspending them depending on the fit between the vignette and the clinical pattern. Second, experts calibrated clinical judgment by assigning different decisional weight to clinical, paraclinical, contextual, and treatment-response cues. Third, experts transformed uncertainty into action through provisional decisions, monitoring, treatment adjustment, or reassessment. Across themes, reasoning strategies varied by vignette context and reflected strong judgment stabilization, open maintenance of uncertainty, or provisional stabilization of judgment.Conclusion Expert physiotherapists made uncertainty actionable through clinical calibration. Differences between experts did not simply reflect disagreement or non-adherence to recommendations, but situated reasoning strategies for weighting cues, managing uncertainty, and deciding when uncertainty was sufficient to act, monitor, or revise judgment.