Delayed Diagnosis in Outpatient Care: A Systematic Review of Documentation Fragmentation as a Hidden Driver of Diagnostic Error

Delayed diagnosis in outpatient care is a major source of preventable patient harm. Unlike inpatient settings, outpatient diagnosis unfolds longitudinally across multiple encounters, increasing reliance on effective documentation and information continuity. Emerging evidence suggests that fragmented documentation may represent a hidden system-level driver of diagnostic error and delayed diagnosis. A PRISMA-compliant systematic review was conducted. PubMed, Scopus, and Google Scholar were searched for studies published within the last 10 years that examined documentation-related contributors to delayed diagnosis in outpatient care. Predefined inclusion and exclusion criteria were applied, and 13 eligible studies were qualitatively synthesized. Across diverse outpatient clinical settings, documentation fragmentation, incomplete longitudinal information synthesis, and failures in diagnostic follow-up were consistently associated with delayed diagnosis. These system-level factors frequently obscured evolving clinical patterns despite appropriate evaluation during individual encounters. Delayed diagnosis in outpatient care is commonly driven by documentation and information continuity failures rather than isolated clinician error. Recognizing documentation fragmentation as a hidden driver of diagnostic error highlights the need for interventions that support longitudinal synthesis and diagnostic follow-up to improve diagnostic timeliness and patient safety.