Figure 4.

Linking multiple symptoms to multiple diseases using a Symptom-Disease Pair Analysis of Diagnostic Error (SPADE) framework. Sankey diagram (adapted from Obermeyer et al⁴²) demonstrating discharge diagnoses from index ED visit (left) and their association with documented causes of death (right) within 7 days of discharge in a subset of Medicare fee-for-service beneficiaries. These results were obtained using a SPADE-style analysis of over 10 million ED discharges and used multiple symptom-disease pairs to identify likely diagnostic errors. Each index and outcome diagnosis category represents an aggregation of related codes (coding details found in ref 42), and line thickness is proportional to the number of beneficiaries. Statistical analyses found excess, potentially preventable deaths based on hospital admission fraction from the ED. These results highlight the viability of using symptom and disease bundling and statistical analysis of visit patterns to track misdiagnosis-related harms—specifically, in this example, mortality associated with diagnostic errors. ED, emergency department.