Should we confirm our clinical diagnostic certainty by autopsies?

To evaluate the frequency of diagnostic errors assessed by autopsies.

Retrospective review of medical and pathological records in an 11-bed closed medical intensive care unit (ICU) at a 860-bed general hospital.

Patients who died in the ICU between January 1998 and December 1999. Medical diagnoses were rated into three levels of clinical diagnostic certainty: complete certainty (group L1), minor diagnostic uncertainty (group L2), and major diagnostic uncertainty (group L3). The patients were divided into three error groups: group A, the autopsy confirmed the clinical diagnosis; group B, the autopsy demonstrated a new relevant diagnosis which would probably not have influenced the therapy and outcome; group C, the autopsy demonstrated a new relevant diagnosis which would probably have changed the therapy and outcome.

The overall mortality was 20.3% (270/1331 patients). Autopsies were performed in 126 patients (46.9% of deaths), more often in younger patients (66.6+/-13.9 years vs 72.7+/-12.0 years, p<0.001), in patients with shorter ICU stay (4.7+/-5.6 days vs 6.7+/-8.7 days, p=0.054), and in patients in group L3 without chronic diseases (15/126 vs 1/144, p<0.001). Fatal but potentially treatable errors [group C, 12 patients (9.5%)] were found in 8.7%, 10.0%, and 10.5% of patients in groups L1, L2, and L3, respectively (NS between groups). An ICU length of stay shorter than 24 h was not related to the frequency of group C errors.

Autopsies are performed more often in younger patients without chronic disease and in patients with a low clinical diagnostic certainty. No level of clinical diagnostic certainty could predict the pathological findings.