Diagnostic accuracy of physician's gestalt in suspected COVID-19: Prospective bicentric study

Abstract

Objectives: Physicians' gestalt is central in the diagnostic pipeline of suspected COVID-19, due to the absence of a single tool allowing conclusive rule in or rule out. The aim of this study was to estimate the diagnostic test characteristics of physician's gestalt for COVID-19 in the emergency department (ED), based on clinical findings or on a combination of clinical findings and bedside imaging results.

Methods: From April 1 to April 30, 2020, patients with suspected COVID-19 were prospectively enrolled in two EDs. Physicians prospectively dichotomized patients in COVID-19 likely or unlikely twice: after medical evaluation of clinical features (clinical gestalt [CG]) and after evaluation of clinical features and results of lung ultrasound or chest x-ray (clinical and bedside imaging-integrated gestalt [CBIIG]). The final diagnosis was adjudicated after independent review of 30-day follow-up data.

Results: Among 838 ED enrolled patients, 193 (23%) were finally diagnosed with COVID-19. The area under the curve (AUC), sensitivity, and specificity of CG and CBIIG for COVID-19 were 80.8% and 91.6% (p < 0.01), 82.9% and 91.4% (p = 0.01), and 78.6% and 91.8% (p < 0.01), respectively. CBIIG had similar AUC and sensitivity to reverse transcription-polymerase chain reaction (RT-PCR) for SARS-CoV-2 on the first nasopharyngeal swab per se (93.5%, p = 0.24; and 87%, p = 0.17, respectively). CBIIG plus RT-PCR had a sensitivity of 98.4% for COVID-19 (p < 0.01 vs. RT-PCR alone) compared to 95.9% for CG plus RT-PCR (p = 0.05).

Conclusions: In suspected COVID-19, CG and CBIIG have fair diagnostic accuracy, in line with physicians' gestalt for other acute conditions. Negative RT-PCR plus low probability based on CBIIG can rule out COVID-19 with a relatively low number of false-negative cases.

Keywords: COVID-19; diagnosis; emergency department; gestalt; lung ultrasound chest x-ray.

FIGURE 1

Flow diagram of the study. % values refer to N = 838 analyzed patients. CBIIG, clinical and bedside imaging–integrated gestalt; RT‐PCR, reverse transcription–polymerase chain reaction

FIGURE 2

Fagan's nomogram showing the effect of RT‐PCR plus CG, and RT‐PCR plus CBIIG, on the posttest probability of COVID‐19. CBIIG, clinical and bedside imaging–integrated gestalt; CG, clinical gestalt; LR–, negative likelihood ratio; RT‐PCR, reverse transcription–polymerase chain reaction