Comparison of Two Symptom Checkers (Ada and Symptoma) in the Emergency Department: Randomized, Crossover, Head-to-Head, Double-Blinded Study.

BACKGROUND: Emergency departments (EDs) are frequently overcrowded and increasingly used by nonurgent patients. Symptom checkers (SCs) offer on-demand access to disease suggestions and recommended actions, potentially improving overall patient flow. Contrary to the increasing use of SCs, there is a lack of supporting evidence based on direct patient use. OBJECTIVE: This study aimed to compare the diagnostic accuracy, safety, usability, and acceptance of 2 SCs, Ada and Symptoma. METHODS: A randomized, crossover, head-to-head, double-blinded study including consecutive adult patients presenting to the ED at University Hospital Erlangen. Patients completed both SCs, Ada and Symptoma. The primary outcome was the diagnostic accuracy of SCs. In total, 6 blinded independent expert raters classified diagnostic concordance of SC suggestions with the final discharge diagnosis as (1) identical, (2) plausible, or (3) diagnostically different. SC suggestions per patient were additionally classified as safe or potentially life-threatening, and the concordance of Ada's and physician-based triage category was assessed. Secondary outcomes were SC usability (5-point Likert-scale: 1=very easy to use to 5=very difficult to use) and SC acceptance net promoter score (NPS). RESULTS: A total of 450 patients completed the study between April and November 2021. The most common chief complaint was chest pain (160/437, 37%). The identical diagnosis was ranked first (or within the top 5 diagnoses) by Ada and Symptoma in 14% (59/437; 27%, 117/437) and 4% (16/437; 13%, 55/437) of patients, respectively. An identical or plausible diagnosis was ranked first (or within the top 5 diagnoses) by Ada and Symptoma in 58% (253/437; 75%, 329/437) and 38% (164/437; 64%, 281/437) of patients, respectively. Ada and Symptoma did not suggest potentially life-threatening diagnoses in 13% (56/437) and 14% (61/437) of patients, respectively. Ada correctly triaged, undertriaged, and overtriaged 34% (149/437), 13% (58/437), and 53% (230/437) of patients, respectively. A total of 88% (385/437) and 78% (342/437) of participants rated Ada and Symptoma as very easy or easy to use, respectively. Ada's NPS was -34 (55% [239/437] detractors; 21% [93/437] promoters) and Symptoma's NPS was -47 (63% [275/437] detractors and 16% [70/437]) promoters. CONCLUSIONS: Ada demonstrated a higher diagnostic accuracy than Symptoma, and substantially more patients would recommend Ada and assessed Ada as easy to use. The high number of unrecognized potentially life-threatening diagnoses by both SCs and inappropriate triage advice by Ada was alarming. Overall, the trustworthiness of SC recommendations appears questionable. SC authorization should necessitate rigorous clinical evaluation studies to prevent misdiagnoses, fatal triage advice, and misuse of scarce medical resources. TRIAL REGISTRATION: German Register of Clinical Trials DRKS00024830; https://drks.de/search/en/trial/DRKS00024830.

The Positive Rate of Pulmonary Embolism by CT Pulmonary Angiography Is High in an Emergency Department, Even in Low-Risk or Young Patients.

OBJECTIVE: The clinical presentation of pulmonary embolism (PE) can be various and misleading. We analyzed patients with suspicion of PE and subsequently performed computed tomography pulmonary angiography (CTPA) in an emergency department of Internal Medicine, focusing on patient groups in which PE might be underestimated in the emergency setting, such as young patients and patients with low clinical probability. MATERIAL AND METHODS: In 2016 and 2017, all patients receiving a CTPA for investigation of PE were retrospectively evaluated for clinical parameters (age, symptoms, and vital parameters) and D-dimers. The Wells score was calculated. RESULTS: CTPA was performed in 323 patients (158 female and 165 male; mean age 62 years). The leading symptoms for admission were dyspnea or chest pain; 62% showed intermediate or high risk for PE, calculated by applying the Wells score. In 123 (38%) of all patients, a PE was proved and pathologic age-adjusted D-dimers were found in 97.6%. Thirty of 121 (25%) patients with low risk according to Wells score had a PE. Deep vein thrombosis was verified in 67/123 (55%) patients; 43% (15/35) of all suspicions for PE in patients <40 years were positive with 4/15 (26%), showing a central PE. Younger patients (<40 years) with PE presented more often with tachycardia or tachypnea and chest pain or dyspnea than elderly patients with PE. CONCLUSION: CTPA frequently proves a PE in patients with suspicion of PE in an emergency department of Internal Medicine. If PE is suspected and CTPA performed accordingly, the presence of PE is quite common even in low-risk patient groups (Wells score) or in young patients <40 years with chest pain or dyspnea.