Diagnostic Agreement between Prehospital Emergency and In-Hospital Physicians.

Background
The aim of the study was to determine the diagnostic agreement between the discharge diagnosis and the suspected diagnosis by the prehospital emergency physician and to run a sensitivity analysis of the most common diagnoses by the prehospital emergency physician.


Methods
The diagnostic agreement was determined by a systematic comparison of the discharge diagnosis with suspected diagnosis by the prehospital emergency physician in a period of 24 months at the emergency medical services in Bad Belzig. The diagnostic agreement of the 13 most common discharge diagnoses was compared to the remaining diagnostic agreement. The results were tested for statistical significance using the chi-squared test.


Results
In 64.1% of cases included, a diagnostic agreement occurred. There was a high proportion of diagnostic agreement for hypoglycemia (97%), atrial fibrillation (87%), cramping seizure (86%), hypertensive crisis (85.5%), and syncope (81%). There was a low proportion of diagnostic agreement for chest wall pain (27%), pneumonia (32%), and cardiac decompensation (53%).


Conclusions
Our attention in practice and emergency medical courses should be directed to chest pain patients and the main symptom of dyspnea, because of the high proportion of incorrect diagnoses by the prehospital emergency physician. It should be noted that 92% of incorrectly diagnosed chest wall pain cases were overestimated with an acute coronary syndrome.


Introduction
Due to the lack of laboratory-chemical examinations and imaging diagnostics in the emergency medical services (EMS), the correct prehospital diagnosis is a challenge for the prehospital emergency physician. Nevertheless, due to the often life-saving nature of prehospital missions, the correct diagnosis is important to the patient outcome. There are several studies done about the diagnostic agreement (dA) in the EMS and in the emergency department (ED) [1][2][3][4]. The results for dA showed a very broad spectrum (46.5%-90%). It should be noted that in these studies the methods for determining dA were different. A breakdown and sensitivity analysis of the most common diagnoses by the prehospital emergency physician has not yet been performed. It is of utmost importance for emergency medical science to know which clinical pictures have a low diagnostic agreement in prehospital missions.
The aim of our study was to determine the dA between emergency mission-related discharge diagnoses and suspected diagnoses by the prehospital emergency physician and to perform a sensitivity analysis of the most common emergency mission-related discharge diagnoses.

Diagnostic Agreement.
First, all prehospital missionrelated discharge diagnoses from the 1055 included cases were determined. In case that the discharge diagnosis from the discharge summaries for the corresponding mission could be confirmed in the suspected diagnoses from the patient care reports by the prehospital emergency physician, a dA occurred. In case that the discharge diagnosis from the discharge summaries for the corresponding mission could not be confirmed in the suspected diagnosis from the patient care reports by the prehospital emergency physician, a dA did not occur. This systematic comparison established the dA for all 1378 prehospital mission-related discharge diagnoses. It was done by two experienced emergency physicians (N. Ramadanov and F. Laue) independently from each other using the ICD 10 coding ( = 0,95). In divergent cases a third emergency physician (W. Behringer) helped find the correct adjudication.

Statistics.
As part of a sensitivity analysis, the dA of the 13 most common prehospital mission-related hospital discharge diagnoses was tested for statistically significant differences compared to the remaining dA. The chi-square test was used with a significance level of p = 0.05. Statistical calculations were performed using IBM SPSS Statistics 19 for Windows.

Exclusion of Cases
. 705 patient care reports were excluded from the study for the following reasons: ambulant treatment in the emergency department; prehospital treatment, lack of admission to the ED; lack of recorded emergency diagnosis; death of the patient during the mission or incorrect/unreadable patient data (see Figure 1).

Patients and Prehospital Emergency
Physicians. The average age of the 1055 patients was 70 years (min. 1, max 100 years). 493 of them were male and 562 were female. 64.5% of the prehospital missions were carried out by internist prehospital emergency physicians, 27% by surgical, 7% by general practitioners, and 1.5% by anesthetic emergency physicians. 70% of the prehospital missions were carried out by resident physicians and 30% by specialist physicians. 33% of the prehospital missions were carried out by prehospital emergency physicians with a higher approval for emergency medicine ("Zusatzbezeichnung Notfallmedizin") and 67% of the prehospital missions by prehospital emergency physicians with a lower approval for emergency medicine ("Fachkunde Rettungsdienst").

Deployed missions during the investigation period, n=1760
Ambulant treatment in the emergency department, n=323 Prehospital treatment, lack of admission to the ED, n=251 Lack of recorded emergency diagnosis, n=54 Death of the patient during the mission, n=42 Included missions during the investigation period, n=1055 Incorrect/unreadab le patient data, n=35

Spectrum of Discharge Diagnoses.
At 1055 included cases, a total of 1378 prehospital mission-related hospital discharge diagnoses were formulated after emergency medical admission. In 238 cases there were made 2 discharge diagnoses for one patient, in 38 cases 3 discharge diagnoses and in 3 cases 4 discharge diagnoses for one patient. Table 1 shows the 13 most common prehospital mission-related discharge diagnoses after emergency medical admission and Figure 2 the distribution of discharge diagnoses by specialty.

Determined Diagnostic Agreement and Sensitivity Analysis.
A dA occurred in 64.1% and did not occur in 35.9% of cases. The results for the sensitivity analysis of the 13 most common prehospital mission-related hospital discharge diagnoses are listed in Table 2.     Table 4 showed a low proportion of dA for chest wall pain with 27% compared to the dA of the rest of diagnoses (chi-square = 19.8, DF = 1, p = 0.01). In 92% of cases of missing dA chest wall pain was considered incorrectly as acute coronary syndrome. Table 5 showed a low proportion of dA for pneumonia with 68% compared to the dA of the rest of diagnoses (chi-square = 24.34, DF = 1, p = 0.01). In 30% of cases of missing dA, pneumonia was considered incorrectly as pulmonary edema and cardiac decompensation. Table 6 showed a low proportion of dA for cardiac decompensation with 47% compared to the dA of the rest of diagnoses (chisquare = 5.12, DF = 1, p = 0.02). In 22% of cases of missing dA, cardiac decompensation was considered incorrectly as exacerbated COPD.
Calculating the dA, it was possible to estimate retrospectively the correctness of the suspected diagnosis by the prehospital emergency physician. Based on 1055 included missions, our findings showed that the suspected diagnosis was correct in 64.1% of the cases. The sensitivity analysis of the 13 most common prehospital mission-related hospital discharge diagnoses showed a significantly high proportion of correct diagnoses for hypoglycemia (97%), arrhythmia absoluta (87%), seizure (86%), hypertensive crisis (85.5%), and syncope (81%) and a significantly high proportion of incorrect diagnoses for chest wall pain (73%), pneumonia (68%), and cardiac decompensation (47%).

Accumulation of Correct Suspected Diagnoses by the Prehospital Emergency Physician.
For diseases with a very remarkable clinical picture such as seizure and syncope, the accumulation of correct suspected diagnosis is understandable. The accumulation of correct suspected diagnoses by the prehospital emergency physician for hypoglycemia, hypertensive crisis, and arrhythmia absoluta can be explained by the fact that there is preclinical possibility for precise diagnostics (blood glucose measurement, blood pressure measurement, 12-channel ECG) in these diseases. The impact of the lack of laboratory and imaging diagnostics in prehospital medicine can be seen in the comparison of our present results with the study by Dormann with similar methods for the determination of the dA. Among other things, the admission diagnosis from the emergency department was compared to the hospital discharge diagnosis in his study [3]. In 4321 hospitalized patients, the dA was 71%, well above the dA of the present study (64.1%), which can be explained simply by the lack of opportunities for laboratory-chemical examinations and imaging diagnostics.

Lack of Correct Suspected Diagnoses by the Prehospital
Emergency Physician for Chest Wall Pain. The chest wall pain represents a prehospital diagnostic challenge with a low proportion of 27% of correct suspected diagnoses by the prehospital emergency physician. This was already discovered in numerous other studies [7,8]. Our findings showed that in 92% of the cases of chest wall pain the prehospital suspected diagnoses by the prehospital emergency physician were considered as an acute coronary syndrome and were accordingly mistreated with drugs (Heparin, acetylsalicylic acid). "Most patients with "pectanginal" symptoms do not suffer from a life-threatening heart disease" [9]. In a study with 1212 "chest pain patients", who visited a GP practice, only 3.6% had an acute coronary syndrome [10]. Obviously the prehospital chest pain needs more attention being a prehospital differential diagnostic challenge. A more accurate medical history and physical examination should improve the correctness of the suspected diagnosis. Table 3 is reproduced from McConaghy et al. (2013) [under the Creative Commons Attribution License/https://www.aafp.org/ afp/2013/0201/p177.html]. It shows a possible differential diagnostic procedure for chest pain patients that was created after evaluation of 13 other studies [5,6,8,[11][12][13][14].

Lack of Correct Diagnoses for Main Symptom "Dyspnea".
Pneumonia with 32% and cardiac decompensation with 53% showed a low proportion of correct suspected diagnoses by the prehospital emergency physician. Furthermore a high proportion of diseases from the cardiopulmonary area with common main symptom "dyspnea" was noticed during the evaluation of the prehospital mission-related hospital discharge diagnoses. So the main symptom "dyspnea" presents a prehospital diagnostic challenge because of its diverse causes. This was already determined in other studies [10,15].

Limitations.
There is a certain degree of subjectivity in the determination of dA in this study as well as in other studies, since the choice of different methods may lead to deviations in the results. Since there are differences in the EMS system over the whole country, the described EMS location is not sufficiently representative. A geographically varying distribution of the diagnoses is conceivable. Transferring the results to other EMS locations and regions is therefore difficult.

Conclusion
(i) Special attention in the prehospital mission and during the education of prehospital emergency physicians should be paid to chest pain patients due to the accumulation of misdiagnosis, as 92% of incorrectly diagnosed patients with chest wall pain were overestimated and mistreated as cases with acute coronary syndrome. Emergency Medicine International 5 Acute thoracic aortic dissection Acute chest or back pain and a pulse differential in the upper extremities 5.3 NA Note: The higher the LR is above 1, the better it rules in disease (greater than 10 is considered good). Conversely, the lower the LR is below 1, the better it rules out disease (less than 0.1 is considered good). LR+ = positive likelihood ration; LR-= negative likelihood ratio; NA = not available. Information is from references [5] through [6].   (ii) Special attention in the prehospital mission and during the education of prehospital emergency physicians should be paid as well on cardiopulmonary diseases with the common main symptom "dyspnea" as a diagnostic challenge.

Data Availability
The datasets used and/or analysed during the current study are available from the corresponding author upon reasonable request.