Development and Validation of a New Risk Score for Infection with Coronavirus (Ri.S.I.Co) Obtained from Treating Coronavirus Disease (COVID-19) Patients on the Field

IRCMJ logo


Early Diagnosis
Mass Casualty Incidents

How to Cite

FugazzolaP., Favi F., Tomasoni M., Zaghi C., Casadei C., Prosperi E., Sermonesi G., Corbella D., Coccolini F., Pratico’ B., Agnoletti V., & Ansaloni L. (2020). Development and Validation of a New Risk Score for Infection with Coronavirus (Ri.S.I.Co) Obtained from Treating Coronavirus Disease (COVID-19) Patients on the Field. Iranian Red Crescent Medical Journal, 22(7). Retrieved from


Background: The Coronavirus Disease 2019 (COVID-19) pandemic has necessitated the alteration of the organization of entire hos- pitals to try to prevent them from becoming epidemiological clusters. The adopted diagnostic tools lack sensitivity or specificity. Objectives: The aim of the study was to create an easy-to-get risk score (Ri.S.I.Co., risk score for infection with the new coronavirus) developed on the field to stratify patients admitted to hospitals according to their risk of COVID-19 infection.

Methods: In this prospective study, we included all patients who were consecutively admitted to the suspected COVID-19 depart- ment of the Bufalini Hospital, Cesena (Italy). All clinical, radiological, and laboratory predictors were included in the multivariate logistic regression model to create a risk model. A simplified model was internally and externally validated, and two score thresh- olds for stratifying the probability of COVID-19 infection were introduced.

Results: From 11th March to 5th April 2020, 200 patients were consecutively admitted. A Ri.S.I.Co lower than 2 showed a higher sensitivity than SARS-Cov-2 nucleic acid detection (96.2% vs. 65.4%; P < 0.001). The presence of ground-glass pattern on the lung-CT scan had a lower sensitivity than a Ri.S.I.Co lower than 2 (88.5% vs. 96.2%; P < 0.001) and a lower specificity than a Ri.S.I.Co higher than 6 (75.0% vs. 96.9%; P < 0.001).

Conclusions: We believe that the Ri.S.I.Co could allow to stratify admitted patients according to their risk, preventing hospitals from becoming the main COVID-19 carriers themselves. Furthermore, it could guide clinicians in starting therapies early in severe- onset cases with a high probability of COVID-19, before molecular SARS-CoV-2 infection is confirmed.



  1. Ren L, Wang Y, Wu Z, Xiang Z, Guo L, Xu T, et al. Identification of a novel coronavirus causing severe pneumonia in human: a descriptive study. Chin Med J. 2020.
  2. Coronaviridae Study Group of the International Committee on Taxonomy of Viruses. The species Severe acute respiratory syndrome-related coronavirus: classifying 2019-nCoV and naming it SARS-CoV-2. Nat Microbiol. 2020;5(4):536-44. doi: 10.1038/s41564-020-0695-z. [PubMed: 32123347]. [PubMed Central: PMC7095448].
  3. World Health Organization. Novel Coronavirus - China. 2020. Available from:
  4. Nacoti M, Ciocca A, Giupponi A, Brambillasca P, Lussana F, Pisano M, et al. At the epicenter of the Covid-19 pandemic and humanitarian crises in Italy: changing perspectives on preparation and mitigation. NEJM Catalyst Innovations in Care Delivery. 2020;1(2).
  5. Moons KG, Altman DG, Reitsma JB, Ioannidis JP, Macaskill P, Steyerberg EW, et al. Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis (TRIPOD): explanation and elaboration. Ann Intern Med. 2015;162(1):W1-73. doi: 10.7326/M14-0698. [PubMed: 25560730].
  6. World Health Organization. Laboratory testing for 2019 novel coronavirus (2019-nCoV) in suspected human cases. WHO - Interim Guid; 2020.
  7. World Health Organization. WHO Director-General's opening remarks at the media briefing on COVID-19. 2020.
  8. Catena F, Biffl W, De Simone B, Sartelli M, Di Saverio S, Kluger Y, et al. Emergency general surgeons: the special forces of general surgery (the “navy seals paradigm”). World Journal of Emergency Surgery. 2020;15(1). doi: 10.1186/s13017-020-0293-7.
  9. Andersson M, Andersson RE. The appendicitis inflammatory response score: a tool for the diagnosis of acute appendicitis that outperforms the Alvarado score. World J Surg. 2008;32(8):1843-9. doi: 10.1007/s00268-008-9649-y. [PubMed: 18553045].
  10. British Society of Thoracic Imaging. Thoracic Imaging in COVID-19 Infection. 2020.
  11. ACR. ACR Recommendations for the use of Chest Radiography and Computed Tomography (CT) for Suspected COVID-19 Infection. 2020.
  12. Xu X, Wu X, Jiang X, Xu K, Ying L, Ma C, et al. Clinical findings in a group of patients infected with the 2019 novel coronavirus (SARS-Cov-2) outside of Wuhan, China: retrospective case series. BMJ. 2020;368.
  13. Ai T, Yang Z, Hou H, Zhan C, Chen C, Lv W, et al. Correlation of Chest CT and RT-PCR Testing for Coronavirus Disease 2019 (COVID-19) in China: A Report of 1014 Cases. Radiology. 2020;296(2):E32-40. doi: 10.1148/radiol.2020200642. [PubMed: 32101510]. [PubMed Central: PMC7233399].
  14. Song C, Xu J, He J, Lu Y. COVID-19 early warning score: a multi-parameter screening tool to identify