The NeoSep Severity and Recovery scores to predict mortality in hospitalized neonates and young infants with sepsis derived from the global NeoOBS observational cohort study

Background Sepsis severity scores are used in clinical practice and trials to define risk groups. There are limited data to derive hospital-based sepsis severity scores for neonates and young infants in high-burden low- and middle-income country (LMIC) settings where trials are urgently required. We aimed to create linked sepsis severity and recovery scores applicable to hospitalized neonates and young infants in LMIC which could be used to inform antibiotic trials. Methods & Findings A prospective observational cohort study was conducted across 19 hospitals in 11 countries in sub-Saharan Africa, Asia, Latin America and Europe. Infants aged <60 days with clinical sepsis fulfilling at least two clinical or laboratory criteria (≥1 clinical) were enrolled. Primary outcome was 28-day mortality. Two prediction models were developed for 1) 28-day mortality from factors at sepsis presentation (baseline NeoSep Severity Score), and 2) daily risk of death on IV antibiotics from daily updated assessments (NeoSep Recovery Score). Multivariable Cox regression models included a randomly selected 85% of infants, with 15% for validation. 3204 infants were enrolled between 2018-2020. Median age was 5 days (IQR 2-15), 90.4% (n=2,895) were <28 days. Median birth weight was 2500g (1400-3000g), and a median of 4 clinical (IQR 2-5) and 1 laboratory (0-2) signs were present. Overall mortality was 11.3% (95%CI 10.2-12.5%; n=350). A baseline NeoSep Severity Score from infants characteristics, respiratory support, and clinical signs (no laboratory tests) at presentation had a C-index 0.77 (95%CI: 0.75-0.80) and 0.76 (0.69-0.82) in derivation and validation samples, respectively. Mortality in the validation sample was 1.6% (3/189; 95%CI: 0.5-4.6%), 11.0% (27/245; 7.7-15.6%), and 27.3% (12/44; 16.3-41.8%) in low (score 0-4), medium (5-8) and high (9-16) risk groups, respectively, with similar performance across subgroups. A related NeoSep Recovery Score based on evolving post-baseline clinical signs and supportive care discriminated well between infants who died or survived the following day or subsequent few days. The area under the ROC curve for score on day 2 and death in the following 5 days was 0.82 (95%CI 0.78-0.85) and 0.85 (95%CI 0.78-0.93) in the derivation and validation data, respectively. Conclusion The baseline NeoSep Severity Score predicted 28-day mortality and could identify infants with high risk of mortality for inclusion in hospital-based sepsis trials. The NeoSep Recovery Score predicts day-by-day inpatient mortality and could, with further validation, help to identify poor response to antibiotics. Why was this study done? What did the researchers do and find? What do these findings mean? ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was funded by the Global Antibiotic Research and Development Partnership (GARDP), made possible by Bill & Melinda Gates Foundation; German Federal Ministry of Education and Research; German Federal Ministry of Health; Government of the Principality of Monaco; the Indian Council for Medical Research; Japanese Ministry of Health, Labour and Welfare; Netherlands Ministry of Health, Welfare and Sport; South African Medical Research Council; UK Department of Health and Social Care (UK National Institute of Health Research and the Global Antimicrobial Resistance Innovation Fund GAMRIF); UK Medical research Council; Wellcome Trust. GARDP has also received core funding from the Leo Model Foundation; Luxembourg Ministry of Development Cooperation and Humanitarian Aid; Luxembourg Ministry of Health; Medecins Sans Frontieres; Swiss Federal Office of Public Health; UK Foreign, Commonwealth & Development Office (previously the UK Department for International Development). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethical approval was obtained from St. Georges, University of London (SGUL) Research Ethics Committee and sites local, central or national ethics committees and other relevant local bodies, where required. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Requests for data should be adressed to GARDP