Cohorts for analysis are defined as follows:

1. All patients with a positive blood culture, admitted to hospital or attending the hospital emergency department
2. All patients with a positive bacterial culture, admitted to hospital or attending the hospital emergency department
3. All patients prescribed antibiotics in hospital

The project focuses on targeting antibiotics better for patients so they are more likely to get the antibiotics they need; patients with severe infections who do not receive active antibiotics are at increased risk of dying. Therefore, the project by aiming to give more patients active antibiotics, aims to provide tools that could reduce deaths, reduce the need for intensive care, shorten length of hospital stay and reduce hospital re-admissions. Use of more targeted antibiotics could also help reduce antibiotic side effects and the risk of future antibiotic resistance.

The following data items are included:

• Patient demographics, including month and year of birth, date of death or last known alive, sex, ethnicity, index of multiple deprivation score, weight, height
• Details of emergency department, outpatient and inpatient episodes, including admission and discharge times, ward stays, elective vs emergency admission, specialty, diagnosis and procedure codes (these factors may influence rates of antibiotic resistance, e.g. through previous hospital exposure, or determine the need for future treatments, e.g. to treat a specific condition)
• Laboratory tests including full blood counts, renal function, liver function, C reactive protein, glucose, blood gases, and clotting
• Vital signs including pulse, blood pressure, temperature, respiratory rate, oxygen saturations, supplementary oxygen, Alert-Confusion-Voice-Pain-Unresponsive (ACVPU) and Glasgow Coma Scale (GCS)
• Antibiotic prescriptions including start and end of doses administered and prescribed, drug, dose, route
• Microbiology samples and results (diagnostic and screening samples), including collection date and time, report date and time, sample type with details of samples sent for bacterial culture whether culture positive or not, for culture positive samples the species identified and the results of antimicrobial susceptibility testing