SwiFT: Swine Flu Triage


The purpose of this study was to use, existing critical care and early pandemic, data to inform care during the pandemic influenza A 2009 (H1N1) pandemic (with a possible use for triage – a system for deciding the order in which patients should be treated depending on the urgency of their need – if the demand for critical care seriously exceeded supply). To monitor the impact of the H1N1 pandemic on critical care services, in real time, with regular feedback to critical care clinicians and other relevant jurisdictions to inform ongoing policy and practice. The aims of the SwiFT study were:

  • to use existing data in the Case Mix Programme database and data collected early during the swine flu (H1N1) pandemic 2009 to guide patient care during the pandemic with a possible use for triage if there was an increased demand for critical care services; and
  • to monitor the impact of the H1N1 pandemic on critical care services with regular feedback to critical care clinicians (doctors and nurses) to inform ongoing policy and practice.


The SwiFT study used a combination of analysing routinely collected data from the Case Mix Programme national clinical audit and a prospective cohort study which collected data on all patients admitted to critical care with confirmed or suspected H1N1.


We analysed data for 105,380 admissions from 148 critical care units included in the Case Mix Programme. This analysis suggested that cancelling or postponing, elective or scheduled surgery would save some capacity in critical care in terms of the number of admissions, number of days spent in critical care and the use of advanced treatments by 10-17%. For the prospective cohort study, we received research approvals from 192 acute hospitals. From these hospitals, a total of 1725 cases (562 confirmed) were reported. Confirmed cases were young, had low severity of illness on admission to critical care, but had long stays in critical care (median 8.5 days) and were likely to be treated using a mechanical ventilator (a device to support breathing).


The SwIFT study suggested there was limited value for triage. Fortunately the H1N1 pandemic did not overwhelm critical care services and the confirmed H1N1 cases in the UK and Republic of Ireland were similar to those reported internationally.

Professor Kathy Rowan, ICNARC

The study was funded by the National Institute for Health Research – Health Technology Assessment (HTA) Programme (Project: 09/86/01)


Noah MA, Peek GJ, Finney SJ, Griffiths MJ, Harrison DA, Grieve R, Sadique MZ, Sekhon JS, McAuley DF, Firmin RK, Harvey C, Cordingley JJ, Price S, Vuylsteke A, Jenkins DP, Noble DW, Bloomfield R, Walsh TS, Perkins GD, Menon D, Taylor BL, Rowan KM. Referral to an extracorporeal membrane oxygenation center and mortality among patients with severe 2009 influenza A(H1N1). JAMA 2011; 306(15):1659-68. http://dx.doi.org/10.1001/jama.2011.1471

Rowan KM, Harrison DA, Walsh TS, McAuley DF, Perkins GD, Taylor BL, Menon DK. The Swine Flu Triage (SwiFT) study: development and ongoing refinement of a triage tool to provide regular information to guide immediate policy and practice for the use of critical care services during the H1N1 swine influenza pandemic. Health Technol Assess 2010; 14(55):335-492. http://dx.doi.org/10.3310/hta14550-05

Fowler RA, Webb SA, Rowan KM, Sprung CL, Thompson BT, Randolph AG, Jouvet P, Lapinsky S, Rubinson L, Rello J, Cobb JP, Rice TW, Uyeki T, Marshall JC. Early observational research and registries during the 2009-2010 influenza A pandemic. Crit Care Med 2010; 38(4 Suppl):e120-32. http://dx.doi.org/10.1097/CCM.0b013e3181d20c77