Imperial College London


Faculty of MedicineSchool of Public Health

Professor of Epidemiology and Public Health



p.aylin Website




Reynolds BuildingCharing Cross Campus





I use routinely collected clinical and administrative data to examine variations in quality and safety in healthcare. My research has increased the use of data in the management and monitoring of healthcare in the UK and internationally. My work has led to the development of innovative statistical and computational methods for processing large data sets derived from electronic medical records and NHS databases. In my work examining paediatric cardiac surgical outcomes for the Bristol Royal Infirmary Inquiry, I confirmed serious concerns around the surgical outcomes at Bristol and established the usefulness of routine administrative data (Hospital Episode Statistics) in helping to identify quality of care issues.  In further research commissioned by the Shipman Inquiry and published in 2003, I established the role that statistical process control charts (specifically log likelihood CUSUM charts), and other routinely collected data (from death certificates) could play in the continuous surveillance of healthcare outcomes, and in this specific case, the detection of unusual patterns of patient mortality within General Practices.  

I have demonstrated comparable (or better) coverage and completeness of routinely collected administrative data compared to clinical audit data. I have also demonstrated the strength of risk prediction models based on hospital administrative data compared to clinical data. I have developed indicators of healthcare performance based on hospital mortality patient safety indicators,and more recently stroke care and returns to theatre. I have also led the development of a national surveillance tool, the Real-Time Monitoring System (RTM as it is known), designed to monitor hospital outcomes across a range of diagnosis and procedure groups in near real time with data updated monthly.

More recent research carried out by the unit since 2007 has refined this system, setting thresholds based on false alarm rates within CUSUM charts for multiple institutions, the automation of multiple risk adjustment models, the incorporation of hierarchical modelling techniques, the refinement of co-morbidity indices and the development of new indicators with potentially greater sensitivity than mortality. Other work on out of hours healthcare outcomes, most recently my work on elective procedures and mortality by day of the week have resulted in policy changes towards increasing clinical cover at weekends within the NHS.


Future research

I want to seek out robust quantitative evidence of whether or not our research has led to measurable improvements in healthcare. This will involve evaluations using mixed methods to correlate information use and outcomes (New NIHR HSDR mortality alerts grant will assist in this).

I have a number of research projects planned which include expanding our available datasets to include cancer, hospital prescribing, primary care and private healthcare.

I intend to develop further metrics such as potentially avoidable complications and composite measures around adverse incident free care.

To expand my international work in collaboration with other members of the Global Comparators network and through work on our recently acquired US Medicare inpatient data set.

Patient Safety

I lead a 5 year NIHR funded research theme on “Information Use” from within the Imperial College Centre For Translational Research Into Patient Safety. The research questions I will be answering will be as follows:

- Find out what information clinicians want and need to deliver quality and safety improvement

- Identify which methods for delivering performance feedback lead to improvement

- Develop statistical methods for comparing units’ performance across the patient pathway

- Identify, implement and evaluate methods of improving the electronic recording and identification of patient safety events in primary care

- Identify core metrics essential for patient safety monitoring in primary careFor three patient groups (colorectal cancer surgery, stroke, and a chronic condition treated primarily in primary care e.g. diabetes) identify those parts of the patient pathway with greatest potential for quality and safety improvements

- Map patient information flow from primary to secondary care and back to identify common problems that impact on safety and quality of care Incorporate lessons learned into the practice of non-high performing organisations.

- Share best practice about improving safety in primary care and across pathways with clinical commissioning groups  and work with them on implementation

- Evaluate impact of innovations around displaying and acting upon information

Healthcare Associated Infection

I am also a theme lead in the National Institutes of Health Research (NIHR) Health Protection Research Unit (HPRU) in Healthcare Associated Infection (HCAI) and Antimicrobial Resistance (AMR).  Together with Public Health England colleague Alan Johnson I lead the "Applied data linkage, syndromic surveillance and modelling" theme.

The HPRU, which was established on 01 April 2014, is a partnership between Imperial College London, Public Health England, Cambridge University Veterinary School, the Wellcome Trust Sanger Institute and Imperial College Health Partners North West London Academic Health Science Network. The Unit was funded along with 12 others, in priority areas from immunisation to radiation hazards, to bring Universities to work in partnership with Public Health England to support excellent health protection research relevant to the needs of Public Health England.


Alan Johnson, Public Health England, Healthcare Associated Infections and Anti-Microbial Resistance, 2014

Professor Cor J. Kalkman, UMC Utrecht, Health Service Research, 2011

Guest Lectures

From big to bigger: The potential for “big data” to improve patient care, The American Nursing Informatics Association, Kentucky, 2020

Personalised Medicine: The potential for “big data” to improve patient care, Princess Alexandra Hospital Health Symposium 2017, Brisbane, Australia, 2017

Trial and tribulations of working with different international data sets, Global Comparators, Los Angeles, USA, 2016

Leveraging Comparative data to improve quality and efficiency, Keck Medicine of USC – Beverly Hills, Los Angeles, 2016

The 'weekend effect': What is the evidence?, British Medical Association Annual Meeting, Belfast, 2016

Casemix adjustment for healthcare comparisons, 2015 Summit on China Hospital Development, Shanghai, China, 2015

Dying for the weekend - John Snow Lecture, ASSOCIATION OF ANAESTHETISTS OF GREAT BRITAIN & IRELAND, Harrogate, 2014

Mortality update: what can mortality indicators and outliers tell us?Quality Accounts: Implementing the Recommendations from the Francis Inquiry, Healthcare Events Conferences, ICO Conference Centre, London, 2013

Identifying outliers from the dataData Quality and Clinical Coding for Improvement, Healthcare Events, Manchester Conference Centre, 2013

Comparing Hospital Performance, Australian Commission on Safety and Quality in Health CareSAX Institute (health services research)Clinical Excellence Commission, Australian Commission on Safety and Quality in Health Care, Sydney, Australia, 2012

Mortality reporting, National Health Performance Authority, National Health Performance Authority, Canberra, Australia, 2012

Monitoring clinical outcomes with administrative data, Health Informatics Society of Australia in Melbourne, Melbourne, 2012

Application of standardised outcome measures in sustainable patient safety improvement, IHI/BMJ Patient Safety Forum, Amsterdam, Netherlands, 2011

How Much Does Consumer Information Matter?, Cambodia Development Resource Institute Oxford Policy InstituteUK Department for Overseas Development, Phnom Penh, Cambodia, 2010

Measuring the Quality of Hospital Care, National Health Research Institute, Convention Center, National Yang-Ming UniversityTaipei, Taiwan, 2009

Health care data for public reporting, MONASH University, MONASH University, Melbourne, 2008

Performance Monitoring, University of Mauritius, International Conference on Primary Health CareUniversity of Mauritius, 2007

Better Monitoring, The Royal Society of Medicine, 2006

Use of Predictive Risk Tools in the Management of Long-Term Conditions and Commissioning, Tanaka Business School, 2006

Monitoring Healthcare, Royal Statistical Society, 2005

La Encuesta Bristol y el Seguimiento de Resultados, Fondo Nacional de Recursos, Fondo Nacional de Recursos, Montevideo, Uruguay., 2005