Risk-adjusted sequential probability ratio tests: applications to Bristol, Shipman and adult cardiac surgery

• Published in: International journal for quality in health care Vol. 15; no. 1; pp. 7 - 13
• Main Authors: SPIEGELHALTER, DAVID, GRIGG, OLIVIA, KINSMAN, ROBIN, TREASURE, TOM
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.02.2003; OXFORD UNIVERSITY PRESS; Oxford Publishing Limited (England)
• Subjects: Adult; adverse clinical outcomes; Aged; Cardiovascular Surgical Procedures - mortality; Female; general practitioners; Health Services Research; Hospital Mortality; Hospitals, Public - standards; Humans; Iatrogenic Disease; Infant; Male; Medical Audit - methods; Medical Audit - statistics & numerical data; Medical Staff, Hospital - standards; monitoring; mortality; Organizational Culture; paediatric and adult cardiac surgery; Probability; Risk Adjustment; Sentinel Surveillance; sequential probability ratio tests; Treatment Outcome; United Kingdom - epidemiology
• ISSN: 1353-4505; 1464-3677
• DOI: 10.1093/intqhc/15.1.7

Objective. To investigate the use of the risk-adjusted sequential probability ratio test in monitoring the cumulative occurrence of adverse clinical outcomes. Design. Retrospective analysis of three longitudinal datasets. Subjects. Patients aged 65 years and over under the care of Harold Shipman between 1979 and 1997, patients under 1 year of age undergoing paediatric heart surgery in Bristol Royal Infirmary between 1984 and 1995, adult patients receiving cardiac surgery from a team of cardiac surgeons in London, UK. Main outcome measure. Annual and 30-day mortality rates. Results. Using reasonable boundaries, the procedure could have indicated an ‘alarm’ in Bristol after publication of the 1991 Cardiac Surgical Register, and in 1985 or 1997 for Harold Shipman depending on the data source and the comparator. The cardiac surgeons showed no significant deviation from expected performance. Conclusions. The risk-adjusted sequential probability test is simple to implement, can be applied in a variety of contexts, and might have been useful to detect specific instances of past divergent performance. The use of this and related techniques deserves further attention in the context of prospectively monitoring adverse clinical outcomes.