CAOS

COPD and Asthma Outcome Study (CAOS)

Status: Published 

What was this study about? 

Chronic obstructive pulmonary disease (COPD) is the name for a collection of lung diseases, primary caused by smoking. When people with COPD experience a severe worsening of their disease, clinicians often have to decide whether a patient is likely to benefit from admission to a critical care unit, or whether admission would be futile.

The aim of this study was to develop and validate a statistical model to provide important prognostic information to guide patients, relatives and clinicians for admissions to critical care units with COPD and asthma. 

All patients aged 45 and above admitted to critical care with COPD or asthma were recruited and characterised.  Patients were then followed up to 180-days after critical care admission to determine individual outcomes. 

92 intensive care units and three respiratory high dependency units took part in the study and collected data on 832 patients admitted between March 2002 and September 2003.

What did the study find? 

Almost two thirds of patients were still alive at 180 days after their critical care admission, which was higher than predicted by clinicians.

The study produced a statistical model (the CAOS model) that was better at determining which patients were likely to survive for a further 180 days than clinicians’ estimates. It has the potential to support risk adjustment and clinical decision making about admission to critical care.

Who led the study? 

Dr Martin Wildman, Department of Public Health & Policy, London School of Hygiene & Tropical Medicine 

The study was funded by the Medical Research Council