Sources of variability in uncertain medical decisions in the ICU: a process tracing study.
BACKGROUND
Consistency of medical decision making (equity) is an important component of quality of care. When patients with chronic obstructive pulmonary disease (COPD) present with an exacerbation needing respiratory support they may die if it is not provided. However, if the disease has reached its terminal stage, ventilation will prolong the process of dying. The ventilation outcome is uncertain and there is evidence of variability when this decision is made, the sources of which are not well understood.


OBJECTIVE
To identify sources of variability and propose ways of tackling them in order to promote equity in this type of medical decision.


METHODS
Six case histories were selected from hospital records of COPD patients. Fourteen senior doctors from seven hospitals in the West Midlands participated. A process tracing approach was used which consisted of (1) withholding case information until specifically requested by the doctors, (2) estimating survival during the decision making process, and (3) concurrent questioning regarding information interpretation and its impact on survival estimates and decisions.


RESULTS
The observed decision variability was attributed to doctors attaching importance to different information, gathering different information, and interpreting information differently. There were significant differences between doctors in the amount of information requested.


CONCLUSIONS
Differences in information gathering and interpretation by clinicians can result in different decisions being made about the same patient. This variation may exist for other uncertain medical decisions and may be tackled by providing clinicians with prognostic models in the form of usable decision aids.
Department of Primary Care and General Practice, University of Birmingham, Birmingham B15 2TT, UK. o.kostopoulou@bham.ac.uk
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D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D003422:Critical Care / Q000379:methods*; D003657:Decision Making; D004739:England; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007362:Intensive Care Units / Q000592:standards* / Q000706:statistics & numerical data; D008297:Male; D008505:Medical Staff, Hospital / Q000523:psychology / Q000592:standards*; D008511:Medicine / Q000592:standards; D008875:Middle Aged; D017064:Process Assessment, Health Care / Q000379:methods*; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D012121:Respiration, Artificial / Q000706:statistics & numerical data*; D018570:Risk Assessment; D013038:Specialization; D016019:Survival Analysis; D035501:Uncertainty