Use of cumulative mortality data in patients with acute myocardial infarction for early detection of variation in clinical practice: observational study.
OBJECTIVE
Use of cumulative mortality adjusted for case mix in patients with acute myocardial infarction for early detection of variation in clinical practice.


METHODS
Observational study.


METHODS
20 hospitals across the former Yorkshire region.


METHODS
All 2153 consecutive patients with confirmed acute myocardial infarction identified during three months.


METHODS
Variable life-adjusted displays showing cumulative differences between observed and expected mortality of patients; expected mortality calculated from risk model based on admission characteristics of age, heart rate, and systolic blood pressure.


RESULTS
The performance of two individual hospitals over three months was examined as an example. One, the smallest district hospital in the region, had a series of 30 consecutive patients but had five more deaths than predicted. The variable life-adjusted display showed minimal variation from that predicted for the first 15 patients followed by a run of unexpectedly high mortality. The second example was the main tertiary referral centre for the region, which admitted 188 consecutive patients. The display showed a period of apparently poor performance followed by substantial improvement, where the plot rose steadily from a cumulative net lives saved of -4 to 7. These variations in patient outcome are unlikely to have been revealed during conventional audit practice.


CONCLUSIONS
Variable life-adjusted display has been integrated into surgical care as a graphical display of risk-adjusted survival for individual surgeons or centres. In combination with a simple risk model, it may have a role in monitoring performance and outcome in patients with acute myocardial infarction.
Lawrance
R A
RA
BHF Heart Research Centre, Leeds General Infirmary Leeds LS2 9JT.
Dorsch
M F
MF
Sapsford
R J
RJ
Mackintosh
A F
AF
Greenwood
D C
DC
Jackson
B M
BM
Morrell
C
C
Robinson
M B
MB
Hall
A S
AS
D000367:Age Factors; D001794:Blood Pressure; D002985:Clinical Protocols / Q000592:standards*; D003325:Coronary Care Units; D006339:Heart Rate; D006767:Hospitals, District; D006801:Humans; D009203:Myocardial Infarction / Q000401:mortality*; D020379:Risk Adjustment; D018570:Risk Assessment / Q000379:methods*; D015996:Survival Rate; D013599:Systole