Present-at-admission diagnoses improve mortality risk adjustment and allow more accurate assessment of the relationship between volume of lung cancer operations and mortality risk.
BACKGROUND
Mortality risk adjustment is a key component of studies that examine the statistical relationship between hospital lung cancer operation volume and in-hospital mortality. Previous studies of this relationship have used different methods of adjusting for factors that influence mortality risk, but none have adjusted for differences in comorbid disease using only diagnoses identified as present-at-admission.


METHODS
This study uses adjustments for conditions identified as present-at-admission to examine the statistical relationship between the volume of lung cancer operations and mortality among 14,456 California hospital patients, and compares these results to other methods of risk adjustment similar to those used in previous studies.


RESULTS
Mortality risk adjustment using present-at-admission diagnoses yielded better discrimination and explained more of the variability in observed deaths. Large increases in hospital procedure volume were associated with much smaller decreases in mortality risk than those estimated using comparable risk-adjustment models.


CONCLUSIONS
Present-at-admission diagnoses can be used to improve mortality risk adjustment and may allow a more accurate assessment of the relationship between procedure volume and mortality risk.
Stukenborg
George J
GJ
Department of Health Evaluation Sciences, University of Virginia, School of Medicine, Charlottesville 22908-0821, USA. gstukenborg@virginia.edu
Kilbridge
Kerry L
KL
Wagner
Douglas P
DP
Harrell
Frank E
FE
Oliver
M Norman
MN
Lyman
Jason A
JA
Einbinder
Jonathan S
JS
Connors
Alfred F
AF
D015897:Comorbidity; D003955:Diagnostic Tests, Routine; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D015995:Prevalence; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate