To explain the variation in total real hospital costs among elderly
patients who died between 1984 and 1991, a cohort analytic study of the
nationally representative sample of elderly subjects included in the Longitudinal
Study on Aging (N = 7,527) was carried out. The cohort comprised the subset
of 1,778 community-dwelling Americans who were age 70 years and older in
1984, had one or more subsequent hospital episodes, and died by 1991. Hospital
charges for 1984 through 1991 were taken from the Medicare Automated Data
Retrieval System. Annual hospital charges were adjusted for inflation (restated
in 1984 dollars) using the hospital market basket component of the consumer
price index. The natural logarithm of aggregated real charges was used
in the analysis. Mean total real hospital charges were $24,956 (SD = $27,847).
A standard multivariable regression model explained 9.7% of the variance
in real total hospital charges. After incorporating additional measures
reflecting a respondent's distribution (mean and standard deviation) of
comorbidities (as measured by the number of ICD-9-CM codes [truncated at
five]) during all hospitalizations in the observation window, the cause
of death, and the concentration of charges in the last year of life, the
explained variance increased to 29.3%. The most important explanatory
factors were the two variables controlling for the distribution of comorbidity,
the variable controlling for population density, and the dichotomous variable
indicating that the patient's death was related to an acute myocardial
infarction. Total real hospital resources consumed by elderly decedents
vary substantially. The concentration of resources consumed in the last
year of a respondent's life was only marginally significant in predicting
total real hospital charges over an 8-year observation window.