## Abstract

Background: Acute myeloid leukemia (AML) is a malignant disorder of the blood with an incidence almost ten times greater among persons 65 years and older than among those younger than 65 years (12.2 vs. 1.3 per 100,000) (

Arch Intern Med
2002
;
162
:
1597
–1603
). Treatment includes conventional cytotoxic chemotherapy [e.g., the “7+3” regimen consisting of cytarabine and daunorubicin or idarubicin (
Leukemia
1996
;
10
:
389
–95
)], which can be associated with serious morbidity and is often not tolerated by older patients. The five-year survival rate for AML is 2% among elderly patients and has not improved appreciably in the past two decades (
Arch Intern Med
2002
;
162
:
1597
–1603
).

Methods: A cross-sectional study was conducted using the Nationwide Inpatient Sample (NIS), a national all-payer inpatient database drawn from 1,000 hospitals, which is part of the Healthcare Cost and Utilization Project (HCUP). Data on AML patients aged 60 years and older from 1998 to 2001 were analyzed for descriptives (demographics and hospital characteristics), comorbidities, outcomes, resource utilization, and charges. Admission mortality, length of stay (LOS), and charges were calculated for AML patients for each year of NIS data from 1993 to 2001 and were weighted using the NIS weighting scheme to adjust for sampling differences across years.

Results: Of all AML admissions from 1998 to 2001 (n=15,327), the mean age was 72.6 years (SD=7.8), and females accounted for 44.6% of admissions. Patients aged 60 to 74 accounted for 61.0% of admissions over these years, whereas patients aged 75 to 84 and 85 and older accounted for only 31.0% and 8.0% of admissions, respectively. Mean LOS per admission was 12.3 days between 1998 and 2001, with a median of 7.0 days. While the majority of these admissions (66.8%) involved discharge to home, patient death occurred in 20.2% of admissions, and the remainder resulted in discharge to other healthcare facilities. Weighted mean admission charges increased overall from 1993 to 2001; mean charges increased steadily from 1993 until 1997 (from $34,222 to$35,781, respectively), at which point they increased at a sharper rate for the remaining years (from $35,781 in 1997 to$47,786 in 2001) (Table 1). Conversely, weighted mean LOS decreased from 14.9 to 12.2 days during the same years, while mortality rates decreased from 23.9% to 20.2%.

Conclusion: Hospitalization charges for elderly AML patients increased overall from 1993 to 2001, with the sharpest increase over the latter four years. This increase in charges occurred in contrast with overall decreases in LOS and mortality.

Table 1: Inpatient Mortality, Length of Stay (LOS) Per Admission, and Charges Per Admission by Year

Year Inpatient Mortality LOS Per Admission (Days) Charges Per Admission ($) Percent Mean SE Mean SE 1993 23.9 14.94 0.48 34,222 1,647 1994 24.7 14.28 0.45 35,243 1,840 1995 22.3 13.48 0.43 34,920 1,996 1996 22.2 13.23 0.46 36,257 1,698 1997 21.9 12.63 0.41 35,781 1,611 1998 19.8 12.55 0.36 37,176 1,452 1999 20.0 12.52 0.34 40,897 2,047 2000 20.4 12.03 0.31 45,759 2,362 2001 20.2 12.23 0.45 47,786 2,875 Year Inpatient Mortality LOS Per Admission (Days) Charges Per Admission ($)
Percent Mean SE Mean SE
1993 23.9 14.94 0.48 34,222 1,647
1994 24.7 14.28 0.45 35,243 1,840
1995 22.3 13.48 0.43 34,920 1,996
1996 22.2 13.23 0.46 36,257 1,698
1997 21.9 12.63 0.41 35,781 1,611
1998 19.8 12.55 0.36 37,176 1,452
1999 20.0 12.52 0.34 40,897 2,047
2000 20.4 12.03 0.31 45,759 2,362
2001 20.2 12.23 0.45 47,786 2,875

## Author notes

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