Predicting red blood cell transfusion in hospitalized patients: role of hemoglobin level, comorbidities, and illness severity

Table 1 Patient characteristics

Patient Characteristics	Transfused	Not transfused
No. patients/ no. hospitalizations	32,493 / 61,988	243,381 / 382,981
% male	43.7	45.8
Age¹	69.1 (15.3)	63.7 (17.8)
% ≥ 65 years	65.4	51.3
LAPS2^1,2	69.3 (44.1)	54.2 (38.2)
COPS2^1,3	49.7 (45.1)	34.7 (37.5)
Charlson score (median, IQR)	2, 1 - 3	1, 0 – 2
Admission Hemoglobin^1,4	9.9 (2.4)	12.9 (1.9)
% with these Primary Conditions⁵
Gastrointestinal bleeding	11.5	1.4
Orthopedic surgery	10.9	4.6
Malignancy	9.5	5.7
Infection	11.8	13.1
Cardiovascular	6.2	11.5
Other Medical	33.6	43.7
Other Surgical	16.5	20.0
% not “full code” at time of admission	15.8	13.5
Hospital Length of Stay¹	8.0 (12.2)	4.6 (4.3)
Mortality rate (%)
In-hospital	6.1	2.5
30-day	8.7	4.6

Footnotes
¹Mean (Standard Deviation).
²Laboratory Acute Physiology Score, version 2 (LAPS2); physiology-based score which includes vital signs, neurological status, and laboratory results.¹⁹ Increasing degrees of physiologic derangement and mortality are reflected in a higher LAPS2, which is a continuous variable that with a range between zero and 282 in this cohort.
³Comorbidity Point Score, version 2 (COPS2); a longitudinal, diagnosis-based score assigned monthly that employs all diagnoses incurred by a patient in the preceding 12 months.¹⁹ Increasing values of COPS2 are associated with increasing mortality with a range between zero and 306 in this cohort.
⁴Admission hemoglobin was available in 410,126 of 444,982 hospitalizations (92.0%).
⁵Primary Conditions are groupings of related International Classification of Disease codes assigned at the time of admission to the hospital. These codes are further grouped based on the schema used by the Agency for Healthcare Research and Quality’s Healthcare Cost & Utilization Project. See Additional file 1 for additional details.

ISSN: 1472-6963