In-Hospital Outcomes Among Sickle Cell Patients with Acute Chest Syndrome: Results From a National Database.

Acute chest syndrome is the leading cause of death and the second most common cause of hospitalization in patients with sickle cell disease (SCD), yet there are no recent estimates of its associated impact on medical resource use and costs. In this study, we compared inpatient mortality, length of stay (LOS) and total costs among hospital discharges for SCD patients with acute chest syndrome (ACS), SCD patients with crisis, and SCD with neither ACS nor crisis (controls).

Using the 2006 Nationwide Inpatient Sample (NIS) data of the Healthcare Cost and Utilization Project, we developed three groups of discharges with SCD (Clinical Classification Code 61): (1) ACS with or without crisis on the basis of ICD-9-CM codes 517.3 (ACS) or 486 (pneumonia), (2) sickle cell crisis without ACS, using ICD-9-CM codes 282.42, 282.62, 282.64 or 282.69; and (3) SCD patients without a diagnosis of ACS or sickle cell crisis. We excluded cases representing elective admissions, patients discharged to short-term hospitals, born in the hospital, and women giving birth. We used generalized linear regression models to compare LOS (negative binomial distribution, log link) and inpatient costs (gamma distribution, log link) between study groups while controlling for gender, age, payer, 29 comorbidities, and hospital characteristics, including rural vs. urban location, teaching status, bed size, ownership type, and hospital region. We did not perform adjusted comparisons for mortality due to small numbers.

We identified 2,971 discharges with ACS, 13,593 with sickle cell crisis, and 4,040 with neither condition coded. Median age was 25 for ACS, 27 for sickle cell crisis, and 29 for sickle cell ‘controls’. Females represented 50.8% of discharges with ACS, 56.1% of discharges with sickle cell crisis, and 55.8% of sickle cell controls. Inpatient mortality was low across all three groups (Table). After adjustment for patient and hospital characteristics, discharges with ACS incurred hospital stays that were 24% longer (95%CI: 1.20-1.28, P<.0001) than those with crisis and 68% longer (95%CI: 1.62-1.74, P>.0001) than SCD controls. Similarly, inpatient costs among ACS discharges were 45% higher (95%CI: 1.40-1.49) than discharges with sickle cell crisis and 62% higher (95%CI: 1.56-1.68,P<.0001) than for SCD controls. Discharges for patients with sickle cell crisis were 35% longer (95%CI: 1.31-1.39, P<.0001) and 12% more costly (95%CI: 1.09-1.15, P<.0001) than for sickle cell controls.

SCD patients admitted to the hospital with ACS incur significantly higher costs and longer stays than SCD patients with crisis or neither of these conditions.

No relevant conflicts of interest to declare.