Acute chest syndrome (ACS) is a dangerous complication of sickle cell disease (SCD), with significant mortality. Two landmark prospective studies in the 1980s and 90s defined much of the etiologic and epidemiologic features of ACS, but much has changed (for the better) in the management of SCD since that time. Can an administrative database study help define current features of ACS?
Source: Takahashi T, Okubo Y, Handa A. Acute chest syndrome among children hospitalized with vaso-occlusive crisis: A nationwide study in the United States. Pediatr Blood Cancer. 2018;65(3): e26885; doi:10.1002/pbc.26885. See AAP Grand Rounds commentary by Dr. Mary-Jane Staba Hogan (subscription required).
Well, the short answer is no, but let's look at the details.
First, the 2 "antique" prospective studies I'm referring to are the Cooperative Study of Sickle Cell Disease (CCSCG) and the National Acute Chest Syndrome Study Group (NACSSG) studies. The CCSCG resulted in a number of publications following children with SCD enrolled over a few years, up to 1981. NACSSG, as the name implies, focused more directly on ACS and remains a highly respected report from that time period. However, in the era of routine antibiotic prophylaxis standards, use of hydroxyurea, and other improvements, we need a fresh look at ACS.
Enter the current study, which analyzed data from the Kids' Inpatient Database (KID), a federally-managed database with reports every 3 years. The key point here, in contrast to CCSCG and NACSSG, is that this is an administrative database: data are limited to diagnosis codes and a small number of demographic features such as age, gender, socioeconomic status, and the like. Missing are all the other important but nuanced clinical features of hospitalized individuals. Still, it's a huge database covering most of the country, so even with those limitations there's a lot of data to mine and learn from.
The key findings of the study showed that from 2003 to 2012, mortality from ACS dropped from 27% to 15%, fairly encouraging. They also found some seasonality, with ACS hospitalizations more common in summer and fall, and also some associated factors with ACS development or complications that included younger age, asthma exacerbation, and obstructive sleep apnea. Much of this isn't strikingly different from prior studies, but it does help to have confirmation from this large database. We'll still need the more labor-intensive and expensive prospective clinical studies to find interventions to decrease rates and complications of ACS.
