Results
Our data captured 37,344,532 patients between the ages of 16 and 24 who were hospitalized between 2003 and 2017. Patients with SCD accounted for 1.2% (446,503) of total hospitalizations over the 15-year period (Supplemental Table 1). A temporal look at hospitalizations revealed an upward trend in the annual percentage of sickle cell admissions (Figure 1). Further analysis found a statistically significant Average Annual Percent Change (AAPC) of +3.2% (Figure 1 and Supplemental Table 1).
The socio-demographic characteristics of patients with SCD in comparison to those without SCD are displayed in Table 1. During the study period, an increase in hospitalizations was noted with increasing age in both patient groups. In SCD, 22-24-year-olds accounted for 42.9% of total hospitalizations, whereas 16-18-year-olds only accounted for 22.9% (Table 1). When classified by gender, the distribution of non-SCD hospitalizations was comprised of majority female patients. On the other hand, female patients accounted for only 54.9% of SCD hospitalizations. The vast majority of patients with SCD were Non-Hispanic (NH) Black, with 81.5% of all patients with SCD identifying as such.
Among discharge outcomes, 92% of sickle cell admissions resulted in routine discharge, 2.1% were transferred, and 0.2% resulted in death; trends were similar in the non-SCD admissions (Table 1). Interestingly, patients with SCD were discharged from the hospital against medical advice (DAMA) 3.7% of time, whereas DAMA only accounted for 1.2% of non-SCD discharge status (Table 1).
Regarding zip code income, nearly half (48.5%) of all hospitalized patients with SCD fell into the lowest quartile. Patients with SCD were also more likely to use public insurance than private insurance, with 70.4% of all patients with SCD using either Medicaid or Medicare (Table 1).
Figure 2 depicts the temporal trend of in-hospital mortality rates for patients with SCD. While crude rates exhibited considerable variation year-by-year, further examination using joinpoint regression analysis revealed an AAPC of -0.7%, however this did not achieve statistical significance.
Table 2 further expounds upon potential associations between socio-demographic characteristics and in-hospital mortality rates of transition-aged patients both with and without SCD. The most prominent finding was an association between increasing age and increased in-hospital mortality in patients with SCD. When using the 16-18-year-old subgroup as a reference, analysis showed an odds ratio (OR) of 2.09 for the 19-21-year-old subgroup (p < 0.0001) and 2.71 for the 22-24-year-old subgroup (p < 0.0001). In contrast, this trend was not exhibited in the non-SCD group, with odd ratios of approximately 1 for each of the aforementioned subgroups (Table 2). In patients with SCD, no statistically significant difference in mortality was noted in respect to race (reference group = NH-Black, Table 2). Female patients had a lower likelihood of mortality both in non-SCD and SCD groups, with an OR of 0.20 and 0.57 respectively (each p < 0.0001, Table 2).
Within the SCD group, there were no observed significant differences in mortality between income quartile (Table 2). Among primary payer types, patients with SCD with private insurance were 1.39 times as likely to suffer in-hospital mortality (p = 0.05), and those with self-pay were 1.53 times as likely (p= 0.04) in comparison to those with Medicaid (Table 2).