A Nationwide Analysis of Temporal Trends and Outcomes in Hospitalized Patients with Predominantly Antibody Deficiency (PAD) Using the National Inpatient Sample (NIS)

Rationale Predominantly antibody deficiency (PAD) is associated with increased susceptibility to infections and chronic complications, yet we lack population-level data on its impact on hospitalization outcomes in the United States. We conducted a nationwide analysis to evaluate healthcare utilization, mortality, and discharge patterns among PAD patients compared with other hospitalized patients. Methods We performed a cross-sectional analysis from 2017 to 2020 using the National Inpatient Sample (NIS), part of the Healthcare Cost and Utilization Project (HCUP) by the Agency for Healthcare Research and Quality. ICD-10 codes were used to identify PAD-associated admissions and assess hospitalization outcomes, including total hospital costs, length of stay, discharge disposition, and in-hospital mortality, as well as temporal trends in these outcomes. Results We identified 36,276 PAD-associated admissions and 27,783,886 non-PAD–associated admissions from 2017 to 2020. Patients with PAD-associated admissions were older (mean age 54.9 vs. 49.9 years), predominantly female (57.2% vs. 55.9%), and predominantly white (81.1% vs. 62.2%). Patients with PAD had hospitalizations that were associated with higher total costs ($33,305 vs. $13,193, p < 0.0001) and longer length of stay (8.8 vs. 4.7 days, p < 0.0001) compared with non-PAD hospitalizations. PAD-associated admissions were less frequently discharged home routinely (59.9% vs. 67.7%, p < 0.0001) and more likely to require home health care (20.6% vs. 13.0%, p < 0.0001) or transfer to other facilities (13.1% vs. 13.7%, p < 0.0001). PAD-associated admissions had significantly higher in-hospital mortality rates (3.8% vs. 2.2%, p < 0.0001). Temporal analysis revealed worsening trends for PAD-associated hospitalizations over time. Total hospital costs increased significantly from $30,224 in 2017 to $40,458 in 2020 (p < 0.0001). The length of stay increased from 8.7 days in 2017 to 9.5 days in 2020 (p = 0.0001). Discharge to home health care became more frequent over time (19.2% in 2017 to 23.3% in 2020), while in-hospital mortality rose from 3.8% in 2017 to 4.5% in 2020 (p = 0.0025). Conclusions Patients with PAD had increased healthcare utilization and worse outcomes, including longer and more costly hospitalizations, and increased in-hospital mortality. These outcomes worsened in 2020, potentially reflecting the impact of COVID-19. Further investigation is warranted to identify underlying drivers and develop targeted strategies to improve outcomes in patients with PAD.