Analysis of Antiphospholipid Antibody Syndrome (APLA) Diagnosis and Outcomes in Hospitalized Patients: A Nationwide Study Using the NIS 2021 Database
Authors: Babu Kalaivani , Rajarajan Srinishant , Jayakumar Jayalekshmi , Ramanan Sruthi P , Ramesh Nithya , Chattaraj Asmi , Dhamija Kriti , Khan Eiraj , Correa Amit , Kasire Sripada Preetham , Ayanambakkam Attanathi Adanma Anji , Roy Arya Mariam 
Published: December 2024

Background:
Antiphospholipid Antibody Syndrome (APLA) is an autoimmune disorder characterized by the presence of antiphospholipid antibodies, which can lead to increased risk of thrombosis and pregnancy complications. Accurate identification and understanding of patient demographics, comorbidities, and outcomes are crucial for effective management of APLA. This study aims to identify the prevalence of APLA in hospitalized patients and analyze associated demographic factors, comorbidities, and healthcare outcomes.
Methods:
This retrospective study utilized data from the Nationwide Inpatient Sample (NIS) database for the year 2021. Patients with a diagnosis of APLA were identified using the ICD-10 code D68.61. The study analyzed demographic variables, including age, gender, race, income quartile, and insurance type. Additionally, hospital characteristics such as bed size and teaching status were examined. Multivariate logistic and linear regression models were used to evaluate mortality rates, hospital length of stay (LOS), and total hospitalization charges. Data analysis was performed using Stata software, with adjustments for survey design and weighting to ensure national representativeness.
Results:
The study identified 6,666,752 hospitalized patients, of which 33,544 were diagnosed with APLA. The gender distribution in the APLA population was 74.76% female and 25.24% male, with a mean age of 51.79 years (95% CI: 51.25-52.33). The racial composition was predominantly White (64.01%), followed by Black (17.51%), Hispanic (12.79%), Asian (2.34%), Native American (0.7%), and Other (2.64%). The majority of patients had a Charlson Comorbidity Index (CCI) of 3 or higher (43.85%), indicating significant comorbidities.
In terms of healthcare outcomes, the mean length of hospital stay for APLA patients was 6.82 days (95% CI: 6.55-7.08). The adjusted analysis showed that females had a significantly lower length of stay compared to males (coefficient: -0.75, p=0.007), while patients with higher CCI scores had longer stays (coefficient: 0.59, p&lt;0.001). The overall mortality rate was 2.94%, with an adjusted odds ratio of 1.02 per year increase in age (p&lt;0.001). Additionally, hospital charges were significantly higher in teaching hospitals and larger bed size facilities, with adjusted coefficients of $28,804.19 (p&lt;0.001) and $35,072.72 (p&lt;0.001), respectively.
Conclusion:
This comprehensive analysis provides valuable insights into the demographic characteristics, comorbidities, and healthcare outcomes of patients diagnosed with APLA. The findings highlight the predominance of older female patients and the association of significant comorbidities with this condition. The study underscores the need for specialized care, particularly in teaching and large hospitals, to manage the complex healthcare needs of APLA patients effectively. Further research is warranted to explore the underlying mechanisms and develop targeted interventions to improve patient outcomes.