Clinical and Economic Burden of Paroxysmal Nocturnal Hemoglobinuria (PNH) in Hospitalized Patients: An Analysis of the 2021 NIS Database
Authors: Rajarajan Srinishant , Babu Kalaivani , Jayakumar Jayalekshmi , Ramesh Nithya , Ramanan Sruthi P , Chattaraj Asmi , Khan Eiraj , Dhamija Kriti , Bhanushali Charmi , Kasire Sripada Preetham , Correa Amit , Roy Arya Mariam , Ayanambakkam Attanathi Adanma Anji , Nusrat Sanober 
Published: December 2024

Background:
Paroxysmal Nocturnal Hemoglobinuria (PNH) is a rare and life-threatening hematologic condition characterized by the destruction of red blood cells, an increased risk of thrombosis, and significant complications such as bone marrow failure. While recent advancements in therapies, particularly complement inhibitors, have improved patient outcomes, PNH remains a major clinical and economic challenge. This study aims to provide an updated analysis of hospital outcomes and the financial burden associated with PNH hospitalizations in the United States, utilizing data from the National Inpatient Sample (NIS) 2021 database.
Methods:
This retrospective cohort study used the NIS 2021 database to identify patients diagnosed with PNH (ICD-10 code D59.5). Data analysis was performed using STATA software. The primary outcomes measured were in-hospital mortality and the length of hospital stay (LOS). The secondary outcome was total hospitalization charges. Descriptive statistics were employed to calculate the overall mortality rate, mean LOS, and mean total charges. Logistic and linear regression analyses were conducted to adjust for potential confounders, including age, gender, race, income quartile, Charlson comorbidity index, hospital location, hospital region, teaching status, and hospital bed size.
Results:
The study identified 764 patients admitted with a principal diagnosis of PNH in 2021. The demographic analysis revealed that the majority of PNH patients were male (58.82%) and middle-aged, with a mean age of 54.41 years. Racial distribution showed that most patients were White (51.33%), followed by Black (21.33%), Hispanic (18.67%), Asian (5.33%), Native American (0.67%), and other races (2.67%). The Charlson Comorbidity Index (CCI) showed significant variation, with 35.29% of patients having no comorbidities, 20.26% having one comorbidity, 17.65% having two comorbidities, and 26.80% having three or more comorbidities.
Income distribution among the patients was as follows: 28.38% in the lowest income quartile, 20.95% in the second quartile, 22.97% in the third quartile, and 27.70% in the highest quartile. The majority of patients had Medicare insurance (47.65%), followed by private insurance (30.20%), Medicaid (17.45%), and self-pay (4.70%). The analysis of hospital characteristics indicated that most patients were admitted to large hospitals (58.17%), with smaller proportions in medium-sized (19.61%) and small hospitals (22.22%). A significant majority of patients were treated in teaching hospitals (84.31%), and predominantly in urban settings (95.42%), compared to rural hospitals (4.58%). Regional distribution of hospitals was 15.09% in the Northeast, 23.27% in the Midwest, 33.33% in the South, and 28.30% in the West.
The estimated number of deaths among PNH patients was approximately 20, resulting in an in-hospital mortality rate of 2.61% (95% CI: 0.98, 6.76). The logistic regression model indicated that older age (OR: 1.13, p=0.08) was a potential risk factor for mortality. Hospital region significantly affected mortality, with hospitals in the South showing a decreased odds of death (OR: 0.06, p=0.013). The mean LOS for PNH patients was 6.52 days (95% CI: 5.36, 7.94). The mean total hospitalization charges were substantial, averaging $125,569.50 (SE = $16,577.52), with a 95% CI ranging from $93,057.48 to $158,081.50.
Conclusion:
Hospitalizations for PNH in 2021 were associated with substantial clinical and economic burdens. The overall in-hospital mortality rate was 2.61%, with an average hospital stay of approximately 6.5 days. The mean total hospitalization charges were significant, exceeding $125,000 per patient. Despite the rarity of PNH, the variability in patient management and high associated costs highlight the need for targeted strategies to improve care and reduce the economic impact. Further research is necessary to explore the determinants of these outcomes and develop cost-effective treatment interventions that can improve the prognosis for PNH patients and reduce the financial burden on healthcare systems.