Hospital cost and length of stay in idiopathic pulmonary fibrosis

Abstract

Objective: To provide a detailed picture of the economic impact of hospitalization in idiopathic pulmonary fibrosis (IPF) and to identify factors associated with cost and length of stay (LOS).

Methods: In this retrospective cross-sectional study using the Nationwide Inpatient Sample (NIS), this study included hospitalizations for IPF (ICD-9-CM 516.3) with a principal diagnosis of respiratory disease (ICD-9-CM 460-519) from 2009–2011; lung transplant admissions were excluded. Total inpatient cost, LOS, in-hospital death, and discharge disposition were reported. Linear regression models were used to determine variables predictive of LOS and cost.

Results: From 2009–2011, 22,350 non-transplant IPF patients with a principal diagnosis of respiratory disease were admitted: mean (±SE) age was 70.0 (0.32), and 49.1% were female. While in hospital, 11.4% of patients received mechanical ventilation and 8.9% received non-invasive ventilation. Mean (±SE) LOS was 7.4 (0.15) days overall (p < .001). The mean (±SD) admission cost was $16,042 (±631). Of hospitalized patients, 14.1% died, 20.6% transferred facilities, and 46.4% were routinely discharged. The adjusted LOS (95% CI) for patients with and without mechanical ventilation was 16.1 days (15–17.5) vs. 6.3 (6–6.5); adjusted costs were $48,772 (43,979–53,565) vs. $11,861 (11,292–12,431).

Limitations: The positive predictive value of the algorithm used to identify IPF is not optimal. The NIS database does not follow patients longitudinally, and claims after admission are not available. Claims do not indicate whether listed diagnoses were present on admission or developed during hospitalization. The exclusion of transplant-related expenditures lead to under-estimation of cost.

Conclusion: Using a nationally-representative database, we found IPF respiratory-related hospitalizations represent a significant economic burden with ∼7,000 non-transplant IPF admissions per year, at a mean cost of $16,000 per admission. Mechanical ventilation is associated with statistically significant increases in LOS and cost. Therapeutic advances that reduce rates and costs of IPF hospitalizations are needed.

Keywords:

• Healthcare outcomes
• cost of care
• respiratory disease
• length of stay
• insurance claims analysis
• hospital database
• mortality
• mechanical ventilation

Transparency

Declaration of funding

This research was funded by Genentech, Inc.

Author contributions: All authors meet the ICMJE criteria for authorship. All authors were equally involved in the design of the study. EC conducted the statistical analyses and all authors contributed equally in the interpretation of results and writing of the manuscript.

Declaration of financial/other interests

K. Raimundo is an employee of Genentech, Inc. E. Chang and M. Broder are employees of Partnership for Health Analytic Research, LLC, a health services research company paid by Genentech to conduct this research.

Previous presentations: This manuscript and associated findings have not been previously presented.

Declaration of financial/other relationships

JM has received reimbursement for clinical trial meeting related expenses from Genentech and Boehringer Ingelheim Pharmaceuticals. KR is an employee of Genentech, Inc. and has stock ownership in Roche Pharmaceuticals Corporation. EC and MB are employees of Partnership for Health Analytic Research, LLC, a health services research company paid by Genentech to conduct this research. JME peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Acknowledgements

No assistance in the preparation of this article is to be declared.