Mechanical Ventilation Increases Costs and Mortality in IPF

Despite recommendations against using mechanical ventilation (MV) in patients with idiopathic pulmonary fibrosis (IFP), MV continues to be used in hospitalized patients. The findings of the retrospective 3-year study were published in BMC Pulmonary Medicine.

Joshua J. Mooney, MD, MS, from Stanford University, California, and colleagues sought to examine the effects of MV on outcomes and cost in patients with IPF. Drawn from the Nationwide Inpatient Sample from 2009 to 2011, data on the use of MV in patients hospitalized with IPF and other respiratory diseases was based on the International Classification of Diseases, 9th Revision, Clinical Modification codes.

The study sample included 42,924 adult patients with IPF, 23,739 of whom had a respiratory disease on admission; 19,185 of the patients with IPF were admitted for non-respiratory complaints. Excluding the 1379 patients admitted for lung transplants and 10 for omitted birthdates, the resulting study sample was 22,350 patients.

 

During the first year of the study (2009) 12.1% of patients had received MV, decreasing to 11.5% in 2010 and 10.7% in 2011 (P =.578). Researchers also tracked non-invasive ventilation use: 7.9% in 2009, 8.3% in 2010, and 10.3% in 2011 (P =.112).

Overall, the use of MV resulted in longer hospital stays, higher costs, and greater mortality. MV length of stay was 16.1 days (95% CI, 15-17.5) vs 6.3 days (95% CI, 6-6.5) for nonusers. Adjusted costs for MV were $48,772 (95% CI, $43,979-$53,565) vs $11,861 (95% CI, $11,292-$12,431) for nonusers. Hospital mortality rates for MV use compared with no MV use were 55.7% (95% CI, 50.3- 61.0) and 7.5% (95% CI, 6.6-8.4), respectively. Likewise, noninvasive ventilation increased hospital stays, costs, and death rates.

Although the study did not capture the severity of the IPF admissions, it did delineate drivers of MV use. Patients were less likely to have received MV if they were younger (odds ratio [OR]: 0.97; 95% CI, 0.97-0.98), women (OR: 0.68; 95% CI, 0.55-0.85), Hispanic (OR: 66; 95% CI, 0.45-0.97), and had a primary diagnosis of IPF (OR: 0.60; 95% CI, 0.48-0.76).

Factors associated with increased MV use include patients with cardiovascular diseases (OR: 1.34; 95% CI, 1.08-1.65; P =.007), bacterial pneumonia (OR: 1.55; 95% CI, 1.27-1.90; P <.001), and admission to a teaching hospital (OR: 1.58; 95% CI, 1.26-1.98; P <.001). When excluding MV as a predictor for in-hospital mortality rates, female sex was associated with lower risk of death (OR: 0.62; 95% CI, 0.52-0.74; P <.001).

Predictors of higher mortality rates included a primary diagnosis of IPF (OR: 1.26; 95% CI, 1.03-1.55; P =.026), teaching hospital admission (OR: 1.37; 95% CI, 1.11-1.69; P =.003), cardiovascular diseases (OR: 1.26; 95% CI, 1.04-1.51; P =.017), and bacterial pneumonia (OR: 1.42; 95% CI, 1.18-1.71; P <.001).

“While recently approved pharmacologic therapies slow disease progression and may reduce acute exacerbations, the course of IPF remains unpredictable,” observed the researchers. “Therefore, early patient-centered discussions on treatment expectations, appropriate referrals for transplant and/or palliative care, and coordination of care across providers, remain integral to honoring patients’ values while ensuring high value care. IPF-specific decision aids are needed to help guide patients.”

Study Limitations

• The Nationwide Inpatient Sample data do not allow researchers to follow patients through to outpatient care, discharge to other facilities, or subsequent hospitalizations.
• The study used ICD-9-CM codes, rather than clinical diagnoses, to identify patients with IPF. Therefore, the study did not capture disease severity or the reasons for hospital admission.
• Likewise, the researchers were not able to account for comorbid conditions such as obesity or gastroesophageal reflux.
• Patients with transplant-related costs were excluded from the study, which may underestimate the entire cost of caring for patients with IPF.

Disclosures

The researchers received funding from Genentech, Inc.