Reducing the Decline in Patients’ Forced Vital Capacity Can Lower Mortality Rates and Healthcare Burden in IPF, Study Says

Reducing the decline of forced vital capacity (FVC), a measure of lung function, can improve the quality of life, and lower the mortality rates and financial burden of patients with idiopathic pulmonary fibrosis (IPF), a new study has found.

The study, titled “Forced Vital Capacity (FVC) decline, mortality and healthcare resource utilization in idiopathic pulmonary fibrosis,” was published in the European Clinical Respiratory Journal.

Clinical trials on IPF mainly enroll patients with moderate impairment of lung function, which is normally defined based on FVC, which is the amount of air that can be forcibly exhaled from the lungs after taking the deepest breath possible. In fact, many trials exclude those with a FVC greater than 90% the predicted value, as they have minimally impaired lung function.

Although some studies have shown that patients with either mildly or significantly impaired lung function respond similarly to anti-fibrotic therapy, limited data is available. This has led to restrictions in who can get reimbursed for anti-fibrotic treatment in many countries. In Finland, for instance, the reimbursement threshold for anti-fibrotic treatment is a FVC from 50%–90% predicted.

Furthermore, while IPF is known to be associated with a substantial healthcare burden, information on healthcare resource utilization (HCRU) and mortality in relation to FVC is largely lacking.

Therefore, and given the restrictions on reimbursement, there is significant interest in determining how a decline in FVC is related to mortality and HCRU.

To shed more light on this topic, a group of researchers in Finland conducted a study to assess IPF progression as measured by FVC decline, mortality, and HCRU, using data reflecting real clinical practice in patients with IPF.

Overall, 266 IPF patients (mean age at diagnosis was 74 years) were identified using electronic medical records of the Hospital District of Southwest Finland, from 2005 and 2017.

At baseline, 24% of the identified IPF patients had a FVC higher than 90% predicted, and 63% a FVC between 50%–90% predicted. The mean FVC of all patients at baseline was 77% predicted. Thus, nearly a quarter of this patient cohort had mild disease, and therefore were not eligible for anti-fibrotic treatment reimbursement.

FVC was found to be related to survival rates. The median survival for patients with FVC higher than 90% predicted at baseline was 6.7 years, compared to 0.7 years for patients with FVC lower than 50% predicted.

In fact, every 1% drop in FVC was associated with a 4% increase in mortality, which means that each percent decline in FVC leads to an exponential increase in mortality risk. Of note, at the end of the follow-up period, 42% of the patients analyzed had died.

Furthermore, among patients with FVC higher than 90%, 14 of them died before a change in their FVC category could be noted. According to the team, this indicates that FVC alone may not always be an adequate measure of disease severity, and efforts should be made to determine quality of life using other clinical indicators.

In healthcare expenditure, 4.7-million euros’ (about $5.1 million US) worth of specialty care resources were spent on IPF patients from 2005 and 2017. The high HCRU was mostly driven by hospital inpatient days — an IPF patient was hospitalized an average of 5.5 days.

Based on the results, the team concluded that “IPF is associated with a high burden of disease, and reimbursement restrictions are in conflict with early care.”

The researchers noted that “there is still a need to improve IPF diagnosis, and enhance the collaboration between primary and specialty care to detect IPF at an early stage,” and emphasized that “as both the economic and the humanistic burdens of disease worsen with advancing disease, it is of outmost importance to postpone FVC decline in order to increase the IPF patients’ quality of life.”