Idiopathic Pulmonary Fibrosis: Effect of Diagnostic Delay on Outcomes, QOL

IPF, Honeycomb, CT lung scan
IPF, Honeycomb, CT lung scan
For patients with IPF, how does diagnostic delay affect quality of life as well as hospitalization and progression-free survival rates?

A diagnostic delay of more than 1 year for idiopathic pulmonary fibrosis (IPF) adversely affects patients’ progression-free survival, quality of life, and hospitalization rates, according to a study in BMJ Open Respiratory Research.

The findings are based on data from the ongoing Pulmonary Fibrosis Biomarker Cohort (ClinicalTrials.gov Identifier: NCT02755441), which includes incident patients diagnosed with IPF according to international guidelines. Patients are recruited immediately after their diagnosis, before initiation of antifibrotic treatment, and are followed for as long as 5 years.

Participants completed the St George’s Respiratory Questionnaire (SGRQ) and the chronic obstructive pulmonary disease assessment test (CAT) at each visit. A validated IPF-specific version of the SGRQ (SGRQ-Ider) was also used.

A total of 264 incident patients with IPF (mean age, 73.26 years; 75% male) were included from April 2016 to June 2021. Of the cohort, 78 patients had a diagnostic delay of less than 1 year, and 186 patients had a diagnostic delay of greater than 1 year. Diagnostic delay was defined as the time from the first occurrence of any IPF-related symptom reported by the patient and the date of the IPF diagnosis.

Among patients who had mild disease at diagnosis (forced vital capacity [FVC] >80% predicted), a long diagnostic delay was associated with lower FVC, higher SGRQ total score, higher SGRQ-Ider total score, and higher dyspnea score. Patients with moderate-to-severe disease at diagnosis (FVC ≤80% predicted) had none of these associations.

Overall, a diagnostic delay of more than 1 year was associated with a worse progression-free survival rate vs a diagnostic delay of less than 1 year (hazard ratio [HR] 1.70; 95% CI, 1.18-2.46, P =.004) in multivariate analysis. A long diagnostic delay was associated with worse progression-free survival in patients with mild disease (HR 2.43; 95% CI, 1.45-4.01, P <.001) but not for patients with moderate-to-severe disease (HR 0.91; 95% CI, 0.51-1.62, P =.76).

Multivariate negative binomial regression analysis showed that patients who had a long diagnostic delay had higher all-cause admission rates during the first year after diagnosis (incidence rate ratio [IRR] 3.28; 95% CI, 1.35-8.55; P =.01) and during the full follow-up (IRR 1.74; 95% CI, 1.01-3.02; P =.04).

Study limitations include the observational design and use of FVC for stratified analysis.

“We report a consistent negative impact of a diagnostic delay of more than 1 year on progression-free survival, quality of life, and hospitalization rates in patients with IPF,” stated the researchers. “These findings were most pronounced in patients with mild disease (FVC >80% predicted) at the time of diagnosis highlighting the importance and potential benefit of an early diagnosis for proper management of IPF patients.”

Disclosure: This study was funded by unrestricted research grants from Aase and Einar Danielsens Foundation, Roche A/S, and Shipowner Per Henriksen, R and wife Foundation. Some of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Reference

Hoyer N, Prior TS, Bendstrup E, Shaker SB. Diagnostic delay in IPF impacts progression-free survival, quality of life and hospitalisation rates. BMJ Open Respir Res. 2022;9(1):e001276. doi:10.1136/bmjresp-2022-001276