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.
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