The impact of a network based approach on lung function and symptom duration at diagnosis in idiopathic pulmonary fibrosis

Background: Idiopathic Pulmonary Fibrosis (IPF) is a debilitating lung disease with mean life expectancy of 3-5 years. With the advent of antifibrotics early detection and diagnosis is paramount to impact disease pathogenesis. Aim: Investigate if a network based approach to care impacts on earlier detection of IPF. Methods: We have a network based approach to care in the North West of England with the aim of facilitating early diagnosis and equal access to therapies for IPF. Symptom duration, forced vital capacity (FVC) and transfer factor (DLCO) at diagnosis were compared from 2014 to 2016. ANOVA and Pearson correlation coefficient analysis was conducted. Results: Overall, there were 330 records across 2014 (n=107), 2015 (n=177) and 2016 (n=130). At diagnosis symptom duration of less than 12 months increased from 8% in 2014 to 32% in 2016. Conversely IPF patients with symptoms greater than 2 years decreased from 71% in 2014 to 52% in 2016. Percentage predicted mean FVC declined from 2.69 (80%) in 2014 to 2.38 (75%) in 2016, meanwhile the mean DLCO increased from 3.59 (41%) in 2014 to 4.0 (45%) in 2016 (p=0.0425). There was a negative correlation with FVC (R2=0.997) and a positive correlation with DLCO percentages (R2=0.902). Conclusions: Our hypothesis is that a network based approach to IPF care would diagnose patients earlier over time. Here we demonstrate over a 3 year period that more patients had shorter duration of symptoms and higher DLCO at presentation denoting potential earlier diagnosis of IPF. The lower FVC over time is likely driven by the UK regulation restriction for prescribing antifibrotics.