Delay and inequalities in the treatment of idiopathic pulmonary fibrosis: the case of two Nordic countries

Background: Idiopathic pulmonary fibrosis (IPF) is characterized by progressive loss of lung function with high mortality within the first 5 years from diagnosis. In 2011-2014, two drugs, pirfenidone and nintedanib, have been approved worldwide for prevention of IPF progression. National IPF-registries have been established in both Finland and Sweden. Our study explored potential differences in the care of IPF in these two countries.

Methods: Patients included consecutively in the Finnish and Swedish IPF-registries from January 1, 2014 through December 31, 2016 were included in the study. Data on demographics and lung function at the time of inclusion were collected. Access to antifibrotic drugs and data on disease outcomes, mortality and the proportion of patients who underwent lung transplantation, was collected during a 3-year follow up.

Results: One-hundred and fifty-two patients from the Finnish and 160 patients from the Swedish IPF-cohorts were included in the study. At inclusion, Finnish patients were significantly older than the Swedish patients (74.6 years vs 72.5 years, p = 0.017). The proportion of non-smokers was significantly higher in the Finnish cohort (41.7% vs 26.9%, p = 0.007). Forced vital capacity (FVC), % of predicted (78.2 vs 71.7 for Finnish and Swedish patients, respectively, p = 0.01) and diffusion capacity for carbon monoxide (DL_CO), % of predicted (53.3 vs 48.2 for Finnish and Swedish patients, respectively, p = 0.002) were significantly higher in the Finnish cohort compared to the Swedish cohort at the time of inclusion. During the 3-year follow up period, 45 (29.6%) Finnish and 111 (69.4%) Swedish patients, respectively, were initiated on treatment with an antifibrotic drug (pirfenidone or nintedanib) (p < 0.001). When comparing possible determinants of treatment, patients with higher FVC % were less likely to start antifibrotic drugs (OR 0.96, 95%CI 0.93-1.00, p < 0.024). To be resident in Sweden was the main determinant for receiving antifibrotic drugs (OR 5.48, 95%CI 2.65-11.33, p < 0.0001). No significant difference in number of deaths and lung transplantation during the follow up period was found.

Conclusions: This study highlights differences concerning how IPF patients are treated in Finland and Sweden. How these differences will influence the long-term outcome of these patients is unknown.