Effect of treatment guidelines on the initial management of idiopathic pulmonary fibrosis.

Abstract

Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal disease with no known aetiology and no proven treatment. Despite the absence of efficacy data, many physicians treat IPF with corticosteroids either as monotherapy or in combination with a cytotoxic agent. Specialty society guidelines published in 1999 and 2000 recognize that treatment may not be appropriate for all patients with IPF, but recommend that if treatment is to be initiated, a combination of corticosteroids with a cytotoxic agent is preferred over corticosteroids alone. It is not known how the use of corticosteroids and cytotoxic agents in the treatment of IPF has changed over time and whether published guidelines have altered prescribing practices. The results of this study demonstrate a modest but statistically significant reduction in the overall use of corticosteroids since the publication of treatment guidelines. At the same time, there was a more pronounced increase in the combined use of corticosteroids and cytotoxic agents consistent with recommendations. Even with the increase in the use of combination therapy, corticosteroid monotherapy remained the most commonly prescribed regimen among treated patients. Given the lack of established benefit and the risks associated with corticosteroid therapy, the reasons for the continued use of corticosteroid monotherapy in the majority of treated patients warrant further investigation. To assess the impact of specialty society guidelines on the use of corticosteroids and cytotoxic agents in the initial management of patients with idiopathic pulmonary fibrosis. A retrospective cohort study of 941 patients with an incident diagnosis of IPF was conducted using a large medical records database. The primary outcome was a new prescription for corticosteroids with or without a cytotoxic agent within 30 days of diagnosis. The primary exposure was whether diagnosis occurred before or after the publication of treatment guidelines. Logistic regression was used to control for changes in population demographics and disease characteristics across time. In total, 187 patients (19.9%) received a new corticosteroid prescription within 30 days of diagnosis. Fewer patients received corticosteroids after the publication of guidelines (22.2% vs. 17.7%; adjusted OR for steroid use after the publication of guidelines 0.65, 95% confidence interval 0.46, 0.92, P = 0.014). Among the 187 patients treated with corticosteroids, 22 (11.8%) also received a cytotoxic agent. The use of cytotoxic agents among users of corticosteroids increased significantly after the publication of guidelines (5.1% vs. 19.3%) with a fully adjusted OR = 4.71 (95% CI 1.56, 14.21, P = 0.006). Since the publication of treatment guidelines, there has been a small reduction in the overall use of corticosteroids. Consistent with these guidelines, the use of cytotoxic agents among those prescribed corticosteroids has increased significantly; however, the use of these agents remains uncommon.