Questions and Answers on Smoking in Patients With Diffuse ILD. Use of PICO Methodology

The Smoking and the Diffuse Interstitial Lung Diseases (ILD) groups of ALAT and SEPAR collaborated in the preparation of this document.

This document uses PICO methodology to answer various questions on the relationship between tobacco use and diffuse ILD.

The main recommendations are: a) moderate level of evidence and strong recommendation to consider smoking as a risk factor for the development and/or modification of the progression of diffuse ILD; b) moderate level of evidence to identify an increase in mortality in diffuse ILD, irrespective of histologic pattern. Low evidence for ascribing it to smoking and strong recommendation for the early identification of patients with diffuse ILD. Further studies are needed to evaluate the effect of smoking cessation in patients with diffuse ILD; c) low level of evidence and weak recommendation for defining the impact of passive smoking in diffuse ILD; d) low level of evidence to demonstrate that smoking cessation improves the outcomes of patients diagnosed with diffuse ILD and strong recommendation to advise smoking cessation in smokers with diffuse ILD, and e) low level of evidence to support the clinical or epidemiological usefulness of active case finding for diffuse ILD in smoking cessation programs, and strong recommendation justifying the performance of spirometry in active case finding, based not on current smoking status, but on previous accumulated consumption, even in asymptomatic cases.