Études de longue durée évaluant les traitements pharmacologiques dans la BPCO. Enseignements et limites

Introduction. - Several long-term studies designed to assess pharmacological treatments for Chronic Obstructive Pulmonary Disease (COPD) have been published recently. Only such long-term studies allow an accurate analysis of the effect of treatments on criteria of effectiveness such as survival or decline in pulmonary function. A review of these studies is opportune. Background.- The high drop out rate, which is not a random event, leads to serious methodological problems that are of importance in the interpretation of these studies. Post hoc analysis of both the TORCH and UPLIFT trials suggest a positive effect of long-acting bronchodilators on survival. Up to now, no treatment has convincingly demonstrated an effect on the rate of decline of FEV¹. The treatments evaluated lead to a decrease in exacerbation rates and an improvement in quality of life although the effects of inhaled corticosteroids are subject to methodological concerns. The treatments are all well tolerated. Viewpoint. - The design of future studies should avoid the withdrawal of treatments at enrolment into a study in order to limit the number of drop outs. Conclusion. - Long-term studies have made important progress in the knowledge, not only of the effects of the treatments assessed but also of the methodological issues which need to be addressed.