Inhaled corticosteroids and FEV(1) decline in chronic obstructive pulmonary disease: a systematic review

Rate of FEV(1) decline in COPD is heterogeneous and the extent to which inhaled corticosteroids (ICS) influence the rate of decline is unclear. The majority of previous reviews have investigated specific ICS and non-ICS inhalers and have consisted of randomised control trials (RCTs), which have specific inclusion and exclusion criteria and short follow up times. We aimed to investigate the association between change in FEV(1) and ICS-containing medications in COPD patients over longer follow up times. MEDLINE and EMBASE were searched and literature comparing change in FEV(1) in COPD patients taking ICS-containing medications with patients taking non-ICS-containing medications were identified. Titles, abstract, and full texts were screened and information extracted using the PICO checklist. Risk of bias was assessed using the Cochrane Risk of Bias tool and a descriptive synthesis of the literature was carried out due to high heterogeneity of included studies. Seventeen studies met our inclusion criteria. We found that the difference in change in FEV(1) in people using ICS and non-ICS containing medications depended on the study follow-up time. Shorter follow-up studies (1 year or less) were more likely to report an increase in FEV(1) from baseline in both patients on ICS and in patients on non-ICS-containing medications, with the majority of these studies showing a greater increase in FEV(1) in patients on ICS-containing medications. Longer follow-up studies (greater than 1 year) were more likely to report a decline in FEV(1) from baseline in patients on ICS and in patients on non-ICS containing medications but rates of FEV(1) decline were similar. Further studies are needed to better understand changes in FEV(1) when ICS-containing medications are prescribed and to determine whether ICS-containing medications influence rate of decline in FEV(1) in the long term. Results from inclusive trials and observational patient cohorts may provide information more generalisable to a population of COPD patients.