Table 1.
5 Domains of potential predictors are listed in the table: (1) packyears; (2) presence of chronic bronchitis; (3) lung function (4) TLCO; and (5) absolute and differential cell counts in induced sputum.
Table 2.
Patient characteristics at baseline.
Characteristics of the study population per treatment group at baseline. Data represent mean (SD).
Fig 1.
Total number of patients randomized and compliant (>70% medication use) per treatment group. At each stage of the study (0, 6 and 30 months) the numbers are listed of those who underwent bronchoscopy amongst the number of patients remaining in the study. We reproduced this flowchart from ‘Lapperre TS et al. (2009) Effect of fluticasone with and without salmeterol on pulmonary outcomes in chronic obstructive pulmonary disease: a randomized trial. Ann Intern Med 151: 517–527, with permission’.
Table 3.
Mean values of predictors per stratum per treatment.
Fig 2.
Long-term predictors of FEV1 decline by fluticasone treatment.
(A) Prediction by packyears smoking of the decline of FEV1 by 2.5 year fluticasone treatment (ml) and placebo, stratified by median values of the predictor by 30 months treatment with fluticasone compared to placebo. #Index category (Idx) is defined relative to median value, and represents the more favourable outcome by fluticasone. Reference category (Ref) is complementary. The group numbers of the patients are mentioned in each graph. For example: Fig 2A shows the decline in FEV1 in ml/yr on the Y axis for patients with many pack years and patients with few pack years with fluticasone or placebo treatment, respectively, on the X axis. All P values are based on the results of the linear mixed effects model. The treatment*time interaction term corresponding to the difference in decline in FEV1 between fluticasone and placebo in the low pack year stratum had a P value of 0.037. The interaction term (treatment*stratum*time) reflects the additional effect of pack years smoking stratum to the effect of treatment with inhaled fluticasone compared to placebo on longitudinal changes in FEV1. The corresponding P value for pack years smoking is 0.023. A favourable effect on decline in FEV1 would be a decrease in decline caused by inhaled corticosteroids. The figure shows that a lower number of packyears (= index category) decreases the decline in FEV1 significantly. (B) Prediction by baseline FEV1 of the decline of FEV1 by 2.5 year fluticasone treatment (ml) and placebo, stratified by median values of the predictor by 30 months treatment with fluticasone compared to placebo. (C) Prediction by RV/TLC of the decline of FEV1 by 2.5 year fluticasone treatment (ml) and placebo, stratified by median values of the predictor by 30 months treatment with fluticasone compared to placebo. (D) Prediction by TLCO of the decline of FEV1 by 2.5 year fluticasone treatment (ml) and placebo, stratified by median values of the predictor by 30 months treatment with fluticasone compared to placebo. (E) Prediction by total number of cell counts in induced sputum of the decline of FEV1 by 2.5 year fluticasone treatment (ml) and placebo, stratified by median values of the predictor by 30 months treatment with fluticasone compared to placebo. (F) Prediction by PC20 methacholine of the decline of FEV1 by 2.5 year fluticasone treatment (ml) and placebo, stratified by median values of the predictor by 30 months treatment with fluticasone compared to placebo. (G) Prediction by percentage of eosinophils in sputum of the decline of FEV1 by 2.5 year fluticasone treatment (ml) and placebo, stratified by median values of the predictor by 30 months treatment with fluticasone compared to placebo.
Table 4.
Predictors of attenuation of long-term FEV1 decline by fluticasone treatment.