Relationship Between FEV1 and Patient-Reported Outcomes Changes: Results of a Meta-Analysis of Randomized Trials in Stable COPD

Abstract

This meta-analysis assessed the relationship between change from baseline (CFB) in spirometric measurements (trough forced expiratory volume in 1 second [FEV] and FEV area under the curve [AUC]) and patient-reported outcomes (St. George's Respiratory Questionnaire total score [SGRQ] CFB, Transition Dyspnea Index [TDI] and exacerbation rates) after 6-12 months' follow-up, using study treatment-group level data. A systematic literature search was performed for randomized controlled trials of ≥24 weeks duration in adults with chronic obstructive pulmonary disease (COPD). Studies reporting ≥1 spirometric measurement and ≥1 patient-reported outcome (PRO) at baseline and at study endpoint were selected. The relationships between PROs and spirometric endpoints were assessed using Pearson correlation coefficient and meta-regression. Fifty-two studies (62,385 patients) were included. Primary weighted analysis conducted at the last assessment showed a large significant negative correlation (r, -0.68 [95% confidence interval (CI); -0.77, -0.57]) between trough FEV and SGRQ. Improvement of 100 mL in trough FEV corresponded to a 5.9 point reduction in SGRQ. Similarly, a reduction of 4 points on SGRQ corresponded to 40 mL improvement in trough FEV (<0.001). The weighted correlation coefficients of trough FEV with TDI, exacerbation rate (all) and exacerbation rate (moderate/severe) at last assessment point were 0.57, -0.69 and -0.57, respectively (all <0.05). For the analyses excluding placebo groups, the correlations of FEV with SGRQ and TDI were lower but significant. A strong association exists between changes in spirometric measurements and changes in PROs.

Rescue medication use as a patient-reported outcome in COPD: a systematic review and regression analysis

“…1). This review included a new analysis of data from a previous systematic literature review [6] and data found in a subsequent systematic literature search.

Fig. 1Data sources and selection criteria for the review.

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“…The inclusion criteria employed in this analysis were consistent with those employed in the previous analysis [ 6 ]. Only studies with the full texts published in English language were included.…”

“…Spirometry assessments are important for the characterization and management of COPD, but the Global initiative for chronic Obstructive Lung Disease (GOLD) guidelines recommend that the symptoms experienced by each individual patient and their exacerbation history should also be considered [ 2 ]. Furthermore, individual studies and meta-analyses have shown variable levels of correlation between the spirometric measure of forced expiratory volume in one second (FEV 1 ) and health status scores [ 3 – 6 ]. For example, in the TORCH study, a deterioration in health status (assessed by the St George’s Respiratory Questionnaire [SGRQ]) at 3 years correlated significantly but relatively poorly with change in FEV 1 ( r = −0.24; p < 0.0001) [ 4 ].…”

“…For example, in the TORCH study, a deterioration in health status (assessed by the St George’s Respiratory Questionnaire [SGRQ]) at 3 years correlated significantly but relatively poorly with change in FEV 1 ( r = −0.24; p < 0.0001) [ 4 ]. A more recent meta-analysis that assessed spirometric measurements and patient-reported outcomes found a much stronger correlation between trough FEV 1 and SGRQ ( r = -0.68; p < 0.0001) [ 6 ].…”

“…However, whilst asthma guidelines focus on minimizing the need for rescue therapy [ 7 ], far less emphasis is placed on rescue therapy in COPD. To the best of our knowledge, no previous systematic reviews have assessed the association between increased rescue medication use and other clinical trial outcomes such as changes in trough FEV 1 , incidence of moderate-to-severe COPD exacerbations or patient-reported outcomes such as SGRQ or the Transition Dyspnoea Index (TDI) [ 5 , 6 ]. Recently, increased levels of rescue medication use and temporal changes in its use have been linked with increased exacerbation risk in patients with moderate-to-very-severe COPD [ 3 ].…”