Minimal Important and Detectable Differences of Respiratory Measures in Outpatients with AECOPD^†

Abstract

Interpreting clinical changes during acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is challenging due to the absence of established minimal detectable (MDD) and important (MID) differences for most respiratory measures. This study established MDD and MID for respiratory measures in outpatients with AECOPD following pharmacological treatment. COPD assessment test (CAT), modified Borg scale (MBS), modified British Medical Research Council questionnaire (mMRC), peripheral oxygen saturation (SpO2), computerised respiratory sounds and forced expiratory volume in one second (FEV1) were collected within 24-48h of an AECOPD and after 45 days of pharmacological treatment. MID and MDD were calculated using anchor-(ROC and linear regression analysis) and distribution-based methods (effect size, SEM, 0.5*SD and MDC95) and pooled using Meta XL. Forty-four outpatients with AECOPD (31♂; 68.2±9.1yrs; FEV1 51.1±20.3%predicted) participated. Significant correlations with CAT were found for the MBS (r=0.34), mMRC (r=0.39) and FEV1 (r=0.33), resulting in MIDs of 0.

<p>Minimal Clinically Important Differences for Patient-Reported Outcome Measures of Cough and Sputum in Patients with COPD</p>

“…Finally, this study is integrated in a larger trial, 34 therefore, a specific sample size calculation to establish MCIDs was not performed, which might have underpowered this study for its goal. Nevertheless, similar samples sizes have been used to establish MCIDs in other studies, 40,68,69 and the fact that all MCIDs fell within the recommended range of 6 to 10% change in the scale range, which corresponded to a desirable effect size of 0.2 to 0.5, 19,38,48 strengthens the validity of our estimates. Moreover, to our best knowledge, this is the first study to provide MCIDs estimations for LCQ and CASA-Q in patients with COPD; thus, we believe that our MCIDs estimates can be useful for health professional and policy makers, ensuring they are used with caution and in accordance with each clinical context.…”

“…Anchor-based methods were weighed more than distribution methods (ie, 2/3 against 1/3). 19,21,38,40 Minimal Important Clinical Differences…”

Psychological distress at hospital admission is related to symptoms severity and health status in malignant pleural effusion patients

“…Dyspnoea was assessed with the Borg scale (Borg, ), which is a comprehensive instrument designed to measure breathlessness in patients with respiratory pathology. Patients rated their dyspnoea from 0 to 10, where 0 represents “no dyspnoea” and 10 represents “maximum dyspnoea.” A difference of 0.9 units was considered as the minimal clinically important difference (MCID), according to previous studies in patients with respiratory disease (Oliveira, Machado, & Marques, ).…”

“…Patients rated their dyspnoea from 0 to 10, where 0 represents "no dyspnoea" and 10 represents "maximum dyspnoea." A difference of 0.9 units was considered as the minimal clinically important difference (MCID), according to previous studies in patients with respiratory disease (Oliveira, Machado, & Marques, 2018).…”

<p>Minimal Clinically Important Difference in Barthel Index Dyspnea in Patients with COPD</p>

“…However, the MRC is the routinely available measurement scale measuring dyspnea in all rehabilitative settings. Despite the MCID has been assessed for outpatients with acute exacerbations of COPD, 29 no formal study has assessed the MCID for MRC in stable patients. However, the value of 1 point has been widely used to assess the benefits of pulmonary rehabilitation.…”