Determination of the minimal important difference for Dyspnoea-12 questionnaire in patients with COPD, after pulmonary rehabilitation

The effects of inspiratory muscle warm-up prior to inspiratory muscle training during pulmonary rehabilitation in subjects with chronic obstructive pulmonary disease: a randomized trial

BACKGROUND

While a whole-body warm-up may not adequately prepare the inspiratory muscles for exercise, inspiratory warm-up is an effective approach in preparing the inspiratory muscles for exertion.

OBJECTIVES

To investigate the effects of inspiratory muscle warm-up performed prior to inspiratory muscle training (IMT) during pulmonary rehabilitation (PR) in patients with moderate-to-severe chronic obstructive pulmonary disease (COPD) and inspiratory muscle weakness.

METHODS

Pulmonary function tests, maximal inspiratory and expiratory pressures (MIP and MEP), 6-minute walk test distance (6MWD), modified Medical Research Council Dyspnea Scale(mMRC), St. George's respiratory questionnaire and the 36-item short-form health survey were evaluated. Both groups performed IMT during PR for 8 weeks. The warm-up group (n = 15), in addition to the standard IMT group (n = 15), performed an inspiratory muscle warm-up protocol before each IMT session.

RESULTS

At the end of the 8-week intervention, improvements in dyspnea (mMRC in score, p =0.033, effect size =0.76); exercise capacity (6MWD in meters, p =0.001, effect size =1.30); pulmonary function [forced expiratory volume in 1 second (FEV1) in %predicted, p =0.006, effect size =1.10]; and inspiratory muscle strength (MIP in cmH2O, p =0.001, effect siz e = 1.35) were significantly greater in the warm-up group. Moreover, there were significant improvements in health-related quality of life (HRQoL) sub-scores after the training in both groups (p <0.05).

CONCLUSIONS

This study demonstrated improvements in both groups, surpassing or closely approaching the established minimal clinically important difference values for the respective outcomes. Performing a warm-up for inspiratory muscles before IMT boosts benefits for pulmonary function, inspiratory muscle strength, exercise capacity, dyspnea, and HRQoL in subjects with moderate-to-severe COPD and inspiratory muscle weakness.

[Effects of gender on pulmonary rehabilitation outcomes in patients with COPD]

INTRODUCTION

COPD has become more prevalent among women, revealing a specific feminine phenotype. Women experience greater dyspnea and a more impaired quality of life. The main objective of this study was to assess the effect of gender on dyspnea during a pulmonary rehabilitation program (PRP).

METHODS

Retrospective study including COPD patients having participated in PRPs. The following data were analyzed according to gender before and after a PRP: dyspnea, quality of life, anxiety and depression, exercise capacity, muscle function (quadriceps and inspiratory muscles).

RESULTS

More than 500 patients (252 men and 252 women) were included. We did not find a significant effect of gender on the evolution of dyspnea, anxiety or depressive disorders, exercise capacity, inspiratory muscle strength, or overall quality of life score. That said, we found a possible effect on the sub-scores of the quality of life questionnaire, and regarding quadriceps strength. All criteria improved during the program in both groups.

CONCLUSIONS

During a PRP, gender does not impact the evolution of dyspnea. While women may nonetheless benefit to a greater extent in terms of quality of life sub-scores (impact, activities, symptoms) and quadriceps strength, these results still require confirmation.

Relevance of multidimensional dyspnea assessment in the context of pulmonary rehabilitation

Objectives: While dyspnea is the main symptom in chronic obstructive pulmonary disease (COPD), it is often inadequately evaluated in pulmonary rehabilitation (PR), as it is typically measured using only the impact dimension (ID). However, dyspnea is a multidimensional construct including perception (PD) and emotional (ED) domains. Our work aimed to study the complementarity of dyspnea dimensions and their respective ability to identify different evolutions during PR. Methods: 145 people with COPD attending PR were included in this retrospective study. Dyspnea scores from the modified Medical Research Council scale (ID) and the Multidimensional Dyspnea Profile questionnaire (PD/ED), exercise capacity, quality of life at the start (T1) and the end of PR (T2) were collected from existing databases/medical files. The evolution of each dyspnea dimension was evaluated using the delta score between T2-T1. PR response was defined using the minimal clinically important difference. Results: Our results show that each dyspnea dimension was associated with different health-outcomes. Positive correlations were found between PD-ED at baseline and between their T2-T1 delta score (ρ = 0.51; ρ = 0.41 respectively, p < .01), but there was no significant correlation between ID-PD or -ED (p > .05). 51% of the patients did not respond on ID, but 85% of them nonetheless responded on either PD or ED. Finally, 92% of patients responded on at least one dimension after PR. Discussion: Our study emphasizes the significance of assessing each dimension of dyspnea independently and complementary, as dimensions are associated with different elements and evolve differently under PR effects. This approach is crucial to identifying weak points and allows professionals to focus on program elements that most effectively address the specific dimension causing problems.

Determination of the minimal important difference for inspiratory muscle strength in people with severe and very severe COPD

OBJECTIVE

Inspiratory muscle training is recommended for people with chronic obstructive pulmonary disease (COPD) with inspiratory muscle weakness. Clinical interpretation of changes in inspiratory muscle strength could be helped by the determination of cut-off values. The aim of this study was to estimate the minimal important difference for inspiratory muscle strength assessed with maximal inspiratory pressure (MIP) in people with COPD.

DESIGN

Post hoc analysis of a randomized controlled trial (EMI2 study) including people with severe to very severe COPD undergoing a pulmonary rehabilitation program was conducted. The determination of the minimal important difference was realized using both anchor-based and distribution-based methods.

SETTING

The study includes patients admitted to the rehabilitation program unit of the Centre Hospitalier des Pays de Morlaix (Morlaix, France) between March 5, 2014 and September 8, 2016.

PARTICIPANTS

Seventy-three people with severe to very severe COPD (age 62.2  ±  8.0 years, forced expiratory volume in 1 s 36.4  ±  9.5% of theoretical) were analyzed.

INTERVENTION

Patients followed a standardized pulmonary rehabilitation program 5 days a week for 4 weeks. The program included aerobic training, ground-based outdoor walking training, and strengthening of lower and upper limb muscles.

MAIN MEASURES

At the end of the pulmonary rehabilitation program, MIP improved by 14.8  ±  14.9 cmH2O (p < 0.05). Regarding the anchor-based method, only the modified Medical Research Council was selected as an appropriate anchor. The receiver operating characteristic curve analysis reported a minimal important difference of 13.5 cmH2O (sensibility: 75% specificity: 67.5%). Using distribution-based methods, the estimate of minimal important difference was 7.9 cmH2O (standard error of measurement method) and 10.9 cmH2O (size effect method).

RESULTS

The estimations proposed by this study ranged from 7.9 to 13.5 cmH2O.

CONCLUSIONS

The measurement of minimal important difference is a simple tool for assessing the changes of inspiratory muscle strength during a pulmonary rehabilitation program. We propose a minimal important difference of 13.5 cmH2O for the improvement of MIP. Further studies are needed to confirm this estimation.ClinicalTrials.gov identifier: NCT02074813.

[The role of the physiotherapist in the assessment and management of dyspnea]

The role of the physiotherapist in the assessment and management of dyspnea. Dyspnea is the most common symptom in cardio-respiratory diseases. Recently improved comprehension of dyspnea mechanisms have underlined the need for three-faceted assessment. The three key aspects correspond to the "breathing, thinking, functioning" clinical model, which proposes a multidimensional - respiratory, emotional and functional - approach. Before initiating treatment, it is essential for several reasons to assess each specific case, determining the type of dyspnea affecting the patient, appraising the impact of shortness of breath, and estimating the effectiveness of the treatment applied. The physiotherapist has a major role to assume in the care of dyspneic patients, not only in assessment followed by treatment but also as a major collaborator in a multidisciplinary team, especially with regard to pulmonary rehabilitation. The aim of this review is to inventory the existing assessment tools and the possible physiotherapies for dyspnea, using a holistic approach designed to facilitate the choice of techniques and to improve quality of care by fully addressing the patient's needs.

Physical and affective components of dyspnoea are improved by pulmonary rehabilitation in COPD

Background

Dyspnoea is a multidimensional experience of breathing discomfort, but its affective dimension is unfrequently assessed in people with chronic obstructive pulmonary disease (COPD). We evaluated the effectiveness of a home-based pulmonary rehabilitation (PR) programme on the physical and affective components of dyspnoea assessed by the Dyspnoea-12 (D-12) questionnaire. We also determined the baseline characteristics that contributed to the change in D-12 scores.

Methods

In this retrospective study, 225 people with COPD (age, 65±11 years; forced expiratory volume in 1 s (FEV₁), 35±15% of predicted value) were enrolled into a person-centric home-based PR, consisting of a weekly supervised 90 min home session during 8 weeks. D-12 questionnaire, health status, anxiety and depressive symptoms, exercise tolerance and general fatigue were assessed at baseline (M0), at the end of PR programme (M2), and 8 (M8) and 14 months (M14) after M0. Multivariable analysis of covariance (ANCOVA) models were performed to identify the baseline characteristics that contributed to the change in D-12 scores.

Results

Both physical and affective components of dyspnoea and all the other outcome measures were improved at M2, M8 and M14 compared with baseline (p<0.05). Baseline body mass index was the only significant independent predictor of the changes in physical dyspnoea score, while the change in the affective dimension of dyspnoea after PR was associated with FEV₁, anxiety symptoms and exercise tolerance (6 min stepper test). However, since these variables had only a small impact on the changes in D-12 questionnaire scores, results from the ANCOVA analysis should be taken cautiously.

Conclusion

Both physical and affective components of dyspnoea were improved, at short term and long term, by 8 weeks of individualised home-based PR. The present results support the importance of assessing dyspnoea as a multidimensional experience during PR, warranting replication by robustly designed randomised and controlled studies.