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.

Effects of pulmonary rehabilitation on fear of falling in Chronic Obstructive Pulmonary Disease (COPD) patients: An observational study.

OBJECTIVE: COPD patients have more fear of falling (FOF) in comparison with control population. One major aim of pulmonary rehabilitation (PR) is to maintain physical activity. Studies show that FOF can limit physical activity. The aim of this study was to assess the impact of PR on FOF in patients with COPD. METHODS: From January to august 2019, COPD patients (stage 2 to 4) undergoing a 4-weeks PR Program (PRP) at Morlaix Hospital Centre were included in this prospective observational study. The objectives were to assess [1] the impact of PR on FOF, [2] the correlations between evolution of FOF and evolution of parameters usually used during PRP, [3] to determine a MID for FOF. The primary endpoint was the Fall Efficacy Scale-International (FES-I) questionnaire. The secondary endpoints were tests and questionnaires usually used to assess exercise capacity, quality of life, dyspnea, anxiety, depression, and balance. RESULTS: 80 patients were included and 72 were analysed. After the PRP, there was a significant decrease of FOF, with significative decrease of FES-I score (-3.36, p<0.001) CI 95% [-5.1; -1.6]). The evolution of FES-I score was moderately correlated to changes in quality of life (QOL) using CAT (Intra-class Correlation Coefficient (ICC)=0.340, p=0.005) and SGRQ (ICC=0.454, p<0.0001), dyspnea using MMRC (ICC=0.311, p=0.009) and LCADL (ICC=0.396, p=0.001); and weakly correlated to changes in balance (ICC=-0.280, p=0.026). Using the distribution-based analysis, we found a MID between -3.6 to -4.9. CONCLUSION: We showed a significant decrease of fear of falling in COPD patients after PRP, correlated with improvement of QOL, balance and decrease of dyspnea. We propose a MID of -4.9 for FES-I. TRIAL REGISTRATION: ClinicalTrials.gov NCT03793452.

Effect of neuromuscular electrical stimulation on exercise capacity in patients with severe chronic obstructive pulmonary disease: A randomised controlled trial.

OBJECTIVE: To compare strengthening by neuromuscular electrical stimulation versus cycle ergometer training during a pulmonary rehabilitation program, in patients with severe to very severe chronic obstructive pulmonary disease. DESIGN: A prospective randomized controlled study. SETTING: Two inpatient pulmonary rehabilitation centers. SUBJECTS: Patients with severe to very severe chronic obstructive pulmonary disease and multidimensional index to predict risk of death ≥5, were randomly assigned to receive neuromuscular electrical stimulation or cycle ergometer training during pulmonary rehabilitation. MAIN MEASURES: The primary endpoint was the change in exercise capacity using 1-min sit-to-stand test Secondary endpoints were the changes in exercise capacity using 6-min walk test, quadriceps strength, quality of life and dyspnea. RESULTS: 102 patients were included. After 3 weeks, 47 patients in the neuromuscular electrical stimulation group, and 45 in the cycle ergometer training group were able to be analyzed. No significant difference was seen in the evolution of exercise capacity using 1-min sit-to-stand test (3.3 ± 3.8 and 2.6 ± 4.1) and 6-min walk test (37.8 ± 58.4 and 33.1 ± 46.7), in the evolution of quadriceps strength and endurance (9.2 ± 12.9 and 6.6 ± 16.1; 9.0 ± 13.2 and 6.2 ± 17.0), in the evolution of quality of life (St George's Respiratory Questionnaire: -11.3 ± 11.7 and -8.1 ± 11.6; COPD Assessment Test: -5.7 ± 7.1 and -4.7 ± 7.0), or in the evolution of dyspnea using Dyspnea 12 (-5.5 ± 10.2 and -5.9 ± 8.5) except using modified medical research council scale (95% confidence interval: 0.48 [0.05; 0.91], p = 0.027). CONCLUSION: We found no significant difference between the two programs on exercise capacity, quadriceps strength and quality of life.

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

INTRODUCTION: The authors of the international task force about the management of Dyspnoea recommend assessing sensory and affective components of dyspnoea. The Dyspnoea-12 questionnaire (D-12) allows to assess both components of dyspnoea. D-12 is valid and reliable but its sensitivity to pulmonary rehabilitation was not studied. The aim of this study was to estimate the minimal important difference (MID) for D-12 in COPD patients undergoing a pulmonary rehabilitation programme (PRP). METHODS: Severe or very severe COPD patients undergoing a PRP were included. Dyspnoea was assessed using D-12, MMRC dyspnoea scale, London chest of Activity of Daily Living questionnaire (LCADL). Quality of life was assessed using Saint-George respiratory questionnaire (SGRQ) and COPD assessment Test (CAT); exercise capacity using 6-Minute walk Test (6MWT) and 1-minute sit to-stand test (1STST). The MID was evaluated using distribution and anchor-based methods. RESULTS: Sixty patients (age: 64.4 ± 8.2; FEV1 (%): 28.6 ± 8.1) were included. At the end of the PRP, patients had significantly decreased their dyspnoea measured with D-12, MMRC, LCADL (D-12:23.9 ± 8.9 to 17.6 ± 9.4; MMRC: 3 ± 0.7 to 2.2 ± 1.1, LCADL: 38 ± 13.9 to 31.6 ± 11; p < 0.0001). Using the distribution-based analysis, MID of -2.67 (standard error of measurement) or -4.45 (standard deviation) was found. According to methodology, we could only use SGRQ as anchor. With SGRQ as anchor, the receiver operating characteristic curve identified MID for the change in D-12 at -6.1 (sensibility: 58%, specificity: 79%). The correlation with SGRQ was modest (r = 0.33), so the calculated MID should be interpreted with caution. CONCLUSION: D-12 is a good tool to assess the decrease of dyspnoea after PR. We propose MID of -6 points. However, Future estimates of MID for the D-12 should use anchors that are more strongly correlated with it.

Effect of different form of upper limb muscles training on dyspnea in chronic obstructive pulmonary disease: A study protocol.

INTRODUCTION: In activities involving upper limbs, patients with chronic obstructive pulmonary disease (COPD) report an increase in dyspnea. For this reason, the authors of the recommendations about pulmonary rehabilitation propose to perform upper limbs muscle strengthening in patients with COPD. However, the modalities of strengthening are not clearly established.The aim of this study is to compare the effects of upper limbs endurance strengthening versus upper limbs force strengthening, in patients with COPD during a pulmonary rehabilitation program. METHODS: This study is a randomized, open-label, bi-center controlled trial in parallel groups distributed in a ratio (1:1) comparing upper limbs force strengthening (group F) to the upper limbs endurance strengthening (group E) during a pulmonary rehabilitation program in patients with COPD stages 2 to 4 (A-D).After randomization, patients will be allocated to follow: A 4 weeks pulmonary rehabilitation program with upper limbs resistance strengthening (group F). A 4 weeks pulmonary rehabilitation program with upper limbs endurance strengthening (group E).The primary outcome is dyspnea measured with the London Chest Activity of daily Living questionnaire. The secondary outcomes are dyspnea (using Modified Medical Research Council dyspnea Scale, dyspnea-12 questionnaire, multidimensional dyspnea profile questionnaire), upper limb exercise capacity (using the 6-minute Peg Board and Ring Test), Maximal voluntary strength of deltoid, biceps, and brachial triceps.The sample size calculated is 140 patients per group, or 280 in total. DISCUSSION: The modalities of upper limb strengthening are not very well known, and evidence based is lacking to recommend endurance or resistance upper limb strengthening.We anticipate that the results of this study will be of relevance to clinical practice. They will bring information about the best modality of upper limb strengthening to use during a pulmonary rehabilitation program. TRIAL REGISTRATION: IdRCB n°2018-A00955-50; V1.1 du 11/07/2018; REHABSUP, clinical trial.gov (NCT03611036), registered August 02, 2018, https://clinicaltrials.gov/ct2/show/NCT03611036.

Comparison of 3-minute Step Test (3MStepT) and 6-minute Walk Test (6MWT) in Patients with COPD.

Chronic obstructive pulmonary disease (COPD) is frequently associated with a reduced functional exercise capacity. This parameter is usually evaluated using 6-minute walking test (6MWT). New tools appear regularly. The aim of this study was to validate the 3-minute step test (3MStepT) and to compare 3MStepT and 6MWT in stable patients with COPD as a tool to quantify the functional exercise capacity. Patients with COPD admitted for a pulmonary rehabilitation program in a dedicated center were recruited and randomly performed both tests: 6MWT and 3MStepT. A training test was performed systematically before each test. Walking distance and number of repetitions (3MStepT) were measured. Cardiorespiratory parameters, dyspnea and lower limb fatigue (Borg) were recorded pre and post the tests. Fifty patients with COPD (FEV1: 45.2 ± 18.3) were included. 6MWT (423.6 ± 96.3 m) was strongly correlated with 3MStepT (62.1 ± 18.0; r = 0.780; p < 0.001). Heart rate and SpO2 were significantly different at the end of the 6MWT and 3MStepT (respectively, 106.2 ± 16.3 vs. 112.9 ± 13.4bpm, p = 0.002; 87.6 ± 5.4 vs. 89.6 ± 5.3bpm, p = 0.001). Lower limb fatigue was significantly higher after the 3MStepT (2.5 ± 2.6 vs. 3.4 ± 2.4, p = 0.01). The 3MStepT is an alternative to the 6MWT to estimate functional exercise capacity in stable patients with COPD but cardiorespiratory adaptation and lower limb fatigue are not similar between these tests.