Physical Activity Enhancing Programme in COPD

Study Design:

For logistical purposes, the study is divided into two work packages (WP): 1) Pilot study of DirectLife activity monitor in the daily routine of patients with COPD (WP1), which is a cross-sectional study; 2) Physical activity enhancing programme - main project (WP2), which is a randomized controlled trial. Both studies will be performed at Leith's Community Treatment Centre (LCTC) and its satellites (Midlothian Community Hospital (Bonnyrigg) \& St Johns Hospital (Livingston) - Edinburgh). Only patients with COPD referred to pulmonary rehabilitation at LCTC and its satellites will be recruited for this study. The standard care treatment (exercise training) is exactly the same in all sites, and it is delivered by the same team of physiotherapists.At the satellite units it would still be the direct care that approach the participants. The recruiting procedure will be the same as that of the original study.

Written and signed consent will be taken prior to the inclusion of each patient. The study will explain the protocol and all the procedures they may undergo during study period before they sign the informed consent. With at least 24 hours in advance and before considering patients to take part in the study, we will send them the patient information sheet explaining the project and all the procedures involved.

WP1: This WP aims at establishing the best wearing position of the DirectLife activity monitor in 20 patients with COPD in their daily routine at home. As the DirectLife was only validated in healthy subjects, this is an important step to understand how this device works in daily routine, which is the best position to wear it, and also how feasible it is to use in patients with COPD.

This WP will be conducted prior to the beginning of WP2 and participants will sign a consent form to participate in the study. Twenty COPD patients will undertake the following assessments: pulmonary function (spirometry), exercise capacity (ISWT and ESWT), quality of life (CRQ), dyspnoea sensation (MRC scale) and physical activity in daily life.

Patients will wear simultaneously three different DirectLife devices in three different body places (on the hip, in the front pocket and on the neck) and a fourth physical activity monitor (Actigraph GT3x) which was recently shown as a valid and accurate device to measure daily PAL in patients with COPD.

Patients will wear all four activity monitors (three DirectLife and one Actigraph GT3x) simultaneously in their daily routine, for a period of at least 10 hours/day during the evaluation period of one week. After this monitoring period, they will answer a simple questionnaire about the feasibility of using DirectLife in day-to-day including questions such as: which position(s) they considered as the best position to wear DirectLife, how easy was to put it on and whether the use of DirectLife interfered or not in their daily routine. At the end of this WP we will be able to establish the best position to use the DirectLife and this position will be used in the WP2. If one site is not favoured over the others for monitor position, we will ask patients to wear DirectLife at the place they judge as the most comfortable. If DirectLife does not provides an accurate measurement of patients' physical activity, we will ask them to wear the device in the pocket (position that the manufacturer states it is the best to wear it).

WP2: This WP aims at comparing a PAEP added to pulmonary rehabilitation against usual care (pulmonary rehabilitation alone). Sixty-four patients with COPD will be randomized into two groups: Usual care (control, [C]) that includes only the pulmonary rehabilitation programme with the use of the DirectLife in daily routine without any feedback or incentive to increase PAL; or usual care + physical activity enhancing programme (PAEP) (Study group, [S]), which includes both pulmonary rehabilitation programme plus the PAEP using the DirectLife activity monitor with set targets of physical activity levels to stimulate and increase PADL. Both groups will perform the same pulmonary rehabilitation programme, composed by (in brief): resistance training of quadriceps femoris, biceps and triceps brachii; aerobic exercises in treadmill and cycle ergometer during 6-10 weeks.

All patients will be assessed before PR (Visit 1), and 3 months after the beginning of PR (Visit 2). Patients will be followed up by 3 months after visit 2 (Visit 3).

Assessment will include lung function (spirometry), exercise capacity, peripheral muscle strength, physical activity in daily life, quality of life, systemic inflammation, anxiety and depression, and dyspnoea sensation (see description below). In addition, patients will fill in a psychological survey on three occasions: visit 1, visit 2, and end of the study (visit 3).

For the follow-up phase, patients from both groups (S and C) will be invited to attend the same assessments performed in Visit 1 (excluding spirometry, ISWT and blood samples), three months after visit 2 (Visit 3) to assess the maintenance of the effects of the programme. This additional monitoring period is optional. Therefore patients can choose whether they want to keep helping us with the study or not. For this three months period, both groups will be wearing the DirectLife (without any feedback or incentive to increase physical activity) to monitor PAL over that period. Over this three months follow up period, patients will not receive any formal physical activity counseling/intervention, and they will be excluded from the analysis if they would be under any treatment that could influence their PAL (i.e., pulmonary rehabilitation).

In both groups, initial physical activity levels (PALi) will also be established by assessing PAL with the DirectLife activity monitor (DirectLife, Philips, The Netherlands) throughout a whole week. The physical activity data collected by the DirectLife activity monitor will be used to facilitate the behavioural intervention in the S group, but not as an outcome of PAL for which a different activity monitor (Actigraph GT3x) validated in COPD will be used. The DirectLife activity monitor is a lightweight and portable device that can be worn in three different places (necklace, on the pocket or on the hip) and provides as main variables the active time (minutes) and energy expenditure (calories). DirectLife tracks the body motion with its triaxial sensor. It also provides feedback to the patients on PAL performed since the beginning of the day; a series of indicator lights on the Activity Monitor shows the accumulated activity at any particular moment of each day. It also shows the daily target of physical activity levels making it easy for them to keep on track towards their goals. The aim of the study will be to achieve increments in 50% of the initial PAL at the end of the 12 weeks programme in the S group.

Exercise training programme

Both groups will perform a 6-10 weeks standard exercise training programme used in the UK, 1-2 times per week. Each training session will last 1 hour. As mentioned before, the exercise programme will include cycling; walking; and strength training for the quadriceps femoris, biceps, and triceps brachii muscle groups. The physiotherapist at LCTC and its satellites will increase the work rate or duration of the exercise programme every week guided by a pre-determined schedule and driven by the patient's perception of symptoms (measured via Borg dyspnoea and fatigue scoring). It is important to note that this is not related to the increments of daily physical activity training in the PAEP (set targets of DirectLife), which will be set by another physiotherapist through Philips website.

Statistical Analysis:

Results will be described as mean±SD or median [IQR], according to the normality in data distribution, analyzed by the Shapiro-Wilk test. In the WP1, depending on data distribution, comparisons among Actigraph GT3x and DirectLife (all the three positions) will be performed using one-way ANOVA or its correspondent Kruskal-Wallis test, with Dunn's post hoc test. To analyze DirectLife validity, correlations between PAL in both devices (week average of measured outputs in both devices) will be tested either by Pearson or Spearman correlation coefficient, depending on data distribution. To assess DirectLife's agreement with the criterion method, we will perform a Bland-Altman plot and calculate the intra-class correlation coefficient (ICC) for the energy expenditure and the time spent actively. The level of significance for all comparisons will be set at p<0.05. Data will be analyzed using the statistical package SAS version 9.3 (SAS Institute Inc, Cary, NC, USA).

For the WP2, results will be described as mean±SD or median [IQR], according to the normality in data distribution, analyzed by the Shapiro-Wilk test. Effects of the PAEP on the group of patients receiving the combined treatment (PR+PAEP) will be assessed by comparing PAL before (Visit 1) and after 3 months of the beginning of PR (Visit 2) using a paired student t-test (or the correspondent test for non-normally distributed variables). Effects of the PAEP on the main outcome (physical activity levels) will be assessed by comparing the differences (post-pre PAEP) in physical activity levels between PAEP and Control by unpaired student t-test (or the correspondent Mann-Whitney test). Correlations of PADL with other variables will be assessed either by the Pearson's or Spearman's coefficients depending on the distribution of the variables. The level of significance for all comparisons will be set at p<0.05. Data will be analyzed using the statistical package SAS version 9.3 (SAS Institute Inc, Cary, NC, USA).

Based on the study of Breyer et al. (2010) exploring the effects of a Nordic walk programme on physical activity in patients with COPD in which they show that the Nordic-walk was able to increase physical activity levels after a 3 month programme (movement intensity, 0.4+/-0.14) in comparison to controls (movement intensity, -0.05+/-0.28), for the comparison between S and C considering changes in physical activity levels as the main outcome, for an alpha of 0.05 and beta 0.1, 24 subjects are required per branch to show statistical significant differences with a 90% power. Assuming a 30% dropouts we plan to include 64 subjects (32 patients per branch, S and C).

To assess the effects of each intervention (S or C) over the short term (three months follow up period), we will perform intra-group analysis (Visit 1, Visit 2, and Visit 3), using One way ANOVA repeated measures test (or the correspondent Friedman's test for non-normally distributed variables). Effects of the PAEP on the main outcome (physical activity levels) will be assessed by comparing the differences (follow up - post PAEP, and post - pre PAEP) in physical activity levels between PAEP and Control by unpaired student t-test (or the correspondent Mann-Whitney test). Results will also be described as mean±SD or median [IQR], according to the normality in data distribution, analyzed by the Shapiro-Wilk test. Correlations of PADL with other variables will be assessed either by the Pearson's or Spearman's coefficients depending on the distribution of the variables. The level of significance for all comparisons will be set at p<0.05. Data will be analyzed using the statistical package SAS version 9.3 (SAS Institute Inc, Cary, NC, USA).