The effects of a physical activity counseling program after an exacerbation in patients with Chronic Obstructive Pulmonary Disease : a randomized controlled pilot study

Background: In some patients with COPD, the disease is characterized by exacerbations. Severe exacerbations warrant a hospitalization, with prolonged detrimental effects on physical activity. Interventions after an exacerbation may improve physical activity, with longstanding health benefits. Physical activity counseling and real-time feedback were effective in stable COPD. No evidence is available on the use of this therapeutic modality in patients after a COPD exacerbation. Methods: Thirty patients were randomly assigned to usual care or physical activity counseling, by telephone contacts at a frequency of 3 times a week and real-time feedback. Lung function, peripheral muscle strength, functional exercise capacity, symptom experience and COPD-related health status were assessed during hospital stay and 1 month later. Results: Both groups significantly recovered in physical activity (PAsteps: control group: 1013 +/- 1275 steps vs intervention group: 984 +/- 1208 steps (p = 0.0005); PAwalk: control group: 13 +/- 14 min vs intervention group: 13 +/- 16 min (p = 0.0002)), functional exercise capacity (control group: 64 +/- 59 m (p = 0.002) vs intervention group: 67 +/- 84 m (p = 0.02)) and COPD-related health status (CAT: control group: -5 [-7 to 1] (p = 0.02) vs intervention group: -3 [-10 to 1] points (p = 0.03)). No differences between groups were observed. Conclusion: From our pilot study, we concluded that telephone based physical activity counseling with pedometer feedback after an exacerbation did not result in better improvements in physical activity and clinical outcomes compared to usual care. Because of the difficult recruitment and the negative intermediate analyses, this study was not continued

Physical activity counselling during pulmonary rehabilitation in patients with COPD : a randomised controlled trial

Background Pulmonary rehabilitation programs only modestly enhance daily physical activity levels in patients with chronic obstructive pulmonary disease (COPD). This randomised controlled trial investigates the additional effect of an individual activity counselling program during pulmonary rehabilitation on physical activity levels in patients with moderate to very severe COPD. Methods Eighty patients (66 +/- 7 years, 81% male, forced expiratory volume in 1 second 45 +/- 16% of predicted) referred for a six-month multidisciplinary pulmonary rehabilitation program were randomised. The intervention group was offered an additional eight-session activity counselling program. The primary outcomes were daily walking time and time spent in at least moderate intense activities. Results Baseline daily walking time was similar in the intervention and control group (median 33 [interquartile range 16-47] vs 29 [17-44]) whereas daily time spent in at least moderate intensity was somewhat higher in the intervention group (17[4-50] vs 12[2-26] min). No significant intervention*time interaction effects were observed in daily physical activity levels. In the whole group, daily walking time and time spent in at least moderate intense activities did not significantly change over time. Conclusions The present study identified no additional effect of eight individual activity counselling sessions during pulmonary rehabilitation to enhance physical activity levels in patients with COPD

Standardizing the analysis of physical activity in patients with COPD following a pulmonary rehabilitation program

BACKGROUND: There is a wide variability in measurement methodology of physical activity. This study investigated the effect of different analysis techniques on the statistical power of physical activity outcomes aft er pulmonary rehabilitation. METHODS: Physical activity was measured with an activity monitor armband in 57 patients with COPD (mean +/- SD age, 66 +/- 7 years; FEV 1, 46 +/- 17% predicted) before and aft er 3 months of pulmonary rehabilitation. The choice of the outcome (daily number of steps [STEPS], time spent in at least moderate physical activity [TMA], mean metabolic equivalents of task level [METS], and activity time [ACT]), impact of weekends, number of days of assessment, post-processing techniques, and influence of duration of daylight time (DT) on the sample size to achieve a power of 0.8 were investigated. RESULTS: The STEPS and ACT (1.6-2.3 metabolic equivalents of task) were the most sensitive outcomes. Excluding weekends decreased the sample size for STEPS (83 vs 56), TMA (160 vs 148), and METS (251 vs 207). Using 4 weekdays (STEPS and TMA) or 5 weekdays (METS) rendered the lowest sample size. Excluding days with, 8 h wearing time reduced the sample size for STEPS (56 vs 51). Differences in DT were an important confounder. CONCLUSIONS: Changes in physical activity following pulmonary rehabilitation are best measured for 4 weekdays, including only days with at least 8 h of wearing time (during waking hours) and considering the difference in DT as a covariate in the analysis

Proprioceptive changes impair balance control in individuals with chronic obstructive pulmonary disease

Copyright @ 2013 Janssens et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Introduction: Balance deficits are identified as important risk factors for falling in individuals with chronic obstructive pulmonary disease (COPD). However, the specific use of proprioception, which is of primary importance during balance control, has not been studied in individuals with COPD. The objective was to determine the specific proprioceptive control strategy during postural balance in individuals with COPD and healthy controls, and to assess whether this was related to inspiratory muscle weakness. Methods: Center of pressure displacement was determined in 20 individuals with COPD and 20 age/gender-matched controls during upright stance on an unstable support surface without vision. Ankle and back muscle vibration were applied to evaluate the relative contribution of different proprioceptive signals used in postural control. Results: Individuals with COPD showed an increased anterior-posterior body sway during upright stance (p=0.037). Compared to controls, individuals with COPD showed an increased posterior body sway during ankle muscle vibration (p=0.047), decreased anterior body sway during back muscle vibration (p=0.025), and increased posterior body sway during simultaneous ankle-muscle vibration (p=0.002). Individuals with COPD with the weakest inspiratory muscles showed the greatest reliance on ankle muscle input when compared to the stronger individuals with COPD (p=0.037). Conclusions: Individuals with COPD, especially those with inspiratory muscle weakness, increased their reliance on ankle muscle proprioceptive signals and decreased their reliance on back muscle proprioceptive signals during balance control, resulting in a decreased postural stability compared to healthy controls. These proprioceptive changes may be due to an impaired postural contribution of the inspiratory muscles to trunk stability. Further research is required to determine whether interventions such as proprioceptive training and inspiratory muscle training improve postural balance and reduce the fall risk in individuals with COPD.This work was supported by the Research Foundation – Flanders (FWO) grants 1.5.104.03, G.0674.09, G.0598.09N and G.0871.13N

The minimal important difference in physical activity in patients with COPD

Background Changes in physical activity (PA) are difficult to interpret because no framework of minimal important difference (MID) exists. We aimed to determine the minimal important difference (MID) in physical activity (PA) in patients with Chronic Obstructive Pulmonary Disease and to clinically validate this MID by evaluating its impact on time to first COPD-related hospitalization. Methods PA was objectively measured for one week in 74 patients before and after three months of rehabilitation (rehabilitation sample). In addition the intraclass correlation coefficient was measured in 30 patients (test-retest sample), by measuring PA for two consecutive weeks. Daily number of steps was chosen as outcome measurement. Different distribution and anchor based methods were chosen to calculate the MID. Time to first hospitalization due to an exacerbation was compared between patients exceeding the MID and those who did not. Results Calculation of the MID resulted in 599 (Standard Error of Measurement), 1029 (empirical rule effect size), 1072 (Cohen's effect size) and 1131 (0.5SD) steps.day(-1). An anchor based estimation could not be obtained because of the lack of a sufficiently related anchor. The time to the first hospital admission was significantly different between patients exceeding the MID and patients who did not, using the Standard Error of Measurement as cutoff. Conclusions The MID after pulmonary rehabilitation lies between 600 and 1100 steps.day(-1). The clinical importance of this change is supported by a reduced risk for hospital admission in those patients with more than 600 steps improvement

Impaired Postural Control Reduces Sit-to-Stand-to-Sit Performance in Individuals with Chronic Obstructive Pulmonary Disease

Abstract Background: Functional activities, such as the sit-to-stand-to-sit (STSTS) task, are often impaired in individuals with chronic obstructive pulmonary disease (COPD). The STSTS task places a high demand on the postural control system, which has been shown to be impaired in individuals with COPD. It remains unknown whether postural control deficits contribute to the decreased STSTS performance in individuals with COPD. Methods: Center of pressure displacement was determined in 18 individuals with COPD and 18 age/gender-matched controls during five consecutive STSTS movements with vision occluded. The total duration, as well as the duration of each sit, sit-to-stand, stand and stand-to-sit phase was recorded. Results: Individuals with COPD needed significantly more time to perform five consecutive STSTS movements compared to healthy controls (1966 vs. 1364 seconds, respectively; p = 0.001). The COPD group exhibited a significantly longer stand phase (p = 0.028) and stand-to-sit phase (p = 0.001) compared to the control group. In contrast, the duration of the sit phase (p = 0.766) and sit-to-stand phase (p = 0.999) was not different between groups. Conclusions: Compared to healthy individuals, individuals with COPD needed significantly more time to complete those phases of the STSTS task that require the greatest postural control. These findings support the proposition that suboptimal postural control is an important contributor to the decreased STSTS performance in individuals with COPD

Accuracy of consumer-based activity trackers as measuring tool and coaching device in patients with COPD and healthy controls

Background Consumer-based activity trackers are used to measure and improve physical activity. However, the accuracy of these devices as clinical endpoint or coaching tool is unclear. We investigated the use of two activity trackers as measuring and coaching tool in patients with Chronic Obstructive Pulmonary Disease (COPD) and healthy age-matched controls. Methods Daily steps were measured by two consumer-based activity trackers (Fitbit Zip, worn at the hip and Fitbit Alta, worn at the wrist) and a validated activity monitor (Dynaport Movemonitor) in 28 patients with COPD and 14 healthy age-matched controls for 14 consecutive days. To investigate the accuracy of the activity trackers as a clinical endpoint, mean step count per patient were compared with the reference activity monitor and agreement was investigated by Bland-Altman plots. To evaluate the accuracy of activity trackers as coaching tool, day-by-day differences within patients were calculated for all three devices. Additionally, consistency of ranking daily steps between the activity trackers and accelerometer was investigated by Kendall correlation coefficient. Results As a measuring tool, the hip worn activity tracker significantly underestimates daily step count in patients with COPD as compared to DAM (mean +/- SD Delta-1112 +/- 872 steps/day; p<0.0001). This underestimation is less prominent in healthy subjects (p = 0.21). The wrist worn activity tracker showed a non-significant overestimation of step count (p = 0.13) in patients with COPD, and a significant overestimation of daily steps in healthy controls (mean +/- SD Delta+1907 +/- 2147 steps/day; p = 0.006). As a coaching tool, both hip and wrist worn activity tracker were able to pick up the day-by-day variability as measured by Dynaport (consistency of ranking resp. r = 0.80; r = 0.68 in COPD). Conclusion Although the accuracy of hip worn consumer-based activity trackers in patients with COPD and wrist worn activity trackers in healthy subjects as clinical endpoints is unsatisfactory, these devices are valid to use as a coaching tool

Demand driven rural agricultural development in South Africa: the case of the agricultural sustainable community investment programme

Food security is high on the development agenda in South Africa. A wide range of agricultural interventions exist across the country initiated by various stakeholders at different levels of society. While many interventions focus on production related constraints of food security, there are far fewer that focus on the integration of smallholder farmers in the supply chain. The research subject is the Agricultural Sustainable Community Investment Project (Agri-SCIP), operating on the south coast of the Kwa-Zulu Natal Province. As a demand driven alternative market model, the focus of the project is on the integration of local smallholder farmers in the fresh produce supply chain. The main research question is whether the participation of smallholder farmers in the fresh produce supply actually has actually improved for participants of the test case. Existing barriers to entry for smallholder farmers are mitigated in the project. Through a literature review five critical factors for market participation by smallholder farmers are identified, namely transport and distance to markets, product quality, product quantity, the buyer-seller relationship and market information. A literature review and empirical data are applied to test the impact of the Agri-SCIP project on the participation of smallholder farmers in the fresh produce supply chain based on these five critical factors. The data indicate that many of the existing barriers to entry in the fresh produce supply chain for the smallholder farmers are mitigated, and have been shifted to a collectively owned co-operative. Therefore, as an alternative market model, Agri-SCIP has the potential to provide a sustainable solution for smallholder development in South Africa with a strong focus on supply chain participation. The development of a strong smallholder farmers base and the development of smallholder farmers into semi-commercial farmers are potential long term results of the Agri-SCIP alternative market model