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1.  Validity and Usability of Low-Cost Accelerometers for Internet-Based Self-Monitoring of Physical Activity in Patients With Chronic Obstructive Pulmonary Disease 
The importance of regular physical activity for patients with chronic obstructive pulmonary disease (COPD) is well-established. However, many patients do not meet the recommended daily amount. Accelerometers might provide patients with the information needed to increase physical activity in daily life.
Our objective was to assess the validity and usability of low-cost Internet-connected accelerometers. Furthermore we explored patients’ preferences with regards to the presentation of and feedback on monitored physical activity.
To assess concurrent validity we conducted a field validation study with patients who wore two low-cost accelerometers, Fitbit and Physical Activity Monitor (PAM), at the same time along with a sophisticated multisensor accelerometer (SenseWear Armband) for 48 hours. Data on energy expenditure assessed from registrations from the two low-cost accelerometers were compared to the well validated SenseWear Armband which served as a reference criterion. Usability was examined in a cross-over study with patients who, in succession, wore the Fitbit and the PAM for 7 consecutive days and filled out a 16 item questionnaire with regards to the use of the corresponding device
The agreement between energy expenditure (METs) from the SenseWear Armband with METs estimated by the Fitbit and PAM was good (r=.77) and moderate (r=.41), respectively. The regression model that was developed for the Fitbit explained 92% whereas the PAM-model could explain 89% of total variance in METs measured by the SenseWear. With regards to the usability, both the Fitbit and PAM were well rated on all items. There were no significant differences between the two devices.
The low-cost Fitbit and PAM are valid and usable devices to measure physical activity in patients with COPD. These devices may be useful in long-term interventions aiming at increasing physical activity levels in these patients.
PMCID: PMC4259960  PMID: 25347989
accelerometers; activity monitoring; chronic obstructive pulmonary disease; validity; usability
2.  Long-Term Outcomes of Internet-Based Self-Management Support in Adults With Asthma: Randomized Controlled Trial 
Long-term asthma management falls short of the goals set by international guidelines. The Internet is proposed as an attractive medium to support guided self-management in asthma. Recently, in a multicenter, pragmatic randomized controlled parallel trial with a follow-up period of 1 year, patients were allocated Internet-based self-management (IBSM) support (Internet group [IG]) or usual care (UC) alone. IBSM support was automatically terminated after 12 months of follow-up. In this study, IBSM support has been demonstrated to improve asthma-related quality of life, asthma control, lung function, and the number of symptom-free days as compared to UC. IBSM support was based on known key components for effective self-management and included weekly asthma control monitoring and treatment advice, online and group education, and communication (both online and offline) with a respiratory nurse.
The objective of the study was to assess the long-term effects of providing patients 1 year of IBSM support as compared to UC alone.
Two hundred adults with physician-diagnosed asthma (3 or more months of inhaled corticosteroids prescribed in the past year) from 37 general practices and 1 academic outpatient department who previously participated were invited by letter for additional follow-up at 1.5 years after finishing the study. The Asthma Control Questionnaire (ACQ) and the Asthma Quality of Life Questionnaire (AQLQ) were completed by 107 participants (60 UC participants and 47 IG participants). A minimal clinical important difference in both questionnaires is 0.5 on a 7-point scale.
At 30 months after baseline, a sustained and significant difference in terms of asthma-related quality of life of 0.29 (95% CI 0.01-0.57) and asthma control of -0.33 (95% CI -0.61 to -0.05) was found in favor of the IBSM group. No such differences were found for inhaled corticosteroid dosage or for lung function, measured as forced expiratory volume in 1 second.
Improvements in asthma-related quality of life and asthma control were sustained in patients who received IBSM support for 1 year, even up to 1.5 years after terminating support. Future research should be focused on implementation of IBSM on a wider scale within routine asthma care.
Trial Registration
International Standard Randomized Controlled Trial Number (ISRCTN): 79864465; (Archived by WebCite at
PMCID: PMC3785973  PMID: 24028826
asthma; quality of life; self-management; long-term; eHealth; Internet; telemedicine
3.  A disintegrin and metalloprotease 33 and chronic obstructive pulmonary disease pathophysiology 
Thorax  2006;62(3):242-247.
Chronic obstructive pulmonary disease (COPD) is a respiratory disorder with increasing prevalence and mortality. It is associated with airway obstruction, increased airway hyper‐responsiveness (AHR), and ongoing airway and lung inflammation dominated by CD8 lymphocytes and neutrophils. Single‐nucleotide polymorphisms (SNPs) in a disintegrin and metalloprotease 33 (ADAM33) gene have been associated with AHR and COPD.
To assess whether SNPs in ADAM33 are associated with the severity of AHR and airway inflammation in COPD.
Eight SNPs in ADAM33 (F+1, Q‐1, S_1, S_2, ST+5, T_1, T_2, V_4) were genotyped in 111 patients with COPD (96 males, 69 current smokers, mean (standard deviation (SD)), aged 62 (8) years, median pack‐years 42 (IQR 31–55), mean postbronchodilator forced expiratory volume in 1 s (FEV1)% predicted 63 (9). Provocative concentration of methacholine causing a decrease in FEV1 of 20% (PC20 methacholine), sputum and bronchial biopsies were collected.
Patients with the ST+5 AA genotype had more severe AHR, higher numbers of sputum inflammatory cells and CD8 cells in bronchial biopsies than patients with the GG genotype (p = 0.03, 0.05 and 0.01, respectively). CD8 cell numbers were lower in patients carrying the minor allele of SNP T_1 and T_2, and homozygotic minor variants of SNP S_2 compared with the wild type (p = 0.02, 0.01 and 0.02, respectively).
This is the first study revealing that SNPs in a gene that confers susceptibility to COPD in the general population—that is, ADAM33—are associated with AHR and airway inflammation in COPD. These findings constitute an important step forward in linking gene polymorphisms with COPD pathophysiology, thereby possibly contributing to better treatments for this progressive and disabling disease in the future.
PMCID: PMC2117167  PMID: 17090574
4.  Implementation strategies of internet-based asthma self-management support in usual care. Study protocol for the IMPASSE cluster randomized trial 
Internet-based self-management (IBSM) support cost-effectively improves asthma control, asthma related quality of life, number of symptom-free days, and lung function in patients with mild to moderate persistent asthma. The current challenge is to implement IBSM in clinical practice.
This study is a three-arm cluster randomized trial with a cluster pre-randomisation design and 12 months follow-up per practice comparing the following three IBSM implementation strategies: minimum strategy (MS): dissemination of the IBSM program; intermediate strategy (IS): MS + start-up support for professionals (i.e., support in selection of the appropriate population and training of professionals); and extended strategy (ES): IS + additional training and ongoing support for professionals. Because the implementation strategies (interventions) are primarily targeted at general practices, randomisation will occur at practice level.
In this study, we aim to evaluate 14 primary care practices per strategy in the Leiden-The Hague region, involving 140 patients per arm. Patients aged 18 to 50 years, with a physician diagnosis of asthma, prescription of inhaled corticosteroids, and/or montelukast for ≥3 months in the previous year are eligible to participate. Primary outcome measures are the proportion of referred patients that participate in IBSM, and the proportion of patients that have clinically relevant improvement in the asthma-related quality of life. The secondary effect measures are clinical outcomes (asthma control, lung function, usage of airway treatment, and presence of exacerbations); self-management related outcomes (health education impact, medication adherence, and illness perceptions); and patient utilities. Process measures are the proportion of practices that participate in IBSM and adherence of professionals to implementation strategies. Cost-effective measurements are medical costs and healthcare consumption. Follow-up is six months per patient.
This study provides insight in the amount of support that is required by general practices for cost-effective implementation of IBSM. Additionally, design and results can be beneficial for implementation of other self-management initiatives in clinical practice.
Trial registration
the Netherlands National Trial Register NTR2970
PMCID: PMC3514342  PMID: 23171672
Asthma; Self-management; Telemanagement; E-health; Self-management; Implementation; Chronic care
5.  Asthma control cost-utility randomized trial evaluation (ACCURATE): the goals of asthma treatment 
Despite the availability of effective therapies, asthma remains a source of significant morbidity and use of health care resources. The central research question of the ACCURATE trial is whether maximal doses of (combination) therapy should be used for long periods in an attempt to achieve complete control of all features of asthma. An additional question is whether patients and society value the potential incremental benefit, if any, sufficiently to concur with such a treatment approach. We assessed patient preferences and cost-effectiveness of three treatment strategies aimed at achieving different levels of clinical control:
1. sufficiently controlled asthma
2. strictly controlled asthma
3. strictly controlled asthma based on exhaled nitric oxide as an additional disease marker
720 Patients with mild to moderate persistent asthma from general practices with a practice nurse, age 18-50 yr, daily treatment with inhaled corticosteroids (more then 3 months usage of inhaled corticosteroids in the previous year), will be identified via patient registries of general practices in the Leiden, Nijmegen, and Amsterdam areas in The Netherlands. The design is a 12-month cluster-randomised parallel trial with 40 general practices in each of the three arms. The patients will visit the general practice at baseline, 3, 6, 9, and 12 months. At each planned and unplanned visit to the general practice treatment will be adjusted with support of an internet-based asthma monitoring system supervised by a central coordinating specialist nurse. Patient preferences and utilities will be assessed by questionnaire and interview. Data on asthma control, treatment step, adherence to treatment, utilities and costs will be obtained every 3 months and at each unplanned visit. Differences in societal costs (medication, other (health) care and productivity) will be compared to differences in the number of limited activity days and in quality adjusted life years (Dutch EQ5D, SF6D, e-TTO, VAS). This is the first study to assess patient preferences and cost-effectiveness of asthma treatment strategies driven by different target levels of asthma control.
Trial registration
Netherlands Trial Register (NTR): NTR1756
PMCID: PMC3295696  PMID: 22114896
6.  Smoking status and anti-inflammatory macrophages in bronchoalveolar lavage and induced sputum in COPD 
Respiratory Research  2011;12(1):34.
Macrophages have been implicated in the pathogenesis of COPD. M1 and M2 macrophages constitute subpopulations displaying pro- and anti-inflammatory properties. We hypothesized that smoking cessation affects macrophage heterogeneity in the lung of patients with COPD. Our aim was to study macrophage heterogeneity using the M2-marker CD163 and selected pro- and anti-inflammatory mediators in bronchoalveolar lavage (BAL) fluid and induced sputum from current smokers and ex-smokers with COPD.
114 COPD patients (72 current smokers; 42 ex-smokers, median smoking cessation 3.5 years) were studied cross-sectionally and underwent sputum induction (M/F 99/15, age 62 ± 8 [mean ± SD] years, 42 (31-55) [median (range)] packyears, post-bronchodilator FEV1 63 ± 9% predicted, no steroids past 6 months). BAL was collected from 71 patients. CD163+ macrophages were quantified in BAL and sputum cytospins. Pro- and anti-inflammatory mediators were measured in BAL and sputum supernatants.
Ex-smokers with COPD had a higher percentage, but lower number of CD163+ macrophages in BAL than current smokers (83.5% and 68.0%, p = 0.04; 5.6 and 20.1 ×104/ml, p = 0.001 respectively). The percentage CD163+ M2 macrophages was higher in BAL compared to sputum (74.0% and 30.3%, p < 0.001). BAL M-CSF levels were higher in smokers than ex-smokers (571 pg/ml and 150 pg/ml, p = 0.001) and correlated with the number of CD163+ BAL macrophages (Rs = 0.38, p = 0.003). No significant differences were found between smokers and ex-smokers in the levels of pro-inflammatory (IL-6 and IL-8), and anti-inflammatory (elafin, and Secretory Leukocyte Protease Inhibitor [SLPI]) mediators in BAL and sputum.
Our data suggest that smoking cessation partially changes the macrophage polarization in vivo in the periphery of the lung towards an anti-inflammatory phenotype, which is not accompanied by a decrease in inflammatory parameters.
PMCID: PMC3072953  PMID: 21426578
7.  Airway inflammation contributes to health status in COPD: a cross-sectional study 
Respiratory Research  2006;7(1):140.
Chronic obstructive pulmonary disease (COPD) is characterized by irreversible airflow limitation and airway inflammation, accompanied by decreased health status. It is still unknown which factors are responsible for the impaired health status in COPD. We postulated that airway inflammation negatively contributes to health status in COPD.
In 114 COPD patients (99 male, age: 62 ± 8 yr, 41 [31–55] pack-years, no inhaled or oral corticosteroids, postbronchodilator FEV1: 63 ± 9% pred, FEV1/IVC: 48 ± 9%) we obtained induced sputum and measured health status (St. George's respiratory questionnaire (SGRQ)), postbronchodilator FEV1, hyperinflation (RV/TLC), and airway hyperresponsiveness to methacholine (PC20). Sputum was induced by hypertonic saline and differential cell counts were obtained in 102 patients.
Univariate analysis showed that SGRQ total and symptom score were positively associated with % sputum macrophages (r = 0.20, p = 0.05; and r = 0.20, p = 0.04, respectively). Multiple regression analysis confirmed these relationships, providing significant contributions of % sputum macrophages (B = 0.25, p = 0.021) and RV/TLC (B = 0.60, p = 0.002) to SGRQ total score. Furthermore, SGRQ symptom score was associated with % sputum macrophages (B = 0.30, p = 0.03) and RV/TLC (B = 0.48, p = 0.044), whilst SGRQ activity score was associated with % sputum macrophages (B = 0.46, p = 0.002), RV/TLC (B = 0.61, p = 0.015), and PC20 (B = -9.3, p = 0.024). Current smoking and FEV1 were not significantly associated with health status in the multiple regression analysis.
We conclude that worse health status in COPD patients is associated with higher inflammatory cell counts in induced sputum. Our findings suggest that airway inflammation and hyperinflation independently contribute to impaired health status in COPD. This may provide a rationale for anti-inflammatory therapy in this disease.
PMCID: PMC1697818  PMID: 17137518

Results 1-7 (7)