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Dive into the research topics where P.D.L.P.M. van der Valk is active.

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Featured researches published by P.D.L.P.M. van der Valk.


Thorax | 2003

Self-management education for patients with chronic obstructive pulmonary disease: a systematic review

Evelyn Monninkhof; P.D.L.P.M. van der Valk; J. van der Palen; C.L.A. van Herwaarden; Martyn R Partridge; Gerhard A. Zielhuis

Background: The idea of self-management is to teach patients how to carry out the activities of daily living optimally in the face of their physiological impairment, and to prevent or decrease the severity of exacerbations by means of life style adaptation. In chronic obstructive pulmonary disease (COPD) the value of self-management education is not clear. This review was undertaken to clarify the effectiveness of self-management programmes in COPD. Methods: A search was made of the Cochrane Airways Group trial registers, Medline, reference lists, and abstracts of medical conferences for controlled trials of self-management education in patients with COPD. Two reviewers independently assessed each paper for methodological quality and extracted the data. Results: The reviewers included 12 articles describing eight randomised controlled trials and one controlled clinical trial in which self-management education was compared with usual care. The studies assessed a broad spectrum of outcome measures with different follow up times so meta-analysis could not be undertaken. Self-management education had no effect on hospital admissions, emergency room visits, days lost from work, and lung function. Inconclusive results were observed on health related quality of life, COPD symptoms, and use of healthcare facilities such as doctor and nurse visits. Self-management education reduced the need for rescue medication and led to increased use of courses of oral steroids and antibiotics for respiratory symptoms. Conclusions: Insufficient data were obtained to make recommendations because of the wide variation in outcome measures used and other limitations to generalisations in the current published literature. Further research in this area is needed.


European Journal of Cancer | 1996

Major Vault Protein LRP-related Multidrug Resistance

Miguel A. Izquierdo; George L. Scheffer; Marcel J. Flens; A. B. Schroeijers; P.D.L.P.M. van der Valk; R. J. Scheper

drugs is a major cause of failure of cancer treatment. The identification of the mechanisms responsible for causing resistance is of considerable interest and potential clinical practice. The problem of drug resistance has been investigated in the laboratory by using drug-selected cancer cell lines. Biochemical studies have described distinct differences between parent cells and the corresponding resistant sublines [ 11. Frequently, upon exposure to natural product drugs, mammalian cells acquire resistance to many structurally and functionally unrelated compounds, including anthracyclines, epipodophyllotoxins, vinca alkaloids and taxanes. Such cells are referred to


Cochrane Database of Systematic Reviews | 2002

Self-management education for chronic obstructive pulmonary disease.

Evelyn Monninkhof; P.D.L.P.M. van der Valk; J. van der Palen; C.L.A. van Herwaarden; Martyn R Partridge; Eh Walters; Gerhard A. Zielhuis

BACKGROUNDnIn asthma, self-management programmes have been proven to be effective. In COPD, their value is not clear.nnnOBJECTIVESnTo assess the efficacy of COPD self-management/ education programmes on health outcomes and use of health servicesnnnSEARCH STRATEGYnWe searched the Cochrane Airways Group trial registers, MEDLINE (January 1985 to October 2001), reference lists, and abstracts of medical conferences. We also contacted research groups in the field for ongoing trials and unpublished material.nnnSELECTION CRITERIAnControlled trials (randomised and non-randomised) of self-management education in patients with COPD. Studies focusing mainly on physical pulmonary rehabilitation were excluded.nnnDATA COLLECTION AND ANALYSISnTwo reviewers independently assessed trial quality and extracted data. Investigators were contacted for additional information.nnnMAIN RESULTSnThe reviewers included 12 articles describing 8 randomised-controlled trials and 1 controlled clinical trial. Self-management education was compared with usual care in 8 studies. The studies in this review assessed a broad-spectrum of outcome measures with different follow-up times. Synthesis of the results using meta-analysis was always not possible. The studies showed no effect of self-management education on hospital admissions, emergency room visits, days lost from work and lung function. Inconclusive results were observed on health-related quality of life (HRQoL): studies using the disease specific SGRQ showed a better quality of life in the patients in the intervention group, but only in the activity component where there was heterogeneity between the results of the two included studies. A potential reason for the absence of convincing effects on HRQoL is the limited use of COPD-specific instruments. Inconclusive results were observed on COPD-symptoms and use of other health care resources such as doctor and nurse visits. Self-management education reduced the need for rescue medication, and led to an increased use of courses of oral steroids and antibiotics for respiratory symptoms.nnnREVIEWERS CONCLUSIONSnThe data available for this review are insufficient for forming recommendations. Further research on the effectiveness of self-management programmes should be focussed on behavioural change evaluated in well designed randomised controlled trials with standardised outcomes designed for use in COPD patients, and with long follow-up time so that definite conclusions can be made.


Thorax | 2009

(Cost)-effectiveness of self-treatment of exacerbations on the severity of exacerbations in patients with COPD: the COPE II study

T. W. Effing; Huib Kerstjens; P.D.L.P.M. van der Valk; Gerhard A. Zielhuis; J. van der Palen

Background: Chronic obstructive pulmonary disease (COPD) is a chronic disease with a high prevalence and rapidly increasing incidence rates. The effect of self-treatment of COPD exacerbations on the severity of exacerbations during a 1-year period was examined and a cost-effectiveness analysis was performed. Methods: Patients were randomly allocated to four 2-hour self-management sessions, with or without training in self-treatment of exacerbations. Patients in the self-treatment group received an action plan with the possibility to initiate a course of prednisolone (with or without antibiotics). During follow-up, all participants kept a daily symptom diary. These provided the data to calculate the frequency of exacerbations, the number of exacerbation days and mean daily severity scores. Results: Data were analysed for 142 randomised patients (self-treatment: nu200a=u200a70; control: nu200a=u200a72). The frequency of exacerbations was identical in both study groups (mean (SD) 3.5 (2.7)). Patients in the self-treatment group reported fewer exacerbation days (median 31 (interquartile range (IQR) 8.9–67.5) in the self-treatment group vs 40 (IQR 13.3–88.2) in the control group; pu200a=u200a0.064); the difference was significant in the group of patients with a high number of exacerbation days per year (>137 (90th percentile of the whole study population); pu200a=u200a0.028). The mean severity score of an exacerbation day was equal in both groups. No between-group differences were found in health-related quality of life. Cost-effectiveness analyses showed that applying self-treatment saved €154 per patient, with a trend towards a lower probability for hospital admissions (0.20/patient/year in the self-treatment group vs 0.33/patient/year in the control group; pu200a=u200a0.388) and a significant reduction of health care contacts (5.37/patient/year in the self-treatment group vs 6.51/patient/year in the control group; pu200a=u200a0.043). Conclusion: Self-treatment of exacerbations incorporated in a self-management programme leads to fewer exacerbation days and lower costs.


European Journal of Preventive Cardiology | 2012

Effect of outpatient exercise training programmes in patients with chronic heart failure: a systematic review.

S. van der Meer; Marlies Zwerink; M. van Brussel; P.D.L.P.M. van der Valk; E.M. Wajon; J. van der Palen

Background: Advantages of outpatient exercise training are reduced waiting lists, better compliance, reduced time investment by the patient with reduced travel expenses, and less dependence on other people to participate. Therefore, this systematic review studies the effects of outpatient exercise training programmes compared with usual care on exercise capacity, exercise performance, quality of life, and safety in patients with chronic heart failure. Design: Systematic review with meta-analysis. Methods: Randomized controlled trials concerning patients with chronic heart failure, with a left ventricular ejection fraction ≤40%, were included. A meta-analysis was performed. Results: Twenty-two studies were included. VO2max, 6-min walking test, and quality of life showed significant differences in favour of the intervention group of 1.85u2009ml/kg/min, 47.9u2009m, and 6.9 points, respectively. In none of the studies, a significant relationship was found between exercise training and adverse events. Conclusion: This meta-analysis illustrates the efficacy and safety of outpatient training programmes for patients with chronic heart failure.


Clinical Rehabilitation | 2014

A telerehabilitation intervention for patients with Chronic Obstructive Pulmonary Disease: a randomized controlled pilot trial:

Monique Tabak; Miriam Marie Rosé Vollenbroek-Hutten; P.D.L.P.M. van der Valk; J. van der Palen; Hermanus J. Hermens

Objective: First, to investigate the effects of a telerehabilitation intervention on health status and activity level of patients with Chronic Obstructive Pulmonary Disease (COPD), compared to usual care. Second, to investigate how patients comply with the intervention and whether compliance is related to treatment outcomes. Design: a randomized controlled pilot trial Subjects: Thirty-four patients diagnosed with COPD. Intervention: The telerehabilitation application consists of an activity coach (3D-accelerometer with smartphone) for ambulant activity registration and real-time feedback, complemented by a web portal with a symptom diary for self-treatment of exacerbations. The intervention group used the application for 4 weeks. The control group received usual care. Main measures: Activity level measured by a pedometer (in steps/day), health status by the Clinical COPD Questionnaire at baseline and after intervention. Compliance was expressed as the time the activity coach was worn. Results: Fourteen intervention and 16 control patients completed the study. Activity level (steps/day) was not significantly affected by the intervention over time. There was a non-significant difference in improvement in health status between the intervention (−0.34±0.55) and control group (0.02±0.57, p=0.10). Health status significantly improved within the intervention group (p=0.05). The activity coach was used more than prescribed (108%) and compliance was related to the increase in activity level for the first two feedback weeks (r=0.62, p=0.03). Conclusions: This pilot study shows the potential of the telerehabilitation intervention: compliance with the activity coach was high, which directly related to an improvement in activity levels.


Chronic Respiratory Disease | 2004

Economic evaluation of a comprehensive self-management programme in patients with moderate to severe chronic obstructive pulmonary disease

E Monninkhofe; P.D.L.P.M. van der Valk; Tjard Schermer; J. van der Palen; C.L.A. van Herwaarden; Gerhard A. Zielhuis

Aims: The main objective of this study was to investigate whether a comprehensive self-management programme, including self-treatment guidelines for exacerbations and a fitness programme, is an efficient treatment option for chronic obstructive pulmonary disease (COPD) patients. Method: We randomly allocated 248 COPD patients to either self-management (127) or usual care (121). Data on preference-based utilities (EuroQol-5D), health-related quality of life (HRQoL), health-care resource use and productivity losses associated with exacerbations were prospectively collected. Quality-adjusted life years (QALYs) were calculated. The economic analysis took the societal perspective and the observation period was one year. Results: As we observed that the groups were equally effective in terms of QALYs and HRQoL (SGRQ), we described a cost minimization analysis only. The self-management programme-specific costs amounted to 6642 per patient. In the base-case cost analysis, the incremental cost difference amounted to 838 per patient per year in favour of usual care. When only direct medical costs were included, the incremental annual cost of self-managementrelative to usual care was 179 per person per year. If time costs for the fitness programme were set to zero, the costs for self-management diminished to 542. Sensitivity analysis showed that these results were robust to changes in the underlying assumptions. Conclusion: We conclude that the COPE self-management programme is not an efficient treatment option for moderate to severe COPD patients who rate their HRQoL relatively high. The programme was twice as expensive as usual care and had no measurable beneficial effects on QALYs or HRQoL.


European Respiratory Journal | 2007

The role of atypical respiratory pathogens in exacerbations of chronic obstructive pulmonary disease

B. M. W. Diederen; P.D.L.P.M. van der Valk; J. A. W. J. Kluytmans; M. Peeters; Ron Hendrix

The aetiology of acute exacerbations of chronic obstructive pulmonary disease (COPD) is heterogeneous and still under discussion. Serological studies have suggested that Mycoplasma pneumoniae, Chlamydia pneumoniae and Legionella pneumophila may play a role in acute exacerbations of COPD. The presence of these atypical pathogens in sputum samples was investigated in patients with stable COPD and with acute exacerbations of COPD using real-time PCR. The present study was part of a randomised, double-blind, single-centre study and a total of 248 sputum samples from 104 COPD patients were included. In total, 122 samples obtained during stable disease (stable-state sputa) and 126 samples obtained during acute exacerbations of COPD (exacerbation sputa) were tested. Of the 122 stable-state sputa, all samples were negative for M. pneumoniae and C. pneumoniae DNA, whereas one sample was positive for Legionella non-pneumophila DNA. Of the 126 exacerbation sputa, all samples were negative for M. pneumoniae and C. pneumoniae DNA, whereas one sample was positive for Legionella non-pneumophila DNA. The possible relationship between the presence of atypical pathogens and the aetiology of acute exacerbations in chronic obstructive pulmonary disease was investigated in patients with stable disease and in those with acute exacerbations using real-time PCR. No indication was found of a role for Legionella spp., Chlamydia pneumoniae or Mycoplasma pneumoniae in stable, moderately severe chronic obstructive pulmonary disease and in its exacerbations.


Respiratory Medicine | 2009

Relation of sputum colour to bacterial load in acute exacerbations of COPD.

Marjolein Brusse-Keizer; A. J. Grotenhuis; Huib Kerstjens; M.C. Telgen; van der Jacobus Palen; M. G. R. Hendrix; P.D.L.P.M. van der Valk

BACKGROUNDnWhen COPD patients present with an exacerbation, one cannot verify a bacterial cause of an exacerbation without time-consuming laboratory analyses. This makes it difficult to decide up front if antibiotic treatment is needed. Therefore, in clinical practice sputum colour and purulence are often used.nnnOBJECTIVEnTo determine whether sputum colour and purulence, assessed by the Stockley colour chart, correlated with overall bacterial load in COPD patients admitted for an exacerbation. To check the robustness of the colour and purulence assessment, we correlated the changes in these parameters and the corresponding change in bacterial load in sputum over the first seven days of hospitalisation.nnnMETHODSnTwenty-two COPD patients admitted to the hospital for an exacerbation were included. During the first seven days daily sputum samples were collected.nnnRESULTSnA very weak association between bacterial load and sputum colour was found. There was no difference in bacterial load between patients with purulent sputum or not. Also, no consistent relationship between change in sputum colour and change in bacterial load during admission was found.nnnCONCLUSIONSnThe very weak association between bacterial load and sputum colour confirms concerns over the usefulness of the colour chart. The distinction between purulent and mucoid sputum at exacerbation is insufficient for distinction between patients who are likely to benefit from antibiotic therapy and those who are not. Complementary studies are needed to determine which other, easily measurable factors can be used as predictors for an indication for use of antibiotics; sputum colour is not the one.


Acta Neurologica Scandinavica | 2000

Tuberculous meningitis: pitfalls in diagnosis.

A.A.J. Joosten; P.D.L.P.M. van der Valk; J. A. G. Geelen; W. P. J. Severin; E.N.H. Jansen Steur

Objectives– The diagnosis of tuberculous meningitis is easily missed because the variety of symptoms give rise to problems with the differential diagnosis. Material– Five cases of difficult to diagnose tuberculous meningitis are presented. Results– Several reasons for the diagnostic delay are highlighted. The fact that tuberculous meningitis is rather rare in developed countries contributes to this problem. Recommendations for a quick diagnosis are given. Conclusion– The diagnosis of tuberculous meningitis in developed countries is often made after a substantial delay. In case of suspicion on the diagnosis additional examination should be performed and treatment should be started immediately.

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Huib Kerstjens

University Medical Center Groningen

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T. W. Effing

Repatriation General Hospital

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