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Dive into the research topics where L. van Dijk is active.

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Featured researches published by L. van Dijk.


Annals of the Rheumatic Diseases | 2012

Use of statins is associated with an increased risk of rheumatoid arthritis

H J I de Jong; Olaf H. Klungel; L. van Dijk; Rob J. Vandebriel; Hubert G. M. Leufkens; J.W. Van Der Laan; J.W. Cohen Tervaert; H. van Loveren

Objectives Statins offer significant cardiovascular benefits. Their use, however, influences immune regulation, which may potentially facilitate autoimmunity, eventually resulting in autoimmune diseases such as rheumatoid arthritis (RA).The authors studied whether statin use was associated with an increased risk of developing RA by conducting a case–control study using the Netherlands Information Network of General Practice database. Methods The authors identified 508 patients aged 40 years or older with a first-time diagnosis of RA in the period 2001–2006. Each RA case was matched to five controls for age, sex and index date, which was selected 1 year before the first diagnosis of RA. Odds ratios for the first-time diagnosis of RA were verified by a referral to a rheumatologist and/or at least one prescription of disease-modifying anti-rheumatic drugs and/or two prescriptions of corticosteroids after the date of first diagnosis. Results Cases were more often users of statins (15.9%) compared to controls (8.6%). After adjustment for cardiovascular risk factors and use of comedication, statin use was associated with an increased risk of incident RA (adjusted OR, 1.71 (95% CI 1.16 to 2.53); p=0.007). A consistent trend of increasing risk with increased cumulative duration, cumulative defined daily doses and number of prescriptions was not observed. However, a small trend between the potency of statin treatment and the risk of RA was found. Conclusions Statin use seems to be associated with an increased risk of developing RA. Our findings should be replicated by additional studies.


Patient Preference and Adherence | 2014

Relationship between medication beliefs, self-reported and refill adherence, and symptoms in patients with asthma using inhaled corticosteroids.

Mna Van Steenis; Jeanine A. Driesenaar; Jozien M. Bensing; R. van Hulten; Patrick C. Souverein; L. van Dijk; Pagm De Smet; A.M. (Sandra) van Dulmen

Background Beliefs play a crucial role in medication adherence. Interestingly, the relationship between beliefs and adherence varies when different adherence measures are used. How adherence, in turn, is related to asthma symptoms is still unclear. Our aim was to investigate the relationship between beliefs (ie, necessities and concerns) about inhaled corticosteroids (ICS) and subjectively as well as objectively measure adherence and the agreement between these measures. Further, the relationship between adherence and asthma symptoms was examined. Methods A total of 280 patients aged 18–80 years who filled at least two ICS prescriptions in the preceding year were recruited to complete a questionnaire. The questionnaire included the Beliefs about Medicines Questionnaire to assess necessity beliefs and concerns about ICS, four questions about ICS use to measure self-reported adherence, and the Asthma Control Questionnaire to assess asthma symptoms. Proportion of days covered was used to determine pharmacy refill adherence. Results Data from 93 patients with asthma were analyzed. Necessities were positively related to self-reported adherence (P = 0.01). No other associations were found between beliefs and subjective or objective adherence. There was no correlation between self-reported and refill adherence. Participants were significantly (P < 0.001) less adherent according to self-report data (24.4%) than according to pharmacy data (57.8%). No relationship was found between adherence and asthma symptoms. Conclusion Higher necessities are associated with higher self-reported adherence, suggesting that it could be more important to focus on necessities than on concerns in an attempt to improve adherence. Self-reported and refill adherence measurements cannot be used interchangeably. No relationship between adherence and asthma symptoms was found.


Diabetic Medicine | 2014

Short- and long-term effects of real-time medication monitoring with short message service (SMS) reminders for missed doses on the refill adherence of people with Type 2 diabetes : Evidence from a randomized controlled trial

M. Vervloet; L. van Dijk; D.H. de Bakker; Patrick C. Souverein; J. Santen-Reestman; B. van Vlijmen; M. C. W. van Aarle; L. van der Hoek; Marcel L. Bouvy

To investigate short‐ and long‐term effects of real‐time monitoring medication use combined with short message service (SMS) reminders for missed doses on refill adherence to oral anti‐diabetic medication.


Psychological Medicine | 2008

The influence of specific chronic somatic conditions on the care for co-morbid depression in general practice

Jasper Nuyen; Peter Spreeuwenberg; L. van Dijk; G. A. M. van den Bos; Peter P. Groenewegen; F.G. Schellevis

BACKGROUND Limited information exists on the relationship between specific chronic somatic conditions and care for co-morbid depression in primary care settings. Therefore, the present prospective, general practice-based study examined this relationship. METHOD Longitudinal data on morbidity, prescribing and referrals concerning 991 patients newly diagnosed with depression by their general practitioner (GP) were analysed. The influence of a broad range of 13 specific chronic somatic conditions on the initiation of any depression care, as well as the prescription of continuous antidepressant therapy for 180 days, was examined. Multilevel logistic regression analysis was used to control for history of depression, psychiatric co-morbidity, sociodemographics and interpractice variation. RESULTS Multilevel analysis showed that patients with pre-existing ischaemic heart disease (72.1%) or cardiac arrhythmia (59.3%) were significantly less likely to have any depression care being initiated by their GP than patients without chronic somatic morbidity (88.0%). No other specific condition had a significant influence on GP initiation of any care for depression. Among the patients being prescribed antidepressant treatment by their GP, none of the conditions was significantly associated with being prescribed continuous treatment for 180 days. CONCLUSIONS Our study indicates that patients with ischaemic heart disease or cardiac arrhythmia have a lower likelihood of GP initiation of any care for depression after being newly diagnosed with depression by their GP. This finding points to the importance of developing interventions aimed at supporting GPs in the adequate management of co-morbid depression in heart disease patients to reduce the negative effects of this co-morbidity.


Optics Express | 2012

Plasmonic nano-antenna a-Si:H solar cell

M. Di Vece; Y Yinghuan Kuang; Snf van Duren; Jm Charry; L. van Dijk; Rei Ruud Schropp

In this work the effects of plasmonics, nano-focusing, and orthogonalization of carrier and photon pathways are simultaneously explored by measuring the photocurrents in an elongated nano-scale solar cell with a silver nanoneedle inside. The silver nanoneedles formed the support of a conformally grown hydrogenated amorphous silicon (a-Si:H) n-i-p junction around it. A spherical morphology of the solar cell functions as a nano-lens, focusing incoming light directly on the silver nanoneedle. We found that plasmonics, geometric optics, and Fresnel reflections affect the nanostructured solar cell performance, depending strongly on light incidence angle and polarization. This provides valuable insight in solar cell processes in which novel concepts such as plasmonics, elongated nanostructures, and nano-lenses are used.


Family Practice | 2011

Variation in formulary adherence in general practice over time (2003-2007).

L. van Dijk; J.D. de Jong; G.P. Westert; D.H. de Bakker

OBJECTIVE To study trends and variation in adherence to the main national formulary for the 20 most prevalent health problems in Dutch general practice over a 5-year period (2003-07). METHODS Routine electronic medical records from a pool of 115 representative general practices were linked to the main national formulary. Analyses included over 2 million prescriptions for 246 391 patients. The outcome variable was whether or not the prescribed medication was congruent with recommendations in the national formulary. Trends and variation were analysed using three-level multilevel logistic regression analyses (general practice, patient, and prescription). RESULTS The percentage of formulary adherent prescriptions for the 20 most prevalent health problems was 73-76% between 2003 and 2007. The percentage varied considerably between guidelines. Lowest adherence rates were found for acute bronchitis and acute upper respiratory infection. Interpractice variation was constant over time. CONCLUSIONS General practice information networks are useful for monitoring general patterns of formulary on a year-to-year basis. Formulary adherence is stable over time but varies across diagnoses, patients and general practices. In the past decade, efforts have been made to increase the level of formulary adherent prescribing. These general efforts managed to stabilize (variation in) adherence in a field where many other initiatives (e.g. by pharmaceutical companies) are undertaken to influence prescribing behaviour.


BMJ Open | 2013

Where to buy OTC medications? A cross-sectional survey investigating consumers’ confidence in over-the-counter (OTC) skills and their attitudes towards the availability of OTC painkillers

A. Brabers; L. van Dijk; Marcel L. Bouvy; J.D. de Jong

Objective To examine consumers’ confidence in their own, and also in other peoples, over-the-counter (OTC) skills and to describe their attitude towards the availability of OTC painkillers. Moreover we examined the association between confidence in OTC skills and attitudes. Design Cross-sectional survey. Mixed methods (postal and electronic) self-administered questionnaire. Participants Members of the Dutch Health Care Consumer Panel. Main outcome measures Consumers’ confidence in their own, and in other peoples, OTC skills was examined. Confidence was measured by three questions regarding obtaining information on, choosing and using OTC medication. Consumers’ attitudes towards availability were assessed using six safety profiles, by asking which channel consumers prefer for each profile. Results The response rate was 68% (n=972). Consumers feel confident about their own OTC skills (mean 3.74; 95% CI 3.69 to 3.79, on a 5-point Likert scale), but have less confidence in OTC skills of others (mean 2.92; 95% CI 2.88 to 2.96). Consumers are conservative in their attitudes towards the availability of OTC painkillers. Most consumers prefer painkillers to be available exclusively in pharmacies (41–71% per profile indicated pharmacy only). Moreover, there is an association between confidence in OTC skills and attitudes (p=0.005; β=−0.114). Consumers who are more confident about their own OTC skills prefer OTC painkillers to be more generally available. Conclusions Consumers feel confident about their own OTC skills. However, they would prefer painkillers with safety profiles resembling those currently available OTC, to be available as OTC in pharmacies exclusively. Consumers’ confidence in the OTC skills of others is more consistent with their attitudes towards availability of OTC painkillers. Until consumers themselves realise that they are also one of the others, they may overestimate their own OTC skills, which may entail health risks.


Respiratory Medicine | 2015

Seasonal changes in prescribing of long-acting beta-2-agonists-containing drugs.

Marietta Rottenkolber; Eef Voogd; L. van Dijk; Paola Primatesta; Claudia Becker; M. C. H. de Groot; E. Plana; Yolanda Alvarez; Julie Durand; Jim Slattery; Ana Afonso; Gema Requena; Consuelo Huerta; Arturo Alvarez; F. de Abajo; Martin Tauscher; Joerg Hasford; Rainald Fischer; Robert Reynolds; Sven Schmiedl

BACKGROUND For patients with asthma, COPD, or asthma-COPD overlap syndrome (ACOS), inter-country comparisons of seasonal changes in drug prescriptions are scarce or missing. Hence, we aimed to compare seasonal changes in prescription rates of long-acting beta-2-agonist (LABA) in four European countries. METHODS A common study protocol was applied to six health care databases (Germany, Spain, the Netherlands (2), and the UK (2)) to calculate age- and sex-standardized point prevalence rates (PPRs) of LABA-containing prescriptions by the 1st of March, June, September, and December of each year during the study period 2002-2009. Seasonal variation of PPRs was quantified using seasonal indexes (SIs; based on the ratio-to-moving-average-method) and SIs averaged over the study period (aSI) stratified by sex, age, and indication (asthma, COPD, or ACOS). RESULTS There was a moderate seasonal change in LABA-containing prescriptions which was more pronounced in asthma or COPD patients compared to ACOS patients. For asthma and ACOS patients, highest seasonal variation was found for patients living in Spain (aSI: 87.3-110.7, aSI: 93.2-103.1) whereas for COPD highest seasonal variation was revealed for the NPCRD database (the Netherlands) (aSI: 92.2-105.6). Regarding age and sex, highest seasonal variation was found in Spanish boys under 10 years of age having a diagnosis of asthma. CONCLUSIONS By applying a common analysis in six databases, we could observe moderate overall seasonal changes in LABA-containing prescription rates in patients with asthma, COPD, or ACOS.


Renewable Energy and the Environment Optics and Photonics Congress (2012), paper JM5A.17 | 2012

Plasmonic effects of nanoholes in a silver back reflector for improved light trapping in thin film amorphous silicon solar cells

L. van Dijk; M. Di Vece; A.D. van Dam; C.H.M. van der Werf; R.E.I. Schropp

The efficiency of thin film Si photovoltaic (PV) cells is lower than cells made of c-Si wafers, but thin film solar cells provide a PV technology with lower materials consumption and less energy used in production. Therefore, research is ongoing to enhance the absorption of these cells while making the silicon layer even thinner. This will boost the electrical performance and increase the industrial production yield as well as reduce manufacturing costs. By implementing a smart geometric design of the solar cell, light is managed such that the absorption is optimized. Apart from geometric optics, plasmonic effects can further enhance the absorption. In this study, improved light management is shown by interaction of light with the dielectric contrast of nanoholes in the Ag back reflector of the cell. The following investigated physical phenomena can be induced by the nanoholes and lead to improved absorption: near field enhancement, light scattering, and surface plasmons. Angular resolved measurements of the quantum efficiency are compared with finite-difference time-domain (FDTD) simulations. This is compared with experimental devices comprising these nanoholes. The presentation will be concluded by remaining challenges and new ways to endeavor.


International Journal of Medical Informatics | 2012

SMS reminders improve adherence to oral medication in type 2 diabetes patients who are real time electronically monitored.

M. Vervloet; L. van Dijk; J. Santen-Reestman; B. van Vlijmen; P. van Wingerden; Marcel L. Bouvy; D.H. de Bakker

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Peter Spreeuwenberg

VU University Medical Center

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Mieke Cardol

Rotterdam University of Applied Sciences

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