Rationeel onkruidbeheer op verhardingen

Verslag van een workshop over duurzaam onkruidbeheer op verhardingen. Belangrijkste thema's waren afspoeling van herbiciden en kosten-effectief onkruidbehee

Oscillation of a shallow lake ecosystem upon reduction in external phosphorus load

A long-term study of eutrophication abatement in the Botshol Nature Reserve, the Netherlands, showed an intriguing response in this shallow lake. Beginning in 1988, the external nutrient load was reduced by hydrological segregation from agricultural areas and by chemical stripping of phosphorus from the water supply. A side effect of the hydrological segregation of Botshol from agricultural areas was an increase in chloride from 500 to 1000 mg l -1. In the first four years after the decrease in nutrient load, reductions were observed in phosphorus and chlorophyll a concentrations, as well as in the density of phytoplankton, zooplankton, and fish. Reduced phytoplankton density resulted in reduced turbidity and increased cover of Characeae from 2 to 80 %. Although the objective of re-establishing submerged macrophytes seemed to be attained, the clear water state appeared unstable. From 1993 onwards, the ecosystem alternated between turbid water with minor macrophyte production (1993-1995, 1999-2003) and clear water with abundant growth of aquatic plants (1996-1998). Phosphorus concentrations in Botshol also showed strong related fluctuations, despite a stable external phosphorus load

Oscillation of a shallow lake ecosystem upon reduction in external phosphorus load

A long-term study of eutrophication abatement in the Botshol Nature Reserve, the Netherlands, showed an intriguing response in this shallow lake. Beginning in 1988, the external nutrient load was reduced by hydrological segregation from agricultural areas and by chemical stripping of phosphorus from the water supply. A side effect of the hydrological segregation of Botshol from agricultural areas was an increase in chloride from 500 to 1000 mg l -1. In the first four years after the decrease in nutrient load, reductions were observed in phosphorus and chlorophyll a concentrations, as well as in the density of phytoplankton, zooplankton, and fish. Reduced phytoplankton density resulted in reduced turbidity and increased cover of Characeae from 2 to 80 %. Although the objective of re-establishing submerged macrophytes seemed to be attained, the clear water state appeared unstable. From 1993 onwards, the ecosystem alternated between turbid water with minor macrophyte production (1993-1995, 1999-2003) and clear water with abundant growth of aquatic plants (1996-1998). Phosphorus concentrations in Botshol also showed strong related fluctuations, despite a stable external phosphorus load

Preventing weight gain: one-year results of a randomized lifestyle intervention

BACKGROUND: Lifestyle interventions targeting prevention of weight gain may have better long-term success than when aimed at weight loss. Limited evidence exists about such an approach in the primary care setting. DESIGN: An RTC was conducted. SETTING/PARTICIPANTS: Participants were 457 overweight or obese patients (BMI=25-40 kg/m(2), mean age 56 years, 52% women) with either hypertension or dyslipidemia, or both, from 11 general practice locations in The Netherlands. INTERVENTION: In the intervention group, four individual visits to a nurse practitioner (NP) and one feedback session by telephone were scheduled for lifestyle counseling with guidance of the NP using a standardized computerized software program. The control group received usual care from their general practitioner (GP). MAIN OUTCOME MEASURES: Changes in body weight, waist circumference, blood pressure, and blood lipids after 1 year (dropout <10%). Data were collected in 2006 and 2007. Statistical analyses were conducted in 2007 and 2008. RESULTS: There were more weight losers and stabilizers in the NP group than in the general practitioner usual care (GP-UC) group (77% vs 65%; p<0.05). In men, mean weight losses were 2.3% for the NP group and 0.1% for the GP-UC group (p<0.05). Significant reductions occurred also in waist circumference but not in blood pressure, blood lipids, and fasting glucose. In women, mean weight losses were in both groups 1.6%. In the NP group, obese people lost more weight (-3.0%) than the non-obese (-1.3%; p<0.05). CONCLUSIONS: Standardized computer-guided counseling by NPs may be an effective strategy to support weight-gain prevention and weight loss in primary care, in the current trial, particularly among men. TRIAL REGISTRATION: The study was registered with the Netherlands Trial Register (NTR), www.trialregister.nl, study no. TC 1365

Determinants for the adoption of angiotensin II receptor blockers by general practitioners

Results of studies conducted 10-20 years ago show the prominence of commercial information sources in the adoption process of new drugs. Over the past decade, there has been a growing emphasis on practicing evidence-based medicine in drug prescribing. This raises the question whether professional information sources currently counterbalance the influence of commercial information sources in the adoption process. The aim of this study was to identify determinants influencing the adoption of a new drug class, the angiotensin II receptor blockers (ARBs), by general practitioners (CPs) in The Netherlands. A retrospective study was conducted to assess prevalent ARB prescribing for hypertensive patients,using the Integrated Primary Care Information (IPCI) database. We conducted a survey among all GPs who participated in the IPCI project in 2003 to assess their exposure to commercial and professional information sources, perceived benefits and risks of ARBs, perceived influences of the professional network, and general characteristics. Multilevel logistic regression was applied to identify determinants of ARB adoption while adjusting for patient characteristics. Data were obtained from 70 GPs and 9470 treated hypertensive patients. A total of 1093 patients received ARBs (12%). GPs who reported frequent use of commercial information sources were more likely to prescribe ARBs routinely in preference to other antihypertensives, whereas GPs who used a prescribing decision support system and those who were involved in pharmacotherapy education were less likely to prescribe ARBs. Other factors that were associated with higher levels of ARB adoption included a more positive perception of ARBs regarding their effectiveness in lowering blood pressure, and working in single-handed practices or in rural areas. Aside from determinants related to the patient population, adoption of a new drug class among Dutch GPs is still determined more by their reliance on promotional information than by their use of professional information sources. (c) 2006 Elsevier Ltd. All rights reserved

Uptake of angiotensin II receptor blockers in the treatment of hypertension

OBJECTIVE: To examine trends in prescribing of angiotensin II receptor blockers (ARBs) as initial and second-line treatment of hypertension. METHODS: We performed a cohort study in the Integrated Primary Care Information database, a general practice research database in The Netherlands. We included hypertensive patients who were newly treated with antihypertensive drugs between 1996 and 1999. Initial treatment was defined as the first prescribed antihypertensive drug after diagnosis of hypertension. As second-line treatment, we considered prescriptions of a second antihypertensive drug class, either as switch or addition. We used logistic regression and Cox proportional hazard analysis to estimate time trends in use of ARBs as initial or second-line treatment. RESULTS: In total, 8% of the 3,102 newly treated hypertensive patients received ARBs as initial treatment. Initial ARB use increased significantly from 4% to 10% during the period 1996-1999, whereas calcium channel blocker and angiotensin-converting enzyme inhibitor (ACE-I) use decreased. ARBs were used as second-line treatment in less than 4% of 2,544 patients who were initially treated with an antihypertensive drug other than an ARB: 2% switched to an ARB (mostly from ACE-Is) and 1% received ARBs as add-on treatment. Diuretics and beta-blockers were used five to ten times more often as add-on treatment than ARBs. CONCLUSION: ARBs achieved a position in the treatment of hypertension as initial rather than second-line therapy

Self-measurement of blood pressure at home reduces the need for antihypertensive drugs: a randomized, controlled trial.

Contains fulltext : 52138.pdf (publisher's version ) (Open Access)It is still uncertain whether one can safely base treatment decisions on self-measurement of blood pressure. In the present study, we investigated whether antihypertensive treatment based on self-measurement of blood pressure leads to the use of less medication without the loss of blood pressure control. We randomly assigned 430 hypertensive patients to receive treatment either on the basis of self-measured pressures (n=216) or office pressures (OPs; n=214). During 1-year follow-up, blood pressure was measured by office measurement (10 visits), ambulatory monitoring (start and end), and self-measurement (8 times, self-pressure group only). In addition, drug use, associated costs, and degree of target organ damage (echocardiography and microalbuminuria) were assessed. The self-pressure group used less medication than the OP group (1.47 versus 2.48 drug steps; P<0.001) with lower costs ($3222 versus$4420 per 100 patients per month; P<0.001) but without significant differences in systolic and diastolic OP values (1.6/1.0 mm Hg; P=0.25/0.20), in changes in left ventricular mass index (-6.5 g/m(2) versus -5.6 g/m(2); P=0.72), or in median urinary microalbumin concentration (-1.7 versus -1.5 mg per 24 hours; P=0.87). Nevertheless, 24-hour ambulatory blood pressure values at the end of the trial were higher in the self-pressure than in the OP group: 125.9 versus 123.8 mm Hg (P<0.05) for systolic and 77.2 versus 76.1 mm Hg (P<0.05) for diastolic blood pressure. These data show that self-measurement leads to less medication use than office blood pressure measurement without leading to significant differences in OP values or target organ damage. Ambulatory values, however, remain slightly elevated for the self-pressure group

Comparison of randomization techniques for clinical trials with data from the HOMERUS-trial.

Contains fulltext : 48963.pdf (publisher's version ) (Closed access)BACKGROUND: Several methods of randomization are available to create comparable intervention groups in a study. In the HOMERUS-trial, we compared the minimization procedure with a stratified and a non-stratified method of randomization in order to test which one is most appropriate for use in clinical hypertension trials. A second objective of this article was to describe the baseline characteristics of the HOMERUS-trial. METHODS: The HOMERUS population consisted of 459 mild-to-moderate hypertensive subjects (54% males) with a mean age of 55 years. These patients were prospectively randomized with the minimization method to either the office pressure (OP) group, where antihypertensive treatment was based on office blood pressure (BP) values, or to the self-pressure (SP) group, where treatment was based on self-measured BP values. Minimization was compared with two other randomization methods, which were performed post-hoc: (i) non-stratified randomization with four permuted blocks, and (ii) stratified randomization with four permuted blocks and 16 strata. In addition, several factors that could influence outcome were investigated for their effect on BP by 24-h ambulatory blood pressure monitoring (ABPM). RESULTS: Minimization and stratified randomization did not lead to significant differences in 24-h ABPM values between the two treatment groups. Non-stratified randomization resulted in a significant difference in 24-h diastolic ABPM between the groups. Factors that caused significant differences in 24-h ABPM values were: region, centre of patient recruitment, age, gender, microalbuminuria, left ventricular hypertrophy and obesity. CONCLUSION: Minimization and stratified randomization are appropriate methods for use in clinical trials. Many outcome factors should be taken into account for their potential influence on BP levels. Recommendation. Due to the large number of potential outcome factors that can influence BP levels, minimization should be the preferred method for use in clinical hypertension trials, as it has the potential to randomize more outcome factors than stratified randomization

Adjuvant Use of PlasmaJet Device During Cytoreductive Surgery for Advanced-Stage Ovarian Cancer: Results of the PlaComOv-study, a Randomized Controlled Trial in The Netherlands

Objective Standard surgical treatment of advanced-stage ovarian carcinoma with electrosurgery cannot always result in complete cytoreductive surgery (CRS), especially when many small metastases are found on the mesentery and intestinal surface. We investigated whether adjuvant use of a neutral argon plasma device can help increase the complete cytoreduction rate. Patients and Methods 327 patients with FIGO stage IIIB-IV epithelial ovarian cancer (EOC) who underwent primary or interval CRS were randomized to either surgery with neutral argon plasma (PlasmaJet) (intervention) or without PlasmaJet (control group). The primary outcome was the percentage of complete CRS. The secondary outcomes were duration of surgery, blood loss, number of bowel resections and colostomies, hospitalization, 30-day morbidity, and quality of life (QoL). Results Complete CRS was achieved in 119 patients (75.8%) in the intervention group and 115 patients (67.6%) in the control group (risk difference (RD) 8.2%, 95% confidence interval (CI) -0.021 to 0.181; P = 0.131). In a per-protocol analysis excluding patients with unresectable disease, complete CRS was obtained in 85.6% in the intervention group and 71.5% in the control group (RD 14.1%, 95% CI 0.042 to 0.235; P = 0.005). Patient-reported QoL at 6 months after surgery differed between groups in favor of PlasmaJet surgery (95% CI 0.455-8.350; P = 0.029). Other secondary outcomes did not differ significantly. Conclusions Adjuvant use of PlasmaJet during CRS for advanced-stage ovarian cancer resulted in a significantly higher proportion of complete CRS in patients with resectable disease and higher QoL at 6 months after surgery. (Funded by ZonMw, Trial Register NL62035.078.17.