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Featured researches published by Geert-Jan Dinant.


BMJ | 2009

Effect of point of care testing for C reactive protein and training in communication skills on antibiotic use in lower respiratory tract infections: cluster randomised trial

Jochen Cals; Christopher Collett Butler; Rogier Hopstaken; Kerenza Hood; Geert-Jan Dinant

Objective To assess the effect of general practitioner testing for C reactive protein (disease approach) and receiving training in enhanced communication skills (illness approach) on antibiotic prescribing for lower respiratory tract infection. Design Pragmatic, 2×2 factorial, cluster randomised controlled trial. Setting 20 general practices in the Netherlands. Participants 40 general practitioners from 20 practices recruited 431 patients with lower respiratory tract infection. Main outcome measures The primary outcome was antibiotic prescribing at the index consultation. Secondary outcomes were antibiotic prescribing during 28 days’ follow-up, reconsultation, clinical recovery, and patients’ satisfaction and enablement. Interventions General practitioners’ use of C reactive protein point of care testing and training in enhanced communication skills separately and combined, and usual care. Results General practitioners in the C reactive protein test group prescribed antibiotics to 31% of patients compared with 53% in the no test group (P=0.02). General practitioners trained in enhanced communication skills prescribed antibiotics to 27% of patients compared with 54% in the no training group (P<0.01). Both interventions showed a statistically significant effect on antibiotic prescribing at any point during the 28 days’ follow-up. Clinicians in the combined intervention group prescribed antibiotics to 23% of patients (interaction term was non-significant). Patients’ recovery and satisfaction were similar in all study groups. Conclusion Both general practitioners’ use of point of care testing for C reactive protein and training in enhanced communication skills significantly reduced antibiotic prescribing for lower respiratory tract infection without compromising patients’ recovery and satisfaction with care. A combination of the illness and disease focused approaches may be necessary to achieve the greatest reduction in antibiotic prescribing for this common condition in primary care. Trial registration Current Controlled Trials ISRCTN85154857.


BMJ | 1997

Medicine based evidence, a prerequisite for evidence based medicine

J. A. Knottnerus; Geert-Jan Dinant

Seeking an evidence base for medicine is as old as medicine itself, but in the past decade the concept of evidence based medicine has done a good job in focusing explicit attention on the application of evidence from valid clinical research to clinical practice.1 2 Although current clinical practice is often evidence based,3 4 there is still much to be gained. Important new evidence from research often takes a long time to be implemented in daily care, while established practices persist even if they have been proved to be ineffective or harmful.5 In the meantime, many clinicians struggle to apply the results of studies that do not seem that relevant to their daily practice. Evidence based medicine has been defined as the “conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients.”2 What can we learn from the limitations of current best evidence for the way that we design future studies? We face the problem that criteria for internal and external validity (that is, clinical …


BMJ | 1993

Adverse reactions to influenza vaccine in elderly people: randomised double blind placebo controlled trial.

T M Govaert; Geert-Jan Dinant; K Aretz; Nic Masurel; M J Sprenger; J A Knottnerus

OBJECTIVE--To assess the frequency and type of side effects after influenza vaccination in elderly people. DESIGN--Randomised double blind placebo controlled study. SETTING--15 general practices in the southern Netherlands. SUBJECTS--1806 patients aged 60 or older, of whom 904 received influenza vaccine and 902 placebo. MAIN OUTCOME MEASURES--Adverse reactions reported on postal questionnaire completed four weeks after vaccination. RESULTS--210 (23%) patients given vaccine reported one or more adverse reactions compared with 127 (14%) given placebo. The frequency of local adverse reactions were 17.5% in the vaccine group and 7.3% in the placebo group (p < 0.001). There was no difference in systemic adverse reactions (11% v 9.4%; p = 0.34). In general, men reported fewer side effects than women. CONCLUSION--Only local side effects were more common in vaccinated patients and all side effects were mild.


Journal of General Internal Medicine | 2011

Gut feelings as a third track in general practitioners' diagnostic reasoning

Erik Stolper; Margje Van de Wiel; Paul Van Royen; Marloes Amantia van Bokhoven; Trudy van der Weijden; Geert-Jan Dinant

BackgroundGeneral practitioners (GPs) are often faced with complicated, vague problems in situations of uncertainty that they have to solve at short notice. In such situations, gut feelings seem to play a substantial role in their diagnostic process. Qualitative research distinguished a sense of alarm and a sense of reassurance. However, not every GP trusted their gut feelings, since a scientific explanation is lacking.ObjectiveThis paper explains how gut feelings arise and function in GPs’ diagnostic reasoning.ApproachThe paper reviews literature from medical, psychological and neuroscientific perspectives.ConclusionsGut feelings in general practice are based on the interaction between patient information and a GP’s knowledge and experience. This is visualized in a knowledge-based model of GPs’ diagnostic reasoning emphasizing that this complex task combines analytical and non-analytical cognitive processes. The model integrates the two well-known diagnostic reasoning tracks of medical decision-making and medical problem-solving, and adds gut feelings as a third track. Analytical and non-analytical diagnostic reasoning interacts continuously, and GPs use elements of all three tracks, depending on the task and the situation. In this dual process theory, gut feelings emerge as a consequence of non-analytical processing of the available information and knowledge, either reassuring GPs or alerting them that something is wrong and action is required. The role of affect as a heuristic within the physician’s knowledge network explains how gut feelings may help GPs to navigate in a mostly efficient way in the often complex and uncertain diagnostic situations of general practice. Emotion research and neuroscientific data support the unmistakable role of affect in the process of making decisions and explain the bodily sensation of gut feelings.The implications for health care practice and medical education are discussed.


Annals of Family Medicine | 2010

Point-of-Care C-Reactive Protein Testing and Antibiotic Prescribing for Respiratory Tract Infections: A Randomized Controlled Trial

Jochen Cals; Marjolein Jc Schot; Sanne A. M. de Jong; Geert-Jan Dinant; Rogier Hopstaken

PURPOSE Antibiotics are only beneficial for subgroups of patients with acute lower respiratory tract infections (LRTI) and rhinosinusitis in family practice, yet overprescribing for these conditions is common. C-reactive protein (CRP) point-of-care testing and delayed prescribing are useful strategies to reduce antibiotic prescribing, but both have limitations. We evaluated the effect of CRP assistance in antibiotic prescribing strategies—including delayed prescribing—in the management of LRTI and rhinosinusitis. METHODS We conducted a randomized controlled trial in which 258 patients were enrolled (107 LRTI and 151 rhinosinusitis) by 32 family physicians. Patients were individually randomized to CRP assistance or routine care (control). Primary outcome was antibiotic use after the index consultation. Secondary outcomes included antibiotic use during the 28-day follow-up, patient satisfaction, and clinical recovery. RESULTS Patients in the CRP-assisted group used fewer antibiotics (43.4%) than control patients (56.6%) after the index consultation (relative risk [RR] = 0.77; 95% confidence interval [CI], 0.56–0.98). This difference remained significant during follow-up (52.7% vs 65.1%; RR = 0.81; 95% CI, 0.62–0.99). Delayed prescriptions in the CRP-assisted group were filled only in a minority of cases (23% vs 72% in control group, P <.001). Recovery was similar across groups. Satisfaction with care was higher in patients managed with CRP assistance (P = .03). CONCLUSIONS CRP point-of-care testing to assist in prescribing decisions, including delayed prescribing, for LRTI and rhinosinusitis may be a useful strategy to decrease antibiotic use and increase patient satisfaction without compromising patient recovery.


Osteoporosis International | 2001

Risk Factors for Osteoporosis Related to their Outcome: Fractures

D. J. M. van der Voort; Piet Geusens; Geert-Jan Dinant

Abstract. The aim of the study was to determine to what extent easy obtainable bone mineral density (BMD)-related risk factors are associated with the occurrence of fractures and to what extent changes in these determinants during a patient”s lifetime are relevant. A cross-sectional population-based study was carried out on 4725 postmenopausal women, 50–80 years of age, registered with 23 general practitioners (GPs). The women were questioned and examined. BMD of the lumbar spine was measured using dual-energy X-ray absorptiometry (QDR-1000, Hologic). We analyzed the total population as well as a random sample of 1155 women for whom additional data were collected on recalled weight at age 20–30 years and on self-reported height. Body mass index (BMI) was estimated in two ways: (1) objective BMI [= measured weight/(measured height)2]; (2) recalled BMI [= recalled body weight at age 20–30/(self-reported height)2]. Fractures (dependent variable) were categorized as: (1) fractures sustained during the patient”s lifetime; (2) fractures after the age of 50 years; (3) fractures that had occurred during the 5 years before BMD measurement took place. Multivariate stepwise backward and forward logistic regression analyses, using fractures as the dependent variable, were performed with all discrete and non-discrete variables (divided into quartiles). The relationship between the presence of osteoporosis and the presence of fractures was related to the changes in BMI (recalled BMI versus objective BMI). More advanced age, positive family history of fractures and BMD had a positive association with the presence of fractures. Low recalled BMI was a statistically significant predictor of “fractures during the patient”s lifetime” and of “fractures after the age of 50”. Hysterectomy was associated with a higher prevalence of “fractures during the patient”s lifetime”. Perimenopausal complaints in the history seemed to be associated with a lower prevalence of “fractures after the age of 50”. Moderate (and heavy) occupational exercise in the past were associated with the presence of fractures “after the age of 50” and “fractures during the past 5 years”. Sporting activities in the past showed a slightly positive relationship with the presence of “fractures during the patient”s lifetime” and “fractures after the age of 50”. Bivariate analysis revealed that current smokers had not sustained significantly more fractures than current nonsmokers, but within the subgroup of current smokers, the prevalence of fractures was significantly higher among those women who had smoked for more than 35 years. Smoking was statistically significantly associated with early menopause. Early menopause was not statistically significantly related to the presence of osteoporosis but appeared to be statistically significantly associated with the prevalence of fractures in the age categories over 65 years. The absolute risks of sustaining one or more fractures ranged from 3% to 44%. Women in the lowest quartile of recalled and objective BMI were often osteoporotic (40%). In this category, women with normal BMD had a statistically significant lower fracture risk than osteoporotic women. Women with a possibly decreased BMI were most often osteoporotic and had sustained more “fractures during the past 5 years” than expected. Women who had (probably) always been obese were less often osteoporotic and had a much lower fracture risk. It is concluded that decreased BMI is associated with a higher risk of developing fractures at an older age. Prevention of fractures should include fall prevention. In addition, in lean women treatment of low BMD is important.


BMC Family Practice | 2013

Family physicians' diagnostic gut feelings are measurable: construct validation of a questionnaire

Christiaan F. Stolper; Margje Van de Wiel; Henrica C.W. de Vet; Alexander L.B. Rutten; Paul Van Royen; Marloes Amantia van Bokhoven; Trudy van der Weijden; Geert-Jan Dinant

BackgroundFamily physicians perceive that gut feelings, i.e. a ‘sense of reassurance’ or a ‘sense of alarm’, play a substantial role in diagnostic reasoning. A measuring instrument is desirable for further research. Our objective is to validate a questionnaire measuring the presence of gut feelings in diagnostic reasoning.MethodsWe constructed 16 case vignettes from real practice situations and used the accompanying ‘sense of reassurance’ or the ‘sense of alarm’ as reference labels. Based on the results of an initial study (26 family physicians), we divided the case vignettes into a group involving a clear role for the sense of reassurance or the sense of alarm and a group involving an ambiguous role. 49 experienced family physicians evaluated each 10 vignettes using the questionnaire. Construct validity was assessed by testing hypotheses and an internal consistency procedure was performed.ResultsAs hypothesized we found that the correlations between the reference labels and corresponding items were high for the clear-case vignettes (0.59 – 0.72) and low for the ambiguous-case vignettes (0.08 – 0.23). The agreement between the classification in clear sense of reassurance, clear sense of alarm and ambiguous case vignettes as derived from the initial study and the study population’s judgments was substantial (Kappa = 0.62). Factor analysis showed one factor with opposites for sense of reassurance and sense of alarm items. The questionnaire’s internal consistency was high (0.91). We provided a linguistic validated English-language text of the questionnaire.ConclusionsThe questionnaire appears to be valid. It enables quantitative research into the role of gut feelings and their diagnostic value in family physicians’ diagnostic reasoning.


Annals of the Rheumatic Diseases | 2008

Clinical subsequent fractures cluster in time after first fractures

T. van Geel; S. van Helden; Piet Geusens; Bjorn Winkens; Geert-Jan Dinant

Objectives: The risk of subsequent fractures is double the risk of having a first fracture. We analysed whether this risk is constant or not over time. Methods: A population-based study in 4140 postmenopausal women, aged between 50 and 90 years, on radiographic confirmed clinical fractures from menopause onwards analysed by Cox regression. Results: A total of 924 (22%) women had a first fracture and 243 (26% of 924) a subsequent fracture. Of all first fractures, 4% occurred in each year from menopause onwards, while after a first fracture 23% of all subsequent fractures occurred within 1 year and 54% within 5 years. When calculated from time of first fracture, the relative risk (RR) of subsequent fracture was 2.1 (95% CI 1.7 to 2.6) and remained increased over 15 years. When calculated for specific time intervals after a first fracture, the RR was 5.3 (95% CI 4.0 to 6.6) within 1 year, 2.8 (95% CI 2.0 to 3.6) within 2–5 years, 1.4 (95% CI 1.0 to 1.8) within 6–10 years and 0.41 (95% CI 0.29 to 0.53) after >10 years. Conclusions: From menopause onwards, clinical fractures cluster in time, indicating the need for early action to prevent subsequent fractures.


Medical Education | 2001

Do short cases elicit different thinking processes than factual knowledge questions do

Lambert Schuwirth; M. M. Verheggen; C.P.M. van der Vleuten; H. P. A. Boshuizen; Geert-Jan Dinant

To assess whether case‐based questions elicit different thinking processes from factual knowledge‐based questions.


BMJ | 2002

Evidence base of clinical diagnosis: Rational, cost effective use of investigations in clinical practice

Ron Winkens; Geert-Jan Dinant

Investigations such as blood tests and radiography are important tools for the making correct diagnoses. The use of diagnostic resources is growing steadily—in the Netherlands, for example, nationwide expenditure on diagnostic tests is growing at the rate of 7% a year. Unfortunately, health status is not improving similarly, which suggests that investigations are being overused. The ordering of tests seems not to be influenced by the fact that their diagnostic accuracy is often disappointing. Considerations other than strict scientific indications seem to be involved, and we may ask whether new knowledge and research findings are adequately reflected in daily practice. Several factors may be responsible for the increasing use of investigations, such as the increasing demand for care (due to ageing of the population and increasing numbers of chronically ill people); the fact that they are available, which in itself leads to ordering; and the urge to make use of new technology. Once an abnormal test result is found, doctors may order further investigations, not realising that on average 5% of test results are outside their reference ranges, and a cascade of testing may result. Furthermore, higher standards of care, the guidelines for which often recommend additional testing, and defensive behaviour have led to more investigations. Unfortunately, when guidelines on selective and rational ordering of investigations are introduced, numerous motives for ignoring evidence based recommendations, such as fear of litigation, or procrastination on the part of the doctor, come into play in daily practice and are difficult to influence. Overuse of investigations—and there is reason to believe that some requests are illogical—leads to overloading of the diagnostic services and overexpenditure: more efficient usage is therefore needed. Interventions focusing on overt examples of inappropriate testing might reduce costs while simultaneously improving quality of care. #### Summary points Intervention is needed to reduce the often …

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Rogier Hopstaken

Public Health Research Institute

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Frank Buntinx

Katholieke Universiteit Leuven

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Paula Rinkens

Public Health Research Institute

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