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Biomedical subjects

Frank Buntinx

Publications and source records attributed to Frank Buntinx.

At least 19 recordsLinked to original sources

Comparison of the diagnostic accuracy of the Cognitive Performance Scale (Minimum Data Set) and the Mini-Mental State Exam for the detection of cognitive impairment in nursing home residents.

OBJECTIVE: To compare the diagnostic accuracy of an outcome measurement scale of the Minimum Data Set of the Resident Assessment Instrument for nursing homes (MDS/RAI-NH), the Cognitive Performance Scale (CPS) and the Mini-Mental State Exam (MMSE) for the detection of cognitive impairment. The Cambridge Examination for Mental Disorders of the Elderly--Revised (CAMDEX-R) was used as the reference standard. STUDY DESIGN AND SETTING: This study was part of a larger prospective study (QUALIDEM) involving a diagnostic procedure and two-year follow-up on the quality of primary care for demented patients. CAMDEX-R and MDS/RAI-NH were administered to 198 residents, aged 65 or more, living in 42 low and high care institutions for aged people. MAIN OUTCOME MEASURES: Indicators of diagnostic accuracy: sensitivity, specificity, predictive values, likelihood ratios, odds ratio and area under receiver operating characteristics curve (AUC). RESULTS: The CAMDEX-based prevalence of cognitive impairment was 75%. The diagnostic values of a CPS score of two or more for the detection of cognitive impairment were: sensitivity = 0.81; specificity = 0.80; PPV = 0.92; NPV = 0.57. The diagnostic values of a MMSE score of less than or equal 23 were: sensitivity = 0.97; specificity = 0.59; PPV = 0.88; NPV = 0.85. For CPS, the area under the receiver operating characteristic (ROC) curve was 0.87 (95% CI, 0.81-0.91), and not significantly different (p = 0.63) from the MMSE score, 0.88 (0.83-0.93). CONCLUSIONS: CPS and MMSE demonstrated similar performance to detect cognitive impairment in nursing home residents.

Aged↗

Are men with low selenium levels at increased risk of prostate cancer?

A meta-analysis was undertaken to quantitatively determine if men with low selenium levels were at increased risk of prostate cancer. PubMed, EMBASE and current contents were searched to identify relevant studies. The effect size was calculated by pooling the mean difference for serum, plasma and toenail selenium levels (95% confidence intervals) separately and combined using a random effects model. Meta-regression analysis explored possible sources of heterogeneity. Twenty epidemiologic studies were selected. Mean differences were: -5.55 microg/l (-9.82; -1.27; p=0.01), -0.01 microg/g (-0.03; 0.006; p=0.19), -0.52 microg/l (-4.63; 3.58; p=0.80) for serum, toenail and plasma studies, respectively. Overall, the pooled standardized mean difference between cases and controls was; -0.23 (-0.40; -0.05; p=0.01) indicating a possible inverse association between selenium levels and risk of prostate cancer. Differences in selenium levels between populations, a possible threshold effect and the relationship between selenium and the different stages of prostate cancer require further investigation.

Humans↗

Fruit consumption reduces the effect of smoking on bladder cancer risk. The Belgian case control study on bladder cancer.

We have hypothesized that consumption of fruit and vegetables may be associated with reduced risk of bladder cancer and that this may interact with cigarette smoking and metabolic genetic polymorphisms. A population-based case-control study was performed in the Belgian province of Limburg among 200 cases and 385 controls. Logistic regression was performed to calculate odds ratios (ORs) for bladder cancer occurrence with corresponding 95% confidence intervals (95% CI). Effect modification by smoking was investigated. We also evaluated interaction between fruit intake and GSTM1, GSTT1, NAT2 and SULT1A1 amongst "ever-smokers." Total vegetable intake was not significantly associated with the risk of bladder cancer (OR 1.15, 95% CI: 0.70-1.88 for the highest compared to the lowest tertile). However, total fruit intake was negatively associated with bladder cancer risk (OR 0.61, 95% CI 0.37-0.99 comparing the same tertiles). Among individuals with low daily fruit consumption, ever smokers had a highly increased risk of bladder cancer risk (OR: 4.23, 95% CI: 1.91-9.40). By increasing the daily fruit consumption, the risk of "ever-smokers" for developing bladder cancer decreased, however it remained significant (OR: 2.15; 95CI%: 1.15-4.05). No interaction was identified between the different genotypes and fruit consumption. We conclude that fruit consumption may decrease the effect of smoking on developing bladder cancer. Antioxidants, found in fruit, may protect against the damage caused by free radicals found in cigarette smoke. Metabolic polymorphisms appear not to modify this relation.

Adult↗

Results of diagnostic accuracy studies are not always validated.

BACKGROUND AND OBJECTIVE: Internal validation of a diagnostic test estimates the degree of random error, using the original data of a diagnostic accuracy study. External validation requires a new study in an independent but similar population. Here we describe whether diagnostic research is validated, which technique is used, and to what extent the validation study results differ from the original. STUDY DESIGN AND SETTING: All original diagnostic accuracy studies published in 1993 in a predefined set of journals were selected. Validation of these studies was assessed in the original article and in articles published within a period of 10 years, through a literature search and contacting the authors. RESULTS: None of the original studies reported any form of validation. Validation studies published later could be identified for 7 of the 11 original studies. Test characteristics were difficult to compare. Despite what was generally believed, not every validation study showed results inferior to the original. We found more studies that evaluated the test in a different population than in a similar one. CONCLUSION: Not every diagnostic accuracy study is validated. Diagnostic tests are more often repeated in different populations.

Databases, Bibliographic↗

Serious infections in children: an incidence study in family practice.

BACKGROUND: Information on the incidence of serious infections in children in general practice is scarce. However, estimates on the incidence of disease are important for several reasons, for example to assess the burden of disease or as a basis of diagnostic research. We therefore estimated the incidence of serious infections in general practice in Belgium. METHODS: Intego is a morbidity registration network, in which 51 general practitioners continuously register all diagnoses and additional data in their electronic medical records. Serious infections were defined as pneumonia, sepsis, meningitis, pyelonephritis and osteomyelitis. Incidences are calculated for the period of 1998 to 2002, per 1000 patients in the yearly contact group, which is the group of patients that consulted their GP at least once that year, and in the practice population, which is the estimated true population of that practice. RESULTS: The incidence of all infectious diseases peaks in children between 0 and 4 years, with 1731 infections per 1000 children per year in the yearly contact group. Incidence drops with increasing age: 972 infections per 1000 children per year in children between 5 and 9 years old, and 732 in children between 10 and 14 years old. The same decline in incidence is observed in the subgroup of serious infections: 21 infections per 1000 children per year in children between 0 and 4 years, 12 in children between 5 and 9 years and 5 in children between 10 and 14 years. The results for the estimated practice population are respectively 17, 9 and 4 serious infections per 1000 children per year. CONCLUSION: In contrast to the total incidence of acute infections, serious infections are rare, around 1% per year. Children younger than 4 years old have the highest risk for serious infections, and incidences of some infections are different for boys and girls.

Acute Disease↗

Does occupational exposure to PAHs, diesel and aromatic amines interact with smoking and metabolic genetic polymorphisms to increase the risk on bladder cancer?; The Belgian case control study on bladder cancer risk.

To investigate the association between occupational exposure to polycyclic aromatic hydrocarbons, aromatic amines and diesel and bladder cancer risk and the modification by smoking and metabolic polymorphisms, have we recruited 200 cases and 385 population controls. The adjusted OR of bladder cancer was 5.75 (95%CI 2.09-15.83) comparing the highest tertile of the cumulative probability of occupational exposure to aromatic amines with no occupational exposure. A possible interaction between occupational exposures to aromatic amines and smoking was found. The increased ORs of GSTM1, GSTT1, NAT2 and SULT1A1 among those ever occupational exposed was explored by estimating the false-positive report probability. We confirm that occupational exposure to aromatic amines is associated with an increase in bladder cancer risk.

Aged↗

Use of selenium in chemoprevention of bladder cancer.

The anticarcinogenic potential of selenium was first identified nearly 40 years ago in geographical studies that reported lower death rates for cancer in regions with high levels of selenium. Cancer of the bladder was one of the body sites found to share this inverse association. Although many subsequent studies have been done on selenium and cancer, only a few have specifically assessed the relation with bladder cancer. However, the high recurrence rate and ability to monitor bladder urothelial-cell carcinoma make selenium a good candidate for chemoprevention. Evidence suggests that selenium is a biologically plausible, safe, and efficacious potential chemoprevention agent for bladder cancer. Large tertiary chemoprevention trials are needed to further investigate the role of selenium in the prevention of bladder cancer. Future studies should assess the best dose and form of selenium, and whether the protective effect of selenium differs between the sexes.

Antioxidants↗

Similar compliance and effect of treatment in chronic hepatitis C resulting from intravenous drug use in comparison with other infection causes.

OBJECTIVES: There is some reluctance to treat intravenous drug users (IVDUs) with chronic hepatitis C (CHC) because of presumed lower compliance and response to antiviral therapy. We intended to evaluate the compliance and response to antiviral treatment for CHC in IVDUs compared with non-IVDUs. METHODS: A retrospective cohort study--secondary analysis of the results of a treatment trial--was performed in Belgium and The Netherlands. A total of 406 previously untreated CHC patients, including 98 (24%) IVDUs, were studied for compliance (presentation at the end of treatment), complete response (alanine aminotransferase within normal limits and serum hepatitis C virus polymerase chain reaction negative) at the end of therapy and sustained virological response (SVR). RESULTS: Non-compliance (8.2%) in IVDUs was not different from non-IVDUs (6.8%) (relative risk=1.20; 95% confidence interval=0.55-2.62). Complete response after controlling for hepatitis C virus was similar (relative risk=1.19; 95% confidence interval=0.89-1.60). Controlling for treatment arm, age, sex, presence of cirrhosis or hepatitis C virus viral load before treatment did not change these results. There was a marginally significant difference in the sustained virological response between IVDUs (46.6%) and non-IVDUs (34.6%) (relative risk=1.35; 95% confidence interval=1.00-1.81), also disappearing after adjusting for genotype. No difference in compliance or sustained virological response was found between active and non-active IVDUs or between IVDU patients in or without a methadone maintenance program. CONCLUSIONS: In this group of Benelux patients, IVDUs showed similar compliance and response to treatment with interferon and ribavirin compared with other patients with CHC infection. Therefore, it is no longer justifiable to withhold treatment to chronic hepatitis C patients who use intravenous drugs.

Adult↗

Selenium is inversely associated with bladder cancer risk: a report from the Belgian case-control study on bladder cancer.

AIM: Selenium is an essential trace element with suspected anticarcinogenic properties in humans. To date, eight epidemiological studies have examined the association between serum selenium concentration and bladder cancer risk. METHODS: The authors carried out a population case-control study in 178 cases and 362 controls to assess the relationship between bladder cancer risk and selenium serum concentrations. Unconditional logistic regression was calculated to determine odds ratios (OR) for bladder cancer occurrence with corresponding 95% confidence intervals (95% CI). Effect modification by smoking status, low fruit and vegetable intake, retinol equivalent, vitamin C, vitamin E and total antioxidant status were also assessed. RESULTS: Serum selenium level was negatively associated with bladder cancer risk. After adjustment for sex, age, smoking and occupational exposure, the OR was 0.48 (95% CI 0.29-0.79) comparing the second with the lowest tertile (serum selenium concentration >82.40 microg/L). The adjusted OR for the highest tertile (serum selenium concentration >96.00 microg/L), was 0.30 (95% CI 0.17-0.52) (P-trend <0.001). An increase of 10 microg/L in serum selenium concentration was associated with a significant decreased bladder cancer risk (OR: 0.76; 95% CI 0.67-0.85). CONCLUSION: This case-control study suggests an inverse association between serum selenium concentration and bladder cancer risk.

Aged↗

Methicillin-resistant Staphylococcus aureus colonization is associated with higher mortality in nursing home residents with impaired cognitive status.

OBJECTIVES: To assess the effect of methicillin-resistant Staphylococcus aureus (MRSA) colonization on morbidity and mortality of nursing home residents. DESIGN: Three-year cohort study from 2000 to 2003. SETTING: Twenty-three nursing homes of all types and regions in the northern part of Belgium (Flanders). PARTICIPANTS: Two thousand eight hundred fourteen nursing home residents. MEASUREMENTS: The consequences of MRSA colonization on mortality and hospitalization were studied, adjusting for potential confounders. Dates and cause of death and hospitalization were collected every 6 months during 3 years of follow-up. RESULTS: After adjustment for age, sex, and Charlson comorbidity index, the risk for 36-month mortality remained significantly higher in MRSA carriers (hazard ratio (HR) = 1.4, 95% confidence interval (CI) = 1.1-1.8) than in noncarriers. The effect of MRSA on mortality was dependent on the degree of cognitive impairment, with the highest effect in patients with severe cognitive impairment (adjusted HR = 1.8, 95% CI = 1.1-2.8) and absence of effect in residents with good mental status (adjusted HR = 0.8, 95% CI = 0.43-1.62). Deaths were more frequently reported to be infection-related in MRSA carriers. No association was found between MRSA colonization and hospitalization for any reason, but during follow-up, MRSA carriers were twice as frequently hospitalized for respiratory tract infections. CONCLUSION: Colonization of MRSA in Belgian nursing home residents was associated with higher mortality. This excess mortality was restricted to residents with impaired cognitive function, probably reflecting differences in therapeutic approaches, in delay of diagnosis of pneumonia and other acute disorders in these patients, or in both.

Aged↗

Implementing evidence-based medicine in general practice: a focus group based study.

BACKGROUND: Over the past years concerns are rising about the use of Evidence-Based Medicine (EBM) in health care. The calls for an increase in the practice of EBM, seem to be obstructed by many barriers preventing the implementation of evidence-based thinking and acting in general practice. This study aims to explore the barriers of Flemish GPs (General Practitioners) to the implementation of EBM in routine clinical work and to identify possible strategies for integrating EBM in daily work. METHODS: We used a qualitative research strategy to gather and analyse data. We organised focus groups between September 2002 and April 2003. The focus group data were analysed using a combined strategy of 'between-case' analysis and 'grounded theory approach'. Thirty-one general practitioners participated in four focus groups. Purposeful sampling was used to recruit participants. RESULTS: A basic classification model documents the influencing factors and actors on a micro-, meso- as well as macro-level. Patients, colleagues, competences, logistics and time were identified on the micro-level (the GPs' individual practice), commercial and consumer organisations on the meso-level (institutions, organisations) and health care policy, media and specific characteristics of evidence on the macro-level (policy level and international scientific community). Existing barriers and possible strategies to overcome these barriers were described. CONCLUSION: In order to implement EBM in routine general practice, an integrated approach on different levels needs to be developed.

Adult↗

Signs and symptoms in children with a serious infection: a qualitative study.

BACKGROUND: Early diagnosis of serious infections in children is difficult in general practice, as incidence is low, patients present themselves at an early stage of the disease and diagnostic tools are limited to signs and symptoms from observation, clinical history and physical examination. Little is known which signs and symptoms are important in general practice. With this qualitative study, we aimed to identify possible new important diagnostic variables. METHODS: Semi-structured interviews with parents and physicians of children with a serious infection. We investigated all signs and symptoms that were related to or preceded the diagnosis. The analysis was done according to the grounded theory approach. Participants were recruited in general practice and at the hospital. RESULTS: 18 children who were hospitalised because of a serious infection were included. On average, parents and paediatricians were interviewed 3 days after admittance of the child to hospital, general practitioners between 5 and 8 days after the initial contact. The most prominent diagnostic signs in seriously ill children were changed behaviour, crying characteristics and the parents' opinion. Children either behaved drowsy or irritable and cried differently, either moaning or an inconsolable, loud crying. The parents found this illness different from previous illnesses, because of the seriousness or duration of the symptoms, or the occurrence of a critical incident. Classical signs, like high fever, petechiae or abnormalities at auscultation were helpful for the diagnosis when they were present, but not helpful when they were absent. CONCLUSION: behavioural signs and symptoms were very prominent in children with a serious infection. They will be further assessed for diagnostic accuracy in a subsequent, quantitative diagnostic study.

Belgium↗

Increased mortality in partners of female myocardial infarction patients.

BACKGROUND: Many studies have been performed on the impact of Alzheimer's disease, stroke and cancer on carers. Information on the influence of a myocardial infarction in a patient on the health of the partner is still scarce. METHODS: Exposed and non-exposed partners were compared with respect to the occurrence of mortality and predefined diseases, using Cox proportional hazards survival analysis. RESULTS: None of the disease incidence rates differed between exposed partners and control partners. Over 12 times as many male partners of (female) heart patients died as compared to their male control partners, when they had a low educational level. CONCLUSION: When exposed to myocardial infarction in a patient, the risk of dying in low educated male partners was over 12 times as large as for male low educated unexposed partners.

Caregivers↗

The denominator in general practice, a new approach from the Intego database.

BACKGROUND: To determine the denominator or the 'population at risk' is a problem which has long been encountered in general practice-based epidemiological research. It is important for calculating epidemiological figures. OBJECTIVES: The aim of this article is to demonstrate how in the absence of a patient list, a reliable denominator can be calculated, starting from the number of patients who contacted their GP in the period of one year. Therefore a brief overview will be given from known approaches, then the new approach will be illustrated on a database named Intego, with data from 43 general practices in Belgium. METHODS: The Intego database contains information about patient contacts, diagnoses, laboratory results and drug prescriptions, extracted from the participants' structured electronic medical record system. The number of patients who contacted the practice in a year can be calculated from the Intego data. On the other hand, the percentage of the population that consults a GP during a particular period was obtained from the reimbursement claims data available from the sickness funds. By combining these two datasets, stratified by age, gender and district, a correction factor was calculated. An estimate of the real size of the Intego practice populations was obtained by extrapolating the yearly contact group by this factor. RESULTS: In 2003 according the Intego-register, 64,161 patients contacted their family practice and this correlated with an estimated practice population of 80,094 patients. The absence of the socio-economic status in the estimation is irrelevant in our model of estimating the practice population. CONCLUSION: The availability of a denominator in general practice-based research is essential to calculate epidemiological figures. This method using a correction factor makes it possible to calculate a reliable practice population. A similar approach will probably also be applicable in other European countries.

Adolescent↗

The Belgian Improvement Study on Oral Anticoagulation Therapy: a randomized clinical trial.

AIMS: In Belgium, general practitioners (GPs) mainly manage oral anticoagulation therapy. To improve the quality of oral anticoagulation management by GPs and to compare different models and interventions, a randomized clinical trial was performed. METHODS AND RESULTS: Stratified randomization divided 66 GP-practices into four groups. A 6-month retrospective analysis assessed the baseline quality. In the prospective study, each group received education on oral anticoagulation, anticoagulation files, and patient information booklets (groups A, B, C, and D). Group B additionally received feedback every 2 months on their anticoagulation performance; group C determined the international normalized ratio (INR) with a CoaguChek device in the doctor's office or at the patient's home; and group D received Dawn AC computer assisted advice for adapting oral anticoagulation. For the different groups, the time spent in target INR range (Rosendaal's method) and adverse events related to anticoagulation were determined and compared with the same quality indicators at baseline. There was a significant increase in per cent of time within 0.5 INR from target, from 49.5% at baseline to 60% after implementing the different interventions. However, neither the per cent in target range nor the event rates differed among the four groups. CONCLUSION: The interventions significantly improved the quality of management of oral anticoagulation by Belgian GPs, mainly as a result of an education and support programme.

Administration, Oral↗

Frequency of the CCR5-Delta32 mutant allele is not increased in Belgian hepatitis C virus-infected patients.

A 32-base pair deletion in the CC-chemokine receptor 5 gene (CCR5), associated with resistance to human immunodeficiency virus type 1 (HIV-1) infection, has recently been suggested to act as an adverse host factor in hepatitis C virus (HCV) infection. To examine this hypothesis, we determined the CCR5-Delta32 allele frequency by polymerase chain reaction in a Belgian cohort of 163 HCV-infected patients and 310 healthy control subjects. The resulting CCR5-Delta32 allele frequencies were 0.080 and 0.119 for the patient group and control group, respectively. In contrast with a previous study, we could not show a statistically significant difference between the CCR5-Delta32 allele frequencies in HCV patients and controls. Moreover, genotype distributions in both populations were in agreement with Hardy-Weinberg equilibrium. Our results do not support the hypothesis that the CCR5-Delta32 mutant allele is a risk factor for hepatitis C virus infection.

Belgium↗

Quality assessment of oral anticoagulation in Belgium, as practiced by a group of general practitioners.

OBJECTIVE: In Belgium oral anticoagulation therapy is mainly supervised by general practitioners (GPs). This study aims to evaluate the quality of management of oral anticoagulation by Belgian GPs and to verify the relation between time in range and a set of potentially influencing co-variables. METHODS: In a retrospective cross-sectional study, involving 66 GP-practices, the INR-values obtained over a 6-month period were analysed. All INR-values were determined by a single clinical laboratory and additional medical information was provided by the GPs. Linear mixed models have been used to model the patient-specific percentage INR in target as a function of different co-variables. RESULTS: 737 patients were included in the study. Patients who underwent a surgical intervention with an interruption of the anticoagulation during the study were excluded. Patients were only included after the initial starting-up period. 5890 INR-values were obtained. A total of 92,566 days of therapy was evaluated. 50% of the day values were within 0.5 INR-units from target (and 66% within 0.75 INR-units from target). In a multiple regression model, a significant relation between the percentage of time in range and the target INR (2.5 or 3.5) and the gender of the patient was shown. The incidence rate for major bleeding was 5.5/100 patient years (and 3.5/100 patient years for thrombo-embolic events). CONCLUSION: The quality of management of oral anticoagulation by the GPs in Belgium is suboptimal. It is unknown whether interventions such as guidelines, feedback, point-of-care monitoring and computer-assisted anticoagulation monitoring could improve the results.

Aged↗