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A Vellinga

Publications and source records attributed to A Vellinga.

16 recordsLinked to original sources
PubMed2005

Decision-making capacity of elderly patients assessed through the vignette method: imagination or reality?

This article evaluates whether providing hypothetical or realistic information influences the assessment of decision-making capacity in elderly patients with (and without) cognitive impairment. Decision-making capacity was assessed by means of a clinical vignette that presented a choice about whether to undergo an endoscopic procedure. The following standards of decision-making capacity were evaluated quantitatively and qualitatively: ability to evidence a choice, to understand, to reason, and to appreciate a situation. The vignette was presented to patients in either a hypothetical or real situation. In the hypothetical situation cognitively impaired patients performed significantly poorer than cognitively non-impaired patients on all abilities associated with decision-making capacity (with the exception of evidencing a choice). The realistic situation showed the same pattern among cognitively impaired and non-impaired patients in their ability to understand and in the total vignette score. Both types of patients reasoned about and appreciated the realistic situation equally well. Qualitative analysis revealed that patients gave comparable answers in both hypothetical and realistic situations. The answers were not related to standards of decision-making capacity. Moreover, personal circumstances were taken as a reference point for making a decision, regardless of the situation. We did not find any major differences between the hypothetical and realistic situation. Our findings do raise questions about the validity of hypothetical vignettes, however, especially when used with cognitively impaired persons.

Aged↗
PubMed2005

Perinatal risk factors for sensitization, atopic dermatitis and wheezing during the first year of life (PIPO study).

OBJECTIVE: To evaluate the influence of perinatal environmental factors on early sensitization, atopic dermatitis and wheezing during the first year. METHODS: Information on pregnancy-related factors, parental atopic history, environmental factors and the clinical course of the infant until age one was gathered by questionnaires, as part of a prospective birth cohort study (Prospective study on the Influence of Perinatal factors on the Occurrence of asthma and allergies [PIPO-study]). Quantification of total and specific IgE was performed in 810 children and their parents. RESULTS: Early sensitization was found in 107/810 (13%) of the infants. Multiple regression analysis showed that specific IgE in fathers was a risk factor for early sensitization in their daughters (adjusted odds ratios (OR(adj)) 2.21 (95% confidence interval (CI) 1.10-4.49); P=0.03), whereas in boys, day care attendance was shown to be protective for early sensitization (OR(adj) 0.38 (95% CI 0.20-0.71); P=0.001). Atopic dermatitis occurred in 195/792 infants (25%). Specific IgE in the mother (OR(adj) 1.52 (95% CI 1.06-2.19); P=0.02) and in the infant (OR(adj) 4.20 (95% CI 2.63-6.68); P<0.001) were both risk factors for the occurence of atopic dermatitis, whereas postnatal exposure to cats was negatively associated with atopic dermatitis (OR(adj) 0.68 (0.47-0.97); P=0.03). Postnatal exposure to cigarette smoke (OR(adj) 3.31 (95% CI 1.79-6.09); P<0.001) and day care attendance (OR(adj) 1.96 (95% CI 1.18-3.23); P=0.009) were significantly associated with early wheezing, which occurred in 25% (197/795) of the infants. CONCLUSION: The effect of paternal sensitization and day care attendance on sensitization is gender dependent. Maternal sensitization predisposes for atopic dermatitis, whereas postnatal exposure to cats had a protective effect.

Allergens↗
PubMed2004

Competence to consent to treatment of geriatric patients: judgements of physicians, family members and the vignette method.

OBJECTIVE: In absence of a gold standard of methods to assess competence, three judgements of competency of geriatric patients are evaluated: the judgements of a physician, the judgement of a family member, and the judgement of an instrument. METHODS: Competence of 80 geriatric patients was judged both by a physician and a family member. Decision making capacity was assessed with a vignette. A vignette describes a treatment choice, after which the following abilities are evaluated: evidencing a choice, understanding, reasoning and appreciating a situation. Cognitive functioning was measured with the Mini-Mental State Examination. RESULTS: Most of the geriatric patients were judged competent by all three methods. Disagreement between the three judgements was found for 25 patients. Agreement about incompetence was only reached for one patient. Physicians appeared to be most lenient in their incompetency judgement: only three patients were judged incompetent. These patients scored significantly lower than competent patients on cognitive functioning, the decisional ability of understanding, and the total vignette score. Family members appeared to be most stringent in their judgement: they considered 22 patients incompetent. Incompetent patients scored significantly lower than competent patients on cognitive functioning, reasoning and the total vignette score. CONCLUSIONS: The disagreement between the judgements suggests a difference in factors given emphasis by the three methods. The finding that both the judgement of physicians and family members are associated with the assessment of the vignette, suggests that the vignette method has more than a legal theoretical base and is associated with daily life experience and knowledge as well. Physicians can be helped to assess competence by the vignette method to evaluate decisional abilities and by family members who can provide more information about patients' values.

Aged↗
PubMed2002

Vaccination coverage estimates by EPI cluster sampling survey of children (18-24 months) in Flanders, Belgium.

UNLABELLED: A random cluster sample according to the EPI cluster sampling technique was conducted in 1999 in Flanders (North Belgium) to ascertain the vaccination coverage of 18 to 24-mo-old children. Polio is the only mandatory vaccine. Diphtheria-tetanus-pertussis (DTP), Haemophilus influenzae type b (Hib), hepatitis B (HB) and measles-mumps-rubella (MMR) are included in the recommended schedule of vaccinations. For Hib and HB, a minimal cost was charged. Professional interviewers conducted interviews with the parents of 1110 children randomly selected in 89 municipalities. Analysis was conducted on the results of 1005 children. The coverage level (95% confidence interval) for the full schedule was 96% (95-97) for polio, 89% (87-91) for DTP, 78% (74-82) for Hib, 68% (64-72) for HB and 83% (81-87) for MMR. The vaccinations were administered by the regional children's health organization (70%), paediatricians (17%) and GPs (11%). No sociodemographic factors could be associated with vaccination coverage. One province showed significantly (p < 0.01) lower vaccination coverage levels compared with those of the other four provinces for DTP (91% vs 82%), Hib (78% vs 53%), HB (73% vs 46%) and MMR (87% vs 66%). CONCLUSION: There is a need for more and better information about vaccination for parents as well as for the healthcare providers.

Belgium↗
PubMed2001

Analysis of factors influencing vaccine uptake: perspectives from Belgium.

METHODS AND OBJECTIVES: To estimate the infant vaccination coverage in Belgium, a random cluster sample according to the expanded program on immunization (EPI) cluster sampling technique was performed in 1999 in the Flemish (Flanders) and French (Wallonia) speaking community of Belgium. The objective was to document the infant vaccination coverage retrospectively in 18-24-month-old children. In addition, the study offered the opportunity to assess some factors influencing vaccine uptake in infants. RESULTS: In the Flemish community infant vaccination coverage could not be associated with any of the socio-demographic factors, with two exceptions: the province (county) and the hepatitis B (HepB) vaccination. The main reason for not complying with the vaccination schedule was mainly carelessness on either parent's or physician's side. In the French speaking community parents feel mostly themselves responsible for the non-vaccination or incomplete vaccination of their child, except for pertussis. For all vaccines, the attitude of the physician is mentioned as being very influential in the decision to vaccinate a child. Most of the socio-demographic factors showed no association with the infant vaccination coverage. CONCLUSION: The surveys in Flanders and Wallonia stress the importance of having information made available, and underline the role parents as well as physicians (and nurses) play in the infant immunization coverage.

Belgium↗
PubMed2001

Repeated-measures models to evaluate a hepatitis B vaccination programme.

In 1985-1986, a hepatitis B vaccination programme was conducted in a Belgian institution for the mentally handicapped. A group of 97 residents was followed up for 11 years in order to characterize the long-term persistence of hepatitis B antibodies after vaccination. This paper proposes the use of linear mixed-effects models to account for serial correlation and between-individual heterogeneity in the data, while adjusting the analysis for various individual characteristics and important risk factors in the response to vaccination. We propose several model building strategies and focus on the prediction of future levels of antibodies.

Belgium↗
PubMed2001

Rigidity decreases resting tremor intensity in Parkinson's disease: A [(123)I]beta-CIT SPECT study in early, nonmedicated patients.

Tremor is one of the clinical hallmarks of Parkinson's disease (PD). Although it is accepted that other classic symptoms of PD such as rigidity and bradykinesia result from a degeneration of the nigrostriatal system and subsequent reduction in striatal dopamine, the pathophysiology of resting tremor remains unclear. The majority of recent single photon emission computed tomography (SPECT) and positron emission tomography (PET) studies, using various radioligands, demonstrated significant correlation between striatal radioligand bindings and the degree of parkinsonian symptoms such as rigidity and bradykinesia, but not tremor. We investigate the relationship between the degeneration of the nigrostriatal pathway and the appearance of resting tremor, taking into account the possible interference of rigidity with the resting tremor. Thirty early and drug-naïve PD patients were examined. Tremor and rigidity of the arms were assessed using UPDRS, and the power of tremor was estimated using spectral analysis of tremor peaks. [(123)I]beta-CIT SPECT was used to assess degeneration of the dopaminergic system in PD patients. A comparison between asymmetry indices showed that in terms of both tremor and rigidity, the most affected arm corresponded significantly with the contralateral striatum, having the largest reduction in radioligand binding. Furthermore, tremor power accounted for a significant part of variance in the contralateral striatum, suggesting a relationship between this PD symptom and the degeneration of the dopaminergic system. Further, the degree of tremor was reduced with increasing rigidity. However, correcting for the influence of rigidity, the significant contribution of tremor in the variance in the contralateral striatal [(123)I]beta-CIT binding disappeared. When the confounding influence of rigidity is taken into account, no significant direct relationship between dopaminergic degeneration and the degree of tremor could be found. Other pathophysiological mechanisms should be similarly investigated in order to further our understanding of the origin of resting tremor in PD.

Adult↗
PubMed1999

Hepatitis B vaccination in mentally retarded: effectiveness after 11 years.

The long-term effectiveness of hepatitis B vaccination was determined in a high-risk group of 105 institutionalized mentally retarded. All individuals were vaccinated in 1986, with three (0, 1, 6 months), four (0, 1, 6 and 12 months) or more doses according to their immune response at month 7, resulting in group 1 (G1), group 2 (G2) and group 3 (G3). They were annually followed up for five years, after which they received a booster dose. Eleven years after the initial vaccination, they were again tested for the presence of hepatitis B virus (HBV) serologic markers. The decline in anti-HBs logtitre over the first five years was 51% for G1 and 45% for G2. From the booster on month 60 to year 11, the overall decline was 31%. Eleven years after the start of vaccination and six years after the booster, 92% of the individuals had protective antibody levels higher than 10 IU/L. G1 had a geometric mean titre of 2015 IU/L, for G2 this was 245 IU/L. The difference in response to vaccination between the groups did not affect their protection. Only two vaccinees seroconverted to anti-HBc positivity without becoming carrier or ill. Long-term protection against HBV by vaccination appears to be excellent.

Adult↗
PubMed1999

Modelling long-term persistence of hepatitis B antibodies after vaccination.

Antibody response to hepatitis B vaccination was measured in 97 institutionalized, mentally handicapped patients after a 0-, 1-, 6-month vaccination schedule. Two groups were formed at month 7 according to the antibody response, which determined whether they needed an additional vaccine dose at month 12, to achieve an antibody titre of 100 IU/liter. All residents were followed up yearly for the first 5 years, after which, they received another booster dose. Another blood sample was taken 11 years after the start of the program. A linear mixed-regression model was used to analyze the data. Random and fixed effects were included to determine the generally known risk factors and the still unknown individual characteristics that influence the titre of hepatitis B surface antibodies (anti-HBs). The mean anti-HBs titre was a function of time, type of mental retardation (Down's syndrome or other types of mental retardation), the use of antiepileptic drugs, and the additional booster at month 12. The immediate and vigorous response of the immune system to booster vaccination shows that the immunologic memory is good after primary vaccination. For the maintenance of protection, the recommendation for mentally retarded patients in institutions is vaccination of all seronegative residents as well as new entrants, after which, no additional boosters will be necessary.

Anticonvulsants↗
PubMed1999

Hepatitis B and C in institutions for individuals with intellectual disability.

People with intellectual disability are a well-known high-risk group for hepatitis B virus (HBV) infection. Hepatitis B virus is a major public health problem, but it is often neglected because of its largely asymptomatic course with long-term complications. Safe and effective vaccines have been available for over 15 years. However, universal vaccination strategies have not or have not completely been implemented to date, even though epidemiological data have indicated the effectiveness and efficacy of vaccination, and economic evaluations have shown that it is cost effective. Hepatitis C virus (HCV), which was discovered in 1989, has similar risk factors and is also a cause of chronic hepatitis. The prevalence of HCV amongst individuals with intellectual disability has not been clearly established. An overview of the literature on the prevalence of HBV and HCV in this population, as well as risk factors, transmission and prevention is presented in the present review. The literature cited in the present article was obtained by searches in MedLine using the following keywords and keyword combinations: hepatitis, hepatitis B virus, hepatitis C virus, mentally retarded, mentally handicapped, developmentally retarded, intellectual disability, institutionalization, Down's syndrome and hepatitis B vaccination. The search was done from 1980 to 1998. Beside this, the older articles found in the references were included if these were considered necessary for completeness.

Global Health↗
PubMedDate not supplied

Changes in respiratory and allergic symptoms in schoolchildren from 1996 to 2002, results from the ISAAC surveys in Antwerp (Belgium).

Two cross sectional surveys (1995/1996 and 2001/2002) were carried out according to the ISAAC protocol among 6-7 and 13-14 year old schoolchildren in Antwerp, Belgium. A total of 8244 children participated in 1996 and 8159 children in 2002. No significant differences in current prevalence of asthma and asthma medication was found in 6-7 year olds and 13-14 year old girls. Significantly less asthma and asthma medication was reported by 13-14 year old boys in 2002. Symptoms of wheeze had lower occurrence in all groups in 2002, which was significant for older age group. Current prevalence of rash was significantly higher in the 6-7 year olds in 2002. No such increase was found for rash in the older age groups but they reported significantly more rhinitis. No differences were found between urban and suburban Antwerp in either survey. No clear changes in the occurrence of asthma were found for school children in Antwerp while wheeze was reported less in 2002 compared to 1996. Allergic disorders had higher occurrences in schoolchildren in 2002.

Adolescent↗