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Biomedical subjects

M C Cornel

Publications and source records attributed to M C Cornel.

At least 19 recordsLinked to original sources
PubMed1999

Artefactual increasing frequency of omphaloceles in the Northern Netherlands: lessons for systematic analysis of apparent epidemics.

BACKGROUND: While monitoring birth defects in a registry, statistically significant increases in prevalence occasionally occur. In the European Registration Of Congenital Anomalies (EUROCAT) in the Northern Netherlands 20000 births are monitored every year. For omphaloceles, a steady increase in the prevalence from 0.86 per 10000 live- and stillbirths in 1981-1983 to 3.11 per 10000 live- and stillbirths in 1994 was seen in the three northern provinces of The Netherlands. METHODS: A stepwise enquiry into this increase, which included checking for misclassification and change in coding and ascertainment when necessary, was done. All cases of omphalocele and associated or similar birth defects registered at the EUROCAT registry were retrieved and if necessary recoded. RESULTS: This study showed that the increase reported previously was not a true time trend. A few cases of e.g. diastasis recti and trisomy 18 were misclassified. The prevalence in more recent years is comparable with that in the rest of Europe, whereas it used to be lower. There was an increase in isolated omphalocele, but the numbers are small. CONCLUSIONS: The stepwise enquiry described should be a standard procedure after noticing an increasing prevalence in a registry. A better subdivision, e.g. in isolated cases versus children with multiple congenital anomalies, before monitoring can contribute to a lower number of false positive signals.

Congenital Abnormalities↗
PubMed1998

[Thalidomide once more in the spotlight].

Thalidomide was withdrawn from the market in the early sixties because of major teratogenic effects such as reduction defects of the limbs. Since, however, it has been found to be an effective drug in erythema nodosum leprosum. In the United States it was decided in September 1997 to admit thalidomide to the market for this indication, and in South America it has been available for this indication all the time. Thalidomide is also efficacious in other major disorders (e.g. aphtae and ulcers in aids) or its efficacy is being investigated in clinical trials (e.g. autoimmune diseases, other complications in aids). The American Food and Drug Administration has imposed conditions for the use of thalidomide. Users have to sign an informed consent and to take adequate contraceptive measures. Physicians should inform the patients and monitor side effects. Pharmacists should record and control the use.

Adult↗
PubMed1998

[Determination of one national standard for children with congenital anomalies in the National Obstetrical Registry and in the National Neonatal Registry].

OBJECTIVE: To determine if the birth prevalence data on congenital malformations in the national perinatal registries, the Landelijke Verloskunde Registratie (LVR) (National Obstetrical Registry) and the Landelijke Neonatologie Registratie (LNR) (National Neonatological Registry), can be combined into one nationwide database, and if so to determine the validity of this database. DESIGN: Descriptive. SETTING: TNO Prevention and Health, Leiden, the Netherlands. METHODS: Investigation of the registered number of congenital malformations in the LVR/LNR, the amount of overlapping and the possibility of combining the LVR and LNR into one nationwide database. The validity of this database was evaluated by comparing the total number of registered children with the total number expected in the Netherlands. Furthermore the total number of children registered in the nationwide database was compared with children registered by the European registration of congenital anomalies and twins (EUROCAT) in the Northern Netherlands. RESULTS: The LVR and LNR were mostly complementary with respect to the registration of congenital anomalies and could be combined to one nationwide database. For sixteen important diagnoses this nationwide database contained approximately 87% of the total number expected in the Netherlands. Comparing this database with the data of EUROCAT in the Northern Netherlands showed that one-third of these congenital malformations (n = 229 in 217 children) were registered in both systems, while 99 (43%) were only registered by EUROCAT and 50 (22%) only by the nationwide database. CONCLUSION: It was possible to create a nationwide database, which can supplement the regional EUROCAT data with nationwide data on sixteen important diagnoses of congenital malformations.

Child↗
PubMed1998

Increasing awareness of and behaviour towards periconceptional folic acid consumption in The Netherlands from 1994 to 1995.

OBJECTIVE: In November 1993, Dutch health authorities advised that women planning a pregnancy should take folic acid in the periconceptional period to reduce the risk of fetal neural tube defects. In the autumn of 1995 a national campaign was organized to inform women and health care professionals in a systematic way. METHODS: We assessed the awareness and behaviour of women at their first or second antenatal visit in two surveys in the spring of 1994 and the autumn of 1995, in order to evaluate the impact of non-systematic information during that period, and to collect baseline data to evaluate the effect of the national folic acid campaign. The two surveys were carried out in the north and the west of The Netherlands. RESULTS: The proportion of women who had heard of folic acid increased from 28% to 78%. The proportion that used folic acid during any period in pregnancy increased from 7.8% to 26%. The proportion that took folic acid tablets during the whole of the recommended period increased from 0.8 to 4.4%. In the group of women who did not take folic acid, the proportion who did "not like to use anything during pregnancy" decreased, as did the proportion who did "not think it is useful". CONCLUSION: In the Netherlands, non-systemic information about periconceptional folic acid use has already led to significant changes in awareness and behaviour before the start of the national folic acid campaign.

Adult↗
PubMed1997

[Epidemiology of prenatal diagnosis and selective pregnancy termination because of fetal neural tube defects in The Netherlands in comparison to other European countries].

OBJECTIVE: To describe the epidemiological impact of prenatal diagnosis and selective abortion on the frequency of neural tube defects (NTD) in the period 1980-1992 in the Northern Netherlands in comparison with data from other European regions. DESIGN: Descriptive. SETTING: 17 'European registration of congenital anomalies' (EUROCAT) registrations, localized in 10 European countries. METHOD: Data were collected actively and retrospectively from multiple sources fed by voluntary registration of congenital anomalies in live births, stillbirths and pregnancies terminated because of congenital anomalies. RESULTS: In Europe the total birth prevalence of NTD in the period 1980-1992 ranged from 5.3 per 10,000 in Switzerland to 29.0 per 10,000 in Glasgow, a difference of a factor 5.5. In live births the difference was ninefold: ranging from 2.0 per 10,000 in Paris to 18.8 per 10,000 in Dublin. The Netherlands had a conspicuously high prevalence among live births, higher than in other regions in continental Europe. For spina bifida the live birth prevalence both in other continental regions and in Glasgow was also lower than in the Netherlands. In Glasgow serum alpha-foetoprotein screening apparently led to frequent early prenatal diagnosis of NTD and to frequent termination of pregnancy. In Paris the use of ultrasound screening appears to lead to frequent later prenatal diagnosis, as well as frequent termination of pregnancy. CONCLUSION: In the Netherlands the impact of prenatal diagnosis and selective abortion is limited, so that primary prevention (periconceptional use of folic acid) is more important than in some other European countries.

Abortion, Therapeutic↗
PubMed1997

[Why the incidence of congenital and hereditary disorders usually is zero].

Incidence is a frequency measure for quantifying new cases of a disease, and prevalence quantifies patients who already have a particular disorder. An exception to this rule is the frequency of congenital and hereditary disorders. If this frequency is expressed as the proportion of the number of births, prevalence is appropriate. Incidence is a meaningful measure only when used to indicate the frequency with which such a disorder is diagnosed during life, as opposed to the frequency with which it originates.

Congenital Abnormalities↗
PubMed1997

A demographic approach to the assessment of Down syndrome screening performance.

The aim of this article is to examine the performance of screening for fetal Down syndrome (DS) in the context of demographic variation in time and place, using population and fertility data for several European countries. Two screening approaches are distinguished: one on the basis of maternal serum screening with human chorionic gonadotropin (hCG) and alpha-fetoprotein (AFP) in combination with maternal age, and one on the basis of maternal age only. Screening performance, as measured by detection and false-positive ratios, is shown to be the result of the screening approach chosen and of the demographic characteristics of the population under consideration. A proper distinction between these two determinants of DS screening performance should be made, in order to distinguish between an improvement in screening performance that is brought about by a new screening approach and an improvement that is brought about by demographic change. We recommend that measures of DS screening performance be standardized for demographic variation. The methodology and demographic data presented in this article can be used for this purpose.

Adolescent↗
PubMed1996

[Prevalence, clinical aspects and prognosis of neural tube defects in The Netherlands].

OBJECTIVE: To determine the live birth prevalence of neural tube defects (NTD) in the Netherlands and describe the clinical picture. DESIGN: Descriptive. SETTING: TNO Prevention and Health, Leiden, the Netherlands. METHOD: Data collected through active surveillance of NTD on a monthly basis by paediatricians throughout the country. RESULTS: From October 1993 to September 1995, 203 infants with NTD were registered. Six were diagnosed with anencephaly, 10 with encephalocele and 157 with spina bifida. On 30 children no further information was available. Seventy-nine per cent of children with spina bifida had a myelomeningocele and 11% had a meningocele. Hydrocephalus was found in 75% of all registered infants and in 81% of infants with myelomeningocele. In 18% of the latter group a kyphosis was diagnosed. In 45% of 131 children prognosis of ambulation fair: they were expected to learn to walk. In 32% prognosis for motor disorder was very poor, and unsupported sitting was considered to be unlikely. At the time of registration, when most children were less than a month old, 55 (27%) had died; in infants with a myelomeningocele this was 35%. In many children treatment had not been started, probably because the prognosis was poor. Some had not been referred to a multidisciplinary team and only one of them received a hydrocephalus valve. CONCLUSION: The prevalence of spina bifida in the Netherlands is at least 100 live-born children per year among 195,000 total births. Mortality in the first month is high and for many surviving infants a severe handicap can be expected. Preventive strategies (such as folic acid supplementation) are urgently needed.

Activities of Daily Living↗
PubMed1995

The role of pharmacists in the recruitment of a cohort for postmarketing surveillance. A case study of acitretin in The Netherlands.

In October 1990, a recall procedure was issued regarding the drug acitretin. The recommended post-therapy contraception period after acitretin therapy was extended from 2 months to 2 years. For a postmarketing surveillance study, we recruited a cohort from the source population of women aged 15-45 years who were exposed to acitretin. Recruitment occurred through dermatologists, and pharmacists plus dispensing general practitioners. We describe the speed of and the response to the recruitment procedures, and the representativeness of the recruited cohort. We also studied whether the individuals who gave informed consent would have preferred to be recruited by either dermatologists or pharmacists, and whether the information obtained from pharmacists and dispensing general practitioners was valid. This study revealed that pharmacists and dispensing general practitioners (drug dispensers) recruited their subjects rapidly, with no or little selection; they attained a 42% response. Dermatologists recruited their subjects slowly and selectively; they attained a 24% response. The majority of women (60%) recruited by dermatologists would have given their informed consent if they would have been recruited by their pharmacists. Drug dispensers are essential contributors to the recruitment of a study population. We do advise that such recruitment for a postmarketing surveillance study occurs by means of a collaboration between pharmacists and physicians.

Acitretin↗
PubMed1994

[Incidence and prevalence of genetically-determined disorders in The Netherlands; a literature study].

OBJECTIVE: To analyse if data now available on frequencies of genetic disorders are sufficient to be used in future as indicators when an evaluation of new developments is desired for policy-making purposes. DESIGN: Literature study. SETTING: The Netherlands. METHOD: Using automated literature search systems, papers published before October 1991 were surveyed and an inventory of incidence and prevalence of genetic disorders in the Netherlands was made. RESULTS: Depending on the pattern of heredity differences in available data and their validity were found. Valid data on most of the II congenital anomalies investigated were available from the EUROCAT registration in the northern Netherlands. This method of data collecting is also suitable for the evaluation of prevalence development. On the 29 multifactorial diseases occurring later in life that were investigated many data were available, although the varying sources made comparison difficult. These data were often out of date and had a highly varying validity. Of 3 chromosomal abnormalities the prevalence at birth was known. Of only 22 out of 650 monogenic disorders, described in the Netherlands up to 1991, the prevalence at birth and(or) in the population was known. CONCLUSION: Data on frequency of genetic disorders can be collected but the information now available is insufficient to serve as an indicator for government policy. Frequencies should also be considered in relation to the impact of the disease on the individual, his environment and society.

Adolescent↗
PubMed1994

Variation in prenatal cytogenetic diagnosis: policies in 13 European countries, 1989-1991. EUROCAT Working Group. European Registration of Congenital Anomalies.

The livebirth prevalence of autosomal chromosomal anomalies is determined by several factors, including maternal age distribution and the impact of prenatal cytogenetic diagnosis (PCD). The impact of PCD varies between countries, as the indications and the uptake vary. In a previous study we described differences in Down syndrome prevalence and the proportion of older mothers. We have now made a survey of the official PCD policies in 25 regions in 13 European countries for the period 1989-1991. In two countries, termination of pregnancy was not available. In the other 11 countries, international agreement existed on five indications: advanced maternal age, a previous child with a chromosomal anomaly, parents who are carries of a balanced translocation, mothers who are carriers of an X-linked disorder, and malformations at ultrasound. The exact limit for advanced maternal age varied from 35 to 38 years. There was a considerable variation for the indications advanced paternal age, amniocentesis for AFP or DNA, parental anxiety, a previous child with a congenital anomaly, abnormal maternal serum markers, and exposure to radiation/chemotherapy. The PCD uptake for mothers above the maternal age limit varied from 10 to 88 per cent. International harmonization of the indications for PCD is not considered feasible at present, because of the rapid changes in PCD policies even within countries.

Abortion, Induced↗