Linking a European cohort of children born with congenital anomalies to vital statistics and mortality records: A EUROlinkCAT study

EUROCAT is a European network of population-based congenital anomaly (CA) registries. Twenty-one registries agreed to participate in the EUROlinkCAT study to determine if reliable information on the survival of children born with a major CA between 1995 and 2014 can be obtained through linkage to national vital statistics or mortality records. Live birth children with a CA could be linked using personal identifiers to either their national vital statistics (including birth records, death records, hospital records) or to mortality records only, depending on the data available within each region. In total, 18 of 21 registries with data on 192,862 children born with congenital anomalies participated in the study. One registry was unable to get ethical approval to participate and linkage was not possible for two registries due to local reasons. Eleven registries linked to vital statistics and seven registries linked to mortality records only; one of the latter only had identification numbers for 78% of cases, hence it was excluded from further analysis. For registries linking to vital statistics: six linked over 95% of their cases for all years and five were unable to link at least 85% of all live born CA children in the earlier years of the study. No estimate of linkage success could be calculated for registries linking to mortality records. Irrespective of linkage method, deaths that occurred during the first week of life were over three times less likely to be linked compared to deaths occurring after the first week of life. Linkage to vital statistics can provide accurate estimates of survival of children with CAs in some European countries. Bias arises when linkage is not successful, as early neonatal deaths were less likely to be linked. Linkage to mortality records only cannot be recommended, as linkage quality, and hence bias, cannot be assessed.

The Baby Hearts Study - a case-control methodology with data linkage to evaluate risk and protective factors for congenital heart disease

Introduction

The Baby Hearts study aimed to investigate risk and protective factors for congenital heart disease (CHD), and to investigate the health behaviours of a representative sample of pregnant women in Northern Ireland.

Objectives

We describe and evaluate the population-based case-control design enhanced with data linkage to administrative health data.

Methods

Cases (mothers of babies with CHD, n=286) were recruited following diagnosis prenatally or postnatally. Controls (mothers of babies without CHD, n=966) were recruited at 18-22 weeks gestation, from all women attending each maternity unit during a designated month. Hybrid data collection methods were used, including a self-administered iPad/postal questionnaire, and linkage to maternity and prescription records.

Results

Refusal rates were low (8%). iPad questionnaire completion at clinic or home visit had high acceptability whereas postal questionnaires were poorly returned leading to a further 9-10% loss of eligible cases/controls. In total, 61% of eligible cases and 68% of eligible controls were recruited, closely representative of the Northern Ireland population, with no evidence of selection bias. Of those recruited, 97% gave consent for linkage to medical records. Thirty-three percent of women had an unplanned pregnancy and 76% suspected they were pregnant by 5 weeks gestation, with no significant differences between cases and controls. There was considerable discordance between self-report, maternity and prescription records regarding medications obtained/taken in the first trimester, but no evidence of differences between cases and controls that would indicate substantial recall bias. Although there was high concordance between self-report and maternity records regarding folic acid supplementation, cases had significantly lower concordance than controls.

Conclusions

Our results suggest hybrid data collection approaches are a useful way forward for aetiological studies to reduce responder burden and address and estimate recall bias, and that the Baby Hearts study protocol is suitable for replication in other populations, modified to the local context.

Prevalence and risk of Down syndrome in monozygotic and dizygotic multiple pregnancies in Europe: implications for prenatal screening

OBJECTIVE

To determine risk of Down syndrome (DS) in multiple relative to singleton pregnancies, and compare prenatal diagnosis rates and pregnancy outcome.

DESIGN

Population-based prevalence study based on EUROCAT congenital anomaly registries.

SETTING

Eight European countries.

POPULATION

14.8 million births 1990-2009; 2.89% multiple births.

METHODS

DS cases included livebirths, fetal deaths from 20 weeks, and terminations of pregnancy for fetal anomaly (TOPFA). Zygosity is inferred from like/unlike sex for birth denominators, and from concordance for DS cases.

MAIN OUTCOME MEASURES

Relative risk (RR) of DS per fetus/baby from multiple versus singleton pregnancies and per pregnancy in monozygotic/dizygotic versus singleton pregnancies. Proportion of prenatally diagnosed and pregnancy outcome.

STATISTICAL ANALYSIS

Poisson and logistic regression stratified for maternal age, country and time.

RESULTS

Overall, the adjusted (adj) RR of DS for fetus/babies from multiple versus singleton pregnancies was 0.58 (95% CI 0.53-0.62), similar for all maternal ages except for mothers over 44, for whom it was considerably lower. In 8.7% of twin pairs affected by DS, both co-twins were diagnosed with the condition. The adjRR of DS for monozygotic versus singleton pregnancies was 0.34 (95% CI 0.25-0.44) and for dizygotic versus singleton pregnancies 1.34 (95% CI 1.23-1.46). DS fetuses from multiple births were less likely to be prenatally diagnosed than singletons (adjOR 0.62 [95% CI 0.50-0.78]) and following diagnosis less likely to be TOPFA (adjOR 0.40 [95% CI 0.27-0.59]).

CONCLUSIONS

The risk of DS per fetus/baby is lower in multiple than singleton pregnancies. These estimates can be used for genetic counselling and prenatal screening.

Trends in the prevalence, risk and pregnancy outcome of multiple births with congenital anomaly: a registry-based study in 14 European countries 1984-2007

OBJECTIVE

To assess the public health consequences of the rise in multiple births with respect to congenital anomalies.

DESIGN

Descriptive epidemiological analysis of data from population-based congenital anomaly registries.

SETTING

Fourteen European countries.

POPULATION

A total of 5.4 million births 1984-2007, of which 3% were multiple births.

METHODS

Cases of congenital anomaly included live births, fetal deaths from 20 weeks of gestation and terminations of pregnancy for fetal anomaly.

MAIN OUTCOME MEASURES

Prevalence rates per 10,000 births and relative risk of congenital anomaly in multiple versus singleton births (1984-2007); proportion prenatally diagnosed, proportion by pregnancy outcome (2000-07). Proportion of pairs where both co-twins were cases.

RESULTS

Prevalence of congenital anomalies from multiple births increased from 5.9 (1984-87) to 10.7 per 10,000 births (2004-07). Relative risk of nonchromosomal anomaly in multiple births was 1.35 (95% CI 1.31-1.39), increasing over time, and of chromosomal anomalies was 0.72 (95% CI 0.65-0.80), decreasing over time. In 11.4% of affected twin pairs both babies had congenital anomalies (2000-07). The prenatal diagnosis rate was similar for multiple and singleton pregnancies. Cases from multiple pregnancies were less likely to be terminations of pregnancy for fetal anomaly, odds ratio 0.41 (95% CI 0.35-0.48) and more likely to be stillbirths and neonatal deaths.

CONCLUSIONS

The increase in babies who are both from a multiple pregnancy and affected by a congenital anomaly has implications for prenatal and postnatal service provision. The contribution of assisted reproductive technologies to the increase in risk needs further research. The deficit of chromosomal anomalies among multiple births has relevance for prenatal risk counselling.

Maternal age-specific risk of non-chromosomal anomalies

OBJECTIVES

To determine the excess risk of non-chromosomal congenital anomaly (NCA) among teenage mothers and older mothers.

DESIGN AND SETTING

Population-based prevalence study using data from EUROCAT congenital anomaly registers in 23 regions of Europe in 15 countries, covering a total of 1.75 million births from 2000 to 2004.

PARTICIPANTS

A total of 38,958 cases of NCA that were live births, fetal deaths with gestational age > or = 20 weeks or terminations of pregnancy following prenatal diagnosis of a congenital anomaly.

MAIN OUTCOME MEASURES

Prevalence of NCA according to maternal age, and relative risk (RR) of NCA and 84 standard NCA subgroups compared with mothers aged 25-29.

RESULTS

The crude prevalence of all NCA was 26.5 per 1000 births in teenage mothers (<20 years), 23.8 for mothers 20-24 years, 22.5 for mothers 25-29 years, 21.5 for mothers 30-34 years, 21.4 for mothers 35-39 years and 22.6 for mothers 40-44 years. The RR adjusted for country for teenage mothers was 1.11 (95% CI 1.06-1.17); 0.99 (95% CI 0.96-1.02) for mothers 35-39; and 1.01 (95% CI 0.95-1.07) for mothers 40-44. The pattern of maternal age-related risk varied significantly between countries: France, Ireland and Portugal had higher RR for teenage mothers, Germany and Poland had higher RR for older mothers. The maternal age-specific RR varied for different NCAs. Teenage mothers were at a significantly greater risk (P < 0.01) of gastroschisis, maternal infection syndromes, tricuspid atresia, anencephalus, nervous system and digestive system anomalies while older mothers were at a significantly greater risk (P < 0.01) of fetal alcohol syndrome, encephalocele, oesophageal atresia and thanatophoric dwarfism.

CONCLUSIONS

Clinical and public health interventions are needed to reduce environmental risk factors for NCA, giving special attention to young mothers among whom some risk factors are more prevalent. Reassurance can be given to older mothers that their age in itself does not confer extra risk for NCA.

Survey of prenatal screening policies in Europe for structural malformations and chromosome anomalies, and their impact on detection and termination rates for neural tube defects and Down's syndrome

Objective

To ‘map’ the current (2004) state of prenatal screening in Europe.

Design

(i) Survey of country policies and (ii) analysis of data from EUROCAT (European Surveillance of Congenital Anomalies) population-based congenital anomaly registers.

Setting

Europe.

Population

Survey of prenatal screening policies in 18 countries and 1.13 million births in 12 countries in 2002–04.

Methods

(i) Questionnaire on national screening policies and termination of pregnancy for fetal anomaly (TOPFA) laws in 2004. (ii) Analysis of data on prenatal detection and termination for Down's syndrome and neural tube defects (NTDs) using the EUROCAT database.

Main outcome measures

Existence of national prenatal screening policies, legal gestation limit for TOPFA, prenatal detection and termination rates for Down's syndrome and NTD.

Results

Ten of the 18 countries had a national country-wide policy for Down's syndrome screening and 14/18 for structural anomaly scanning. Sixty-eight percent of Down's syndrome cases (range 0–95%) were detected prenatally, of which 88% resulted in termination of pregnancy. Eighty-eight percent (range 25–94%) of cases of NTD were prenatally detected, of which 88% resulted in termination. Countries with a first-trimester screening policy had the highest proportion of prenatally diagnosed Down's syndrome cases. Countries with no official national Down's syndrome screening or structural anomaly scan policy had the lowest proportion of prenatally diagnosed Down's syndrome and NTD cases. Six of the 18 countries had a legal gestational age limit for TOPFA, and in two countries, termination of pregnancy was illegal at any gestation.

Conclusions

There are large differences in screening policies between countries in Europe. These, as well as organisational and cultural factors, are associated with wide country variation in prenatal detection rates for Down's syndrome and NTD.

Please cite this paper as: Boyd P, DeVigan C, Khoshnood B, Loane M, Garne E, Dolk H, and the EUROCAT working group. Survey of prenatal screening policies in Europe for structural malformations and chromosome anomalies, and their impact on detection and termination rates for neural tube defects and Down's syndrome. BJOG 2008;115:689–696.

Trends and geographic inequalities in the prevalence of Down syndrome in Europe, 1980-1999

BACKGROUND

EUROCAT is a network of population-based registries for the epidemiologic surveillance of congenital anomalies covering approximately one quarter of births in the European Union. Down syndrome constitutes approximately 8% of cases of registered congenital anomaly in Europe, with over 7000 affected pregnancies in the 15 current member states of the European Union each year. In this paper, we aim to examine trends in the live birth prevalence of Down syndrome in Europe in the light of trends in maternal age and in prenatal diagnosis.

METHODS

Descriptive analysis of data from 24 EUROCAT registries, covering 8.3 million births 1980-99. Cases include live births, stillbirths and terminations of pregnancy following prenatal diagnosis.

RESULTS

Since 1980, the proportion of births to mothers of 35 years of age and over has risen quite dramatically from 8 to 14% for the European Union as a whole, with steeper rises in some regions. By 1995-1999, the proportion of "older" mothers varied between regions from 10% to 25%, and the total prevalence (including terminations of pregnancy) of Down syndrome varied from 1 to 3 per 1000 births. Some European regions have shown a more than twofold increase in total prevalence of Down syndrome since 1980. The proportion of cases of Down syndrome which were prenatally diagnosed followed by termination of pregnancy in 1995-1999 varied from 0% in the three regions of Ireland and Malta where termination of pregnancy is illegal, to less than 50% in 14 further regions, to 77% in Paris. The extent to which terminations of pregnancy were concen trated among older mothers varied between regions. The live birth prevalence has since 1980 increasingly diverged from the rising total prevalence, in some areas remaining approximately stable, in others decreasing over time.

CONCLUSION

The rise in average maternal age in Europe has brought with it an increase in the number of pregnancies affected by Down syndrome. The widespread practice of prenatal screening and termination of pregnancy has in most of the regions covered by EUROCAT counteracted the effect of maternal age in its effect on live birth prevalence. Under the joint influences of maternal age and prenatal screening the pattern of geographic inequalities in Down syndrome live birth prevalence in Europe has also been changed.

Prenatal diagnosis of severe structural congenital malformations in Europe

OBJECTIVES

To assess at a population-based level the frequency with which severe structural congenital malformations are detected prenatally in Europe and the gestational age at detection, and to describe regional variation in these indicators.

METHODS

In the period 1995-1999, data were obtained from 17 European population-based registries of congenital malformations (EUROCAT). Included were all live births, fetal deaths and terminations of pregnancy diagnosed with one or more of the following malformations: anencephalus, encephalocele, spina bifida, hydrocephalus, transposition of great arteries, hypoplastic left heart, limb reduction defect, bilateral renal agenesis, diaphragmatic hernia, omphalocele and gastroschisis.

RESULTS

The 17 registries reported 4366 cases diagnosed with the 11 severe structural malformations and of these 2300 were live births (53%), 181 were fetal deaths (4%) and 1863 were terminations of pregnancy (43%); in 22 cases pregnancy outcome was unknown. The overall prenatal detection rate was 64% (range, 25-88% across regions). The proportion of terminations of pregnancy varied between regions from 15% to 59% of all cases. Gestational age at discovery for prenatally diagnosed cases was less than 24 weeks for 68% (range, 36-88%) of cases. There was a significant relationship between high prenatal detection rate and early diagnosis (P < 0.0001). For individual malformations, the prenatal detection rate was highest for anencephalus (469/498, 94%) and lowest for transposition of the great arteries (89/324, 27%). Termination of pregnancy was performed in more than half of the prenatally diagnosed cases, except for those with transposition of the great arteries, diaphragmatic hernia and gastroschisis, in which 30-40% of the pregnancies with a prenatal diagnosis were terminated.

CONCLUSION

European countries currently vary widely in the provision and uptake of prenatal screening and its quality, as well as the "culture" in terms of decision to continue the pregnancy. This inevitably contributes to variation between countries in perinatal and infant mortality and in childhood prevalence and cost to health services of congenital anomalies.

A review of guidelines and standards for telemedicine

We conducted a review to establish the range and scope of current telemedicine guidelines and standards. Published guidelines were identified by searching the Medline and Telemedicine Information Exchange (TIE) databases, and by performing a Google search using the term 'telemedicine guidelines'. Three types of guidelines were identified, namely clinical, operational and technical. Clinical guidelines included those for teleradiology, telepsychiatry, home telenursing, minor injuries telemedicine, surgical telemedicine, teledermatology and telepathology. Operational guidelines included those for email communication, Internet access and videoconferencing. Technical guidelines included those from the American Telemedicine Association and the US Office for the Advancement of Telehealth. The main standards relevant to telemedicine include those of the International Telecommunication Union and the DICOM standard. The scarcity of guidelines and standards suggests that telemedicine is not yet near to routine use. If an international telemedicine organization were to take responsibility for defining guidelines, under the direction of clinicians with appropriate telemedicine experience, this might speed up their development.

Telemedicine and clinical genetics: establishing a successful service

There is a surprising lack of published experience on the use of videoconferencing in clinical genetics. Patients were randomly allocated to either a telegenetic (cases) or face-to-face (control) conventional clinic. The telegenetic consultation was done by videoconferencing, using ISDN lines at 384 kbit/s. Evaluation by the doctor and counsellor took place immediately after each appointment. The patient was asked to evaluate the appointment by telephone questionnaire about four weeks after the event. Forty-two patients were invited to participate and 33 (79%) returned their consent forms. Four patients declined to participate and were seen in ordinary face-to-face clinics. Preliminary results showed that the assessment of the telegenetics consultations by doctors, counsellors and patients was very favourable, and they responded positively when asked if they would be happy to use telemedicine in the future. For use in selected consultations, videoconferencing does appear to fulfil a useful role in clinical genetics.

A simulation model for analysing patient activity in dermatology

We developed a general model to assess patient activity within the primary and secondary health-care sectors following a dermatology outpatient consultation. Based on observed variables from the UK teledermatology trial, the model showed that up to 11 doctor-patient interactions occurred before a patient was ultimately discharged from care. In a cohort of 1000 patients, the average number of health-care visits was 2.4 (range 1-11). Simulation analysis suggested that the most important parameter affecting the total number of doctor-patient interactions is patient discharge from care following the initial consultation. This implies that resources should be concentrated in this area. The introduction of teledermatology (either realtime or store and forward) changes the values of the model parameters. The model provides a quantitative tool for planning the future provision of dermatology health-care.

The effect of videoconferencing on the depth perception of observers

The ability of the human eye to perceive depth was measured using a specially designed instrument. Visual acuity and both monocular and binocular stereoacuity were measured when viewing the instrument directly and via a videoconferencing link. Ten subjects with an average age of 32.5 years (range 24-50) took part in the study. The group mean visual acuity using both eyes under normal test conditions was -0.04 logMAR (Snellen 6/5) compared with 0.18 logMAR (Snellen 6/10) for the video-link. The mean stereoacuity using both eyes was 37" (SD 18") under normal test conditions. When a videoconferencing link was used, the mean stereoacuity fell to 1218" (SD 1203") using one eye and to 1651" (SD 1419") using both eyes. The ability to perceive depth remotely via a video-link was significantly decreased compared with normal test conditions.

A follow-up study of remote trauma teleconsultations

We conducted a follow-up study of patients who had attended a nurse-led minor accident and treatment service (MATS) and who had participated in a teleconsultation. Over three and a half years, 31,510 patients had attended the MATS unit and 1854 patients (5.9%) of these had participated in a teleconsultation. Of the 1854 telemedicine patients, 1199 had been referred to hospital or clinic and 1153 had actually attended. Retrospective examination of the relevant hospital records showed that in 25 cases (2%) the original telediagnosis was considered incorrect at face-to-face review and that treatment was either begun or changed in 264 cases (23%). All patients, including those discharged home after the teleconsultation, were sent a questionnaire about any changes to their injury. Of the 655 patients discharged home, a questionnaire response was obtained from 598 (91%). Following discharge, 43 of these patients had sought help from another health-care provider (the majority from their general practitioner). Of the 46 patients referred to hospital who did not keep their follow-up appointments, questionnaire results were obtained from 35 (76%). Nine of these patients had sought help from another health-care provider (the majority from their general practitioner) but there had been no change in diagnosis or treatment. Our findings suggest that teleconsultations are an effective means of delivering minor injuries care.

Transfer of telemedical support to Cornwall from a national telemedicine network during a solar eclipse

During late 1998 and early 1999, planning officers in Cornwall predicted a huge increase in summer visitors to the county to observe the August solar eclipse. There was the possibility that a mass gathering in Cornwall could overload existing arrangements for handling accident and emergency patients. We therefore set up a telemedicine system to support the county's minor injury units (MIUs) from hospitals throughout the UK. Six main hospital accident and emergency departments outside Cornwall with existing links to their own MIUs were twinned with 10 of the 11 MIUs in Cornwall before the expected date of the gathering. The network was live for nine days, starting four days before the eclipse, and 2045 patients were seen in the 10 MIUs. There were 93 telemedicine calls from the 10 MIUs, involving 91 patients. Overall, 4.6% of the patients required a telemedicine consultation. Fifty-seven calls were made during working hours. Thirty-four patients were referred for further management, of whom 18 were referred on the same day. The transfer of telemedical support to a national network was successful.

The potential for telemedicine in home nursing

We assessed the proportion of home nursing visits that could be replaced by home telenursing in the UK. A retrospective review of nursing notes in the UK was undertaken using an abstraction instrument developed and tested in the US. A total of 1951 episodes of patient care at home were reviewed: 1450 from Liverpool and 501 from Belfast. A total of 1626 (83%) of the episodes involved 'hands-on' interventions. In Belfast two observers estimated that 14% of home nursing visits could be done via telemedicine while in Liverpool two more observers gave an estimate of 16%. Inter-rater agreement was high (kappa = 0.93 for the Belfast observers and 0.79 for the Liverpool observers). Pilot trials of an analogue video-phone in Belfast suggested that even relatively low-quality compressed video might be useful for home nursing. These findings suggest that telemedicine may have a significant role in the delivery of home health care in the UK.

Can x rays be accurately interpreted using a low cost telemedicine system?

OBJECTIVE

To assess whether the quality of x ray films transmitted via a low cost (low resolution) telemedicine link was satisfactory for clinical diagnosis.

METHODS

A retrospective study of a set of consecutive accident and emergency (A&E) radiographs. An A&E registrar viewed these directly on a standard x ray viewing box and via a telemedicine link.

RESULTS

There were 81 abnormalities out of 234 x ray films. Three abnormalities were missed both on the x ray viewing box and telemedicine link, one of which was significant. There were five additional abnormalities missed on the telemedicine link but detected on the x ray viewing box, of which two were significant. One normal x ray film was interpreted as abnormal on the telemedicine link. There were no false positives on direct viewing.

CONCLUSION

Transference of plain radiographs using a low cost/low resolution telemedicine link by A&E doctors is adequate for clinical interpretation.

A joint US-UK study of home telenursing

Nursing notes for patients nursed at home in the USA and the UK were reviewed using an abstraction instrument developed and tested in the US. More than 1700 episodes of patient care at home were reviewed: 906 in the US and 839 in the UK. Preliminary data suggest that in the US approximately 45% of home nursing visits could be done via telemedicine, while the figure is lower in the UK, less than 15%. Pilot trials of an analogue video-telephone in Kansas City and Belfast suggest that even relatively low-quality compressed video may be useful for home nursing. Clearly, there are differences between the two countries which merit further study, but there is evidence to suggest that telemedicine may have a role in the delivery of home health care.

Diagnostic accuracy of teledermatology: results of a preliminary study in New Zealand

AIM

To determine the accuracy of a video conferencing system (telemedicine) in diagnosis of dermatological disorders.

METHODS

New patients referred to a dermatology clinic were initially examined by telemedicine and then by a standard face to face consultation. The diagnoses made by each type of consultation were compared and accuracy of telemedicine determined.

RESULTS

One hundred and four patients with 135 dermatological conditions were analysed. Seventy five percent of conditions were correctly diagnosed by telemedicine. In a further 7% a differential diagnosis was made, which included the final diagnosis made face to face. In 12%, the diagnosis was incorrect using the telemedicine system, and in 3% no diagnosis was made. Four per cent of diagnoses were only made when the patient was seen face to face.

CONCLUSION

This preliminary study suggests that video conferencing equipment can be used with a reasonable degree of accuracy for the diagnosis of dermatological disease.

Assessing for glaucoma in general practice

Examining patients appropriately for primary open angle glaucoma in the general practice setting has traditionally been extremely difficult. The authors review important issues in the early detection of primary open angle glaucoma and discuss new assessment tools to assist GPs in this area.

Keratoconus: diagnosis and management

Keratoconus is a common condition whose clinical features represent a common effect on the cornea of a number of diverse processes. This review deals with the clinical signs and accompanying histological and biochemical changes within the cornea, evaluates the significance of associated ocular and systemic conditions and assesses the incidence and prevalence of the disorder. The wider ophthalmic community shares in the treatment of keratoconus, so the general principles of contact lens fitting associated with this difficult condition are examined and the specific protocol used at the Flinders Medical Centre is presented. When contact lenses are not tolerated or an adequate improvement in visual acuity is not achieved, surgery is the next option, so a full assessment is made of the risks and benefits of penetrating keratoplasty. Older techniques, such as thermokeratoplasty and lamellar keratoplasty, are examined and the new technique of epikeratophakia is evaluated.