Using multiple sources to improve and measure case ascertainment in surveillance studies: 20 years of the British Paediatric Surveillance Unit

Neonatal stroke surveillance study protocol in the United Kingdom and Republic of Ireland

Neonatal stroke is a devastating condition that causes brain injury in babies and often leads to lifelong neurological impairment. Recent prospective population studies of neonatal stroke are lacking. Neonatal strokes are different from those in older children and adults. A better understanding of its aetiology, current management, and outcomes could reduce the burden of this rare condition. The study aims to explore the incidence and 2 year outcomes of neonatal stroke across an entire population in the UK and Republic of Ireland. This is an active national surveillance study using a purpose-built integrated case notification-data collection online platform. Over a 13 month period, with a potential 6 month extension, clinicians will notify neonatal stroke cases presenting in the first 90 days of life electronically via the online platform monthly. Clinicians will complete a primary questionnaire via the platform detailing clinical information, including neuroimaging, for analysis and classification. An outcome questionnaire will be sent at 2 years of age via the platform. Appropriate ethics and regulatory approvals have been received. The neonatal stroke study represents the first multinational population surveillance study delivered via a purpose-built integrated case notification-data collection online platform and data safe haven, overcoming the challenges of setting up the study.

Using capture-recapture methods to estimate influenza hospitalization incidence rates

Background

Accurate population estimates of disease incidence and burden are needed to set appropriate public health policy. The capture–recapture (C‐R) method combines data from multiple sources to provide better estimates than is possible using single sources.

Methods

Data were derived from clinical virology test results and from an influenza vaccine effectiveness study from seasons 2016–2017 to 2018–2019. The Petersen C‐R method was used to estimate the population size of influenza cases; these estimates were then used to calculate adult influenza hospitalization burden using a Centers for Disease Control and Prevention (CDC) multiplier method.

Results

Over all seasons, 343 influenza cases were reported in the clinical database, and 313 in the research database. Fifty‐nine cases (17%) reported in the clinical database were not captured in the research database, and 29 (9%) cases in the research database were not captured in the clinical database. Influenza hospitalizations were higher among vaccinated (58%) than the unvaccinated (35%) in the current season and were similar among unvaccinated (51%) and vaccinated (49%) in the previous year. Completeness of the influenza hospitalization capture was estimated to be 76%. The incidence rates for influenza hospitalizations varied by age and season and averaged 307–309 cases/100,000 adult population annually.

Conclusion

Using C‐R methods with more than one database, along with a multiplier method with adjustments improves the population estimates of influenza disease burden compared with relying on a single‐data source.

Coverage of the national surveillance system for human Salmonella infections, Belgium, 2016-2020

Introduction

The surveillance of human salmonellosis in Belgium is dependent on the referral of human Salmonella isolates to the National Reference Center (NRC). Knowledge of current diagnostic practices and the coverage of the national Salmonella surveillance system are important to correctly interpret surveillance data and trends over time, to estimate the true burden of salmonellosis in Belgium, and to evaluate the appropriateness of implementing whole-genome sequencing (WGS) at this central level.

Methods

The coverage of the NRC was defined as the proportion of all diagnosed human Salmonella cases in Belgium reported to the NRC and was assessed for 2019 via a survey among all licensed Belgian medical laboratories in 2019, and for 2016–2020 via a capture-recapture study using the Sentinel Network of Laboratories (SNL) as the external source. In addition, the survey was used to assess the impact of the implementation of culture-independent diagnostic tests (CIDTs) at the level of peripheral laboratory sites, as a potential threat to national public health surveillance programs.

Results

The coverage of the NRC surveillance system was estimated to be 83% and 85%, based on the results of the survey and on the two-source capture-recapture study, respectively. Further, the results of the survey indicated a limited use of CIDTs by peripheral laboratories in 2019.

Conclusion

Given the high coverage and the limited impact of CIDTs on the referral of isolates, we may conclude that the NRC can confidently monitor the epidemiological situation and identify outbreaks throughout the country. These findings may guide the decision to implement WGS at the level of the NRC and may improve estimates of the true burden of salmonellosis in Belgium.

Involvement of community paediatricians in the care of children and young people with mental health difficulties in the UK: implications for case ascertainment by child and adolescent psychiatric, and paediatric surveillance systems

Objective

To ascertain the extent to which community paediatricians are involved in the care of children with mental health conditions in order to determine which difficulties are appropriate for single or joint surveillance by the British Paediatric Surveillance Unit (BPSU) and Child and Adolescent Psychiatry Surveillance System (CAPSS).

Design

An online survey of the 1120 members of the British Association of Community Child Health (BACCH) working in 169 Community Child Health (CCH) services in the UK.

Results

A total of 245 community paediatricians responded to the survey. This represents 22% of members of BACCH but likely to have covered many of the 169 CCH units because participants could respond on behalf of other members in their unit. The survey showed that children and young people (CYP) with neurodevelopmental conditions presented more frequently to paediatrics than to Child and Adolescent Mental Health Services (CAMHS). In addition, a sizeable proportion of CYP with emotional difficulties presented to paediatricians (eg, 29.5% for anxiety/obsessive compulsive disorder (OCD), and 12.8% for depression)-mainly due to difficulty with accessing CAMHS. More than half of the community paediatricians are involved in the care of CYP with anxiety and OCD, while 32.3% are involved in the care of those with depression.

Conclusion

There is significant involvement of community paediatricians in the care of CYP with mental health conditions. Involvement is highest for neurodevelopmental conditions, but also significant for CYP with emotional difficulties. The implication of the findings for surveillance case ascertainment is that joint BPSU and CAPSS is recommended for surveillance studies of neurodevelopmental conditions. However, for emotional disorders, single or joint surveillance should be made based on the specific research question and the relative trade-offs between case ascertainment, and the additional cost and reporting burden of joint surveillance. Single CAPSS studies remain appropriate for psychosis and bipolar disorder.

A prospective, population-based, surveillance (BOSU) study of uveal effusion syndrome in the UK

PURPOSE

To determine the incidence and demographic profile of uveal effusion syndrome (UES), and to describe the visual and anatomic outcome following deep sclerectomy or vortex vein decompression.

METHODS

The British Ophthalmological Surveillance Unit (BOSU) mails reporting cards monthly to 1149 senior UK ophthalmologists, who are requested to report incident cases of specified rare diseases. UES was included in the reporting system from October 2009 to October 2011. If UES was identified, ophthalmologists were mailed a questionnaire to collect anonymized clinical data at baseline, and 12 months after.

RESULTS

Over 2 years, 29 cases were reported. Two cases were duplicates and 12 failed to meet the eligibility criteria. Of the 15 eligible cases, age ranged from 11 to 91 years (mean 62) and nine were males (60%). Ten patients were hypermetropic; three had an axial length of 19.0 mm or less. Estimated annual incidence was 1.2 per 10 million population. Seven cases were managed nonsurgically, including observation (one case), topical steroids (two cases), systemic steroids (three cases), and cyclodiode laser (one case). Eight cases (11 eyes) underwent full-thickness sclerectomy; the elevated flap was retained in four. The sclera was noted to be thick and rigid during surgery in five cases. Median preoperative visual acuity was 6/18, changing slightly to 6/21.5 at final review, with three eyes showing complete anatomic response, five showing some improvement, and three failing to respond.

CONCLUSIONS

UES is extremely rare. It occurs in a range of ages, but is most common in middle-aged, hypermetropic men. Visual acuity can be materially reduced. The most commonly used surgical treatment in the UK is deep sclerectomy.

Using Capture-Recapture Methods to Estimate Local Influenza Hospitalization Incidence Rates

Background

Accurate population estimates of disease incidence and burden are needed to set appropriate public health policy. The capture-recapture (C-R) method combines data from multiple sources to better estimate prevalence than is possible using single sources. This study used the C-R method to estimate influenza cases using research and administrative databases to calculate county-wide influenza hospitalization burden.

Methods

Data were derived from a database of clinical virology test results and research data from an influenza vaccine effectiveness study from seasons 2015-2016 to 2018-2019. Missed influenza cases were estimated using C-R method. These estimates were used to calculate disease burden using the multiplier method to correct for underreporting due to curtailing data collection before the end of influenza circulation.

Results

Over all seasons, 422 influenza cases were reported in the administrative database and 382 influenza cases in the research database. Seventy-five cases (18%) reported in the administrative database were not captured in the research database, and 35 (9%) cases in the research database were not captured in the administrative database. Completeness of the influenza hospitalization was estimated to be 76%. Influenza hospitalizations were higher among unvaccinated (32%) than vaccinated (22%) in the current season and among unvaccinated (28%) than vaccinated (23%) in the previous year. The incidence rates for influenza hospitalizations varied by age and season and averaged 421 cases/100,000 population annually.

Conclusion

The capture-recapture method offers a more accurate method for estimating influenza hospitalization than relying on a single data source. Using the multiplier method with adjustments improves the detection of influenza disease burden through a matched database. The incidence rates are consistent with national estimates.

The transition from children’s services to adult services for young people with attention deficit hyperactivity disorder: the CATCh-uS mixed-methods study

Background

Attention deficit hyperactivity disorder was previously seen as a childhood developmental disorder, so adult mental health services were not set up to support attention deficit hyperactivity disorder patients who became too old for child services. To our knowledge, this is the first in-depth study of the transition of attention deficit hyperactivity disorder patients from child to adult health services in the UK.

Objectives

Our objectives were to explore how many young people with attention deficit hyperactivity disorder are in need of services as an adult, what adult attention deficit hyperactivity disorder services are available and how attention deficit hyperactivity disorder stakeholders experience transition from child to adult services.

Design

An interactive mixed-method design was adopted with three study streams: (1) a 12-month surveillance study with 9-month follow-up to find out how many young people required ongoing medication when they were too old for child services (929 surveys completed by children’s clinicians); (2) a mapping study to identify and describe services for young adults with attention deficit hyperactivity disorder (2686 respondents to online surveys for patients and health workers and freedom of information requests to service providers and commissioners); and (3) a qualitative study to explore key stakeholders’ experiences of transition from child to adult services (144 interviews with 64 attention deficit hyperactivity disorder patients, 28 parents and 52 health clinicians; 38 working in child or adult secondary health services and 14 general practitioners). Members of the public advised at each stage of the study.

Results

When corrected for non-response and case ascertainment, the annual number of young people with an ongoing need for medication for attention deficit hyperactivity disorder lies between 270 and 599 per 100,000 people aged 17–19 years. Among 315 individuals eligible for transition, 64% were accepted, but only 22% attended their first adult services appointment. Our interactive map describes 294 unique services for adults with attention deficit hyperactivity disorder across the UK, of which 44 are ‘dedicated’ attention deficit hyperactivity disorder services. Few services provide the full range of recommended provision; most focus on diagnosis and medication. Services are unevenly distributed across the UK, with nearly all ‘dedicated’ services being in England. Exploring stakeholders’ experiences revealed how invested the stakeholders are in continuing attention deficit hyperactivity disorder treatment and how the architecture of services affects transition. An association between attention deficit hyperactivity disorder, education and continuance of medication into young adulthood, plus parent involvement and feeling prepared for transition and adult life with attention deficit hyperactivity disorder, influenced investment. However, even with investment, how accessible adult services are, how patient needs fit with the remit of the adult service and the level of patient information available affect transition outcomes. The results also highlight how general practitioners can end up as care co-ordinators during transition by default.

Limitations

Transition estimates were based on those who want medication, so these indicate a minimum level of need.

Conclusions

Few of those who need ongoing support for attention deficit hyperactivity disorder successfully transfer to adult services, and a small proportion of those who transfer experience optimal transitional care. Adult attention deficit hyperactivity disorder service provision is patchy. Even among ‘dedicated’ services, few provide the whole range of National Institute for Health and Care Excellence-recommended treatments.

Future work

We need to evaluate various models of transitional care and adult attention deficit hyperactivity disorder provision, as well as develop and evaluate psychosocial interventions for young people and adults with attention deficit hyperactivity disorder.

Trial registration

Current Controlled Trials ISRCTN12492022.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 8, No. 42. See the NIHR Journals Library website for further project information.

Case ascertainment in active paediatric surveillance systems: a report from the British Paediatric Surveillance Unit Ascertainment Group

The British Paediatric Surveillance Unit (BPSU) conducts surveillance of rare paediatric conditions using active, or prospective, case finding. The reliability of estimates of incidence, which is the primary outcome of public health importance, depends on ascertainment being as near complete as possible. This paper reviews evidence of the completeness of ascertainment in recent surveillance studies run through the BPSU. Ascertainment varied between 49% and 94% depending on the study. These are upper estimates. This was the basis of a discussion on barriers and facilitators of ascertainment which we have separated into factors related to the condition, factors related to the study methods, factors related to the study team and factors related to the surveillance system infrastructure. This leads to a series of recommendations to ensure continuing high levels of ascertainment in active surveillance studies.

How to measure the need for transition to adult services among young people with Attention Deficit Hyperactivity Disorder (ADHD): a comparison of surveillance versus case note review methods

BACKGROUND

Health services have not provided adequate support for young people with long term health conditions to transfer from child to adult services. National Institute of Health and Care (NICE) guidance on transition has been issued to address these gaps. However, data are often sparse about the number of young adults who might need to transition. Using Attention Deficit Hyperactivity Disorder (ADHD) as an exemplar, this study used an existing surveillance system and a case note review to capture the incidence of the transition process, and compared and contrasted the findings.

METHODS

The Child and Adolescent Psychiatry Surveillance System (CAPSS) was used to estimate the incident transition of young people with Attention Deficit Hyperactivity Disorder (ADHD) from child to adult services. This involves consultant child and adolescent psychiatrists from the United Kingdom (UK) and Republic of Ireland (ROI) reporting relevant young people as they are seen in clinics. In parallel, a case note review was conducted using the Maudsley Biomedical Research Centre (BRC) Clinical Records Interactive Search (CRIS). The study period ran for twelve months with a nine month follow up to see how the transition proceeded.

RESULTS

CRIS identified 76 cases in the study period, compared to 18 identified using surveillance via CAPSS. Methodological issues were experienced using both methods. Surveillance issues; eligibility criteria confusion, reporting errors, incomplete questionnaires, difficulties contacting clinicians, and surveillance systems do not cover non-doctors and psychiatrists who are not consultants. Case note review issues using CRIS included the need for researchers to interpret clinical notes, the availability and completeness of data in the notes, and data limited to the catchment of one particular mental health trust.

CONCLUSIONS

Both methods demonstrate strengths and weaknesses; the combination of both methods in the absence of strong routinely collected data, allowed a more robust estimate of the level of need for service planning and commissioning.

The impact of the National Institute for Health Research Health Technology Assessment programme, 2003-13: a multimethod evaluation

BACKGROUND

The National Institute for Health Research (NIHR) Health Technology Assessment (HTA) programme supports research tailored to the needs of NHS decision-makers, patients and clinicians. This study reviewed the impact of the programme, from 2003 to 2013, on health, clinical practice, health policy, the economy and academia. It also considered how HTA could maintain and increase its impact.

METHODS

Interviews (n = 20): senior stakeholders from academia, policy-making organisations and the HTA programme. Bibliometric analysis: citation analysis of publications arising from HTA programme-funded research. Researchfish survey: electronic survey of all HTA grant holders. Payback case studies (n = 12): in-depth case studies of HTA programme-funded research.

RESULTS

We make the following observations about the impact, and routes to impact, of the HTA programme: it has had an impact on patients, primarily through changes in guidelines, but also directly (e.g. changing clinical practice); it has had an impact on UK health policy, through providing high-quality scientific evidence - its close relationships with the National Institute for Health and Care Excellence (NICE) and the National Screening Committee (NSC) contributed to the observed impact on health policy, although in some instances other organisations may better facilitate impact; HTA research is used outside the UK by other HTA organisations and systematic reviewers - the programme has an impact on HTA practice internationally as a leader in HTA research methods and the funding of HTA research; the work of the programme is of high academic quality - the Health Technology Assessment journal ensures that the vast majority of HTA programme-funded research is published in full, while the HTA programme still encourages publication in other peer-reviewed journals; academics agree that the programme has played an important role in building and retaining HTA research capacity in the UK; the HTA programme has played a role in increasing the focus on effectiveness and cost-effectiveness in medicine - it has also contributed to increasingly positive attitudes towards HTA research both within the research community and the NHS; and the HTA focuses resources on research that is of value to patients and the UK NHS, which would not otherwise be funded (e.g. where there is no commercial incentive to undertake research). The programme should consider the following to maintain and increase its impact: providing targeted support for dissemination, focusing resources when important results are unlikely to be implemented by other stakeholders, particularly when findings challenge vested interests; maintaining close relationships with NICE and the NSC, but also considering other potential users of HTA research; maintaining flexibility and good relationships with researchers, giving particular consideration to the Technology Assessment Report (TAR) programme and the potential for learning between TAR centres; maintaining the academic quality of the work and the focus on NHS need; considering funding research on the short-term costs of the implementation of new health technologies; improving the monitoring and evaluation of whether or not patient and public involvement influences research; improve the transparency of the priority-setting process; and continuing to monitor the impact and value of the programme to inform its future scientific and administrative development.

Recapture or precapture? Fallibility of standard capture-recapture methods in the presence of referrals between sources

Capture-recapture methods, largely developed in ecology, are now commonly used in epidemiology to adjust for incomplete registries and to estimate the size of difficult-to-reach populations such as problem drug users. Overlapping lists of individuals in the target population, taken from administrative data sources, are considered analogous to overlapping “captures” of animals. Log-linear models, incorporating interaction terms to account for dependencies between sources, are used to predict the number of unobserved individuals and, hence, the total population size. A standard assumption to ensure parameter identifiability is that the highest-order interaction term is 0. We demonstrate that, when individuals are referred directly between sources, this assumption will often be violated, and the standard modeling approach may lead to seriously biased estimates. We refer to such individuals as having been “precaptured,” rather than truly recaptured. Although sometimes an alternative identifiable log-linear model could accommodate the referral structure, this will not always be the case. Further, multiple plausible models may fit the data equally well but provide widely varying estimates of the population size. We demonstrate an alternative modeling approach, based on an interpretable parameterization and driven by careful consideration of the relationships between the sources, and we make recommendations for capture-recapture in practice.

The Australasian Maternity Outcomes Surveillance System: an evaluation of stakeholder engagement, usefulness, simplicity, acceptability, data quality and stability

BACKGROUND

The Australasian Maternity Outcomes Surveillance System (AMOSS) conducts active, prospective surveillance of severe maternal conditions in Australia and New Zealand (ANZ). AMOSS captures greater than 96% of all births, and utilises an online, active case-based negative reporting system.

AIM

To evaluate AMOSS using the United States Centres for Disease Control (MMWR 2001; 50 (RR13): 1-35.) surveillance system evaluation framework.

METHODS

Data were gathered using multiple methods, including an anonymous online survey administered to 353 AMOSS data collectors, in addition to review of case data received during 2009-2011, documented records of project board and advisory group meeting minutes, publications, annual reports and the AMOSS database.

RESULTS

AMOSS is a research system characterised by its simplicity and efficiency. The socio-demographic, risk factor and severe morbidity clinical data collected on rare conditions are not duplicated in other routine data systems. AMOSS is functioning well and has sustained buy-in from clinicians, stakeholders and consumers and a high level of acceptability to data collectors in ANZ maternity units.

CONCLUSIONS

AMOSS is the only existing national system of surveillance for rare and severe maternal conditions in ANZ and therefore serves an important function, utilising data collected from reliable sources, in an effective, efficient and timely way.

Ascertainment of early onset eating disorders: a pilot for developing a national child psychiatric surveillance system

BACKGROUND

  A Child & Adolescent Psychiatric Surveillance System was established as part of a British Paediatric Surveillance Unit study of early onset eating disorders (EOED).

METHOD

  A study of EOED presenting to paediatricians was undertaken through the BPSU over 15 months in 2005-06.

RESULTS

  Monthly report cards compliance was 83%, identifying 208 EOED cases. On evaluation, 99% of psychiatrists responding supported the need for surveillance and 95% would continue to contribute.

CONCLUSIONS

  The findings of this pilot study suggest that a monthly surveillance of rare conditions in child and adolescent psychiatry is feasible and enhances ascertainment.

Population-based study of incidence and clinical characteristics of rheumatic fever in Abruzzo, central Italy, 2000-2009

OBJECTIVE

To investigate the incidence and describe the characteristics of acute rheumatic fever (ARF) in the pediatric population in a community-based healthcare delivery system of the central Italy region of Abruzzo during 2000-2009.

STUDY DESIGN

A retrospective study was conducted in Abruzzo to identify patients aged <18 years with a diagnosis of ARF between January 1, 2000, and December 31, 2009. Each patient's age, sex, date of diagnosis, age at disease presentation, and fulfilled Jones criteria were recorded.

RESULTS

A total of 88 patients meeting the Jones criteria for the diagnosis of ARF were identified, with arthritis in 59.1% of the patients, carditis in 48.9%, erythema marginatum in 11.4%, 5.7% with chorea, and 4.6% with subcutaneous nodules. Residual chronic rheumatic heart disease was present in 44.3% of the children. Age at diagnosis ranged from 2.5 to 17 years (average, 8.7 ± 4.0 years). Twelve children (13.6%) were under age 5 years. The overall incidence rate of ARF was 4.1/100 000. The lowest incidence rate was documented in the year 2000 (2.26/100 000), and the highest in 2006 (5.58/100 000).

CONCLUSION

Our data indicate that ARF has not disappeared in industrialized countries and still causes significant residual rheumatic heart disease. Pediatricians should routinely consider the diagnoses of streptococcal pharyngitis and ARF to reduce long-term morbidity and mortality.

Paediatric acquired demyelinating syndromes: incidence, clinical and magnetic resonance imaging features

Objective:

Changing trends in multiple sclerosis (MS) epidemiology may first be apparent in the childhood population affected with first onset acquired demyelinating syndromes (ADSs). We aimed to determine the incidence, clinical, investigative and magnetic resonance imaging (MRI) features of childhood central nervous system ADSs in the British Isles for the first time.

Methods:

We conducted a population active surveillance study. All paediatricians, and ophthalmologists (n = 4095) were sent monthly reporting cards (September 2009–September 2010). International Paediatric MS Study Group 2007 definitions and McDonald 2010 MS imaging criteria were used for acute disseminated encephalomyelitis (ADEM), clinically isolated syndrome (CIS) and neuromyelitis optica (NMO). Clinicians completed a standard questionnaire and provided an MRI copy for review.

Results:

Card return rates were 90%, with information available for 200/222 positive notifications (90%). After exclusion of cases, 125 remained (age range 1.3–15.9), with CIS in 66.4%, ADEM in 32.0% and NMO in 1.6%. The female-to-male ratio in children older than 10 years (n = 63) was 1.52:1 (p = 0.045). The incidence of first onset ADS in children aged 1–15 years old was 9.83 per million children per year (95% confidence interval [CI] 8.18–11.71). A trend towards higher incidence rates of ADS in children of South Asian and Black ethnicity was observed compared with White children. Importantly, a number of MRI characteristics distinguished ADEM from CIS cases. Of CIS cases with contrast imaging, 26% fulfilled McDonald 2010 MS diagnostic criteria.

Conclusions:

We report the highest surveillance incidence rates of childhood ADS. Paediatric MS diagnosis at first ADS presentation has implications for clinical practice and clinical trial design.

Completeness of infectious disease notification in the United Kingdom: A systematic review

OBJECTIVES

Infectious disease legislation in the United Kingdom has recently changed. Our aim was to provide a baseline against which to assess the impact of these changes by synthesising current knowledge on completeness of notification and on factors associated with better reporting rates.

METHODS

We systematically reviewed the literature for studies reporting completeness of reporting of notifiable infectious diseases in the United Kingdom over the past 35 years.

RESULTS

Altogether, 46 studies met our search criteria. Reporting completeness varied from 3% to 95% and was most strongly correlated with the disease being reported. Median reporting completeness was 73% (range 6%-93%) for tuberculosis, 65% (range 40%-95%) for meningococcal disease, and 40% (range 3%-87%) for other diseases (Kruskal-Wallis test, p < 0.05). Reporting completeness did not change for either tuberculosis or meningococcal disease over the period studied. In multivariate analysis, none of the factors examined (study size, study time period, number of data sources used to assess completeness, uncorrected or corrected study design) were significantly associated with reporting completeness.

CONCLUSION

Reporting completeness has not improved over the past three decades. It remains sub-optimal even for diseases which are under enhanced surveillance or are of significant public health importance.

Surveillance of rare diseases: a public health evaluation of the British Paediatric Surveillance Unit

BACKGROUND

The British Paediatric Surveillance Unit (BPSU), a joint undertaking between the Royal College of Paediatrics and Child Health, Institute of Child Health and Health Protection Agency, undertakes nationwide surveillance of rare paediatric disorders. In 2007-09, formal evaluation to examine its effectiveness commenced.

METHODS

Centres of Disease Control guidelines for appraising public health surveillance systems were applied. Data sources included BPSU databases, published and unpublished reports. Questionnaires were sent to 600 participating paediatricians and 27 researchers. Half of the questionnaires were administered online to assess the feasibility of electronic reporting.

RESULTS

Three thousand UK paediatricians report monthly to the BPSU (94% return) and eighty BPSU studies have been published. These studies have influenced immunization and screening policy, altered clinical practice and informed health service configuration. Surveillance operations are simple, stable, representative and responsive to changing demands. Returns from the paediatricians' survey were 75%; investigators 89%. Paediatricians valued the BPSU and did not find participation burdensome. Most supported online questionnaires (56%) but not monthly electronic reporting (35%).

CONCLUSIONS

Evaluation demonstrated the effectiveness of the BPSU as a valuable resource for clinicians and policy-makers. Opportunities identified for future development include secure online reporting, improved responsiveness to urgent health threats and promoting public involvement.

Increasing incidence of childhood type 1 diabetes in Montenegro from 1997 to 2006

OBJECTIVE

To determine and analyze the incidence of type 1 diabetes mellitus (T1DM) in 0- to 14-yr-old children in Montenegro from 1997 to 2006.

RESEARCH DESIGN AND METHODS

This was a prospective study. Primary case ascertainment came from a diabetes register and secondary independent data source was from prescription data. Age and sex-standardized incidence rates were calculated using direct method, assuming an equal distribution in each age/sex group. The 95% confidence interval (CI) were estimated assuming the Poisson distribution. The independent effects of calendar year, two 5-yr time periods, sex and age groups were estimated with Poisson regression modeling.

RESULTS

During the 10-yr period, 184 new cases of type 1 diabetes were identified. Case ascertainment was 100% complete using the capture-recapture method. The mean annual standardized incidence rate over the 10-yr period was 13.4/100 000/yr (95% CI: 11.5-15.5). It increased on average by 4.6% per year (95% CI: -0.4 to -9.6%, p = 0.07). The time-period specific incidence rate from year 1997 to 2001 was significantly lower (10.8; 8.5-13.5) compared with the second period from 2002 to 2006 (16.3; 13.3-19.7), (p < 0.0001). The age-specific incidence for the 0-4-yr age group was significantly lower (8.9; 6.3-12.3) than in 5- to 9-yr age group (14.1; 10.8-18.1); and in the 10-14 yr group (17.2; 13.7-21.3) per 100,000 children.

CONCLUSIONS

The incidence rate in last 5 yr places Montenegro in the group of countries with moderate risk for development of type 1 diabetes in children. The average annual increase in incidence is 4.6%.

Evaluation of a national resource to identify and study rare diseases: the Australian Paediatric Surveillance Unit

AIMS

To evaluate the Australian Paediatric Surveillance Unit (APSU).

METHODS

We used criteria recommended by the Centres for Disease Control and Prevention (CDC) for evaluating surveillance systems and reviewed productivity, response rates, completeness of the mailing list and impacts of APSU studies. Anonymous evaluation questionnaires were sent to 1260 reporting clinicians, 42 researchers and 86 public health professionals to seek their feedback as users of the APSU.

RESULTS

APSU provides national epidemiological and clinical data about rare childhood conditions that inform public health policy and clinical practice. Between 2000 and 2007, APSU data were disseminated in 106 journal articles, 207 scientific presentations and 85 media items. Of paediatricians and paediatric sub-specialists actively practicing in Australia and listed as Fellows of the Royal Australasian College of Physicians, 92% participate in APSU surveillance. An average 96% of monthly report cards were returned per annum since 2000. Sensitivity of case ascertainment was difficult to calculate for many conditions because alternative sources of ascertainment do not exist. Evaluation questionnaires were returned by 818 (65%) reporting clinicians, who believe APSU is valuable for generating knowledge 665 (81%), identifying research priorities 635 (78%), guiding clinical practice 572 (70%) and informing public health policy 575 (70%). Similar responses were received from researchers and public health professionals.

CONCLUSIONS

The APSU fulfils its objectives and meets relevant CDC criteria for usefulness, simplicity, acceptability and representativeness, sensitivity and timeliness of data quality. However, stability is threatened by lack of continuing core funding. APSU is highly productive and valued by child health clinicians, researchers and public health professionals.

Proof of concept of a method that assesses the spread of microbial infections with spatially explicit and non-spatially explicit data

Background

A method that assesses bacterial spatial dissemination was explored. It measures microbial genotypes (defined by electrophoretic patterns or EP), host, location (farm), interfarm Euclidean distance, and time. Its proof of concept (construct and internal validity) was evaluated using a dataset that included 113 Staphylococcus aureus EPs from 1126 bovine milk isolates collected on 23 farms between 1988 and 2005.

Results

Construct validity was assessed by comparing results based on the interfarm Euclidean distance (a spatially explicit measure) and those produced by the (non-spatial) interfarm number of isolates reporting the same EP. The distance associated with EP spread correlated with the interfarm number of isolates/EP (r = .59, P < 0.02). Internal validity was estimated by comparing results obtained with different versions of the same indices. Concordance was observed between: (a) EP distance (estimated microbial dispersal over space) and EP speed (distance/year, r = .72, P < 0.01), and (b) the interfarm number of isolates/EP (when measured on the basis of non-repeated cow testing) and the same measure as expressed by repeated testing of the same animals (r = .87, P < 0.01). Three EPs (2.6% of all EPs) appeared to be super-spreaders: they were found in 26.75% of all isolates. Various indices differentiated local from spatially disseminated infections and, within the local type, infections suspected to be farm-related were distinguished from cow-related ones.

Conclusion

Findings supported both construct and internal validity. Because 3 EPs explained 12 times more isolates than expected and at least twice as many isolates as other EPs did, false negative results associated with the remaining EPs (those erroneously identified as lacking spatial dispersal when, in fact, they disseminated spatially), if they occurred, seemed to have negligible effects. Spatial analysis of laboratory data may support disease surveillance systems by generating hypotheses on microbial dispersal ability.

The epidemiology of convulsive status epilepticus in children: a critical review

There is ongoing debate regarding the most appropriate definition of status epilepticus. This depends upon the research question being asked. Based on the most widely used "30 min definition," the incidence of childhood convulsive status epilepticus (CSE) in developed countries is approximately 20/100,000/year, but will vary depending, among others, on socioeconomic and ethnic characteristics of the population. Age is a main determinant of the epidemiology of CSE and, even within the pediatric population there are substantial differences between older and younger children in terms of incidence, etiology, and frequency of prior neurological abnormalities or prior seizures. Overall, incidence is highest during the first year of life, febrile CSE is the single most common cause, around 40% of children will have previous neurological abnormalities and less than 15% will have a prior history of epilepsy. Outcome is mainly a function of etiology. However, the causative role of CSE itself on mesial temporal sclerosis and subsequent epilepsy or the influence of age, duration, or treatment on outcome of CSE remains largely unknown. Future studies should aim at clarifying these issues and identifying specific ethnic, genetic, or socioeconomic factors associated with CSE to pinpoint potential targets for its primary and secondary prevention.

Rising incidence of type 2 diabetes in children in the U.K

OBJECTIVE

To estimate the incidence of type 2 diabetes in children <17 years of age and to investigate the relationship of diabetes with increasing childhood obesity in the U.K. and the Republic of Ireland (ROI).

RESEARCH DESIGN AND METHODS

Active monthly reporting of cases by consultant pediatricians occurred through the framework of the British Pediatric Surveillance Unit, with additional reports from specialist diabetes nurses. All children <17 years of age and diagnosed by their clinician as having non-type 1 diabetes from 1 October 2004 to 31 October 2005 were included.

RESULTS

A total of 168 confirmed cases of non-type 1 diabetes were reported, resulting in a national incidence (excluding the ROI) of 1.3 x 100,000(-1) x year(-1). Of these, 40% were diagnosed with type 2 diabetes giving a minimum incidence of 0.53 x 100,000(-1) x year(-1). Children of ethnic minorities were greatly overrepresented, with those of black and South-Asian origin (England data only) having an incidence of 3.9 and 1.25 x 100,000(-1) x year(-1), respectively, compared with 0.35 x 100,000(-1) x year(-1) in those defined as white. Of those diagnosed with type 2 diabetes, 95% were overweight and 83% obese according to International Obesity Task Force guidelines. Eighty-four percent had a family history of type 2 diabetes.

CONCLUSIONS

Type 2 diabetes is still less common than type 1 diabetes in U.K. children. However, compared with previous prevalence data, the frequency of type 2 diabetes appears to be increasing. Incidence among ethnic minorities is far higher than in whites, as previously described in the U.S. Increased adiposity and family history of type 2 diabetes were strongly associated with the diagnosis of type 2 diabetes in U.K. children.