Variation in coverage by ethnic group of neonatal (Guthrie) screening programme in south London

Implementation of universal newborn bloodspot screening for sickle cell disease and other clinically significant haemoglobinopathies in England: screening results for 2005-7

Early results from the National Health Service Sickle Cell and Thalassaemia Screening programme covering the whole of England are reported following the implementation of the national newborn blood-spot screening programme. Of the 13 laboratories performing screening, 10 chose high-performance liquid chromatography as the first screen, with isoelectric focusing as the second confirmatory test. Screening results for April 2005 to March 2007 are presented and include data from all the laboratories screening newborns in England, and almost 1.2 million infants. The screen-positive results show a national birth prevalence of almost 1 in 2000. The birth prevalence in London is five times that of most of the rest of the country. Over 17 000 carriers have been identified. Approximately seven per 1000 samples are reported as post-transfusion with wide ethnic category variation. Given the prevalence of the conditions, and coverage by ethnicity, 3–4 screen-positive cases could be missed each year. National implementation of newborn screening in England has increased the number of children identified with sickle cell disease, in many areas almost doubling the workload. Underascertainment of the condition has allowed a downplaying of the scale of need. It may also have contributed to infant mortality rates in urban areas as babies died without a diagnosis or treatment. The value of a co-ordinated national approach to policy development and implementation is emphasised by the English experience. The programme provides a model for Europe as well as other countries with significant minority populations, such as Canada. Potentially it also offers important lessons for Africa where the World Health Organization is supporting the introduction of newborn screening.

Implementation of the newborn screening programme for sickle cell disease in England: results for 2003-2005

OBJECTIVES

This paper reports early screening results from the newborn sickle cell disease screening programme recently implemented in England.

SETTING

England. Screening is offered at 5-8 days of age as part of the existing bloodspot test and offered to all babies irrespective of ethnicity.

METHODS

The laboratory methods recommended are high performance liquid chromatography (HPLC) and iso-electric focusing (IEF). Two methods of analysis must be applied to all screen positive results. The conditions screened for are:- Sickle cell anaemia (Hb SS), Hb SC disease, Hb S/beta-thalassaemia, Hb S/D(Punjab), Hb S/O(Arab), Hb S/HPFH. Carriers identified for the common haemoglobin variants are reported to parents and follow-up counselling is offered. A bespoke laboratory quality assurance programme has been established which has defined standards of satisfactory performance.

RESULTS

Provisional figures from the first seven months of screening (up to March 2004) 108,255 infants were screened gave a screen positive rate of 1:900 for these high prevalence areas and a carrier rate of 2.7%. Figures for 2004-2005 show about 250 significant screen positive results for sickle cell disorders and about 6,500 carriers were identified. The birth prevalence for screen positive results from 2004-05 is 1:1500. We estimate that when there is countrywide data, the national birth prevalence will be about 1:2000-1:2,500.

CONCLUSION

The results from the national newborn sickle cell screening programme in England-show that the sickle cell disorders are as common as cystic fibrosis (CF) in England, although the distribution of cases is concentrated in London and other urban areas. The findings and approach to implementation adopted in England may be of interest to other Western European countries with increasing rates of sickle cell disease who are considering such programmes and also to other developed countries.

Coverage of neonatal screening: failure of coverage or failure of information system

OBJECTIVES

To evaluate neonatal screening coverage using data routinely collected on the laboratory computer.

SUBJECTS

90 850 births in 14 North East Thames community provider districts over a 21 month period.

METHODS

Births notified to local child health computers are electronically copied to the neonatal laboratory computer system, and incoming Guthrie cards are matched against these birth records before testing. The computer records for the study period were processed to estimate the coverage of the screening programme.

RESULTS

Out of an estimated 90 850 births notified to child health computers, all but 746 (0.82%) appeared to have been screened or could be otherwise accounted for (0.14% in non-metropolitan districts, 0.39% in suburban districts, and 1.68% in inner city districts). A further 893 resident infants had been tested, but could not be matched to the list of notified resident births. The calculated programme coverage already exceeds the 99.5% National Audit Programme standard in 7/14 districts. Elsewhere it is not clear whether it is coverage or recording of coverage that is low.

CONCLUSION

Previous reports of low coverage may have been exaggerated. High coverage can be shown using routine information systems. Design of information systems that deliver accurate measures of coverage would be more useful than comparison of inadequately measured coverage with a national standard. The new NHS number project will create an opportunity to achieve this.

Who gets missed: coverage in a provincial newborn screening program for metabolic disease

OBJECTIVE

To determine coverage of the newborn screening program (NSP) for metabolic disease in Alberta, Canada, and to determine reasons for not being screened.

STUDY DESIGN

Coverage was estimated by deterministic matching of live birth registration data with newborn screening data for the year 1992. Demographic characteristics of not-matched infants were compared with good-match infants using logistic regression.

RESULTS

For 42 392 live births, there were 41 553 screening records, of which 40 593 infants were very good matches to NSP records. Another 960 were possible matches. A total of 839 infants were not matched at all, and coverage was estimated at 98.0%. Determinants of infant not-matched status were death in week 1 (adjusted odds ratio [OR]: 383); birth weight of <1500 g (adjusted OR: 18.9) or between 1500 and 2500 g (adjusted OR: 3.2); having a mother who was single (adjusted OR: 2.7) or formerly married (adjusted OR: 12.9); or being born out of hospital (OR: 19. 2). The calculated 98% coverage is close to an estimate of 98.3% made by the NSP comparing total births with initial screenings.

CONCLUSION

The matched data give insight as to who was missed and point to the need for closer attention for infants at greater risk of not being screened for metabolic disease.

Audit of neonatal screening programme for phenylketonuria and congenital hypothyroidism

The performance of the neonatal screening programme was audited against clinical standards in the Bath clinical area from 1 April 1994 to 31 March 1996. The standards and policy were agreed by local service provider representatives of the screening and were audited, using laboratory and child health computer systems and medical records. Two annual reports were produced with recommendations for improvement communicated to representatives of the service. Thus the first audit loop has been completed. The audit shows that the coverage of the service is excellent, with all eligible babies being offered screening; those with congenital hypothyroidism or phenylketonuria receive appropriate treatment by the 28 day standard. The process works extremely well, although areas for improvement have been identified, to increase the efficiency of the service. It is concluded that an effective and efficient audit cycle can be established, to monitor and improve the performance of the neonatal screening service.

Use of stored newborn blood spots in research on birth defects: variation in retrieval rates by type of defect and infant characteristics

Stored blood spots from state newborn screening programs represent a potential source of DNA for molecular genetics research on birth defects. The stored blood spots of cases and controls from an epidemiologic database on congenital heart defects were sought in the present study, which aimed to establish the feasibility of linking the data sources and to examine blood spot retrieval rates for selected cardiac defects. Blood spots were located on 341 of 522 infants (65%) with congenital heart defects and for 1,484 of 1,645 infants without birth defects (84%) born in Maryland during 1981-1989. Retrieval rates were low among infants with clinically severe lesions such as truncus arteriosus (26%) but were considerably higher in infants with coarctation of the aorta (62%), pulmonic valve stenosis (71%), and atrial septal defect (76%). Retrieval rates were significantly lower for premature and low-birth-weight infants than among full-term, normal-birth-weight infants. Retrieval rates did not vary significantly by gender, race, county of residence, or parental socioeconomic characteristics. These results demonstrate the feasibility of linking epidemiologic databases with stored newborn blood specimens, especially for normal infants and even for infants with certain congenital heart defects, but raise concerns about the adequacy of such methods to obtain stored specimens from premature infants and from those with severe heart defects.

Impact of incomplete coverage of neonatal dried blood spot screening on estimating HIV-1 seroprevalence

The aim of this study was to determine the extent to which selective under-coverage of births to mothers more likely to be at risk of HIV-1 infection will result in a significant under-estimation of the true neonatal seroprevalence. Census data, local birth statistics, maternity data and data from the prevalence monitoring programme were used to produce a model to predict the effects of under-coverage in the uptake of neonatal metabolic screening which has been observed in babies with a mother of ethnic group black African. The adjustment factor which allows for under-coverage is the relative inclusion ratio (RIR); the probability that samples from a group at different risk of HIV infection were included in the survey divided by the probability of inclusion for samples from all other babies. The RIR was found to be close to unity (0.97), indicating a minimal bias. Under usual conditions only if the relative inclusion ratio (RIR) declined to values of 0.87 or below would there be a substantial bias. Despite some selective under representation, the results obtained from the Unlinked Anonymous HIV Monitoring Programme Dried Blood Spot Survey would seem to identify levels of prevalence in the population of child-bearing women with a good degree of accuracy and remains a useful tool for resource allocation, planning of services, provision of care and counselling.

An audit of the organisation of neonatal screening for phenylketonuria and congenital hypothyroidism in the Northern Region

BACKGROUND

The objectives of the study were to identify whether all districts in the Northern Region had a system in place to ensure that all resident babies were being screened for phenylketonuria and congenital hypothyroidism and to identify potential delays which could influence whether a result was available on all residents before 28 days of age.

METHODS

Lead professionals involved in the screening programmes were interviewed in 1993 in all 16 districts. Recommendations for improving the service were made to each district. Six months later a follow up telephone interview with the doctor involved in the screening programmes was undertaken to identify the changes that had been made in the service.

RESULTS

In 1993 three districts made no attempt to match neonatal screening results to birth notifications. Of the 13 districts that undertook matching, two districts did no further checks to identify babies without a result and five districts undertook a check on a monthly basis only. Only six districts were, therefore, found to have a timely fail-safe system for checking that results were available for resident babies. In 1994, following recommendations to improve the timeliness and completeness of the screening programmes, all districts except two had improved their fail-safe systems.

CONCLUSION

This multi-disciplinary regional audit resulted in organisational improvements to the neonatal metabolic screening programmes in the Northern Region.