Newborn screening for cystic fibrosis in Victoria: 10 years' experience (1989-1998)

Cystic Fibrosis Cases Missed by Newborn Bloodspot Screening-Towards a Consistent Definition and Data Acquisition

Repeated European surveys of newborn bloodspot screening (NBS) have shown varied strategies for collecting missed cases, and information on data collection differs among countries/regions, hampering data comparison. The ECFS Neonatal Screening Working Group defined missed cases by NBS as either false negatives, protocol-related, concerning analytical issues, or non-protocol-related, concerning pre- and post-analytical issues. A questionnaire has been designed and sent to all key workers identified in each NBS programme to assess the feasibility of collecting data on missed cases, the stage of the NBS programme when the system failed, and individual patient data on each missed case.

Evaluating the Alimentary and Respiratory Tracts in Health and disease (EARTH) research programme: a protocol for prospective, longitudinal, controlled, observational studies in children with chronic disease at an Australian tertiary paediatric hospital

INTRODUCTION

Chronic gastrointestinal and respiratory conditions of childhood can have long-lasting physical, psychosocial and economic effects on children and their families. Alterations in diet and intestinal and respiratory microbiomes may have important implications for physical and psychosocial health. Diet influences the intestinal microbiome and should be considered when exploring disease-specific alterations. The concepts of gut-brain and gut-lung axes provide novel perspectives for examining chronic childhood disease(s). We established the 'Evaluating the Alimentary and Respiratory Tracts in Health and disease' (EARTH) research programme to provide a structured, holistic evaluation of children with chronic gastrointestinal and/or respiratory conditions.

METHODS AND ANALYSIS

The EARTH programme provides a framework for a series of prospective, longitudinal, controlled, observational studies (comprised of individual substudies), conducted at an Australian tertiary paediatric hospital (the methodology is applicable to other settings). Children with a chronic gastrointestinal and/or respiratory condition will be compared with age and gender matched healthy controls (HC) across a 12-month period. The following will be collected at baseline, 6 and 12 months: (i) stool, (ii) oropharyngeal swab/sputum, (iii) semi-quantitative food frequency questionnaire, (iv) details of disease symptomatology, (v) health-related quality of life and (vi) psychosocial factors. Data on the intestinal and respiratory microbiomes and diet will be compared between children with a condition and HC. Correlations between dietary intake (energy, macro-nutrients and micro-nutrients), intestinal and respiratory microbiomes within each group will be explored. Data on disease symptomatology, quality of life and psychosocial factors will be compared between condition and HC cohorts.Results will be hypothesis-generating and direct future focussed studies. There is future potential for direct translation into clinical care, as diet is a highly modifiable factor.

ETHICS AND DISSEMINATION

Ethics approval: Sydney Children's Hospitals Network Human Research Ethics Committee (HREC/18/SCHN/26). Results will be presented at international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04071314.

Newborn Screening for Cystic Fibrosis in Mersin Province: Yearly Assessment of the National Program

OBJECTIVES

A national newborn screening program for cystic fibrosis (CF) was started using immunoreactive trypsinogen (IRT) test on January 1, 2015, in Turkey. We aimed to analyze the characteristics of newborn screen-positive (NBSP) infants in Mersin province.

MATERIALS AND METHODS

The data on NBSP infants were retrospectively analyzed between 2015 and 2017 from records of Mersin Women & Children's Hospital and Mersin City Training and Research Hospital.

RESULTS

A total of 82,273 newborns were screened for CF by IRT test between January 2015 and December 2017 in Mersin. Among those, 512 infants were defined as NBSP after two repeated IRT tests (IRT/IRT) (138 infants in 2015, 217 in 2016, and 157 in 2017). Sweat test was normal in the majority of infants (115 infants [83.3%] in 2015, 189 [87.1%] in 2016, and 129 [82.2%] in 2017). Overall, between 2015 and 2017, after two repeated sweat tests, 4 infants had sweat test results in the intermediate range and 9 infants had positive sweat tests. The incidence of CF for a 3-year period was approximately 1/9300 in our region. The positive predictive value of IRT test for defining CF was 1.8%, with a sensitivity of 90.0% and specificity of 99.4%.

CONCLUSION

IRT/IRT test as a newborn screening strategy provides the opportunity for earlier diagnosis and treatment of CF patients. More data are needed to understand the frequency of CF on a national level.

Current Genetic Service Delivery Models for the Provision of Genetic Testing in Europe: A Systematic Review of the Literature

Background: The provision of genetic services, along with research in the fields of genomics and genetics, has evolved in recent years to meet the increasing demand of consumers interested in prediction of genetic diseases and various inherited traits. The aim of this study is to evaluate genetic services in order to identify and classify delivery models for the provision of genetic testing in European and in extra-European countries. Methods: A systematic review of the literature was conducted using five electronic resources. Inclusion criteria were that studies be published in English or Italian during the period 2000-2015 and carried out in European or extra-European countries (Canada, USA, Australia, or New Zealand). Results: 148 genetic programs were identified in 117 articles and were delivered mostly in the UK (59, 40%), USA (35, 24%) or Australia (16, 11%). The programs were available nationally (66; 45%), regionally (49; 33%) or in urban areas (21, 14%). Ninety-six (64%) of the programs were integrated into healthcare systems, 48 (32.21%) were pilot programs and five (3%) were direct-to-consumer genetic services. The genetic tests offered were mainly for BRCA1/2 (59, 40%), Lynch syndrome (23, 16%), and newborn screening (18, 12%). Healthcare professionals with different backgrounds are increasingly engaged in the provision of genetic services. Based on which healthcare professionals have prominent roles in the respective patient care pathways, genetic programs were classified into five models: (i) the geneticists model; (ii) the primary care model; (iii) the medical specialist model; (iv) the population screening programs model; and (v) the direct-to-consumer model. Conclusions: New models of genetic service delivery are currently under development worldwide to address the increasing demand for accessible and affordable services. These models require the integration of genetics into all medical specialties, collaboration among different healthcare professionals, and the redistribution of professional roles. An appropriate model for genetic service provision in a specific setting should ideally be defined according to the type of healthcare system, the genetic test provided within a genetic program, and the cost-effectiveness of the intervention. Only applications with proven efficacy and cost-effectiveness should be implemented in healthcare systems and made available to all citizens.

The Incidence of Cystic Fibrosis in the Central Region of Anatolia in Turkey Between 2015 and 2016

Background

Cystic fibrosis is the most common metabolic chronic disease among European Caucasian children. Cystic fibrosis incidence in Northern Europeans countries is approximately 1 in 3000 births while the worldwide prevalence varies considerably.

Aims

To determine the incidence of cystic fibrosis in the central region of Anatolia in Turkey using the newborn screening program data.

Study Design

Cross-sectional study

Methods

We used the records of the newborn screening program which is implemented by the Konya and Kayseri Provincial Health Directories. Between January 2015 and December 2016, there were a total of 119006 live births in Konya and Kayseri. The newborn screening test was applied to all these babies.

Results

During this period, there were 22 live born babies diagnosed with cystic fibrosis in Konya with an incidence of 2.9 per 10000 live births and 13 live born babies diagnosed with cystic fibrosis in Kayseri with an incidence of 2.8 per 10000 live births. In genetic of 30 patients, fifteen patients were homozygous, and 15 patients were a compound heterozygote. Twenty-one different gene variants were detected and the most common mutation was F508del (17/30).

Conclusion

We found the incidence of cystic fibrosis in central Anatolia similar to northern European countries.

Differences in Outcomes between Early and Late Diagnosis of Cystic Fibrosis in the Newborn Screening Era

OBJECTIVES

To evaluate children with cystic fibrosis (CF) who had a late diagnosis of CF (LD-CF) despite newborn screening (NBS) and compare their clinical outcomes with children diagnosed after a positive NBS (NBS-CF).

STUDY DESIGN

A retrospective review of patients with LD-CF in New South Wales, Australia, from 1988 to 2010 was performed. LD-CF was defined as NBS-negative (negative immunoreactive trypsinogen or no F508del) or NBS-positive but discharged following sweat chloride < 60 mmol/L. Cases of LD-CF were each matched 1:2 with patients with NBS-CF for age, sex, hospital, and exocrine pancreatic status.

RESULTS

A total of 45 LD-CF cases were identified (39 NBS-negative and 6 NBS-positive) with 90 NBS-CF matched controls. Median age (IQR) of diagnosis for LD-CF and NBS-CF was 1.35 (0.4-2.8) and 0.12 (0.03-0.2) years, respectively (P <.0001). Estimated incidence of LD-CF was 1 in 45 000 live births. Compared with NBS-CF, LD-CF had more respiratory manifestations at time of diagnosis (66% vs 4%; P <.0001), a higher rate of hospital admission per year for respiratory illness (0.49 vs 0.2; P = .0004), worse lung function (forced expiratory volume in 1 second percentage of predicted, 0.88 vs 0.97; P = .007), and higher rates of chronic colonization with Pseudomonas aeruginosa (47% vs 24%; P = .01). The LD-CF cohort also appeared to be shorter than NBS-CF controls (mean height z-score -0.65 vs -0.03; P = .02).

CONCLUSIONS

LD-CF, despite NBS, seems to be associated with worse health before diagnosis and worse later growth and respiratory outcomes, thus providing further support for NBS programs for CF.

Carrier testing in children and adolescents

Many international guidelines recommend that carrier testing in minors should be postponed either until the age of majority or until the child can be actively involved in the decision making process. Although a number of high school programs exist which provide carrier screening to adolescents in at-risk populations, recent guidelines published by the American Society of Human Genetics do not advocate this testing. Despite this, there are some circumstances in which carrier testing does occur in minors. This testing might be intentional, in which identification of carrier status is the goal of the test, or unintentional, where carrier status is identified as a by-product of testing. In this review we outline the situations in which carriers may be identified in childhood and the positions of professional guidelines that address carrier testing in children. We then review the arguments for and against carrier testing presented in the literature and compare this to the empirical evidence in this field.

The impact of a national population carrier screening program on cystic fibrosis birth rate and age at diagnosis: Implications for newborn screening

BACKGROUND

Population carrier screening (PCS) has been available in Israel since 1999 and universally subsidized since 2008. We sought to evaluate its impact.

METHODS

A retrospective review of governmental databanks, the national CF registry and CF centers.

RESULTS

CF rate per 100,000 live births has decreased from 14.5 in 1990 to 6 in 2011. From 2004-2011 there were 95 CF births: 22 utilized PCS; 68 (72%) had 2 known CFTR mutations; 37% were pancreatic sufficient. At diagnosis, age was 6 (0-98) months; 53/95 had respiratory symptoms, 41/95 failure to thrive and 19/95 pseudomonas. Thirty-four (36%) were Arabs and 19 (20%) orthodox Jews, compared to 20% and 8% respectively, in the general population.

CONCLUSIONS

PCS markedly reduced CF birth rates with a shift towards milder mutations, but was often avoided for cultural reasons. As children regularly have significant disease at diagnosis, we suggest a balanced approach, utilizing both PCS and newborn screening.

Cost of care for cystic fibrosis: an investigation of cost determinants using national registry data

Cystic fibrosis (CF) is a progressive disease with treatments intensifying as patients get older and severity worsens. To inform policy makers about the cost burden in CF, it is crucial to understand what factors influence the costs and how they affect the costs. Based on 1,060 observations (from 731 patients) obtained from the Australian Data Registry, individual annual health care costs were calculated and a regression analysis was carried out to examine the impact of multiple variables on the costs. A method of retransformation and a hypothetical patient were used for cost analysis. We show that an additional one unit improvement of FEV1pp (i.e., forced expiratory volume in 1 s as a percentage of predicted volume) reduces the costs by 1.4%, or for a hypothetical patient whose FEV1pp is 73 the cost reduction is A$252. The presence of chronic infections increases the costs by 69.9-163.5% (A$12,852-A$30,047 for the hypothetical patient) depending on the type of infection. The type of CF genetic mutation and the patient's age both have significant effects on the costs. In particular, being homozygous for p.F508del increases the costs by 26.8% compared to all the other gene mutations. We conclude that bacterial infections have a very strong influence on the costs, so reducing both the infection rates and the severity of the condition may lead to substantial cost savings. We also suggest that the patient's genetic profile should be considered as an important cost determinant.

Prenatal and preconception population carrier screening for cystic fibrosis in Australia: where are we up to?

AIMS

To describe prenatal and preconception population carrier screening for cystic fibrosis (CF) in Australia and consider progress towards establishing a universal program.

METHOD

Medline and Embase databases (1989-2013) were searched for all publications with Australian data. Existing programs for CF carrier screening in Australia were reviewed and professional peak body websites accessed to determine recommendations.

RESULTS

Twenty-two studies met the inclusion criteria. Key stakeholder groups believe that prenatal and preconception carrier screening for CF should be available. Health-economic analyses support that CF carrier screening can be cost-effective. There are small programs for CF carrier screening, in Victoria, New South Wales and Queensland. The Human Genetics Society of Australasia (HGSA) specifically recommend that screening be offered to women and couples planning a pregnancy and in the early stages of pregnancy. Other peak bodies indirectly endorse the availability of CF carrier screening. Barriers to screening include not being offered screening, the cost of testing, inequity of access and an incorrect perception that not having a family history of CF lowers risk.

CONCLUSIONS

There is support for prenatal and preconception CF carrier screening by the community, health professionals and peak professional bodies in Australia. The barriers to development of a national screening program could be overcome with greater physician engagement and government support.

IMPLICATIONS

In the interest of equity, government funded testing should be routinely offered to all pregnant women and couples planning a pregnancy.

Caregiver coping, mental health and child problem behaviours in cystic fibrosis: a cross-sectional study

BACKGROUND

In children with cystic fibrosis (CF) sleep, eating/mealtime, physiotherapy adherence and internalising problems are common. Caregivers also often report elevated depression, anxiety and stress symptoms.

PURPOSE

To identify, through principal components analysis (PCA), coping strategies used by Australian caregivers of children with CF and to assess the relationship between the derived coping components, caregiver mental health symptoms and child treatment related and non-treatment related problem behaviours.

METHOD

One hundred and two caregivers of children aged 3 to 8 years from three CF clinic sites in Australia, completed self-report questionnaires about their coping and mental health and reported on their child's sleep, eating/mealtime, treatment adherence and internalising and externalising behaviours.

RESULTS

Two caregiver coping components were derived from the PCA: labelled 'proactive' and 'avoidant' coping. 'Avoidant' coping correlated moderately with caregiver depression (0.52), anxiety (0.57) and stress (0.55). For each unit increase in caregiver use of avoidant coping strategies, the odds of frequent child eating/mealtime behaviour problems increased by 1.3 (adjusted 95 % CI 1.0 to 1.6, p = .03) as did the odds of children experiencing borderline/clinical internalising behaviour problems (adjusted 95 % CI 1.1 to 1.7, p = .01). Proactive coping strategies were not associated with reduced odds of any child problem behaviours.

CONCLUSIONS

Avoidant coping strategies correlated with caregiver mental health and child problem behaviours. Intervening with caregiver coping may be a way to improve both caregiver mental health and child problem behaviours in pre-school and early school age children with CF.

Cystic fibrosis carrier screening

Carrier screening for cystic fibrosis (CF) has been available since the early 1990s, yet there are few programs, and none funded as part of a national health care strategy. The aim of this paper is to provide a description of carrier screening for CF and examine the progress that has been made towards the establishment of universal population-based carrier screening programs. This is an evidence based commentary on population-based carrier screening for CF. Peak body recommendations were examined and existing programs for CF carrier screening are reviewed. The attitudes from the non-CF community, CF healthcare professionals and people with CF were studied. Data from health economic assessments is examined. The future of carrier screening for CF in the context of advancing genetic technologies and potentially curative therapies is considered.

The natural history and predictors of persistent problem behaviours in cystic fibrosis: a multicentre, prospective study

BACKGROUND

In cystic fibrosis (CF), problems with sleep, eating/mealtime behaviours, physiotherapy adherence and parental mental health issues are common, yet their natural history and the extent of service use to address them are unknown.

OBJECTIVE

Follow up the 2007 cohort to determine: (1) prevalence of child sleep, eating/mealtime behaviours, physiotherapy adherence, and externalising/internalising problem behaviours and primary caregiver mental health status after a 3-year period; (2) natural history of child behaviours; (3) potentially modifiable predictors of persistent problems; and (4) service use for behaviours.

DESIGN

Prospective cohort.

SETTING

Royal Children's Hospital, Monash Medical Centre and Sydney Children's Hospital (Australia) CF clinics.

PARTICIPANTS

Caregivers, of children aged 3-8 years, who completed the baseline questionnaire.

MAIN OUTCOME MEASURES

Child sleep, eating/mealtime behaviours, adherence with therapy and externalising and internalising behaviours.

PREDICTORS

parenting style (low warmth), caregiver mental health status and sleep quality at baseline.

RESULTS

102 of 116 (88%) families participated. The prevalence of sleep and eating/mealtime problems at follow-up was similar to baseline. The prevalence of caregiver mental health symptoms remained higher than the community data. 71 out of 102 (70%) of the children experienced at least one persistent behaviour problem. Caregiver mental health difficulties predicted persistent child moderate to severe sleep problems (adjusted OR 6.5, 95% CI 1.2 to 36.2, p=0.03) and their persistently poor adherence to the physiotherapy regimen (adjusted OR 3.5, 95% CI 1.3 to 9.2, p=0.01).

CONCLUSIONS

Child problem behaviours are common in children with CF, persist and are often predicted by the mental health of the parent. Routine surveillance for and management of child problem behaviours are recommended.

Changes in cystic fibrosis mortality in Australia, 1979-2005

OBJECTIVE

To assess mortality trends among people with cystic fibrosis (CF) in Australia.

DESIGN AND SETTING

We augmented Australian summary data for deaths from CF registered during 1979-2005 with information from Australian transplant centres on lung transplantation among CF patients for 1989-2005 to allow us to follow trends in all "mortality events" (death or lung transplantation).

MAIN OUTCOME MEASURE

Age at death or lung transplantation.

RESULTS

Between 1979 and 2005, the mean age at death increased from 12.2 years to 27.9 years for males and from 14.8 years to 25.3 years for females. Overall, female deaths in childhood (0-14 years) occurred at an age-standardised rate of 0.40 per 100,000 (95% CI, 0.34-0.45) during 1979-2005, which exceeded the corresponding rate for males of 0.24 (95% CI, 0.20-0.28) per 100,000. Among 0-14-year-old boys, event rates declined markedly after 1989, but they declined later and more gradually for girls, with the result that the age-standardised rate for girls was 2.38 times that of boys during 1989-2005 (95% CI, 1.69-3.36).

CONCLUSIONS

The pattern of CF mortality in Australia has changed substantially. Mortality rates continue to be higher for girls than for boys, but death in childhood has become uncommon. Survival has increased since 1979, but females continue to have reduced length of life.

Immunisation rates of children with cystic fibrosis using the Australian Childhood Immunisation Register

AIM

The Australian Immunisation Handbook (ninth edition) recommends children with cystic fibrosis (CF) receive routine scheduled immunisations plus annual influenza vaccine and an additional pneumococcal vaccine at both 12 months and 4-5 years. Adherence with these recommendations is unknown. This study aimed to determine the immunisation status of children with CF attending the Royal Children's Hospital (RCH), Melbourne.

METHODS

A retrospective audit of children with CF aged 6 months to 7 years (at 1 January 2008) was performed on the RCH CF outpatient clinic database. The Australian Childhood Immunisation Register (ACIR) and RCH Immunisation Service records were used to determine immunisation status.

RESULTS

Eighty-nine children with CF were identified, 52 (58%) were male, with median age of 3.6 years. Eighty-two of 89 children (92%) were up to date with routine immunisations. According to the ACIR, of the 89 children sampled, 24 (27%) were given influenza vaccine in accordance with recommendations in 2007. Eighty children were older than 12 months of age at 1 January 2008 and 17 (21%) of these children had received the additional pneumococcal vaccine at 12 months. Thirty-eight children were older than 4 years of age at 1 January 2008 and 6 (16%) received the recommended 23vPPV booster.

CONCLUSION

Most children with CF received their routine childhood immunisations but not the additional recommended immunisations. This highlights the potential value of the ACIR to accurately record all vaccines administered and for ACIR reminder letters to include the additional vaccines for children in special-risk groups.

Uptake of carrier testing in families after cystic fibrosis diagnosis through newborn screening

Newborn screening (NBS) for cystic fibrosis (CF) provides the opportunity for cascade carrier testing of relatives. Uptake of testing by adult non-parent relatives of children diagnosed with CF through NBS has not been previously described, and this study describes uptake by both parents and adult non-parent relatives in Victoria, Australia. Pedigrees were taken from parents of children who were born in 2000-2004 and diagnosed with CF. A total of 40 families were eligible for the study and 30 (75%) were recruited. In all, 716 non-parent relatives were identified from the pedigrees as eligible for carrier testing, and 82 (adjusted uptake percentage: 11.8%; 95% confidence interval 8.0-15.7) have had carrier testing by March 2009. On average, 2.7 non-parent relatives per family had CF carrier testing after diagnosis through NBS. The odds of being tested were greater for females than males (adjusted odds ratio 1.61; 95% confidence interval 1.11-2.33; P=0.01) and greater for those more closely related to the child with CF (adjusted odds ratio 5.17; 95% confidence interval 2.38-11.24; P<0.001). Most relatives who undergo testing are tested immediately after the baby's diagnosis; however, some testing is undertaken up to 8 years later. These results indicate that in a clinical setting, the diagnosis of a baby with CF by NBS does not lead to carrier testing for the majority of the baby's non-parent relatives. We suggest re-contact with parents to offer cascade carrier testing.

Chronic respiratory symptoms and diseases among indigenous children

Children from Indigenous populations experience more frequent, severe, and recurrent lower respiratory infections as infants and toddlers. The consequences of these infections are chronic lung disorders manifested by recurrent wheezing and chronic productive cough. These symptoms are aggravated more frequently by active and passive tobacco smoke exposure among Indigenous groups. Therapies for these symptoms, although not specific to children of Indigenous origins, are described as is the evidence for their use.

Population screening for reproductive risk for single gene disorders in Australia: now and the future

Abstract As the results of the Human Genome Project are realized, it has become technically possible to identify carriers of numerous autosomal and X-linked recessive disorders. Couples at risk of having a child with one of these conditions have a number of reproductive options to avoid having a child with the condition should they wish. In Australia the haemoglobinopathies are the only group of conditions for which population screening is widely offered and which is government funded. In some Australian states there are also population screening programs for cystic fibrosis and autosomal recessive conditions more common in Ashkenazi Jewish individuals which are generally offered on a user pays basis. It is predicted that as consumer demand increases and testing becomes cheaper, that many people planning or in the early stages of pregnancy will have carrier screening for multiple genetic conditions. This will have significant implications for genetic counseling, laboratory and prenatal testing resources. In addition such screening raises a number of ethical issues including the value of lives of those born with genetic conditions for which screening is available.

A new scoring system in Cystic Fibrosis: statistical tools for database analysis - a preliminary report

Background

Cystic fibrosis is the most common fatal genetic disorder in the Caucasian population. Scoring systems for assessment of Cystic fibrosis disease severity have been used for almost 50 years, without being adapted to the milder phenotype of the disease in the 21^st century. The aim of this current project is to develop a new scoring system using a database and employing various statistical tools. This study protocol reports the development of the statistical tools in order to create such a scoring system.

Methods

The evaluation is based on the Cystic Fibrosis database from the cohort at the Royal Children's Hospital in Melbourne. Initially, unsupervised clustering of the all data records was performed using a range of clustering algorithms. In particular incremental clustering algorithms were used. The clusters obtained were characterised using rules from decision trees and the results examined by clinicians. In order to obtain a clearer definition of classes expert opinion of each individual's clinical severity was sought. After data preparation including expert-opinion of an individual's clinical severity on a 3 point-scale (mild, moderate and severe disease), two multivariate techniques were used throughout the analysis to establish a method that would have a better success in feature selection and model derivation: 'Canonical Analysis of Principal Coordinates' and 'Linear Discriminant Analysis'. A 3-step procedure was performed with (1) selection of features, (2) extracting 5 severity classes out of a 3 severity class as defined per expert-opinion and (3) establishment of calibration datasets.

Results

(1) Feature selection: CAP has a more effective "modelling" focus than DA.

(2) Extraction of 5 severity classes: after variables were identified as important in discriminating contiguous CF severity groups on the 3-point scale as mild/moderate and moderate/severe, Discriminant Function (DF) was used to determine the new groups mild, intermediate moderate, moderate, intermediate severe and severe disease. (3) Generated confusion tables showed a misclassification rate of 19.1% for males and 16.5% for females, with a majority of misallocations into adjacent severity classes particularly for males.

Conclusion

Our preliminary data show that using CAP for detection of selection features and Linear DA to derive the actual model in a CF database might be helpful in developing a scoring system. However, there are several limitations, particularly more data entry points are needed to finalize a score and the statistical tools have further to be refined and validated, with re-running the statistical methods in the larger dataset.

Implementation of the French nationwide cystic fibrosis newborn screening program

OBJECTIVES

To describe optimization of a nationwide newborn screening program for cystic fibrosis (CF) that combines an immunoreactive trypsinogen (IRT) assay and DNA mutation analysis in dried blood samples at day 3.

STUDY DESIGN

Data from regional screening laboratories and CF care centers were centralized and periodically analyzed to allow adaptation, thus limiting the number of false-positive cases.

RESULTS

A total of 2717905 infants were screened between 2002 and 2005. Flow chart protocol was modified twice. First, the IRT d3 cutoff value increased from 60 to 65 microg/L, thus decreasing the percentage of samples requiring mutation analysis from 0.82% to 0.64%. Second, for infants with no mutations using the screening panel, a recall for IRT was performed only if IRT d3 was > 100 microg/L; the percentage of recalls decreased from 0.51% to 0.12%, and the percentage of infants requiring a sweat test decreased from 0.14% to 0.01%. No significant change in the CF detection rate was observed after these 2 modifications. A total of 625 CF cases were detected, and 22 false-negative findings (3.4%) were observed, most of them inevitable, with a low initial IRT.

CONCLUSIONS

The centralized data analysis led to changes in the screening strategy to optimise the newborn screening program.

Guidelines for diagnosis of cystic fibrosis in newborns through older adults: Cystic Fibrosis Foundation consensus report

Newborn screening (NBS) for cystic fibrosis (CF) is increasingly being implemented and is soon likely to be in use throughout the United States, because early detection permits access to specialized medical care and improves outcomes. The diagnosis of CF is not always straightforward, however. The sweat chloride test remains the gold standard for CF diagnosis but does not always give a clear answer. Genotype analysis also does not always provide clarity; more than 1500 mutations have been identified in the CF transmembrane conductance regulator (CFTR) gene, not all of which result in CF. Harmful mutations in the gene can present as a spectrum of pathology ranging from sinusitis in adulthood to severe lung, pancreatic, or liver disease in infancy. Thus, CF identified postnatally must remain a clinical diagnosis. To provide guidance for the diagnosis of both infants with positive NBS results and older patients presenting with an indistinct clinical picture, the Cystic Fibrosis Foundation convened a meeting of experts in the field of CF diagnosis. Their recommendations, presented herein, involve a combination of clinical presentation, laboratory testing, and genetics to confirm a diagnosis of CF.

Economic evaluation of cystic fibrosis screening: A review of the literature

OBJECTIVES

To critically examine the economic evidence regarding cystic fibrosis (CF) carrier screening and to understand issues relating to the transferability of international findings to any national context for policy decisions.

METHODS

A systematic literature search identified 14 studies (out of 29 economic studies on CF) focusing on preconception or prenatal screening between 1990 and 2006. These studies were then assessed against international benchmarks on conducting and reporting of economic evaluations, costing methodology used and focusing on the transferability of the evidence to national contexts.

RESULTS

The primary outcome measures varied considerably between studies and there was considerable ambiguity and variation on how costs were estimated. The Incremental Cost Effectiveness Ratio (ICER) and net savings, for preconception and prenatal screening were inconsistent and varied significantly, even after adjusting for timing and exchange rates. Differences in screening participation rates, reproductive choices, test sensitivity, cost of test and lifetime cost of care make up a large part of the ICER variations.

CONCLUSION

The heterogeneity in study design, model inputs and reporting of economic evaluations of CF carrier screening makes comparability and transferability across countries and even within countries difficult. This reinforces the need to assess any technology within the relevant context, and to not simply generalize from reported studies. In turn, this adds to the complex task of making efficient resource allocation decisions in the area of CF carrier screening. Our evaluation adds weight to the calls for revisiting the way economic studies are conducted and reported.

Time trends in birth incidence of cystic fibrosis in two European areas: data from newborn screening programs

OBJECTIVE

To determine the incidence of cystic fibrosis (CF) and its time trends over a 16-year period (1990 to 2005) in 2 European regions with a long history of newborn screening (NBS) for CF, and to investigate the impact of some external factors.

STUDY DESIGN

This study focused on data from NBS and prenatal diagnosis (PD) in Brittany (western France) and Veneto/Trentino Alto-Adige (northeastern Italy).

RESULTS

Similar birth incidences of CF were observed in the 2 regions (1/3153 vs 1/3540; P = .245). Time trend analysis using Poisson regression revealed that the birth incidence decreased significantly in the Italian area only (average annual percent change [AAPC] = -4.7%; 95% confidence interval [CI] = -7.3 to -2; P = .0008). The use of PD appeared more common in Brittany, and considering the terminations of CF-affected fetuses, the adjusted incidence was 1/2191 in Brittany and 1/3116 in Veneto/Trentino, corresponding to variations of 30.5% (highly significant; P = .0002) and 12% (not significant; P = .16), respectively. Recording the reason for each PD allowed ready assessment of the affect of various public health policies on incidence. The affect of population mixing also appeared to be relevant in the Italian area.

CONCLUSIONS

This study highlights how the incidence of CF has evolved in 2 European regions that have different attitudes toward PD and immigration policy.

'It is not in my world': an exploration of attitudes and influences associated with cystic fibrosis carrier screening

Carrier screening for cystic fibrosis has been recommended for pregnant women and their partners, individuals and couples prior to conception, and for people with a family history. Many pilot programmes offering cystic fibrosis carrier screening, most commonly in the prenatal setting, have shown that uptake and acceptability are high. This article explores perspectives of the Victorian community regarding carrier screening for cystic fibrosis prior to offering screening. In particular whether or not such carrier screening should be offered, the best time for offering carrier screening, the information required for making a decision about carrier screening, and how this information can best be provided. A qualitative approach was taken to enable exploration of the views of stakeholders. Four focus groups and 32 interviews were conducted with a total of 68 participants. Participants were in agreement that cystic fibrosis carrier screening should be made available to everyone. However, potential consumers viewed cystic fibrosis carrier screening as 'not in my world' and were unlikely to request such screening unless it was offered by a health professional, or they had a family history. The best time for carrier screening was seen to be an individual preference and an information brochure was perceived to be useful when considering carrier screening. Lack of knowledge around the irrelevance of family history is a barrier to cystic fibrosis carrier screening. This study highlights the importance of community consultation, with stakeholders, prior to implementation of carrier screening programmes.

Community-wide screening for cystic fibrosis carriers could replace newborn screening for the diagnosis of cystic fibrosis

Most babies with cystic fibrosis (CF) are born to parents who did not know they were carriers until their baby was diagnosed with CF, usually by newborn screening. It is only after the birth of their first child with CF that couples are offered genetic counselling and reproductive choices. Most use this information for prenatal testing of subsequent pregnancies. With the high uptake of first trimester screening for Down syndrome (80% in Victoria) most couples have had screening during the CF affected pregnancy. Yet screening for CF carrier status is available, costs are similar to that for Down syndrome screening and CF carrier screening only ever needs to be done once. Waiting for couples to have a baby with CF before they are identified as carriers denies them choice. A national policy on CF carrier screening in Australia, and determination to equitably fund such a programme, is required.

Cost-effectiveness of 4 neonatal screening strategies for cystic fibrosis

OBJECTIVES

The purpose of this work was to assess the costs of 4 neonatal screening strategies for cystic fibrosis in relation to health effects. In each strategy, the first test was the measurement of serum concentration of immunoreactive trypsin. The second step consisted of either a second immunoreactive trypsin test (strategy 1) or a multiple mutation analysis (strategy 2). In strategies 3 and 4, a third step was added to strategy 2: a second immunoreactive trypsin test (strategy 3) or an extended mutation analysis of the cystic fibrosis gene, that is, a denaturing gradient gel electrophoresis analysis (strategy 4).

METHODS

We conducted an economic-modeling exercise in the Netherlands based on published data and expert opinions. Subjects were a hypothetical cohort of 200 000 neonates, the approximate number of children born annually in the Netherlands, and we assessed the costs and number of life-years gained as a result of neonatal screening for cystic fibrosis. The costs and effects of changes in reproductive decisions because of neonatal screening were also assessed.

RESULTS

Immunoreactive trypsin + immunoreactive trypsin had the most favorable cost-effectiveness ratio of 24,800 euro per life-year gained. Immunoreactive trypsin + DNA + denaturing gradient gel electrophoresis achieved more health effects than immunoreactive trypsin + DNA + immunoreactive trypsin at lower cost. The incremental costs per life-year gained of the immunoreactive trypsin + DNA + denaturing gradient gel electrophoresis strategy compared with the immunoreactive trypsin + immunoreactive trypsin strategy were 130,700 euro, whereas the incremental costs of the immunoreactive trypsin + DNA strategy compared with the immunoreactive trypsin + DNA + denaturing gradient gel electrophoresis strategy were 2,154,300 euro. When changes in reproductive decisions as a result of neonatal screening are also taken into account, neonatal screening for cystic fibrosis may lead to financial savings of approximately 1.8 million euro annually, depending on the screening strategy used.

CONCLUSIONS

Cystic fibrosis screening for neonates is a good economic option, and positive health effects can also be expected. Immunoreactive trypsin + immunoreactive trypsin and immunoreactive trypsin + DNA + denaturing gradient gel electrophoresis are the most cost-effective strategies.

Parental attitudes to the identification of their infants as carriers of cystic fibrosis by newborn screening

AIM

To investigate parental attitudes to cystic fibrosis (CF) carrier detection of their infant by newborn screening (NBS).

METHODS

Data were collected from a postal questionnaire sent to parents of infants identified as CF carriers by NBS in 1996-1997 (inclusive) and 2001 in Victoria, Australia (n = 66).

RESULTS

Almost all parents remembered their child being identified as a CF carrier (97%: 1996/1997; 100%: 2001); yet the majority were unaware at the time that NBS could detect carriers (70%: 1996/1997; 49%: 2001). More parents in the later cohort reported having carrier testing compared with the earlier cohort (85% and 53% respectively) but recall was more uncertain in the earlier cohort when validated against health records. Cascade testing was not utilised frequently by other family members in either cohort. Residual risk of being a carrier if testing was negative was not well understood by parents. Some parents (28%: 1996/1997; 18%: 2001) had residual anxiety about the current health of their carrier child and their future reproductive decision making. Most parents were satisfied with the information provided to them at the time of the sweat test. Few differences were seen between the cohorts.

CONCLUSION

Although the NBS process for CF in Victoria is working efficiently for the majority of families whose infant is identified as a carrier there are areas that can be improved. We recommend that greater attention should be given to informing parents that a consequence of NBS is CF carrier detection and strategies to improve utilisation of cascade testing should be developed.

Markedly elevated neonatal immunoreactive trypsinogen levels in the absence of cystic fibrosis gene mutations is not an indication for further testing

AIMS

To investigate the immunoreactive trypsinogen (IRT) values above the usual 99th centile laboratory cut-off and determine the value of offering further testing to those infants with a markedly elevated IRT but no cystic fibrosis transmembrane regulator (CFTR) gene mutation identified by the screening programme.

METHODS

All babies born in Victoria, Australia, between 1991 and 2003, were screened by IRT followed by CF gene mutation analysis.

RESULTS

Of the 806,520 babies born, 9268 with the highest IRT levels had CFTR mutation analysis. There were 123 DeltaF508 homozygotes and 703 heterozygotes (86 with CF, 617 carriers). A total of 8442 babies had no CFTR gene mutation, of whom 18 (0.21%) had CF. The total number of CF babies with IRT greater than the laboratory cut-off was 227 (2.4%). The IRT results of the CF patients were distributed normally, with the majority above the laboratory cut-off of newborn IRT results. There was no evidence of an excess of babies with CF in the very highest levels of IRT above the 99th centile.

CONCLUSIONS

Only a small proportion of babies with a neonatal IRT >99th centile have CF. Additional CF testing for infants with an elevated IRT but no CFTR gene mutation has an extremely low yield, no matter how high the IRT result.

Immunoreactive trypsin levels in neonates with meconium ileus

Serum immunoreactive trypsin (IRT) is used as a screening test for cystic fibrosis (CF) in neonates in many countries. Variations in IRT levels are observed in healthy and cystic neonates within the first few weeks of life. Fifteen percentage of CF neonates present with meconium ileus (MI). We hypothesised that there may be differences in serum IRT levels in cystic babies with simple and complicated MI. The aim of this study was to investigate the serum levels of IRT in neonates with CF presenting with MI. IRT levels were sequentially measured in neonates (n = 29) with CF with intestinal obstruction due to simple or complicated MI. These were compared to levels obtained from non-cystic neonates/controls admitted with a variety of other intra-abdominal pathologies (n = 49) IRT levels were significantly higher in the CF-MI group than the non-cystic controls (P < 0.001). There was no statistical difference in IRT levels between the simple or complicated MI groups. In the MI group there was no statistical difference between those who required operation, no difference between the pre- and post-operative IRT levels and no significant relationship between IRT levels and birth weight or gestation. Serum IRT levels are significantly elevated in neonates with CF and MI compared with non-cystic, non-MI neonates. The results of this observational study highlight that a single raised level of IRT in a neonate should prompt the analysis for CF regardless of any underlying surgical pathology.

Lower airway inflammation in infants with cystic fibrosis detected by newborn screening

Controversy exists over whether the lower airway inflammation that characterizes cystic fibrosis (CF) is initiated primarily by the genetic defect. To determine if inflammation precedes infection, we examined bronchoalveolar lavage (BAL) fluid cytology, cytokines (interleukin (IL)-1beta, IL-4, IL-5, IL-6, IL-8, IL-10, and tumor necrosis factor-alpha), and free neutrophil elastase activity from 70 CF (aged 1.5-71 months) children detected by newborn screening and 19 (aged 2.0-48 months) controls with chronic stridor. CF subjects were selected and categorized as pristine (13 aged </= 6 months, lacking prior respiratory symptoms and exposure to antibiotics, and without respiratory pathogens on BAL), infected (42 with viruses or >/= 10(5) colony-forming units/ml of pathogenic bacteria in BAL), and uninfected (15 aged > 6 months, asymptomatic, not taking antibiotics at bronchoscopy, and free of pathogens in their BAL). To further resolve if inflammation develops without infection, inflammatory mediators in paired annual BAL samples from 38 CF subjects were measured, and results were grouped according to whether BAL showed persistence (n = 6), acquisition (n = 8), clearance (n = 13), or absence (n = 11) of infection. While pristine, uninfected, and control subjects had similar BAL profiles, infected patients showed elevated inflammatory indices, including increased IL-10 (P < 0.001). Pristine subjects had the fewest signs of inflammation. Analysis of BAL pairs found differences between the four infection groups for changes in neutrophil percentages, IL-8 (P < 0.001), and free neutrophil elastase (P = 0.009). Infection was associated with elevated inflammatory mediators in BAL fluid. In contrast, minimal or reduced signs of inflammation accompanied absence of eradication of infection from BAL fluid. We conclude that in CF, infection initiates and sustains airway inflammation.

Effects of Segregation on an EpidemicPseudomonas aeruginosaStrain in a Cystic Fibrosis Clinic

The detection of a clonal Pseudomonas aeruginosa strain in 21% of children attending a cystic fibrosis clinic during 1999, which may have led to a worse prognosis, prompted strict infection control measures, including cohort segregation. We determined whether these strategies interrupted cross-infection within the clinic. Patients from 1999 were observed and a cross-sectional study of the 2002 clinic was performed. By 2002, the epidemic strain prevalence had decreased from 21 to 14% (p = 0.03), whereas the proportion of patients with nonepidemic P. aeruginosa strains was unchanged. The age- and sex-adjusted relative risk for epidemic strains among sputum producers in 2002 compared with 1999 was 0.64 (95% confidence interval, 0.47, 0.87; p = 0.004). Increased mortality or transfer to another clinic did not explain this reduction. Although children with epidemic strains may have had increased mortality (adjusted odds ratio, 2.0; 95% confidence interval, 0.6-6.8), they did not demonstrate greater morbidity than those with other P. aeruginosa isolates. Successful infection control measures provided additional indirect evidence for person-to-person transmission of an epidemic strain within the clinic. Further studies are needed to resolve whether cohort segregation completely eliminates cross-infection and if acquisition of epidemic isolates is associated with worse outcomes.

Diagnosis of cystic fibrosis after newborn screening: the Australasian experience--twenty years and five million babies later: a consensus statement from the Australasian Paediatric Respiratory Group

Newborn screening for cystic fibrosis has been used in Australia and New Zealand for over 20 years. In that time, considerable experience has been developed regarding the early diagnosis of cystic fibrosis after newborn screening. To date, there has not been a consensus on the process of screening and clinical evaluation leading to the diagnosis of cystic fibrosis in infants, many of whom are not symptomatic at time of notification of the screening result. The aim of this paper is to provide some consensus on the important issues of a cystic fibrosis diagnosis arising from newborn screening, based on the experience gained in Australia and New Zealand over the last 20 years.

Update on newborn screening for cystic fibrosis

PURPOSE OF REVIEW

Cystic fibrosis (CF) is the most common lethal genetic disorder in the United States to be identified in childhood. In November 2003 the US Cystic Fibrosis Foundation and the Centers for Disease Control and Prevention convened an expert panel to review the indications for CF newborn screening. In this review we discuss the information during the year leading up to this meeting as well as publications since the meeting.

RECENT FINDINGS

During the past several years an increasing number of CF patients have been diagnosed with newborn screening. These patients have demonstrated several benefits to screening while also uncovering new challenges. Health benefits have included improved nutrition persisting for many years and the avoidance of nutritional complications. Early identification has also meant that these often clinically healthy infants are being followed in CF centers for care. This has added to the need for avoiding infection risks to which these patients might not have otherwise been exposed. Psychosocial benefits include the avoidance of stress due to delayed diagnosis as well as assistance with family planning. Psychosocial challenges include carrier identification and detection of patients with mild disease or without a clear diagnosis.

SUMMARY

Although no study has definitively shown reduced lung disease or prolonged survival in CF patients detected by newborn screening, the general consensus is that improved nutrition and cognitive potential, in addition to the reduced costs for hospitalization and intensive therapies, support the benefits of screening.

What follows newborn screening? An evaluation of a residential education program for parents of infants with newly diagnosed cystic fibrosis

OBJECTIVE

The diagnosis of a severe life-limiting condition, such as cystic fibrosis (CF), is generally followed by assessment and treatment of the child and education and counseling for parents. The introduction of newborn screening for CF provides an opportunity for standardized assessment and education. The aim of this study was to evaluate a 5-day residential assessment and education program for parents of infants who receive a diagnosis of CF after newborn screening.

METHODS

Eligible parents had a 6- to 30-month-old infant with CF diagnosed by newborn screening. Parents were interviewed by telephone using a structured questionnaire that addressed 3 main themes: 1) initial communication of the diagnosis of CF, 2) the perceived value of the 5-day assessment and education program, and 3) the perceived advantages and disadvantages of the residential component (Care-By-Parent unit) of the program.

RESULTS

Fifteen of 17 eligible families took part in the 5-day assessment and education program, 12 of whom used the residential Care-By-Parent unit. At the end of the program, parents believed that they had the knowledge and skills required to manage their child's CF at home. One hundred percent endorsed the timing of the assessment and education program immediately after the child's diagnosis and would recommend it to other families in the same situation. Perceived advantages of the residential program were not having to travel (89%), being able to concentrate on CF (50%), and the benefit of a "home base" at the hospital (39%). Twenty-two percent reported that financial costs related to participation (paternal time off work) were a disadvantage, 17% reported additional strain on family members caring for siblings, and 17% mentioned lack of comfort within the unit.

CONCLUSIONS

This time-intensive residential program was evaluated positively by parents of children with newly diagnosed CF. It provides a model for education programs after the diagnosis of CF by newborn screening, as well as for other pediatric conditions that require intensive parent education.

Newborn screening programmes for cystic fibrosis

We review the current situation with respect to newborn cystic fibrosis screening (NCFS) across the world. The challenges of establishing an NCFS programme are reflected in the diversity of those programmes identified. All employ an initial immunoreactive trypsinogen (IRT) measurement during the first week of life. If this is positive, a second IRT analysis at 4 weeks of age improves the specificity of the test; most programmes have, however, moved to DNA analysis at this point, which improves their sensitivity. Incorporating DNA analysis results in the identification of carriers, which may have implications for families but is generally considered positive. Some programmes have incorporated a second IRT test as well as DNA analysis, either to increase the sensitivity of the test in an area with a low DeltaF508 frequency or to reduce the number of infants requiring a sweat test. Whichever algorithm is selected, the implementation of a successful programme relies on clear pathways and good information for parents.