Analysis of the costs of diagnosing cystic fibrosis with a newborn screening program

Innovative assessment of inpatient and pulmonary drug costs for children with cystic fibrosis

BACKGROUND

Previous estimates of the cost of care for pediatric Cystic fibrosis (CF) showed wide variation, without specific summary of pulmonary drug costs.

METHODS

Enrolled CF children from the Wisconsin newborn screening trial were evaluated quarterly per protocol. Assessments systematically included all treatments, hospitalizations, and nutritional and pulmonary outcomes. Direct medical costs from hospital billing and medical records from 1989 to 2010 were used to describe costs by age-ranges and subgroups throughout follow-up. Outpatient drugs were separated by category (pulmonary/otherwise). Inpatient and drug costs were examined by clinical risk factors (presence of meconium ileus, pancreatic insufficiency, and expected severity of genetic mutations).

RESULTS

Seventy-three children were followed for an average of 12.9 years with an average annual total cost of care of $24,768. Outpatient drug costs (53%) and hospitalizations (32%) represented the majority of costs. Drug costs were 48% for pulmonary indications and 52% for non-pulmonary. Pulmonary drug costs for children taking dornase were 54% of their drug costs while pulmonary drug costs were only 31% for children not taking dornase. Significant differences in frequency of inpatient stays existed for children with pancreatic insufficiency. Substantial differences in treatment costs exist as children age and by clinical risk factor.

CONCLUSION

This study provides more accurate longitudinal estimates of CF care costs throughout childhood and shows that increasing age, pancreatic insufficiency, use of dornase, and hospitalizations are key determinants of cost. These estimates can be included in evaluations of the cost-effectiveness of new, highly expensive treatments being introduced for any CF population. Pediatr Pulmonol. 2016;51:1295-1303. © 2016 Wiley Periodicals, Inc.

Sweat test practice in pediatric pulmonology after introduction of cystic fibrosis newborn screening

The influence of the generalization of cystic fibrosis newborn screening (CFNBS) in France on sweat test (ST) prescription is unknown. In this French retrospective, descriptive, and multicenter study, we studied the indications, number, methods, and results of STs prescribed by a pediatric pulmonologist in children who had a negative CFNBS and an ST for respiratory symptoms in 2012. We included 502 children with 523 STs, performed with four different methods. The main indication was asthma (71.3 %), then chronic cough (52.4 %), atypical lower airway infections (42.2 %), and bronchiectasis (7 %). Four children had a diagnosis of CF (0.8 %), all presenting with chronic productive cough and recurrent respiratory infections.

CONCLUSION

Asthma is the most frequent indication of ST in our cohort. Because of the systematic CFNBS in France, some prescriptions should be avoided, particularly in case of severe or moderate asthma with no other associated symptom. Moreover, methods of STs often do not follow the guidelines and need standardization.

WHAT IS KNOWN

• Newborn screening (NBS) has become the most frequent circumstance of the diagnosis of cystic fibrosis (CF) in France after its generalization. • The prescription of sweat test (ST) in children with respiratory symptoms who already had a negative NBS has not been studied.

WHAT IS NEW

• In children with a negative CF NBS referred to a university hospital for respiratory diseases, despite important variations of ST methods, only 4 children among 502 have been diagnosed as CF. • Despite recommendations, ST prescription should be avoided in children with moderate to severe asthma and no other associated symptom.

Showing Value in Newborn Screening: Challenges in Quantifying the Effectiveness and Cost-Effectiveness of Early Detection of Phenylketonuria and Cystic Fibrosis

Decision makers sometimes request information on the cost savings, cost-effectiveness, or cost-benefit of public health programs. In practice, quantifying the health and economic benefits of population-level screening programs such as newborn screening (NBS) is challenging. It requires that one specify the frequencies of health outcomes and events, such as hospitalizations, for a cohort of children with a given condition under two different scenarios-with or without NBS. Such analyses also assume that everything else, including treatments, is the same between groups. Lack of comparable data for representative screened and unscreened cohorts that are exposed to the same treatments following diagnosis can result in either under- or over-statement of differences. Accordingly, the benefits of early detection may be understated or overstated. This paper illustrates these common problems through a review of past economic evaluations of screening for two historically significant conditions, phenylketonuria and cystic fibrosis. In both examples qualitative judgments about the value of prompt identification and early treatment to an affected child were more influential than specific numerical estimates of lives or costs saved.

Fiscal implications of newborn screening in the diagnosis of severe combined immunodeficiency

In the United States, newborn screening (NBS) is currently recommended for identification of 31 debilitating and potentially fatal conditions. However, individual states determine which of the recommended conditions are screened. The addition of severe combined immunodeficiency (SCID) screening to the recommended NBS panel has been fully instituted by 18 states, with another 11 states piloting programs or planning to begin screening in 2014. Untreated, SCID is uniformly fatal by 2 years of age. Hematopoietic stem cell transplantation usually is curative, but the success rate depends on the age at which the procedure is performed. Short-term implementation costs may be a barrier to adding SCID to states' NBS panels. A retrospective economic analysis was performed to determine the cost-effectiveness of NBS for early (<3.5 months) versus late (≥3.5 months) treatment of children with SCID at 3 centers over 5 years. The mean total charges at these centers for late treatment were 4 times greater than early treatment ($1.43 million vs $365,785, respectively). Mean charges for intensive care treatments were >5 times higher ($350,252 vs $66,379), and operating room-anesthesia charges were approximately 4 times higher ($57,105 vs $15,885). The cost-effectiveness of early treatment for SCID provides a strong economic rationale for the addition of SCID screening to NBS programs of other states.

Improving the Rate of Sufficient Sweat Collected in Infants Referred for Sweat Testing in Michigan

Objective. Sweat collected for testing should have quantity not sufficient (QNS) rate of ≤10% in babies ≤3 months of age. Michigan (MI) cystic fibrosis (CF) centers' QNS rates were 12% to 25% in 2009. This project was initiated to reduce sweat QNS rates in MI. Methods/Steps. (a) Each center's sweat testing procedures were reviewed by a consultant. (b) Each center received a report with recommendations to improve QNS rates. (c) Technicians visited other participating centers to observe their procedures. Results. A total of 778 infants were identified as positive via CF newborn screening over a 2-year period. The mean age at time of sweat test was 23.2 days (SD ± 13.0 days). The overall QNS percent decreased from 14.4% to 9.5% (P = .04) during the study. Conclusion. This project and teamwork approach led to a decrease of sweat test QNS rates, opportunities to solve a common problem, and improved quality of care.

A decision-tree approach to cost comparison of newborn screening strategies for cystic fibrosis

OBJECTIVE

Because cystic fibrosis can be difficult to diagnose and treat early, newborn screening programs have rapidly developed nationwide but methods vary widely. We therefore investigated the costs and consequences or specific outcomes of the 2 most commonly used methods.

METHODS

With available data on screening and follow-up, we used a simulation approach with decision trees to compare immunoreactive trypsinogen (IRT) screening followed by a second IRT test against an IRT/DNA analysis. By using a Monte Carlo simulation program, variation in the model parameters for counts at various nodes of the decision trees, as well as for costs, are included and applied to fictional cohorts of 100 000 newborns. The outcome measures included the numbers of newborns given a diagnosis of cystic fibrosis and costs of screening strategy at each branch and cost per newborn.

RESULTS

Simulations revealed a substantial number of potential missed diagnoses for the IRT/IRT system versus IRT/DNA. Although the IRT/IRT strategy with commonly used cutoff values offers an average overall cost savings of $2.30 per newborn, a breakdown of costs by societal segments demonstrated higher out-of-pocket costs for families. Two potential system failures causing delayed diagnoses were identified relating to the screening protocols and the follow-up system.

CONCLUSIONS

The IRT/IRT screening algorithm reduces the costs to laboratories and insurance companies but has more system failures. IRT/DNA offers other advantages, including fewer delayed diagnoses and lower out-of-pocket costs to families.

Predictors of insufficient sweat production during confirmatory testing for cystic fibrosis

Michigan's Newborn Screening (NBS) Program began statewide screening for cystic fibrosis (CF) in October 2007. Confirmatory sweat testing is performed in infants having initial immunoreactive trypsinogen concentrations ≥ 99.8th percentile or ≥ 96 th percentile and at least one CF mutation identified by DNA analysis. Some infants fail to produce a sufficient quantity of sweat (QNS-quantity not sufficient) to test for CF, meaning disease confirmation is delayed and sweat testing is later repeated. In this study, we evaluate predictors of QNS results. Information from the linked birth certificates and NBS diagnostic confirmation data were used. The study population was resident infants born in Michigan in 2008 who underwent a sweat test. Bivariate analyses revealed that preterm birth, low birth weight, CF care center, and race were significantly associated with QNS sweat testing results. Adjusted analyses indicated that preterm infants were 2.4 times more likely to have QNS results (95% CI 0.9, 6.4). When age at time of test, accounting for gestational age (gestational age at delivery plus postdelivery age of life=corrected age), was used in the multivariable model, infants <39 weeks were 7.4 times more likely to have QNS results (95% CI 2.5, 21.8). Waiting to sweat test until an infant is aged 39 weeks or more (corrected age) would likely reduce the rate of QNS results, thereby reducing the burden of repeat sweat testing on families and healthcare providers. Further research is necessary to understand the impact of potential delays in diagnosis/treatment relative to postponing sweat testing.

PGD for all cystic fibrosis carrier couples: novel strategy for preventive medicine and cost analysis

Over 1000 children affected with cystic fibrosis (CF) are born annually in the USA. Since IVF with preimplantation genetic diagnosis (PGD) is an alternative to raising a sick child or to aborting an affected fetus, a cost-benefit analysis was performed for a national IVF-PGD program for preventing CF. The amount spent to deliver healthy children for all CF carrier-couples by IVF-PGD was compared with the average annual and lifetime direct medical costs per CF patient avoided. Treating annually about 4000 CF carrier-couples with IVF-PGD would result in 3715 deliveries of non-affected children at a cost of $57,467 per baby. Because the average annual direct medical cost per CF patient was $63,127 and life expectancy is 37 years, savings would be $2.3 million per patient and $2.2 billion for all new CF patients annually in lifetime treatment costs. Cumulated net saving of an IVF-PGD program for all carrier-couples for 37 years would be $33.3 billion. A total of 618,714 cumulative years of patients suffering because of CF and thousands of abortions could be prevented. A national IVF-PGD program is a highly cost-effective novel modality of preventive medicine and would avoid most births of individuals affected with debilitating genetic disease.

Newborn screening for cystic fibrosis

BACKGROUND

Does newborn screening for cystic fibrosis (CF) improve clinical outcomes, quality of life and survival?

OBJECTIVES

To examine whether newborn screening for CF prevents or reduces irreversible organ damage and improves clinical outcomes, quality of life and survival in people with CF without unacceptable adverse effects.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from electronic database searches, handsearches of relevant journals and abstract books of conference proceedings.The Group's Trials Register last searched: June 2008.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials, published and unpublished, comparing screening to clinical diagnosis in people with CF.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility and quality and independently extracted data. Allocation concealment was unclear in both studies and sequence generation adequate in one.

MAIN RESULTS

Searches identified six trials. Two trials involving 1,124,483 neonates (210 with CF) with a maximum follow up of 17 years were eligible for inclusion. Varying study designs, outcomes reported and summary measures precluded calculation of pooled estimates and only data from one study were analysed. Severe malnutrition was less common among screened participants. Compared with screened participants, the odds ratio of weight below the tenth percentile was 4.12 (95% CI 1.64 to 10.38) and for height was 4.62 (95% CI 1.69 to 12.61) in the control group.At age seven, 88% of screened participants and 75% of controls had lung function parameters within normal limits of at least 89% predicted. At diagnosis chest radiograph scores were significantly better among screened participants; 33% of screened versus 50% of control participants had Wisconsin chest X-ray (WCXR) scores over five (P = 0.097) and 24% of screened versus 45% of control participants had Brasfield chest X-ray (BCXR) scores under 21 (P = 0.042)). Over time, chest radiograph scores were worse in the screened group (WCXR P = 0.017 and BCXR P = 0.041). Results were no longer significant after adjustment for genotype, pancreatic status, and Pseudomonas aeruginosa-culture results. In screened participants colonisation with Pseudomonas aeruginosa occurred earlier. Estimates suggest diagnosis through screening is less expensive.

AUTHORS' CONCLUSIONS

Two randomised controlled trials assessing neonatal screening in CF were identified; data from one study were included. Nutritional benefits are apparent. Screening provides potential for better pulmonary outcomes, but confounding factors influenced long-term pulmonary prognosis of people with CF. Screening seems less expensive than traditional diagnosis.

Is newborn screening for cystic fibrosis a basic human right?

Because it is clearly in the best interests of children with cystic fibrosis to be diagnosed early at <2 months, which can only be achieved routinely by newborn screening, it can be argued that this should be a human right. However, if more harm than good is likely, or if regional "readiness" does not exist, newborn screening should be deferred.

A sweat test centered protocol for the disclosure and diagnosis of cystic fibrosis in a newborn screening program

We describe the development of a sweat test centered protocol for disclosure and diagnosis of Cystic Fibrosis. Our protocol aims to identify infants early, minimizes the time of uncertainty for the parents, and yet gives them time to begin to come to terms with the possibility of diagnosis. Over a 9-year period 295,247 newborn infants were screened for CF in Wales, of whom 121 infants were diagnosed as having CF. During this period there were four false negatives (3.3%). Parental satisfaction with the process appears very high 6 months after disclosure.

Newborn screening for cystic fibrosis: techniques and strategies

Newborn screening for cystic fibrosis has been carried out for over 25 years, and clinical and cost benefits have been documented. There is still much variation in the methods and strategies adopted. All current screening programmes use a measurement of immunoreactive trypsin as a primary screening test, and in most, a second tier test involves analysing DNA mutations. The choice of DNA mutations depends on the genetic background in the region, and considerations of cost. Using DNA analysis as part of a screening procedure has introduced unwanted carrier detection, and protocols have now been devised in an attempt to avoid this. There are at least seven distinct protocols in use, all of which have different advantages and disadvantages, and no method or strategy will suit every region. Further careful study of performance and costs of various strategies is needed.

Neonatal screening: from the 'Guthrie age' to the 'genetic age'

Newborn screening has 'traditionally' been performed to detect metabolic or endocrine diseases that are severe, frequent and treatable, according to criteria established in the late 1960s. Technological advances in laboratory testing over the past ten years open new possibilities. However, many new problems have to be explored before the establishment or expansion of a newborn screening programme. The purpose of this paper is to present some of the major problems that screening programmes will face in the near future.

Newborn screening for cystic fibrosis

Newborn screening for cystic fibrosis (CF) was considered over 3 decades ago in 1970; however, the technology did not exist then for an accurate neonatal screening test. With the development of immunoreactive trypsinogen analysis, alone or coupled with DNA mutation analysis, the means were developed for CF newborn screening. Studies have demonstrated benefits of newborn screening in the areas of nutrition, cognitive function, pulmonary function, and survival.

Economic implications of newborn screening for cystic fibrosis: a cost of illness retrospective cohort study

BACKGROUND

Newborn screening for cystic fibrosis might not be introduced if implementation and running costs are perceived as prohibitive. Compared with clinical diagnosis, newborn screening is associated with clinical benefit and reduced treatment needs. We estimate the potential savings in treatment costs attributable to newborn screening.

METHODS

Using the UK Cystic Fibrosis Database, we used a prevalence strategy to undertake a cost of illness retrospective snapshot cohort study. We estimated yearly costs of long-term therapies and intravenous antibiotics for 184 patients who were diagnosed as a result of screening as newborn babies, and 950 patients who were clinically diagnosed aged 1-9 years in 2002. Costs of adding cystic fibrosis screening to an established newborn screening service in Scotland were adjusted to 2002 prices and applied to the UK as a whole. Costs were recalculated in US$.

FINDINGS

Cost of therapy for patients diagnosed by newborn screening was significantly lower than equivalent therapies for clinically diagnosed patients: mean ($7228 vs $12 008, 95% CI of difference -6736 to -2028, p<0.0001) and median ($352 vs $2442, -1916 to -180, p<0.0001). When we limited the clinically diagnosed group to only those diagnosable with a 31 cystic fibrosis transmembrane regulator mutation assay and assumed similar disease progression in the clinically diagnosed group as in the newborn screening group, we showed that mean ($3,397,344) or median ($947,032) drug cost savings could have offset the estimated cost of adding cystic fibrosis to a UK national newborn screening service ($2,971,551).

INTERPRETATION

Including indirect costs savings, newborn screening for cystic fibrosis might have even greater financial benefits to society than our estimate shows. Clinical, social, and now economic evidence suggests that universal newborn screening programmes for cystic fibrosis should be adopted internationally.

Guidelines for implementation of cystic fibrosis newborn screening programs: Cystic Fibrosis Foundation workshop report

Newborn screening for cystic fibrosis offers the opportunity for early intervention and improved outcomes. This summary, resulting from a workshop sponsored by the Cystic Fibrosis Foundation to facilitate implementation of widespread high quality cystic fibrosis newborn screening, outlines the steps necessary for success based on the experience of existing programs. Planning should begin with a workgroup composed of those who will be responsible for the success of the local program, typically including the state newborn screening program director and cystic fibrosis care center directors. The workgroup must develop a screening algorithm based on program resources and goals including mechanisms available for sample collection, regional demographics, the spectrum of cystic fibrosis disease to be detected, and acceptable failure rates of the screen. The workgroup must also ensure that all necessary guidelines and resources for screening, diagnosis, and care be in place prior to cystic fibrosis newborn screening implementation. These include educational materials for parents and primary care providers; systems for screening and for providing diagnostic testing and counseling for screen-positive infants and their families; and protocols for care of this unique population. This summary explores the benefits and risks of various screening algorithms, including complex situations that can occur involving unclear diagnostic results, and provides guidelines and sample materials for state newborn screening programs to develop and implement high quality screening for cystic fibrosis.

Current impact of gene technology on healthcare

OBJECTIVES

It has been claimed that gene technology will induce revolutionary changes in healthcare. This paper investigates how and to what extent these changes have been economically assessed.

METHODS

A generic framework was developed to distinguish between methodologically similar evaluations of healthcare technology. Methodological issues and the current state of economic evidence concerning human DNA technology were extracted from publications within these groups of evaluations.

RESULTS

Economic evaluations of "healthcare consisting of gene technology" were identified primarily for in vitro diagnostics for hereditary disease and others for pharmacogenetics and molecular pathology. "Healthcare enabled by gene technology" is far more encompassing and includes, e.g., biotechnology drugs for which various health economic evaluations can be found. Yet here, the impact of gene technology intertwines with the impact of other technologies and is therefore hardly susceptible to evaluation. The fields of evaluation may be classified best according to the two dimensions "purpose" and "stage of development". Current evaluations cover screening, diagnostic and treatment technologies in investigational, new and established stages. Apart from prenatal screening, healthcare consisting of gene technology was cost saving only for genotype tests replacing continuous phenotype tests and for one pharmacogenetic test. Conclusive evidence of favourable cost-effectiveness ratios is available only for few conditions.

CONCLUSION

Hypotheses about the impact of gene technology on healthcare must be explicit about the definition of "genetic" medicine. A general statement regarding healthcare enabled by gene technology is not possible. Based on current evidence, an era of healthcare consisting of gene technology built on widespread predictive testing is not desirable from a health economic viewpoint.

Extended gene analysis can increase specificity of neonatal screening for cystic fibrosis

AIM

To assess whether carriers and patients can be accurately identified by extended gene analysis for cystic fibrosis (CF) in dried blood spots.

METHODS

A blinded analysis was performed in 10-mm2 blood spots on Guthrie cards, punched as if to remove material for the IRT test, from 10 CF patients and 10 carriers with known CF mutations. Genomic DNA was isolated. Aliquots of 1 microl dissolved DNA were used for subsequent PCRs. Analysis of the deltaF508 mutation was followed by an oligonucleotide ligation assay. Denaturing gradient gel electrophoresis of the whole CFTR gene was carried out in samples with only one identified mutation. Amplicons revealing an aberrant pattern were sequenced.

RESULTS

In all cases, the blood-spot genotype was identical to that previously determined from whole-blood analysis. Estimated time needed to complete the procedure in a series of Guthrie cards was 3-4 wk.

CONCLUSION

Extended gene analysis in dried blood spots can discriminate CF patients and carriers. If proven equally reliable in larger series, an approach to neonatal screening in which tests are only considered as screen positive when two CF mutations are found is possible. This can increase the specificity of the screening programme, and carrier detection can practically be avoided.

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.

Genetic screening by DNA technology: A systematic review of health economic evidence

Objectives:The Human Genome Project has led to a multitude of new potential screening targets on the level of human DNA. The aim of this systematic review is to critically summarize the evidence from health economic evaluations of genetic screening in the literature.

Methods:Based on an extensive explorative search, an appropriate algorithm for a systematic database search was developed. Twenty-one health economic evaluations were identified and appraised using published quality criteria.

Results:Genetic screening for eight conditions has been found to be investigated by health economic evaluation: hereditary breast and ovarian cancer, familial adenomatous polyposis (FAP) colorectal cancer, hereditary nonpolyposis colorectal carcinoma (HNPCC), retinoblastoma, familial hypercholesterolemia, hereditary hemochromatosis, insulin-dependent diabetes mellitus, and cystic fibrosis. Results range from dominated to cost-saving. Population-wide genetic screening may be considered cost-effective with limited quality of evidence only for three conditions. The methodology of the studies was of varying quality. Cost-effectiveness was primarily influenced by mutation prevalence, genetic test costs, mortality risk, effectiveness of treatment, age at screening, and discount rate.

Conclusions:Health economic evidence on genetic screening is limited: Only few conditions have properly been evaluated. Based on the existing evidence, healthcare decision makers should consider the introduction of selective genetic screening for FAP and HNPCC. As genetic test costs are declining, the existing evaluations may warrant updating. Especially in the case of hereditary hemochromatosis, genetic population screening may be about to turn from a dominated to a cost-effective or even cost-saving intervention.

Review of outcomes of neonatal screening for cystic fibrosis versus non-screening in Europe

We reviewed the published results of European prospective cohort and controlled studies and 1 randomized controlled study to assess whether newborn screening (NBS) for cystic fibrosis (CF) leads to an improved prognosis. We used long-term survival, early mortality, nutritional and pulmonary status, and the number of hospital admissions as outcome measures. Effects on reproductive behavior of the parents and relatives were also assessed. In 2 studies, a similar trend for improved long-term survival rate of the screened cohort was observed, whereas in 2 other studies CF NBS appeared to prevent CF-related deaths in infancy and early childhood. Screened patients born in the last 2 decades showed normal growth for height and weight from infancy until late childhood. In most studies, patients who were screened were found to have less lung damage than their non-screened peers. CF NBS significantly reduced the number of affected children who ever required hospitalization. In Brittany, France, a reduction of 15.7% in CF prevalence at birth was attributed to the introduction of a NBS program for CF. We conclude that there is accumulating evidence that CF NBS prevents early CF-related deaths and leads to a substantial and prolonged health gain for patients with CF.

Newborn screening for cystic fibrosis in Wisconsin: nine-year experience with routine trypsinogen/DNA testing

OBJECTIVE

To describe the development and follow-up confirmatory results of the routine cystic fibrosis (CF) newborn screening (NBS) program in Wisconsin.

METHODS

CF NBS has been performed on a routine clinical basis in Wisconsin since July 1994. The 2-tiered immunoreactive trypsinogen (IRT)/DNA technique was used on dried blood on filter paper spots. From July 1994 to February 2002, mutation analysis was for the DeltaF508 allele. Beginning in March 2002, multimutation analysis of 25 CF mutations was performed. Infants with a positive result on NBS were seen in certified CF centers for sweat testing by means of quantitative pilocarpine iontophoresis, and families received genetic counseling.

RESULTS

From July 1994 to February 2002, there were 120 cases of CF detected by means of NBS (509,794 infants screened), with 53 DeltaF508 homozygotes and 67 compound heterozygotes. There were 8 clinically diagnosed cases of CF (no DeltaF508 allele). The CF incidence was 1:3983 (95%CI, 1:3373-1:4774). From March 2002 to June 2003, multimutation analysis identified 21 cases of classic CF (90,142 infants screened). Sweat tests were successfully performed in infants younger than 1 month.

CONCLUSIONS

Early diagnosis of CF through NBS was successfully performed, with an estimated sensitivity rate of 99% using the IRT/25 CFTR multimutation assay.

Evidence on improved outcomes with early diagnosis of cystic fibrosis through neonatal screening: enough is enough!

OBJECTIVE

To generate and examine evidence in support of diagnosing cystic fibrosis (CF) early through newborn screening (NBS).

STUDY DESIGN

Using a randomized controlled trial with unique unblinding/surveillance, we evaluated patients with CF receiving similar treatment after assignment to an early diagnosis (screened) group or to a control group. Outcomes studied at diagnosis and longitudinally included measures of nutritional status and lung disease.

RESULTS

Assessment of patients with CF without meconium ileus who had pancreatic insufficiency revealed marked differences in age and condition at diagnosis--screened patients had significantly better length/height, weight, and head circumference. Follow-up evaluation for 16 years showed that height and weight differences persisted long term. Although screened patients had better chest x-ray scores at diagnosis, our trial suggests that the effects of confounders such as Pseudomonas aeruginosa infections led to deterioration of their scores after 10 years, but there were no significant differences between the 2 CF/pancreatic insufficiency subgroups.

CONCLUSIONS

Early diagnosis of CF and aggressive nutritional management can prevent malnutrition and growth failure. Although CF NBS provides a potential opportunity for better pulmonary outcomes, it appears that other factors can predominate over time in pulmonary prognosis. Overall, the Wisconsin trial is positive and provides enough evidence for routine CF NBS.

Sweat-testing in preterm and full-term infants less than 6 weeks of age

Our objective was to examine the characteristics of preterm and full-term infants < or = 6 weeks old that influence the success of obtaining sufficient sweat for diagnosis of CF, and corresponding sweat chloride concentrations. A retrospective chart review of 119 sweat tests was performed on 103 preterm and full-term infants < or = 6 weeks of age. Bivariate and multivariate regression analyses were used to determine the predictors of successful sweat testing and characteristics influencing sweat chloride concentrations. Adequate amounts of sweat (> or = 75 mg) were obtained for analysis in 73.8% of initial attempts in the infant group. The following characteristics were associated with increased odds of obtaining a quantity not sufficient (QNS) for sweat chloride concentration measurement: African-American race, infant weight < 2,000 g, preterm birth, and postmenstrual age (PMA) < 36 weeks. With a multivariable logistic model, the only significant predictors were African-American race (7.3, 2.4-21.7) and PMA < 36 weeks (17.9, 4.2-75.9). Sweat chloride concentration in non-CF individuals is inversely related to both gestational age and age at testing, and this effect is additive in a linear regression model. In conclusion, sweat collection can be reliably performed in infants > or = 36 weeks postmenstrual age, > 2,000 g, and > 3 days postnatal age. Maturational factors have a mild impact on sweat chloride concentration.

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.

Multiplexed genetic analysis using an expanded genetic alphabet

Background: All states require some kind of testing for newborns, but the policies are far from standardized. In some states, newborn screening may include genetic tests for a wide range of targets, but the costs and complexities of the newer genetic tests inhibit expansion of newborn screening. We describe the development and technical evaluation of a multiplex platform that may foster increased newborn genetic screening.

Methods: MultiCode® PLx involves three major steps: PCR, target-specific extension, and liquid chip decoding. Each step is performed in the same reaction vessel, and the test is completed in ∼3 h. For site-specific labeling and room-temperature decoding, we use an additional base pair constructed from isoguanosine and isocytidine. We used the method to test for mutations within the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The developed test was performed manually and by automated liquid handling. Initially, 225 samples with a range of genotypes were tested retrospectively with the method. A prospective study used samples from >400 newborns.

Results: In the retrospective study, 99.1% of samples were correctly genotyped with no incorrect calls made. In the perspective study, 95% of the samples were correctly genotyped for all targets, and there were no incorrect calls.

Conclusions: The unique genetic multiplexing platform was successfully able to test for 31 targets within the CFTR gene and provides accurate genotype assignments in a clinical setting.

Newborn screening for cystic fibrosis

BACKGROUND

This review was performed to test the hypothesis that presymptomatic diagnosis, for example by newborn screening, and early treatment may prevent or reduce irreversible organ damage and thereby improve outcome and quality of life in patients with cystic fibrosis.

OBJECTIVES

To determine whether there is evidence that early diagnosis of cystic fibrosis by means of neonatal screening, followed by current treatment, improves survival and long term morbidity, without unacceptable adverse effects.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Trials Register. Additional studies were identified by one of the reviewers from handsearching conference proceedings not included in the Cochrane Register. Pharmaceutical companies manufacturing screening tests for cystic fibrosis were also contacted to identify any trials of neonatal screening for cystic fibrosis. Date of the most recent search of the Group's specialised register: January 2001.

SELECTION CRITERIA

All randomised or pseudorandomised controlled trials, published and unpublished, comparing screening followed by early treatment to clinical diagnosis and later treatment in patients with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Four reviewers independently assessed trial eligibility and methodological quality and two of these reviewers independently extracted data.

MAIN RESULTS

Two trials involving a total of 1,124,483 neonates met inclusion criteria. A total of 210 patients with cystic fibrosis aged from zero to 11 years with a maximum follow-up of eleven years are included. Concealment of allocation was unclear in both studies. Sequence generation was adequate in one study and unclear in the other. Method to ascertain cases was similar in one study and not similar in the other. An intention-to-screen-analysis was possible in one study, but could not be made due to lack of data and was not performed in the other. Differences in study design, variation in outcomes reported and their summary measures precluded calculation of pooled screening estimates. Only data from one study could be analysed in this review. This study reported a reduced risk of weight and height below the fifth percentile among screened patients (odds ratio control compared with screened group for: weight 6.16, 95% CI 2.44, 15.57 and height 5.03, 95% CI 1.63, 15.63). Adverse effects among parents in the screened and control populations were examined, but it is difficult to assess how meaningful these results are as the timing of the administration of the questionnaire to each group was not clear. Estimation of direct medical costs of screening suggested it was cheaper to diagnose cystic fibrosis by screening rather than other methods. The costing methods used however were not fully described and costs have not been related to effect.

REVIEWER'S CONCLUSIONS

There are few randomised controlled trials assessing the effectiveness of neonatal screening in cystic fibrosis. From the data available at this time, there is little evidence suggesting benefit from screening for cystic fibrosis in the neonatal period, although there is similarly little evidence of harm. This systematic review has identified the need for individual patient data from both included studies. Although we have not been able to perform a meta-analysis, this review provides a summary of all the information currently available from randomised controlled trials on the effectiveness of neonatal screening for cystic fibrosis.