Rikard E. Juttmann

Study objective: To illustrate to what extent the cost‐effectiveness of an evidence‐based prevention programme may depend on evidence‐based performance, by the example of screening for congenital heart disease in Dutch child health care. Methods: A patient follow‐up study on 290 children with congenital heart disease, of which 83 with significant disorders, diagnosed over two years, and born in the south west of the Netherlands. Results: Adequate screening for congenital heart disease at Dutch child health centres, compared to inadequate screening, proves to be effective (OR: 0.18; 95% CI: 0.04–0.87). However only 15% of all patients with significant disorders in this study was adequately screened. Total health care costs involved over two years amount to over $3 million. Of these costs, 13% are to be attributed to screening tests; 8% to referrals resulting from screening. The costs for screening and referrals, as they were actually performed, are estimated at about $72.000 per patient benefiting from it. Were all children to be screened adequately this sum would be reduced to about $15.000. Conclusion: Not only should prevention programmes be evidence‐based, but also outcome and quality, monitored by periodically establishing whether they are optimally performed.

To collect information for the purpose of establishing starting points and possibilities for a cost-effectiveness analysis of screening for adolescent idiopathic scoliosis (AIS). Interviews, literature review, questionnaires, an estimation of costs and discussions with experts and involved parties. Following an initial interview with 16 orthopaedic surgeons and school doctors a literature study into the efficacy of treatment was carried out regarding the years 1989-1999. The variation in current practice was delineated by means of a questionnaire sent to all 51 municipal health services in the Netherlands. The costs of screening and treatment were estimated on the basis of health insurance premiums and a municipal health service cost model. All of the results were presented to five methodological experts and finally the study results and the recommendations of the five methodological experts were evaluated during a meeting of persons especially invited for this purpose. Screening for AIS was established to realise early diagnosis and treatment with a brace, so as to reduce unsatisfactory cosmetic outcomes and the need for surgery. Screening was performed using the bending test and was performed in 40/48 (83%) of the participating municipal health services. The overall costs of screening and treatment amount to 6 million euros per year. There was no convincing evidence that the screening programme was sufficiently sensitive and bracing sufficiently effective. Neither was there proof of the opposite. The following was recommended: obtain reliable data by carrying out a randomised controlled trial on the effectiveness of treating AIS with bracing in an early stage; carry out a case-control study combined with a retrospective patient follow-up study to evaluate the current screening practice; draw up a national standard for the screening of postural disorders in youth healthcare to ensure effective practice.

BACKGROUND RAMSES is a 7 year follow up study, aiming at the evaluation of the effectiveness and the efficiency of screening for amblyopia. In this first report, concerning the first 2 years of life, the compliance with the prevention programme and the positive predictive value (PPV) of the screening tests used, are presented. METHODS All results of the standardised screening test for strabismus, applied by child healthcare physicians, within a birth cohort of 4072 Rotterdam children at the age of 9, 14, and 24 months, were registered. Children with a positive test result were referred to their general practitioner, who was asked to arrange a definitive referral to an ophthalmological centre. The results of the examinations at these centres were registered in standardised forms and served as reference for establishing the PPV. RESULTS The screening was (at least one time) attended by 3958 children (97%). 160 of these children (4%) were referred, of whom 101 (64%) visited an ophthalmological centre, so that a conclusive diagnostic evaluation was possible. For amblyopia, the predictive value of a positive test result followed by an effective referral was 0.42. CONCLUSION Referral procedures after a positive test result in the Dutch child healthcare screening programme for amblyopia need to be improved. The Dutch screening test used to detect amblyopia exhibits a relatively favourable PPV.

OBJECTIVE To discuss the merits of the patient follow up study design for the evaluation of some specific mass screening programmes. DESIGN Theoretical evaluation illustrated by two examples. SETTING Department of Public Health Erasmus University Rotterdam. MAIN RESULTS The gold standard for evaluation of favourable effects of screening is the randomised controlled trial (RCT). Application of an RCT, however, is often not feasible, in which cases observational studies will have to be relied on. The case-control study design is generally considered to be second best. In some situations, however, a patient follow up study design may be applicable and may have some major advantages. The use of the patient follow up design for screening evaluation will often be very problematic or even unacceptable, particularly as far as screening for cancer is concerned. The most important objections are resulting from lead time bias, length bias, selection bias and over-treatment bias. For the evaluation of screening for congenital heart disease and congenital hip dislocation in Dutch child health care, however, these objections may relatively simply be overcome. Lead time bias will be of little importance, as the ages of onset of these disorders are fixed, namely at birth, and their ultimate outcomes may be expected within relatively short time. Length bias may largely be avoided by correction for severity of the disorder, which can be adequately assessed by modern diagnostic procedures. Selection bias is generally hard to rule out, but in these cases it probably plays a minor part. Over-treatment can be avoided by the policy of “watchful waiting”, which in these disorders can be applied with little risk for fatal outcomes. In principle bias might be avoided more successfully in a case-control screening evaluation than in a patient follow up study. However, the patient follow up study is for both screening programmes discussed here the more feasible design and can provide more supplementary information. The results of two example studies suggest that both screenings probably yield considerable benefits CONCLUSION Under a number of specific conditions a patient follow up study is an efficient alternative to more customary designs for screening evaluation.

Background The actual yield from current screening for clinically significant congenital heart malformations in Dutch child health care is far from optimal. In this study factors that determine the effectiveness of this screening are identified and recommendations for the optimization of the screening programme are formulated. Methods Eighty-two patients with a clinically significant congenital heart malformation were consecutively included in this study. Parents and child health centre physicians were interviewed in order to establish the screening, detection and referral history. Paediatric cardiologists established whether these patients were diagnosed ‘in time’ or ‘too late’. Results Incomplete performance of the screening examination has more influence on the occurrence of delayed diagnoses than failure by parents to adhere to the complete visit schedule. Adequate screening advances detection of congenital heart malformations. Severity, however, is the most predominant determinant of the age at referral and diagnosis, as well as of the risk of complications. In only 7 out of 39 patients diagnosed ‘too late’, could no avoidable cause for an adverse outcome be found. In 10 cases (25%) there was a prolonged interval between first referral and diagnosis. Conclusion To optimize the yield of the screening programme, improvement in the performance of the child health centre physicians and the co-operation of other physicians involved in reducing the interval between referral and diagnosis are required. Thus a considerable improvement in the prevention of complications of congenital heart malformations can be obtained.

A summary of research data on the evaluation of eight screening activities in Child Health Care in the Netherlands. Literature review. Department of Public Health, Erasmus University Rotterdam, the Netherlands. The literature was reviewed regarding screening effects on congenital hip pathology, congenital heart disease, retained testis, hydrocephalus, hearing loss, psychomotor retardation, visual disabilities, and phenylketonuria (PKU) and congenital hypothyroidism (CHT). For 8 types of screenings 17 targets could be established. Targets were defined in terms of a decrease of the adverse outcome of the diseases as a result of the screening. The efficacy of the screening for 3 of these targets (decrease of the adverse outcomes of PKU and CHT and needless orchidopexy) was convincingly established. For the other targets the available data were insufficient. Data on undesirable effects of screening were scarce. For 6 of the 8 screening activities some data on test properties were available. Research data on the effects of screening in Child Health Care in the Netherlands are incomplete. It is important to improve the scientific basis of these prevention activities.